Unnamed: 0 int64 0 2.34M | titles stringlengths 5 21.5M | abst stringlengths 1 21.5M |
|---|---|---|
12,100 | Hypertrophic cardiomyopathy in 2013: Current speculations and future perspectives. | Hypertrophic cardiomyopathy (HCM), the most variable cardiac disease in terms of phenotypic presentation and clinical outcome, represents the most common inherited cardiomyopathic process with an autosomal dominant trait of inheritance. To date, more than 1400 mutations of myofilament proteins associated with the disease have been identified, most of them "private" ones. This striking allelic and locus heterogeneity of the disease certainly complicates the establishment of phenotype-genotype correlations. Additionally, topics pertaining to patients' everyday lives, such as sudden cardiac death (SCD) risk stratification and prevention, along with disease prognosis, are grossly related to the genetic variation of HCM. This review incorporates contemporary research findings and addresses major aspects of HCM, including preclinical diagnosis, genetic analysis, left ventricular outflow tract obstruction and SCD. More specifically, the spectrum of genetic analysis, the selection of the best method for obstruction alleviation and the need for a unique and accurate factor for SCD risk stratification are only some of the controversial HCM issues discussed. Additionally, future perspectives concerning HCM and myocardial ischemia, as well as atrial fibrillation, are discussed. Rather than enumerating clinical studies and guidelines, challenging problems concerning the disease are critically appraised by this review, highlighting current speculations and recommending future directions. |
12,101 | Amiodarone versus lidocaine for the prevention of reperfusion ventricular fibrillation: A randomized clinical trial. | Reperfusion ventricular fibrillation after aortic cross clamp is one of the important complications of open cardiac surgery and its prevention could reduce myocardial injuries. This study aimed to evaluate the efficacy of single dose of amiodarone or lidocaine by the way of pump circuit three minutes before aortic cross clamp release and compare the results with normal saline as placebo in a randomized double blinded controlled trial.</AbstractText>One hundred fifty patients scheduled for first time elective coronary artery bypass graft surgery were randomly assigned to receive either single dose of amiodarone (150 mg), lidocaine (100 mg), or normal saline (5 ml) three minutes before aortic cross clamp release. The incidence of ventricular fibrillation and the need for reuse of drug were compared between these groups by chi-square, Student's t-test, Mann-Whitney test, and One-way ANOVA. SPSS software was used for statistical analysis.</AbstractText>The incidence of ventricular fibrillation is higher in the placebo group (15.9%) compare to lidocaine (11.8%) and amiodarone (8.9%) groups; however, there was no statistical difference among the three groups (P = 0.41). Moreover, the reuse of amiodarone (22.7%) was statistically higher (P < 0.05) than lidocaine (5.9%).</AbstractText>This study showed no difference among lidocaine, amiodarone, and placebo in preventing ventricular fibrillation after aortic cross clamp release.</AbstractText> |
12,102 | Heart rate-corrected QT interval is an independent predictor of all-cause and cardiovascular mortality in individuals with type 2 diabetes: the Diabetes Heart Study. | Heart rate-corrected QT (QTc) interval is associated with mortality in the general population, but this association is less clear in individuals with type 2 diabetes. We assessed the association of QTc interval with all-cause and cardiovascular disease (CVD) mortality in the Diabetes Heart Study.</AbstractText>We studied 1,020 participants with type 2 diabetes (83% European Americans; 55% women; mean age 61.4 years) who were free of atrial fibrillation, major ventricular conduction defects, and antiarrhythmic therapy at baseline. QT duration was automatically calculated from a standard 12-lead electrocardiogram (ECG). Following American Heart Association/American College of Cardiology Foundation recommendations, a linear scale was used to correct the QT for heart rate. Using Cox regression, risk was estimated per 1-SD increase in QTc interval as well as prolonged QTc interval (>450 ms) vs. normal QTc interval for mortality.</AbstractText>At baseline, the mean (SD) QTc duration was 414.9 ms (18.1), and 3.0% of participants had prolonged QTc. After a median follow-up time of 8.5 years (maximum follow-up time 13.9 years), 204 participants were deceased. In adjusted multivariate models, a 1-SD increase in QTc interval was associated with an 18% higher risk for all-cause mortality (hazard ratio 1.18 [95% CI 1.03-1.36]) and 29% increased risk for CVD mortality (1.29 [1.05-1.59]). Similar results were obtained when QTc interval was used as a categorical variable (prolonged vs. normal) (all-cause mortality 1.73 [0.95-3.15]; CVD mortality 2.86 [1.35-6.08]).</AbstractText>Heart rate QTc interval is an independent predictor of all-cause and CVD mortality in this population with type 2 diabetes, suggesting that additional prognostic information may be available from this simple ECG measure.</AbstractText> |
12,103 | Clinical usefulness, angiographic characteristics, and safety evaluation of intracoronary acetylcholine provocation testing among 921 consecutive white patients with unobstructed coronary arteries. | Coronary spasm can cause myocardial ischemia and angina in patients with and those without obstructive coronary artery disease. However, provocation tests using intracoronary acetylcholine administration are rarely performed in clinical routine in the United States and Europe. Thus, we assessed the clinical usefulness, angiographic characteristics, and safety of intracoronary acetylcholine provocation testing in white patients with unobstructed coronary arteries.</AbstractText>From September 2007 to June 2010, a total of 921 consecutive patients (362 men, mean age 62±12years) who underwent diagnostic angiography for suspected myocardial ischemia and were found to have unobstructed coronary arteries (no stenosis ≥50%) were enrolled. The intracoronary acetylcholine provocation testing was performed directly after angiography according to a standardized protocol. Three hundred forty-six patients (35%) reported chest pain at rest, 222 (22%) reported chest pain on exertion, 238 (24%) reported a combination of effort and resting chest pain, and 41 (4%) presented with troponin-positive acute coronary syndrome. The overall frequency of epicardial spasm (>75% diameter reduction with angina and ischemic ECG shifts) was 33.4%, and the overall frequency of microvascular spasm (angina and ischemic ECG shifts without epicardial spasm) was 24.2%. Epicardial spasm was most often diffuse and located in the distal coronary segments (P<0.01). No fatal or irreversible nonfatal complications occurred. However, 9 patients (1%) had minor complications (nonsustained ventricular tachycardia [n=1], fast paroxysmal atrial fibrillation [n=1], symptomatic bradycardia [n=6], and catheter-induced spasm [n=1]).</AbstractText>Epicardial and microvascular spasm are frequently found in white patients with unobstructed coronary arteries. Epicardial spasm is most often diffuse and located in the distal coronary segments. The intracoronary acetylcholine provocation test is a safe technique to assess coronary vasomotor function.</AbstractText> |
12,104 | Successful treatment of a young woman with acute complicated myocardial infarction. | Therapeutic hypothermia is method used to improve the neurological status of patients who are at risk of ischaemia after myocardial infarction. We report a case of a 28-year-old woman who suffered acute myocardial infarction complicated by ventricular fibrillation. The patient was successfully resuscitated. Invasive and non-invasive medical treatment was applied including therapeutic hypothermia. Success was achieved due to adequate public reaction, fast transportation, blood vessel revascularization and application of therapeutic hypothermia. The patient was successfully discharged after one week of treatment, and just minor changes in heart function were present. |
12,105 | Expanded indications for transcatheter renal denervation. | Renal denervation (RDN) is a catheter-based procedure introduced in 2009 as a treatment of resistant hypertension. The method is based on the concept that resistant hypertension is a result of hyperactivity of the sympathetic nervous system (SNS), and therefore reducing the impact of the SNS by ablating the renal nerves should eliminate the condition. Since 2009 numerous investigators have proven the procedure to be safe and effective, which contributed to the quick success and wide spread of the method, subsequently triggering further research in this area. The dynamic distribution of the procedure induced investigators to examine the influence of RDN on other conditions involving hyperactivity of the SNS (such as atrial fibrillation or ventricular arrhythmia). A few studies aiming to explain the influence of RDN on arrhythmias in patients with resistant hypertension have been conducted. The results in treating atrial fibrillation additionally to pulmonary vein ablation and electrical storm appear to be promising; however, the data are limited and further investigations needs to be done. The influence of RDN on insulin resistance, left ventricular hypertrophy and heart failure are possible. Perspectives of expanding indications are discussed. Renal denervation appears to be a promising way of treating hypertension and raises hope for a wider group of patients with conditions closely related to hyperactivity of the sympathetic nervous system such as arrhythmia. |
12,106 | Cardiac arrest due to left circumflex coronary artery embolism as a complication of subtherapeutic oral anticoagulation in a patient with mitral and aortic mechanical valve prostheses. | We report a case of a 65-year-old female patient after replacement of aortic and mitral valve with mechanical prostheses and implantation of a pacemaker hospitalized in our clinic due to acute coronary syndrome complicated with cardiac arrest due to ventricular fibrillation. The electrocardiogram performed on admission showed signs of myocardial infarction with concomitant ventricular pacing. After successful resuscitation the coronary angiography was performed, which showed occlusion of the left circumflex artery (LCx) by thrombus. On the basis of intravascular ultrasound imaging the presence of vulnerable plaque, parietal thrombus and dissection of LCx were excluded. It suggested that occlusion of the LCx resulted from its embolism by left-sided heart thrombus due to subtherapeutic oral anticoagulation. In this case suboptimal anticoagulation was partially iatrogenic. Two weeks before the patient had been given vitamin K intravenously due to indeterminable international normalized ratio (INR) level, which caused transient resistance to oral anticoagulants. This case report illustrates tragic difficulties in the treatment with vitamin K antagonists, which concern as many as 2/3 of anticoagulated patients. These troubles contributed to the search for new, more efficient and safer anticoagulants. There are two classes of new oral anticoagulant drugs, which do not require monitoring of coagulation: direct thrombin inhibitors (e.g. dabigatran) and factor Xa inhibitors (e.g. rivaroxaban). In spite of their proven efficacy in the prevention of ischaemic stroke related to atrial fibrillation and prevention or treatment of deep vein thrombosis and pulmonary embolism, the use of new oral anticoagulants for the treatment of patients with mechanical valve prostheses needs further research.</Abstract><AuthorList CompleteYN="Y"><Author ValidYN="Y"><LastName>Protasiewicz</LastName><ForeName>Marcin</ForeName><Initials>M</Initials><AffiliationInfo><Affiliation>Department of Cardiology, Medical University of Wroclaw, Poland.</Affiliation></AffiliationInfo></Author><Author ValidYN="Y"><LastName>Rojek</LastName><ForeName>Aleksandra</ForeName><Initials>A</Initials><AffiliationInfo><Affiliation>Department of Cardiology, Medical University of Wroclaw, Poland.</Affiliation></AffiliationInfo></Author><Author ValidYN="Y"><LastName>Gajek</LastName><ForeName>Jacek</ForeName><Initials>J</Initials><AffiliationInfo><Affiliation>Department of Cardiology, Medical University of Wroclaw, Poland.</Affiliation></AffiliationInfo></Author><Author ValidYN="Y"><LastName>Mysiak</LastName><ForeName>Andrzej</ForeName><Initials>A</Initials><AffiliationInfo><Affiliation>Department of Cardiology, Medical University of Wroclaw, Poland.</Affiliation></AffiliationInfo></Author></AuthorList><Language>eng</Language><PublicationTypeList><PublicationType UI="D002363">Case Reports</PublicationType></PublicationTypeList><ArticleDate DateType="Electronic"><Year>2013</Year><Month>03</Month><Day>21</Day></ArticleDate></Article><MedlineJournalInfo><Country>Poland</Country><MedlineTA>Postepy Kardiol Interwencyjnej</MedlineTA><NlmUniqueID>101272671</NlmUniqueID><ISSNLinking>1734-9338</ISSNLinking></MedlineJournalInfo><OtherAbstract Type="Publisher" Language="pol">Przedstawiono przypadek 65-letniej chorej po wszczepieniu mechanicznej zastawki mitralnej i aortalnej oraz po implantacji sztucznego stymulatora serca, hospitalizowanej w Klinice Kardiologii z powodu ostrego zespołu wieńcowego powikłanego nagłym zatrzymaniem krążenia w mechanizmie migotania komór. Przy przyjęciu do Kliniki w EKG obserwowano zapis świadczący o zawale mięśnia serca w obrazie stymulacji serca. Po skutecznej resuscytacji pacjentce wykonano koronarografię, w której stwierdzono amputację gałęzi okalającej lewej tętnicy wieńcowej (Cx) spowodowaną zakrzepem w świetle naczynia. Na podstawie obrazowania metodą ultrasonografii wewnątrzwieńcowej wykluczono obecność niestabilnych zmian miażdżycowych, zakrzepu przyściennego oraz dysekcji Cx w miejscu jej amputacji. Uznano, że przyczyną zamknięcia Cx był zator materiałem zakrzepowym z lewych jam serca, którego powstanie prawdopodobnie zostało spowodowane nieskutecznym leczeniem przeciwkrzepliwym. W przedstawionym przypadku suboptymalny poziom wskaźnika protrombinowego (<i>international normalized ratio</i> – INR) miał częściowo przyczynę jatrogenną. Około 2 tygodni przed obecnym incydentem sercowo-naczyniowym pacjentka z powodu nieoznaczalnych wartości INR otrzymała dożylnie witaminę K, co spowodowało przejściową oporność na pochodne kumaryny. Przypadek ten jest dramatyczną ilustracją trudności w leczeniu przeciwkrzepliwym, dotyczących nawet 2/3 chorych wymagających takiej terapii. Wymienione trudności potwierdzają zasadność poszukiwania skuteczniejszych, bezpieczniejszych i bardziej przewidywalnych metod profilaktyki przeciwzakrzepowej. Wynikiem tych poszukiwań są aktualnie dwie nowe grupy doustnych leków przeciwkrzepliwych niewymagających monitorowania efektu antykoagulacyjnego. Należą do nich: bezpośrednie inhibitory trombiny (dabigatran) oraz inhibitory czynnika Xa (riwaroksaban). Chociaż udowodniono skuteczność wymienionych leków w profilaktyce udaru niedokrwiennego u pacjentów z migotaniem przedsionków oraz profilaktyce i leczeniu żylnej choroby zakrzepowo-zatorowej, bezpieczeństwo ich zastosowania u pacjentów ze sztucznymi zastawkami serca wymaga potwierdzenia w badaniach klinicznych. |
12,107 | Ventricular tachyarrhythmia after coronary bypass surgery: incidence and outcome. | Ventricular tachyarrhythmia after coronary artery bypass graft is common and the occurrence has been described, but the incidence and risk factors are not well defined.</AbstractText>To evaluate the incidence of arrhythmias and to detect high-risk populations.</AbstractText>In this prospective study, 856 consecutive patients undergoing coronary artery bypass graft were monitored for new-onset ventricular tachyarrhythmias: non-sustained monomorphic ventricular tachyarrhythmia, sustained monomorphic ventricular tachyarrhythmia, sustained polymorphic ventricular tachyarrhythmia, and ventricular fibrillation. Detailed analyses of the clinical, demographic, echocardiographic, and surgical findings and arrhythmias occurrence was carried out during 6 months of follow-up.</AbstractText>The incidence of ventricular tachyarrhythmia was 26.6% (17.6% non-sustained monomorphic ventricular tachycardia, 5.5% sustained monomorphic ventricular tachycardia, 0.8% sustained polymorphic ventricular tachycardia, and 2.7% ventricular fibrillation). The strongest degrees of statistical significance were for low ejection fraction (p = 0.01) and ischemic heart disease (p = 0.02). The incidence of ventricular fibrillation (61%) was greatest in the first 48 h after surgery. Postoperative myocardial infarction (p = 0.03) and hemodynamic instability (p = 0.05) were also predictors of arrhythmia occurrence. Recurrence of arrhythmia was highest in the ventricular fibrillation group (52%). The correlations between tachyarrhythmia, age, sex, electrolyte disorders, body mass index, and systemic or pulmonary hypertension were not significant.</AbstractText>In view of the strong relationship between ventricular arrhythmias and low ejection fraction, ischemic heart disease, coronary artery disease severity, postoperative myocardial infection, and hemodynamic impairment, continuous monitoring is necessary, especially in the first 48 h after coronary artery bypass surgery.</AbstractText> |
12,108 | How does β-adrenergic signalling affect the transitions from ventricular tachycardia to ventricular fibrillation? | Ventricular tachycardia (VT) and fibrillation (VF) are the most lethal cardiac arrhythmias. The degeneration of VT into VF is associated with the breakup of a spiral wave of the action potential in cardiac tissue. β-Adrenergic (βAR) signalling potentiates the L-type Ca current (ICaL) faster than the slow delayed rectifier potassium current (IKs), which transiently prolongs the action potential duration (APD) and promotes early after depolarizations. In this study, we aimed at investigating how βAR signalling affects the transition from VT to VF.</AbstractText>We used a physiologically detailed computer model of the rabbit ventricular myocyte in a two-dimensional tissue to determine how spiral waves respond to βAR activation following administration of isoproterenol. A simplified mathematical model was also used to investigate the underlying dynamics. We found that the spatiotemporal behaviour of spiral waves strongly depends on the kinetics of βAR activation. When βAR activation is rapid, a stable spiral wave turns into small fragments and its electrocardiogram reveals the transition from VT to VF. This is due to the transiently steepened APD restitution induced by the faster activation of ICaL vs. IKs upon sudden βAR activation. The spiral wave may also disappear if its transient wavelength is too large to be supported by the tissue size upon sudden strong βAR activation that prolongs APD transiently. When βAR activation is gradual, a stable spiral wave remains such, because of more limited increase in both APD and slope of APD restitution due to more contemporaneous ICaL and IKs activation.</AbstractText>Changes in APD restitution during βAR activation revealed a novel transient spiral wave dynamics; this spatiotemporal characteristic strongly depends on the protocol of isoproterenol application.</AbstractText> |
12,109 | Mechanistic insights into hypothermic ventricular fibrillation: the role of temperature and tissue size. | Hypothermia is well known to be pro-arrhythmic, yet it has beneficial effects as a resuscitation therapy and valuable during intracardiac surgeries. Therefore, we aim to study the mechanisms that induce fibrillation during hypothermia. A better understanding of the complex spatiotemporal dynamics of heart tissue as a function of temperature will be useful in managing the benefits and risks of hypothermia.</AbstractText>We perform two-dimensional numerical simulations by using a minimal model of cardiac action potential propagation fine-tuned on experimental measurements. The model includes thermal factors acting on the ionic currents and the gating variables to correctly reproduce experimentally recorded restitution curves at different temperatures. Simulations are implemented using WebGL, which allows long simulations to be performed as they run close to real time. We describe (i) why fibrillation is easier to induce at low temperatures, (ii) that there is a minimum size required for fibrillation that depends on temperature, (iii) why the frequency of fibrillation decreases with decreasing temperature, and (iv) that regional cooling may be an anti-arrhythmic therapy for small tissue sizes however it may be pro-arrhythmic for large tissue sizes.</AbstractText>Using a mathematical cardiac cell model, we are able to reproduce experimental observations, quantitative experimental results, and discuss possible mechanisms and implications of electrophysiological changes during hypothermia.</AbstractText> |
12,110 | The predictive value of echocardiographic parameters associated with left ventricular diastolic dysfunction on short- and long-term outcomes of catheter ablation of atrial fibrillation. | Recurrence of atrial fibrillation (AF) is frequently observed after AF catheter ablation. However, the predictive value of echocardiographic parameters associated with left ventricular diastolic dysfunction (LVDD) has not been well studied.</AbstractText>In 124 consecutive patients (mean age 61 ± 10 years, 60% male) with paroxysmal (n = 70) or persistent AF (n = 54) undergoing AF catheter ablation, mitral early diastolic peak (E-wave) and late peak (A-wave) velocities, E/A ratio, deceleration time (DT) of mitral early velocity, early diastolic mitral annulus peak velocity (e'), and E/e' ratio were determined by transthoracic echocardiography. Early (ERAF) and late AF recurrence (LRAF) were monitored with 7-day Holter electrocardiograms directly after catheter ablation and after 6 and 12 months. Early AF recurrence occurred in 34% of the patients, while LRAF was observed in 27% of the patients. Patients with ERAF had higher E-wave (0.9 ± 0.2 vs. 0.8 ± 0.2 m/s, P = 0.035) and lower A-wave velocity (0.5 ± 0.2 vs. 0.6 ± 0.2 m/s, P = 0.038), higher E/A ratio (1.8 ± 0.9 vs. 1.5 ± 0.9, P = 0.089), and slower DT (214 ± 67 vs. 243 ± 68 ms, P = 0.073), while E/e', left atrial diameter, and left ventricular ejection fraction were similar. In multivariable regression analysis, the E/A ratio was the only independent predictor of ERAF (odds ratio 2.905, 95% confidence interval 1.072-7.870, P = 0.036). None of the echocardiographic parameters influenced the late therapy outcome.</AbstractText>Early results of the catheter ablation, but not the late rhythm outcome, are influenced by an impaired mitral inflow pattern, which is associated with LVDD.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
12,111 | Tools for risk stratification of sudden cardiac death: a review of the literature in different patient populations. | While various modalities to determine risk of sudden cardiac death (SCD) have been reported in clinical studies, currently reduced left ventricular ejection fraction remains the cornerstone of SCD risk stratification. However, the absolute burden of SCD is greatest amongst populations without known cardiac disease. In this review, we summarize the evidence behind current guidelines for implantable cardioverter defibrillator (ICD) use for the prevention of SCD in patients with ischemic heart disease (IHD). We also evaluate the evidence for risk stratification tools beyond clinical guidelines in the general population, patients with IHD, and patients with other known or suspected medical conditions. |
12,112 | Sudden cardiac death--historical perspectives. | Sudden cardiac death (SCD) is an unexpected death due to cardiac causes that occurs in a short time period (generally within 1 h of symptom onset) in a person with known or unknown cardiac disease. It is believed to be involved in nearly a quarter of human deaths, with ventricular fibrillation being the most common mechanism. It is estimated that more than 7 million lives per year are lost to SCD worldwide. Historical perspectives of SCD are analyzed with a brief description on how the developments in the management of sudden cardiac arrest evolved over time. |
12,113 | Mechanisms of sudden cardiac death. | Worldwide, sudden cardiac death (SCD) is a major problem. It is most frequently caused by ventricular tachyarrhythmias: Monomorphic and polymorphic ventricular tachycardia (VT), torsade de pointes (TdP), and ventricular fibrillation (VF). Beta blockade, ACE inhibition, coronary reperfusion and other treatments have reduced the incidence of VT but pulseless electrical activity (PEA) is increasingly seen, particularly in patients with advanced chronic heart disease. From existing data, bradyarrhythmia in the form of asystole (usually complete heart block without escape rhythm) causes only a minor proportion (10-15%) of SCD. In patients aged 50 years and more, coronary artery disease plays a dominant role causing more than 75% of SCD cases, either by acute ischemia and ventricular fibrillation or by chronic scar formation and reentrant VT. In younger patients, SCD may occur in patients with structurally normal hearts. A number of arrhythmogenic disorders with an increased risk of SCD have been detected and better understood recently, such as long and short QT syndrome, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, and the early repolarization syndrome. Most importantly, ECG signs and clinical features indicating high risk for SCD have been identified. Knowledge of the exact electrophysiologic mechanisms of ventricular tachyarrhythmias at the cellular level has been improved and mechanisms such as phase 2 reentry and reflection proposed to better understand why and how SCD occurs. |
12,114 | Tachycardia-induced cardiomyopathy in a cat. | A 10-year-old male castrated Domestic Shorthair cat was evaluated for an asymptomatic tachyarrhythmia noted two weeks prior. Electrocardiography revealed a normal sinus rhythm with atrial premature complexes and paroxysms of supraventricular tachycardia with a heart rate between 300 and 400 min-1. Echocardiography was unremarkable, and concentrations of circulating cardiac troponin I, T4, and blood taurine were within reference ranges. The cat was treated with sotalol (2.1 mg/kg q12h, PO) but the arrhythmia was insufficiently controlled as determined during several re-examinations within a two-year time period. Twenty four months after initial presentation atrial fibrillation with fast ventricular response rate (200 to 300 min-1) was diagnosed, along with severe eccentric chamber remodeling and systolic dysfunction. The cat developed congestive heart failure and cardiogenic shock and was euthanized nearly 27 months after the first exam. Gross and histopathologic findings ruled out commonly seen types of primary myocardial disease in cats. The persistent nature of the tachyarrhythmia, the progressive structural and functional cardiac changes, and comparative gross and histopathologic post-mortem findings are consistent with the diagnosis of tachycardia-induced cardiomyopathy.</Abstract><AuthorList CompleteYN="Y"><Author ValidYN="Y"><LastName>Schober</LastName><ForeName>K E</ForeName><Initials>KE</Initials><AffiliationInfo><Affiliation>Departments of Veterinary Clinical Sciences, The Ohio State University, Columbus, OH, USA.</Affiliation></AffiliationInfo></Author><Author ValidYN="Y"><LastName>Kent</LastName><ForeName>A M</ForeName><Initials>AM</Initials><AffiliationInfo><Affiliation>Departments of Veterinary Clinical Sciences, The Ohio State University, Columbus, OH, USA.</Affiliation></AffiliationInfo></Author><Author ValidYN="Y"><LastName>Aeffner</LastName><ForeName>F</ForeName><Initials>F</Initials><AffiliationInfo><Affiliation>Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA.</Affiliation></AffiliationInfo></Author></AuthorList><Language>eng</Language><PublicationTypeList><PublicationType UI="D002363">Case Reports</PublicationType><PublicationType UI="D016428">Journal Article</PublicationType></PublicationTypeList></Article><MedlineJournalInfo><Country>Switzerland</Country><MedlineTA>Schweiz Arch Tierheilkd</MedlineTA><NlmUniqueID>0424247</NlmUniqueID><ISSNLinking>0036-7281</ISSNLinking></MedlineJournalInfo><CitationSubset>IM</CitationSubset><MeshHeadingList><MeshHeading><DescriptorName UI="D000818" MajorTopicYN="N">Animals</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D009202" MajorTopicYN="N">Cardiomyopathies</DescriptorName><QualifierName UI="Q000175" MajorTopicYN="N">diagnosis</QualifierName><QualifierName UI="Q000209" MajorTopicYN="N">etiology</QualifierName><QualifierName UI="Q000503" MajorTopicYN="N">physiopathology</QualifierName><QualifierName UI="Q000662" MajorTopicYN="Y">veterinary</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D002371" MajorTopicYN="N">Cat Diseases</DescriptorName><QualifierName UI="Q000175" MajorTopicYN="N">diagnosis</QualifierName><QualifierName UI="Q000503" MajorTopicYN="Y">physiopathology</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D002415" MajorTopicYN="N">Cats</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D004562" MajorTopicYN="N">Electrocardiography</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D037901" MajorTopicYN="N">Euthanasia, Animal</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D006333" MajorTopicYN="N">Heart Failure</DescriptorName><QualifierName UI="Q000175" MajorTopicYN="N">diagnosis</QualifierName><QualifierName UI="Q000209" MajorTopicYN="N">etiology</QualifierName><QualifierName UI="Q000503" MajorTopicYN="N">physiopathology</QualifierName><QualifierName UI="Q000662" MajorTopicYN="Y">veterinary</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D008297" MajorTopicYN="N">Male</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D013610" MajorTopicYN="N">Tachycardia</DescriptorName><QualifierName UI="Q000150" MajorTopicYN="N">complications</QualifierName><QualifierName UI="Q000175" MajorTopicYN="N">diagnosis</QualifierName><QualifierName UI="Q000503" MajorTopicYN="N">physiopathology</QualifierName><QualifierName UI="Q000662" MajorTopicYN="Y">veterinary</QualifierName></MeshHeading></MeshHeadingList><OtherAbstract Type="Publisher" Language="ger">Eine 10-jährige männlich-kastrierte Kurzhaarkatze wurde wegen einer asymptomatischen Tachykardie vorgestellt, die erstmalig vor zwei Wochen diagnostiziert worden war. Bei der elektrokardiographischen Untersuchung wurde ein normaler Sinusrhythmus mit atrialen Extraystolen und Perioden von paroxysmaler supraventrikulärer Tachykardie mit einer Herzfrequenz von 300 bis 400 min–1 festgestellt. Die echokardiographische Untersuchung war unauffällig und die Blutkonzentrationen von kardialem Troponin I, Gesamtthyroxin sowie Taurin lagen in den jeweiligen Normbereichen. Die Katze wurde mit Sotalol (2.1 mg/kg zweimal täglich, per os) behandelt, was allerdings nicht zur gewünschten Kontrolle der Arrhythmie führte, wie bei wiederholten Untersuchungen innerhalb einer zweijährigen Zeitperiode festgestellt wurde. 24 Monate nach der Erstuntersuchung entwickelte die Katze Vorhofflimmern mit schneller Kammerfrequenz (200 bis 300 min–1). Ausserdem lag eine schwere Dilatation der Herzkammern mit systolischer Dysfunktion vor. Die Katze entwickelte Herzinsuffizienz und kardiogenen Schock und wurde auf Wunsch des Besitzers 27 Monate nach Erstvorstellung euthanasiert. Die pathologisch-anatomische und histologische Untersuchung des Herzens war unauffällig, wobei die klassischen primären Kardiomyopathien der Katze mit Sicherheit ausgeschlossen werden konnten. Die lange Dauer der Tachyarrhythmie, die progressiven strukturellen und funktionellen Veränderungen des Herzens sowie die ähnlichen pathologischen und histologischen Befunde lassen auf das Vorliegen einer Tachykardie-induzierten Kardiomyopathie schliessen. |
12,115 | Optical mapping of sarcoplasmic reticulum Ca2+ in the intact heart: ryanodine receptor refractoriness during alternans and fibrillation. | Sarcoplasmic reticulum (SR) Ca(2+) cycling is key to normal excitation-contraction coupling but may also contribute to pathological cardiac alternans and arrhythmia.</AbstractText>To measure intra-SR free [Ca(2+)] ([Ca(2+)]SR) changes in intact hearts during alternans and ventricular fibrillation (VF).</AbstractText>Simultaneous optical mapping of Vm (with RH237) and [Ca(2+)]SR (with Fluo-5N AM) was performed in Langendorff-perfused rabbit hearts. Alternans and VF were induced by rapid pacing. SR Ca(2+) and action potential duration (APD) alternans occurred in-phase, but SR Ca(2+) alternans emerged first as cycle length was progressively reduced (217±10 versus 190±13 ms; P<0.05). Ryanodine receptor (RyR) refractoriness played a key role in the onset of SR Ca(2+) alternans, with SR Ca(2+) release alternans routinely occurring without changes in diastolic [Ca(2+)]SR. Sensitizing RyR with caffeine (200 μmol/L) significantly reduced the pacing threshold for both SR Ca(2+) and APD alternans (188±15 and 173±12 ms; P<0.05 versus baseline). Caffeine also reduced the magnitude of spatially discordant SR Ca(2+) alternans, but not APD alternans, the pacing threshold for discordance, or threshold for VF. During VF, [Ca(2+)]SR was high, but RyR remained nearly continuously refractory, resulting in minimal SR Ca(2+) release throughout VF.</AbstractText>In intact hearts, RyR refractoriness initiates SR Ca(2+) release alternans that can be amplified by diastolic [Ca(2+)]SR alternans and lead to APD alternans. Sensitizing RyR suppresses spatially concordant but not discordant SR Ca(2+) and APD alternans. Despite increased [Ca(2+)]SR during VF, SR Ca(2+) release was nearly continuously refractory. This novel method provides insight into SR Ca(2+) handling during cardiac alternans and arrhythmia.</AbstractText> |
12,116 | The value of diastolic function parameters in the prediction of left atrial appendage thrombus in patients with nonvalvular atrial fibrillation. | Left ventricular diastolic impairment and consequently elevated filling pressure may contribute to stasis leading to left atrial appendage thrombus (LAAT) in nonvalvular atrial fibrillation (AF). We investigated whether transthoracic echocardiographic parameters can predict LAAT independent of traditional clinical predictors.</AbstractText>We conducted a retrospective cohort study of 297 consecutive nonvalvular AF patients who underwent transthoracic echocardiogram followed by a transesophageal echocardiogram within one year. Multivariate logistic regression analysis models were used to determine factors independently associated with LAAT.</AbstractText>Nineteen subjects (6.4%) were demonstrated to have LAAT by transesophageal echocardiography. These patients had higher mean CHADS2 scores [2.6 ± 1.2 vs. 1.9 ± 1.3, P = 0.009], higher E:e' ratios [16.6 ± 6.1 vs. 12.0 ± 5.4, P = 0.001], and lower mean e' velocities [6.5 ± 2.1 cm/sec vs. 9.1 ± 3.2 cm/sec, P = 0.001]. Both E:e' and e' velocity were associated with LAAT formation independent of the CHADS2 score, warfarin therapy, left ventricular ejection fraction (LVEF), and left atrial volume index (LAVI) [E:e' odds-ratio = 1.14 (95% confidence interval = 1.03 - 1.3), P = 0.009; e' velocity odds-ratio = 0.68 (95% confidence interval = 0.5 - 0.9), P = 0.007]. Similarly, diastolic function parameters were independently associated with spontaneous echo contrast.</AbstractText>The diastolic function indices E:e' and e' velocity are independently associated with LAAT in nonvalvular AF patients and may help identify patients at risk for LAAT.</AbstractText> |
12,117 | Effect of left ventricular diastolic dysfunction on left atrial appendage function and thrombotic potential in nonvalvular atrial fibrillation. | We aimed to investigate effects of left ventricular diastolic dysfunction on left atrial appendage functions, spontaneous echo contrast and thrombus formation in patients with nonvalvular atrial fibrillation.</AbstractText>In 58 patients with chronic nonvalvular atrial fibrilation and preserved left ventricular systolic function, left atrial appendage functions, left atrial spontaneous echo contrast grading and left ventricular diastolic functions were evaluated using transthoracic and transoesophageal echocardiogram. Patients divided in two groups: Group D (n=30): Patients with diastolic dysfunction, Group N (n=28): Patients without diastolic dysfunction. Categorical variables in two groups were evaluated with Pearson's chi-square or Fisher's exact test. The significance of the lineer correlation between the degree of spontaneous echo contrast (SEC) and clinical measurements was evaluated with Spearman's correlation analysis.</AbstractText>Peak pulmonary vein D velocity of the Group D was significantly higher than the Group N (p=0.006). However, left atrial appendage emptying velocity, left atrial appendage lateral wall velocity, peak pulmonary vein S, pulmonary vein S/D ratio were found to be significantly lower in Group D (p=0.028, p<0.001, p<0.001; p<0.001). Statistically significant negative correlation was found between SEC in left atrium and left atrial appendage emptying, filling, pulmonary vein S/D levels and lateral wall velocities respectively (r=-0.438, r=-0.328, r=-0.233, r=-0.447). Left atrial appendage emptying, filling, pulmonary vein S/D levels and lateral wall velocities were significantly lower in SEC 2-3-4 than SEC 1 (p=0.003, p=0.029, p<0.001, p=0.002).</AbstractText>In patients with nonvalvular atrial fibrillation and preserved left ventricular ejection fraction, left atrial appendage functions are decreased in patients with left ventricular diastolic dysfunction. Left ventricular diastolic dysfunction may constitute a potential risk for formation of thrombus and stroke.</AbstractText> |
12,118 | Discriminating atrial flutter from atrial fibrillation using a multilevel model of atrioventricular conduction. | The discrimination between atrial flutter (AFlu) and atrial fibrillation (AFib) can be made difficult by an irregular ventricular response owing to complex conduction phenomena within the atrioventricular (AV) node, known as multilevel AV block. We tested the hypothesis that a mathematical algorithm might be suitable to discriminate both arrhythmias.</AbstractText>To discriminate AFlu with irregular ventricular response from AFib based on the sequence of R-R intervals.</AbstractText>Intracardiac recordings of 100 patients (50 patients with AFib and 50 patients with AFlu) were analyzed. On the basis of a numerical simulation of variable flutter frequencies followed by 2 levels of AV block in series, a given sequence of R-R intervals was analyzed.</AbstractText>Although the ventricular response displays absolute irregularity in AFib, the sequences of R-R intervals follow certain rules in AFlu. We find that using a mathematical simulation of multilevel AV block, based on the R-R sequence of 16 ventricular beats, a stability of atrial activation could be predicted with a sensitivity of 84% and a specificity of 74%. When limiting the ventricular rate to 125 beats/min, discrimination could be performed with a sensitivity of even 89% and a specificity of 80%. In cases of AFlu, the atrial cycle length could be predicted with high accuracy.</AbstractText>On the basis of the electrophysiological mechanism of multilevel AV block, we developed a computer algorithm to discriminate between AFlu and Afib. This algorithm is able to predict the stability and cycle length of atrial activation for short R-R sequences with high accuracy.</AbstractText>Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,119 | Beta-blocker use in ST-segment elevation myocardial infarction in the reperfusion era (GRACE). | Current guidelines recommend early oral beta-blocker administration in the management of acute coronary syndromes for patients who are not at high risk of complications.</AbstractText>Data from patients enrolled between 2000 and 2007 in the Global Registry of Acute Coronary Events (GRACE) were used to evaluate hospital outcomes in 3 cohorts of patients admitted with ST-elevation myocardial infarction, based on beta-blocker use (early [first 24 hours] intravenous (IV) [± oral], only early oral, or delayed [after first 24 hours]).</AbstractText>Among 13,110 patients with ST-elevation myocardial infarction, 21% received any early IV beta-blockers, 65% received only early oral beta-blockers, and 14% received delayed (>24 hours) beta-blockers. Higher systolic blood pressure, higher heart rate, and chronic beta-blocker use were independent predictors of early beta-blocker use. Early beta-blocker use was less likely in older patients, patients with moderate to severe left ventricular dysfunction, and in those presenting with inferior myocardial infarction or Killip class II or III heart failure. IV beta-blocker use and delayed beta-blocker use were associated with higher rates of cardiogenic shock, sustained ventricular fibrillation/ventricular tachycardia, and acute heart failure, compared with oral beta-blocker use. In-hospital mortality was increased with IV beta-blocker use (propensity score adjusted odds ratio, 1.41; 95% confidence interval, 1.03-1.92) but significantly reduced with delayed beta-blocker administration (propensity adjusted odds ratio, 0.44; 95% confidence interval, 0.26-0.74).</AbstractText>Early beta-blocker use is common in patients presenting with ST-elevation myocardial infarction, with oral administration being the most prevalent. Oral beta-blockers were associated with a decrease in the risk of cardiogenic shock, ventricular arrhythmias, and acute heart failure. However, the early receipt of any form of beta-blockers was associated with an increase in hospital mortality.</AbstractText>Copyright © 2014 Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,120 | Value analysis of continuous EEG in patients during therapeutic hypothermia after cardiac arrest. | Therapeutic hypothermia (TH) is standard of care after ventricular fibrillation cardiac arrest (CA). Continuous EEG monitoring (cEEG) is increasingly used during TH. Analysis regarding value of cEEG utilization in this population in the context of cost and outcome has not been performed. We compared outcome and EEG charges in CA patients with selective versus routine cEEG.</AbstractText>A protocol for TH after CA without routine cEEG was implemented in December 2005, comprising our TH-pre-cEEG cohort. In November 2009, this protocol was changed to include cEEG in all CA-TH patients, comprising our TH-cEEG cohort. Clinical outcome using the Cerebral Performance Category (CPC) at discharge and estimated EEG charges were calculated retrospectively for both cohorts, based on National Charge Data 50th percentile charges expressed in USD per the CMS 2010 Standard Analytical File as reported in Code Correct by MedAssets, Inc.</AbstractText>Our TH-pre-cEEG cohort comprised 91 patients, our TH-cEEG cohort 62. In the TH-pre-cEEG cohort, 19 patients (21%) had rEEGs, 4 (4%) underwent cEEG. The mean estimated EEG charges for the TH-pre-cEEG cohort was $1571.59/patient, and TH-cEEG cohort was $4214.93/patient (p<0.0001). Two patients (2.1%) in the TH-pre-cEEG cohort had seizures, compared to five (8.1%) in the TH-cEEG cohort (p=0.088). There was no difference in mortality or clinical outcome in these cohorts.</AbstractText>Routine use of cEEG during TH after CA improved seizure detection, but not outcomes. There was a three-fold increase in EEG estimated charges with routine use of cEEG.</AbstractText>Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
12,121 | Incomplete recovery of mechanical and endocrine left atrial functions one month after electrical cardioversion for persistent atrial fibrillation: a pilot study. | Restoration of the mechanical and endocrine functions of the left atrium remains controversial after electrical cardioversion treatment for persistent atrial fibrillation. The objective of the prospective study was to describe the recovery of the endocrine and mechanical functions of the left atrium.</AbstractText>Evaluation of left atrium recovery after electrical cardioversion by the new speckle-tracking echocardiography technique and proANP measurement.</AbstractText>Twenty patients suffering from persistent atrial fibrillation with no alteration of left ventricular ejection fraction were prospectively evaluated at baseline and then one month later by echocardiography, measuring left atrial volume and left atrial deformation (MPALS), as well as the proANP and BNP concentrations. One month after cardioversion 10 patients remained in sinus rhythm and 10 showed recurrent atrial fibrillation. No significant differences between the two groups in terms of clinical, echocardiographic and endocrine parameters were observed at baseline evaluation. We observed a significant reduction of left atrial volume only in the sinus group, whereas restoration of the left atrial deformation was only partial (18%) in that group. By contrast, we registered no significant changes in ANP concentration at one month in either the sinus or the atrial fibrillation groups.</AbstractText>These results suggest that restoration of left atrium mechanical function is only partial one month after treatment of persistent atrial fibrillation by electrical cardioversion, whereas a significant reduction of left atrial volume was noted, explaining the remaining high level of ANP in the sinus group.</AbstractText> |
12,122 | [Anesthetic management of patients with dilated cardiomyopathy undergoing non-cardiac surgery]. | There is little information on the perioperative management of patients with dilated cardiomyopathy (DCM) undergoing non-cardiac surgery. The presence of a history or signs of heart failure and un-diagnosed DCM preoperatively, may be associated with an increased risk during non-cardiac surgery. In these patients, preoperative assessment of LV function, including echocardiography, and assessment of an individual's capacity to perform a spectrum of common daily tasks may be recommended to quantify the severity of systolic function. It is important to prevent low cardiac output and arrhythmia for the perioperative management of patients with DCM. Sympathetic hyperactivity often causes atrial or ventricular tachyarrhythmia, which could worsen systemic hemodynamics in these patients. In particular, the prevention of life-threatening arrhythmia, such as, ventricular tachycardia or ventricular fibrillation is important. To prevent perioperative low output syndrome, inotropic support, using catecholamines or phosphodiesterase inhibitors with or without vasodilators should be performed under careful monitoring. It is desirable to use a pulmonary-artery catheter during moderate to high risk surgery, because the optimum level of left ventricular pre-load is very narrow in these patients. Every effort must be made to detect postoperative heart failure by careful monitoring, including PAC, and physical examination. |
12,123 | [Perioperative management of patients with cardiomyopathies: preface and comments]. | Cardiomyopathies are a heterogeneous group of diseases of the myocardium. Cardiomyopathies are characterized by myocardial dysfunction resulting in heart failure due to systolic dysfunction and/or diastolic dysfunction. Prognosis of the patients with cardiomyopathies is usually poor due to progressive heart failure. Sudden death due to serious arrhythmia is not uncommon. Because of the heterogeneity of cardiomyopathies, the perioperative management of the patients with cardiomyopathies varies according to the pathological physiology. Management of low cardiac output is important as well as arrhythmias. Because of arrhythmias such as atrial fibrillation and poor ventricular function, anticoagulation is also important. Through evaluation and management of implantable pacemakers and implantable cardioverter defibrillator are essential. |
12,124 | Bipolar ablation for deep intra-myocardial circuits: human ex vivo development and in vivo experience. | Current conventional ablation strategies for ventricular tachycardia (VT) aim to interrupt reentrant circuits by creating ablation lesions. However, the critical components of reentrant VT circuits may be located at deep intramural sites. We hypothesized that bipolar ablations would create deeper lesions than unipolar ablation in human hearts.</AbstractText>Ablation was performed on nine explanted human hearts at the time of transplantation. Following explant, the hearts were perfused by using a Langendorff perfusion setup. For bipolar ablation, the endocardial catheter was connected to the generator as the active electrode and the epicardial catheter as the return electrode. Unipolar ablation was performed at 50 W with irrigation of 25 mL/min, with temperature limit of 50°C. Bipolar ablation was performed with the same settings. Subsequently, in a patient with an incessant septal VT, catheters were positioned on the septum from both the ventricles and radiofrequency was delivered with 40 W. In the explanted hearts, there were a total of nine unipolar ablations and four bipolar ablations. The lesion depth was greater with bipolar ablation, 14.8 vs. 6.1 mm (P < 0.01), but the width was not different (9.8 vs. 7.8 mm). All bipolar lesions achieved transmurality in contrast to the unipolar ablations. In the patient with a septal focus, bipolar ablation resulted in termination of VT with no inducible VTs.</AbstractText>By using a bipolar ablation technique, we have demonstrated the creation of significantly deeper lesions without increasing the lesion width, compared with standard ablation. Further clinical trials are warranted to detail the risks of this technique.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
12,125 | Prediction of arrhythmic events by Wedensky modulation in patients with coronary artery disease. | Prediction of arrhythmic events (AEs) has gained importance with the availability of implantable cardioverter-defibrillators (ICDs), but is still imprecise. This study evaluated the innovative Wedensky modulation index (WMI) as predictor of AEs.</AbstractText>In this prospective cohort, 179 patients with coronary artery disease (CAD) referred for AE risk assessment underwent baseline evaluation including measurement of R-/T-wave WMI (WMI(RT)) and left ventricular ejection fraction (LVEF). Two endpoints were assessed 3 years after the baseline evaluation: sudden cardiac death or appropriate ICD event (EP1) and any cardiac death or appropriate ICD event (EP2). Associations between baseline predictors (WMI(RT) and LVEF) and endpoints were evaluated in regression models.</AbstractText>Only three patients were lost to follow-up. EP1 and EP2 occurred in 24 and 27 patients, respectively. WMI(RT) (odds ratio [OR] per 1 point increase for EP1 20.1, 95% confidence interval [CI] 1.8-221.4, p = 0.014, and for EP2 73.3, 95% CI 6.6-817.7, p <0.001) and LVEF (OR per 1% increase for EP1 0.94, 95% CI 0.90-0.99, p = 0.013, and for EP2 0.93, 95% CI 0.89-0.97, p = 0.002) were significantly associated with both endpoints. In bivariable regression controlled for LVEF, WMI(RT) was independently associated with EP1 (p = 0.047) and EP2 (p = 0.007). The combination of WMI(RT) ≥0.60 and LVEF ≤30% resulted in a positive predictive value of 36% for EP1 and 50% for EP2.</AbstractText>WMI(RT) is a significant predictor of AEs independent of LVEF and has potential to improve AE risk prediction in CAD patients. However, WMI(RT) should be evaluated in larger and independent samples before recommendations for clinical routine can be made.</AbstractText> |
12,126 | Increased levels of inflammatory and extracellular matrix turnover biomarkers persist despite reverse atrial structural remodeling during the first year after atrial fibrillation ablation. | Left atrial (LA) remodeling associated with atrial fibrillation (AF) is known to be related to inflammation and collagen turnover. We investigated the changes in the biomarkers of inflammation and collagen turnover in relation to LA reverse remodeling during the 1st year after AF ablation.</AbstractText>Biomarkers of inflammation [high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6)] and collagen turnover [matrix metalloproteinase-2 (MMP-2), tissue inhibitor of MMP-2 (TIMP-2), transforming growth factor beta 1 (TGF-β1)], as well as asymmetric dimethylarginine (ADMA) and adiponectin levels were measured, and echocardiographic measurements were obtained before and 3, 6, and 12 months after ablation in 60 AF patients (49 males; age, 57.6 ± 10.9 years).</AbstractText>During a 12.1 (11.5-12.9)-month follow-up period, AF recurred in 29 patients (48 %). Neither the LA volume (LAV) nor the left ventricular ejection fraction (LVEF) changed significantly during the 1st year in this group, but the LAV decreased significantly, and the LVEF increased significantly in the nonrecurrence group. The hs-CRP and IL-6 decreased after ablation but returned near to baseline levels in both groups by 12 months. The MMP-2 remained increased during the 1st year in both groups, whereas the TIMP-2 increased markedly in the nonrecurrence group but did not change substantially in the recurrence group. The TGF-β1 increased in both groups, but the change was less pronounced in the recurrence group. The ADMA and adiponectin levels did not change substantially in either group.</AbstractText>Despite reverse remodeling, the inflammation and collagen turnover biomarker levels are quite progressive during the 1st year after ablation and may explain the late AF recurrence.</AbstractText> |
12,127 | Simultaneous hybrid carotid stenting and coronary bypass surgery versus concomitant open carotid and coronary bypass surgery: a pilot, feasibility study. | Concomitant carotid and cardiac surgery carries an increased perioperative morbidity and mortality risk. Whether the hybrid procedure of carotid artery stenting (CAS) and coronary bypass surgery decreases the risk of stroke and other complications is still unknown. The aim of this study was to assess early outcomes after simultaneous hybrid CAS and coronary bypass grafting versus open concomitant carotid and coronary bypass surgery.</AbstractText>We included 20 patients in this study. According to the protocol, all the patients were divided into two groups: Group 1 (10 patients) with hybrid CAS and coronary bypass surgery and Group 2 (10 patients) with concomitant carotid and coronary surgery. Different preoperative, intraoperative and postoperative variables were compared. The primary end point was combined incidence of stroke and death 30 days after surgery or during initial hospitalization. The secondary end points were myocardial infarction, atrial fibrillation, blood loss and need for blood transfusion and duration of intensive care unit and hospital stay.</AbstractText>Groups 1 and 2 were similar in preoperative characteristics including age (65.3 ± 6.8 vs 70.7 ± 7.0, P = 0.191) New York Heart Association class (2.3 ± 0.5 vs 1.8 ± 0.7, P = 0.218), EuroSCORE (2.8 ± 2.0 vs 3.6 ± 2.3, P = 0.547), the degree of carotid stenosis (79 ± 12 vs 87 ± 13%, P = 0.224) and average left ventricular ejection fraction (44.3 ± 12.4 vs 43.4 ± 13.3%, P = 0.896). Also, the groups did not differ in intraoperative variables with an exception of extracorporeal circulation time (65.7 ± 14.1 vs 90.0 + 17.4 min, P = 0.023), which was significantly shorter in Group 1. Although rare, and without significant difference, primary end point occurred only in Group 2 (1 stroke and 1 death, 20%). There was no difference in the duration of mechanical ventilation, need for transfusion and duration of intensive care unit and hospital stay between the two groups.</AbstractText>Although limited by a small sample size, our results show that the hybrid procedure of carotid stenting and coronary surgery might be a good therapeutic option but further extended studies are needed to assess its real value.</AbstractText>© The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.</CopyrightInformation> |
12,128 | Perioperative risk of major non-cardiac surgery in patients with severe aortic stenosis: a reappraisal in contemporary practice. | Severe aortic stenosis (SAS) is a major risk factor for death after non-cardiac surgery, but most supporting data are from studies over a decade old. We evaluated the risk of non-cardiac surgery in patients with SAS in contemporary practice.</AbstractText>SAS patients (valve area ≤1 cm(2), mean gradient ≥40 mmHg or peak aortic velocity ≥4 m/s) undergoing intermediate or high-risk surgery were identified from surgical and echo databases of 2000-2010. Controls were matched for age, sex, and year of surgery. Post-operative (30 days) death and major adverse cardiovascular events (MACE), including death, stroke, myocardial infarction, ventricular tachycardia/fibrillation, and new or worsening heart failure, and 1-year survival were determined. There were 256 SAS patients and 256 controls (age 76 ± 11, 54.3% men). There was no significant difference in 30-day mortality (5.9% vs. 3.1%, P = 0.13). Severe aortic stenosis patients had more MACE (18.8% vs. 10.5%, P = 0.01), mainly due to heart failure. Emergency surgery, atrial fibrillation, and serum creatinine levels of >2 mg/dL were predictors of post-operative death by multivariate analysis [area under the curve: 0.81, 95% confidence intervals: 0.71-0.91]; emergency surgery was the strongest predictor of 30-day mortality for both SAS and controls. Severe aortic stenosis was the strongest predictor of 1-year mortality.</AbstractText>Severe aortic stenosis is associated with increased risk of MACE. In contemporary practice, perioperative mortality of patients with SAS is lower than previously reported and the difference from controls did not reach statistical significance. Emergency surgery is the strongest predictor of post-operative death. These results have implications for perioperative risk assessment and management strategies in patients with SAS.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
12,129 | Aortic luminal thrombus and intramural hematoma after cardiopulmonary resuscitation. | We describe the case of a patient with an intramural hematoma and floating thrombus after cardiopulmonary resuscitation. The 92-year old man had a cardiac arrest due to ventricular fibrillation and witnesses immediately initiated manual cardiopulmonary resuscitation. Transesophageal echocardiography was performed immediately on hospital admission because the patient was in cardiogenic shock. In addition to an akinetic anterior wall, examination of the descending thoracic aorta demonstrated an intramural hematoma and a floating intra-aortic thrombus at a distance of 40cm from the dental arch. There was no aortic dissection. The thrombus was attributed to aortic compression during cardiopulmonary resuscitation. Although the aortic thrombus and intramural hematoma were not associated with any complications in this patient, insertion of an intra-aortic balloon may have led to aortic rupture or embolic events. Transesophageal echocardiography should be performed, when available, prior to insertion of an intra-aortic balloon for counterpulsation in patients who have undergone cardiopulmonary resuscitation.</Abstract><AuthorList CompleteYN="Y"><Author ValidYN="Y"><LastName>Fagnoul</LastName><ForeName>David</ForeName><Initials>D</Initials></Author><Author ValidYN="Y"><LastName>Herpain</LastName><ForeName>Antoine</ForeName><Initials>A</Initials></Author><Author ValidYN="Y"><LastName>Vincent</LastName><ForeName>Jean-Louis</ForeName><Initials>JL</Initials></Author><Author ValidYN="Y"><LastName>De Backer</LastName><ForeName>Daniel</ForeName><Initials>D</Initials></Author></AuthorList><Language>eng</Language><Language>por</Language><PublicationTypeList><PublicationType UI="D002363">Case Reports</PublicationType><PublicationType UI="D016428">Journal Article</PublicationType></PublicationTypeList></Article><MedlineJournalInfo><Country>Brazil</Country><MedlineTA>Rev Bras Ter Intensiva</MedlineTA><NlmUniqueID>9506692</NlmUniqueID><ISSNLinking>0103-507X</ISSNLinking></MedlineJournalInfo><CitationSubset>IM</CitationSubset><MeshHeadingList><MeshHeading><DescriptorName UI="D000369" MajorTopicYN="N">Aged, 80 and over</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D001013" MajorTopicYN="N">Aorta, Thoracic</DescriptorName><QualifierName UI="Q000473" MajorTopicYN="N">pathology</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D001018" MajorTopicYN="N">Aortic Diseases</DescriptorName><QualifierName UI="Q000209" MajorTopicYN="Y">etiology</QualifierName><QualifierName UI="Q000473" MajorTopicYN="N">pathology</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D016887" MajorTopicYN="N">Cardiopulmonary Resuscitation</DescriptorName><QualifierName UI="Q000009" MajorTopicYN="Y">adverse effects</QualifierName><QualifierName UI="Q000379" MajorTopicYN="N">methods</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D017548" MajorTopicYN="N">Echocardiography, Transesophageal</DescriptorName><QualifierName UI="Q000379" MajorTopicYN="N">methods</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D006323" MajorTopicYN="N">Heart Arrest</DescriptorName><QualifierName UI="Q000209" MajorTopicYN="N">etiology</QualifierName><QualifierName UI="Q000628" MajorTopicYN="N">therapy</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D006406" MajorTopicYN="N">Hematoma</DescriptorName><QualifierName UI="Q000209" MajorTopicYN="Y">etiology</QualifierName><QualifierName UI="Q000473" MajorTopicYN="N">pathology</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D006801" MajorTopicYN="N">Humans</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D008297" MajorTopicYN="N">Male</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D013927" MajorTopicYN="N">Thrombosis</DescriptorName><QualifierName UI="Q000209" MajorTopicYN="Y">etiology</QualifierName><QualifierName UI="Q000473" MajorTopicYN="N">pathology</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D014693" MajorTopicYN="N">Ventricular Fibrillation</DescriptorName><QualifierName UI="Q000150" MajorTopicYN="N">complications</QualifierName></MeshHeading></MeshHeadingList><OtherAbstract Type="Publisher" Language="por">Descrevemos o caso de um paciente com hematoma intramural e trombo flutuante após ressuscitação cardiopulmonar. Esse homem, de 92 anos de idade, teve uma parada cardíaca causada por fibrilação atrial e testemunhas iniciaram imediatamente manobras manuais de ressuscitação cardiopulmonar. Ao ser admitido no hospital, o paciente apresentava-se em choque cardiogênico, sendo, então, imediatamente submetido a ecocardiografia transesofágica. Além de uma parede anterior acinética, o exame da aorta torácica descendente mostrou um hematoma intramural e um trombo intra-aórtico flutuante a uma distância de 40cm do arco dental. Não havia dissecção da aorta. O trombo foi atribuído à compressão aórtica durante a ressuscitação cardiopulmonar. Embora o trombo aórtico e o hematoma intramural não tenham se associado a qualquer complicação nesse paciente, a inserção de um balão intra-aórtico poderia ter levado a uma ruptura da aorta ou a eventos embólicos. Recomenda-se a realização de ecocardiografia transesofágica, quando disponível, antes da inserção de um balão intra-aórtico de contrapulsação em pacientes submetidos à ressuscitação cardiopulmonar. |
12,130 | Atrial fibrillation in essential hypertension: an issue of concern. | Many clinical studies indicate that atrial fibrillation is closely related to hypertension. Atrial fibrillation is not only associated with the level of blood pressure (BP) but also with the circadian rhythms of BP. However, the underlying mechanisms of atrial fibrillation in essential hypertension patients remain largely unknown. Hypertension may facilitate the onset and persistence of atrial fibrillation by stretch-induced changes in the repolarization of atrial myocytes (triggers of atrial fibrillation) and atrial remodeling (structural and electrical remodeling). Importantly, the effects of hypertension on atrial fibrillation are progressive. These progressive anatomic, functional, electrophysiological and structural changes occur at different times. This characterization of the time course of atrial changes presents an intervention window before remodeling progresses to changes that are difficult to reverse. Given that the medium to long-term efficacy of antiarrhythmic drugs has proved poor, it is essential to seek new therapies to prevent the onset of atrial fibrillation and to effectively control recurrences of atrial fibrillation. The study of nonantiarrhythmic drugs that act on the atrial remodeling that constitutes the substrate of the arrhythmia is a new and very interesting field of research. Treatment with angiotensin-converting enzyme inhibitors angiotension-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) seems more promising. However, from recent trials, only hypertension with structural heart disease, left ventricular dysfunction and left ventricular hypertrophy benefit from ACEIs and ARBs. This article reviews many aspects of atrial fibrillatio in essential hypertension patients to provide the foundation of atrial fibrillatio treatment. |
12,131 | Racial differences in incident atrial fibrillation among hypertensive patients during antihypertensive therapy. | Blacks have a higher prevalence of risk factors for atrial fibrillation (AF), such as hypertension, obesity, and heart failure, than nonblacks. Although population-based studies have demonstrated a lower prevalence and incidence of AF in blacks, the relationship of incident AF to race among hypertensive patients undergoing blood pressure lowering has been less extensively examined.</AbstractText>Incident AF was examined in 518 black and 8,313 nonblack hypertensive patients with electrocardiographic left ventricular hypertrophy (LVH) with no history of AF in sinus rhythm on their baseline electrocardiogram, who were randomly assigned to losartan- or atenolol-based treatment.</AbstractText>During a mean of 4.7±1.1 years of follow-up, new-onset AF occurred in 701 patients (7.9%); 5-year AF incidence was significantly lower in black than nonblack patients (6.1 vs. 8.3%; P = 0.03). In univariable Cox analyses, black race was associated with a 37% lower risk of new AF (hazard ratio (HR) = 0.63; 95% confidence interval (CI) = 0.45-1.00; P = 0.05). In multivariable Cox analyses adjusting for randomized treatment, age, sex, diabetes, history of heart failure, myocardial infarction, ischemic heart disease, stroke, peripheral vascular disease, smoking status, baseline body mass index, serum total and high-density lipoprotein cholesterol, creatinine, glucose, and urine albumin/creatinine ratio as standard risk factors, and for incident myocardial infarction, in-treatment heart rate, systolic and diastolic pressure, Cornell product, and Sokolow-Lyon voltage LVH treated as time-varying covariables, black race remained associated with a 45% decreased risk of developing new AF (HR = 0.55; 95% CI = 0.35-0.87; P = 0.01).</AbstractText>Incident AF is substantially less common among black than nonblack hypertensive patients.</AbstractText>© American Journal of Hypertension, Ltd 2014. All rights reserved. For Permissions, please email: journals.permissions@oup.com.</CopyrightInformation> |
12,132 | Activation of peripheral delta opioid receptors increases cardiac tolerance to arrhythmogenic effect of ischemia/reperfusion. | The objective of this study was to investigate the role of peripheral μ, δ1, δ2, and nociceptin opioid receptors agonists in the regulation of cardiac tolerance to the arrhythmogenic effect of ischemia/reperfusion in rats.</AbstractText>Anesthetized open-chest male Wistar rats were subjected to either 45 minutes of left coronary artery occlusion (phase 1a 10 minutes and phase 2b 35 minutes) and 2 hours of reperfusion in Experiment 1 or 10 minutes of ischemia and 10 minutes of reperfusion in Experiment 2. In Experiment 1, saline or vehicle controls and the mu-specific opioids dermorphin-H (Derm-H) and ([d-Ala2, N-Me-Phe4, Gly-ol5] enkephalin (DAMAGO); the delta-1-specific opioid d-Pen2,5enkephalin (DPDPE); nociceptin; and the delta-2-specific opioids deltorphin-II (Delt-II), Delt-Dvariant (Delt-Dvar), and deltorphin-E (Delt-E) were infused 15 minutes prior to ischemia. In Experiment 2, DPDPE, Delt-D, Delt-Dvar, and Delt-E were infused at 15 minutes prior to ischemia. The universal opioid receptor antagonist naltrexone, the peripherally acting antagonist naloxone methiodide, the selective δ1 antagonist 7-benzylidene naltrexone maleate, and the specific δ2 antagonist naltriben mesylate were infused 25 minutes prior to ischemia.</AbstractText>In Experiment 1, pretreatment with the μ opioids Derm-H and DAMGO, DPDPE, and nociceptin at all doses tested did not reduce the incidence of ischemia-induced arrhythmias compared to controls during 45 minutes of ischemia. The δ2 opioids Delt-II (0.12 mg/kg), Delt-Dvar (0.3 mg/kg), and Delt-E (0.18 mg/kg) all demonstrated significant antiarrhythmic effects at the 150 nmol/kg dose compared to saline or vehicle controls. Nine of 19 animals treated with Delt-II were tolerant without ventricular arrhythmias to the arrhythmogenic effect of ischemia during the first 10 minutes of ischemia (phase 1a) and 11 of 19 were without ventricular arrhythmias during the following 35 minutes of ischemia (phase 1b). Delt-II also decreased the incidence of premature ventricular contractions and ventricular tachycardia by almost half during phase 1a. Delt-II did not affect the incidence of ventricular fibrillation (VF). Pretreatment with Delt-Dvar and Delt-E completely blocked the incidence of VF in phase 1b. Delt-E also decreased premature ventricular contractions by 50%, and the incidence of ventricular tachycardia decreased over twofold in phase 1b of ischemia. There was no enhanced tolerance by any of the delta-2 opioids to the arrhythmogenic effect of reperfusion after long-term ischemia. In Experiment 2, after 10 minutes of ischemia and 10 minutes of reperfusion, Delt-II (0.12 mg/kg) reduced the incidence of premature ventricular contractions and ventricular tachycardia compared to controls, and completely blocked the incidence of VF following 10 minutes of reperfusion. Delt-Dvar and Delt-E were without effect, as was DPDPE following 10 minutes of reperfusion. The antiarrhythmic effect of Delt-II during 10 minutes of ischemia and 10 minutes of reperfusion was completely blocked by the peripherally acting opioid receptor inhibitor naloxone methiodide and the selective delta-2 opioid receptor inhibitor naltriben mesylate, but not by the selective delta-1 inhibitor 7-benzylidene naltrexone maleate. The antagonists alone had no effect on arrhythmogenesis.</AbstractText>Peripheral delta-2 opioid receptor activation by Delt-II, Delt-Dvar, and Delt-E enhanced cardiac tolerance to the arrhythmogenic effects of ischemia.</AbstractText>© 2013 by the Society for Academic Emergency Medicine.</CopyrightInformation> |
12,133 | Periprocedural management of cardiac resynchronization therapy. | Cardiac resynchronization therapy (CRT) is an important therapy in heart failure but 30 %‒40 % of patients may not respond. Improving this rate is an important goal and requires attention to candidate selection, intraoperative procedure, and postoperative follow-up. Factors to be considered are QRS morphology, duration, and left ventricular lead position with attention to paced effects on QRS. Postprocedure follow-up is critical to correct interfering conditions (eg, anodal capture, loss of 100 % biventricular pacing because of premature ventricular complexes (PVCs) or atrial fibrillation (AF). Echocardiographic improvement following CRT, which may take up to 18 months, is a potent predictor of long-term outcomes. Correcting the status of nonresponders, when possible, is important. Remote monitoring, in conjunction with CRT optimization clinics, may facilitate multidisciplinary follow-up and enable early intervention to improve outcome. |
12,134 | Incidence of new onset atrial fibrillation in patients with permanent pacemakers and the relation to the pacing mode. | Atrial fibrillation is a relatively common arrhythmia often seen in patients with permanent pacemakers. In this study we aimed to assess the incidence of atrial fibrillation in patients whose pacemakers were programmed to pace in the right ventricle (VVI) and compared it with patients whose pacemakers were programmed in non-VVI mode(i.e. AAI or DDD).</AbstractText>Records of the patients with permanent pacemaker or implantable-cardioverter-defibrillator were evaluated and analyzed. These patients had regular periodic follow-up evaluation over the last 10 years. (January 1, 2002 to December 31, 2012). Patient demographic, pacemaker data, pacing mode, review and analysis of arrhythmia log for occurrence of new atrial fibrillation and echocardiographic findings for left atrial size, mitral regurgitation, were analyzed and recorded. Left atrial size was classified as mild, moderate or severe enlargement, depending on the left atrial dimension.</AbstractText>Average age was 68 years. There was no gender predominance (51% male). Mean follow-up duration was 6 years and 3 months. Hispanic population represented the majority of the patients (65.4%). Majority of the devices (80.0%) were programmed as DDD pacing mode. Fifty-five patients (52.8%) did not develop atrial fibrillation. 85.7% of the patients paced in VVI-mode had atrial fibrillation while atrial fibrillation occurred in 37.4% among patients paced in non-VVI-mode. This difference was statistically significant (P<0.0001).</AbstractText>Right ventricular pacing in a VVI mode was associated with higher incidence of atrial fibrillation, mitral regurgitation and left atrial enlargement. Non-VVI based pacing demonstrated lower incidence of new onset atrial fibrillation.</AbstractText> |
12,135 | [Nocturnal heart rhythm disorder in patients with obstructive sleep apnea syndrome]. | To explore the clinical characteristics of patients with obstructive sleep apnea syndrome (OSAS) and nocturnal arrhythmia.</AbstractText>During September 2010 to August 2011, a total of 446 subjects were recruited from Department of Sleep Breathing Disorder, Third Hospital, Hebei Medical University to receive polysomnography examination and electrocardiogram monitoring. According to the results, they were classified as mild (5 ≤ AHI < 15/h) or moderate (15 ≤ AHI < 40/h) or severe (AHI ≥ 40/h) OSAS. Then the incidence of different types of arrhythmias, risk factors and the relationship with OSAS severity were examined.</AbstractText>Among 446 patients, the incidence of arrhythmia was 24.4% (109/446). The severity of OSAS (r = 1.857, P = 0.043) and age (r = 1.030, P = 0.003) had a positive relationship with the incidence of arrhythmias.Sinus bradycardia (79.8%, 87/109) and accidental ventricular premature beat (54.1%, 59/109) were most likely to occur than other types of arrhythmias (P < 0.01).In moderate and severity OSAS patients, the incidence of sinus bradycardia, frequent atrial premature beat, combined over two kinds of arrhythmias, atrial fibrillation and atrioventricular block were 50.0%, 0, 42.9%, 7.1%,0 and 90.9%, 14.8%, 57.9%, 4.5%, 5.7% respectively. And they were significantly higher than those of mild patients (all = 0) (all P < 0.05).</AbstractText>Age and severity of OSAS have a positive relationship with the incidence of nocturnal arrhythmias.Sinus bradycardia and ventricular premature beat are the most likely to occur in OSAS patients.In moderate and severe group, sinus bradycardia, frequent atrial premature beat, combined over two kinds of arrhythmias, atrial fibrillation and atrioventricular block are more commonly encountered.</AbstractText> |
12,136 | Comparison of epinephrine and Shen-Fu injection on resuscitation outcomes in a porcine model of prolonged cardiac arrest. | Epinephrine has been used as a first-choice vasopressor drug for cardiac arrest (CA) since 1974. However, the administration of epinephrine is controversial. This study aims to compare the effects of Shen-Fu injection (SFI) and epinephrine on resuscitation outcomes in a porcine model of prolonged CA.</AbstractText>Ventricular fibrillation (VF) was electrically induced. After 8 minutes of untreated VF and 2 minutes of chest compressions, 24 pigs were randomly divided into 3 groups (n = 8 per group): central venous injection of SFI (SFI group), epinephrine (EPI group), or saline solution (SA group). The haemodynamic status and oxygen metabolism parameters, including cardiac output, mean arterial pressure, left ventricular dp/dtmax and negative dp/dtmax, oxygen delivery (DO2), and oxygen consumption (VO2), were calculated.</AbstractText>SFI shortened the time to restoration of spontaneous circulation (ROSC) and decreased the number of shocks, similar to epinephrine. However, the mean arterial pressure, cardiac output, left ventricular dp/dtmax and negative dp/dtmax were significantly higher in the SFI group than in the EPI group at 4 and 6 hours after ROSC. VO2 and ERO2 decreased after ROSC and then increased. VO2 and ERO2 were significantly higher in the SFI group than in the EPI and SA groups after ROSC, while those were lowest in the EPI group among all groups.</AbstractText>SFI shortened the time to ROSC and decreased the number of shocks, similar to epinephrine. However, SFI improved oxygen metabolism, and produced a better hemodynamic status compared with epinephrine. SFI might be a potentially vasopressor drug for the treatment of CA.</AbstractText> |
12,137 | Effect of catheter radiofrequency ablation on C-reactive protein, brain natriuretic peptide and echocardiograph in patients with persistent and permanent atrial fibrillation. | Radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) has developed rapidly, and is a commonly performed ablation in many major hospitals throughout the world, due to its satisfactory results. The aim of this study was to detect the effect of RFCA on C-reactive protein (CRP), brain natriuretic peptide (BNP), and echocardiograph in patients with persistent and permanent AF.</AbstractText>A total of 120 patients (71 males, mean age (50.8 ± 12.0) years) with persistent and permanent AF undergoing RFCA under guidance of the Carto merge technique were studied. Left atrial diameter (LAD), right atrial diameter (RAD), left ventricular ejection fraction (LVEF), CRP, and BNP were observed 3, 6 and 12 months after RFCA and compared with results before RFCA. The recurrence of atrial arrhythmias was observed 3 and 12 months after the procedure.</AbstractText>Compared with that before RFCA, LAD and RAD decreased and LVEF increased significantly after RFCA. Meanwhile, the levels of CRP and BNP were reduced significantly at 3, 6, and 12 months after RFCA (P < 0.05). In the non-recurrent patients, LVEF was increased significantly compared with the recurrent patients at 3, 6, and 12 months after RFCA (P < 0.05). CRP and BNP levels were decreased significantly in the non-recurrent patients compared with the recurrent patients at 3, 6, and 12 months after RFCA (P < 0.05). After one or two applications of RFCA, during a follow-up of 12 months, 12 patients (10.0%) had AF, 10 patients (8.3%) had atrial flutter, and 5 patients had atrial tachycardia (4.2%).</AbstractText>Conversion of AF to sinus rhythm by RFCA, has been shown to reduce LA size and improve LVEF. It can also significantly decrease the levels of CRP and BNP in patients with persistent and permanent AF and reduce the risk of inflammation and developing heart failure.</AbstractText> |
12,138 | Impact of single atrial fibrillation catheter ablation on implantable cardioverter defibrillator therapies in patients with ischaemic and non-ischaemic cardiomyopathies. | Atrial fibrillation (AF) is associated with frequent appropriate and inappropriate implantable cardioverter defibrillator (ICD) therapies. Catheter ablation of AF has been shown to reduce AF burden and improve left ventricular function in heart failure patients but the impact on ICD therapies has not yet been studied. The aim of this study was to test the hypothesis that AF ablation reduces ICD therapies in patients with cardiomyopathies.</AbstractText>In 73 consecutive patients (mean age 59 ± 10 years, 85% male) with previously implanted ICD due to ischaemic (n = 30) or dilated cardiomyopathy (n = 43) undergoing AF ablation, the prevalence and frequency of ICD therapies before and after AF ablation were compared. During the total follow-up of 3.3 ± 3 years prior to AF ablation, 5.1 ± 14.7 therapies per patient-year were delivered as opposed to 1.8 ± 10.9 in a period of 1.1 ± 0.9 years after ablation (P = 0.002). Prior to AF ablation, 39 patients (53%) received at least one ICD therapy when compared with 15 patients (21%) after ablation. Atrial fibrillation ablation was associated with freedom from any therapy regardless of appropriateness (odds ratio, OR, 0.366, CI 0.164-0.816, P = 0.014, adjusted for follow-up). Appropriate shocks significantly decreased from 0.3 ± 1.3 to 0.1 ± 0.5 per patient-year (P = 0.030). While heart failure medication and use of antiarrhythmic drugs were comparable during the entire follow-up, a statistically significant improvement of left ventricular ejection fraction (LVEF) from 36.9 ± 12.3% to 40.7 ± 6.7% (P = 0.008) was observed after AF ablation.</AbstractText>In patients with ischaemic or dilated cardiomyopathy, catheter ablation of AF is associated with the reduction of inappropriate and appropriate ICD therapies and improvement of LVEF.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
12,139 | Towards evidence-based emergency medicine: Best BETs from the Manchester Royal Infirmary. BET 2: Is there value in testing troponin levels after ICD discharge? | A short cut review was carried out to establish whether testing for troponin levels is useful after discharge of an Implanted Cardioverter-Defibrillator (ICD). Many papers were found using the reported searches, none of which directly addressed the problem but some 13 presented the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of those best papers are tabulated. It is concluded that the number of ICD discharges must be taken into account when evaluating any troponin level rise. Overall a positive troponin assay post ICD discharge is independently associated with an increased mortality. |
12,140 | Increase in pulmonary arterial pressure after atrial fibrillation ablation: incidence and associated findings. | The stiff left atrial (LA) syndrome is defined as pulmonary hypertension (PH) secondary to reduced LA compliance and has recently been shown to be one cause of PH after atrial fibrillation (AF) ablation. We aimed to determine the incidence of an increase in pulmonary arterial (PA) pressure post-ablation and examine the clinical and echocardiographic associations.</AbstractText>Patients who underwent AF ablation between 1999 and 2011 were included if they had both an echocardiogram pre-ablation and 3 months post-ablation. Patients were then separated into two groups with the increased PA pressure group defined as patients with >10 mmHg increase in right ventricular systolic pressure (RVSP) post-ablation and a post-ablation RVSP >35 mmHg.</AbstractText>Of the 499 patients meeting the study criteria, 41 (8.2%) had an increase in RVSP >10 mmHg and RVSP >35 mmHg post-ablation. On echocardiogram, the two groups had similar E/A and E/e' ratios pre-ablation. However, post-ablation, the increased PA pressure group had higher E/A (2.12 vs. 1.49, p < 0.01) and E/e' (14.7 vs. 11.2, p < 0.01) ratios. LA expansion index values were lower in the increased PA pressure group pre-ablation (51 vs. 92%, p < 0.01), but not significantly different post-ablation (82 vs. 88%, p = 0.44).</AbstractText>Around 8% of patients develop an increase in estimated PA pressure after AF ablation. Echocardiographic parameters suggest that patients who develop increased PA pressure are developing (or unmasking) left ventricular diastolic dysfunction.</AbstractText> |
12,141 | Early repolarization pattern: its ECG characteristics, arrhythmogeneity and heritability. | Early repolarization (ER) has been accepted as a benign ECG variant for decades. Two seminal studies challenged this notion and have demonstrated that ER pattern is associated with an increased risk of arrhythmic and cardiac mortality in patients with idiopathic ventricular fibrillation (IVF) and in the general population. Recent clinical studies demonstrate its varying impact as an arrhythmogenic substrate on different diseases. For example, in ER syndrome, a primary electrical disease, ER appears as a major arrhythmogenic substrate for development of VF whereas in patients with coronary artery disease, an ER pattern may exist as a silent substrate, increasing the risk of VF during episodes of cardiac ischaemia. Due to the high prevalence of an ER pattern in the general population and a low VF event rate, it remains challenging to differentiate a malignant ER pattern from a benign form. Recent research suggests that a J-wave amplitude of more than 0.1 mV combined with a descending/horizontal ST segment may constitute a malignant ER pattern. Further studies are however necessary to evaluate its prognostic value for cardiac and arrhythmic death in the general population as well as in cases with a malignant ER pattern. While genetic testing has revealed putative causal DNA variants in sporadic cases, the lack of co-segregation with the disease in affected families suggests that ER syndrome is not monogenic but is likely a complex disorder influenced by multiple genetic as well as environmental factors. |
12,142 | [Medicinal rate control in atrial fibrillation]. | Atrial fibrillation is the most common form of persistent arrhythmia. Atrial fibrillation frequently causes rapid ventricular response with severe clinical symptoms requiring acute control of the ventricular rate. This leads to hemodynamic stabilization and improvement of symptoms. The long-term treatment target is to minimize patient symptoms and prevention of complications. As a rhythm control strategy does not provide a survival benefit compared to a rate control strategy, decisions on the best long-term treatment have to be individualized. Important factors affecting this decision are age of the patient, chances to re-establish and maintain sinus rhythm, tolerance of antiarrhythmic medication and accompanying diseases of the heart. For younger patients a rhythm control strategy will usually be the preferred option. For rate control beta blockers are considered first line therapy, alternative drugs include calcium antagonists and digoxin. Occasionally, amiodarone may also be used for rate control. If pharmacological rate management fails ablation of the atrioventricular (AV) node may be an option to control the ventricular rate. |
12,143 | The subcutaneous defibrillator: a review of the literature. | The recently commercially available subcutaneous implantable cardioverter-defibrillator (S-ICD) uses a completely subcutaneous electrode configuration to treat potentially lethal ventricular tachyarrhythmia. Clinical trials have proven its effectiveness in detecting and treating ventricular fibrillation and tachycardia. The S-ICD offers the advantage of eliminating the need for intravenous and intracardiac leads and their associated risks and shortcomings. However, its major disadvantage is its inability to provide bradycardia rate support and antitachycardia pacing to terminate ventricular tachycardia. This paper discusses the S-ICD clinical trials and advantages and disadvantages of this novel technology to help the physician identify its role and select candidate patients who will benefit from this device. |
12,144 | Extracorporeal cardiopulmonary resuscitation versus conventional cardiopulmonary resuscitation in adults with out-of-hospital cardiac arrest: a prospective observational study. | A favorable neurological outcome is likely to be achieved in out-of-hospital cardiac arrest (OHCA) patients with ventricular fibrillation or pulseless ventricular tachycardia (VF/VT) on the initial electrocardiogram (ECG). However, in patients without pre-hospital restoration of spontaneous circulation despite the initial VF/VT, the outcome is extremely low by conventional cardiopulmonary resuscitation (CPR). Extracorporeal CPR (ECPR) may enhance cerebral blood flow and recovery of neurological function. We prospectively examined how ECPR for OHCA with VF/VT would affect neurological outcomes.</AbstractText>The design of this trial was a prospective, observational study. We compared differences of outcome at 1 and 6 months after OHCA between ECPR group (26 hospitals) and non-ECPR group (20 hospitals). Primary endpoints were the rate of favorable outcomes defined by the Glasgow-Pittsburgh Cerebral Performance and Overall Performance Categories (CPC) 1 or 2 at 1 and 6 months after OHCA. Based on intention-to-treat analysis, CPC 1 or 2 were 12.3% (32/260) in the ECPR group and 1.5% (3/194) in the non-ECPR group at 1 month (P<0.0001), and 11.2% (29/260) and 2.6% (5/194) at 6 months (P=0.001), respectively. By per protocol analysis, CPC 1 or 2 were 13.7% (32/234) in the ECPR group and 1.9% (3/159) in the non-ECPR group at 1 month (P<0.0001), and 12.4% (29/234) and 3.1% (5/159) at 6 months (P=0.002), respectively.</AbstractText>In OHCA patients with VF/VT on the initial ECG, a treatment bundle including ECPR, therapeutic hypothermia and IABP was associated with improved neurological outcome at 1 and 6 months after OHCA.</AbstractText>Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
12,145 | Regional TNFα mapping in the brain reveals the striatum as a neuroinflammatory target after ventricular fibrillation cardiac arrest in rats. | Cardiac arrest (CA) triggers neuroinflammation that could play a role in a delayed neuronal death. In our previously established rat model of ventricular fibrillation (VF) CA characterized by extensive neuronal death, we tested the hypothesis that individual brain regions have specific neuroinflammatory responses, as reflected by regional brain tissue levels of tumor necrosis factor (TNF)α and other cytokines. In a prospective study, rats were randomized to 6min (CA6), 8min (CA8) or 10min (CA10) of VF CA, or sham group. Cortex, striatum, hippocampus and cerebellum were evaluated for TNFα and interleukin (IL)-1α, IL-1β, IL-2, IL-4, IL-6, IL-10, IL-12 and interferon gamma at 3h, 6h or 14 d after CA by ELISA and Luminex. Immunohistochemistry was used to determine the cell source of TNFα. CA resulted in a selective TNFα response with significant regional and temporal differences. At 3h after CA, TNFα-levels increased in all regions depending on the duration of the insult. The most pronounced increase was observed in striatum that showed 20-fold increase in CA10 vs. sham, and 3-fold increase vs. CA6 or CA8 group, respectively (p<0.01). TNFα levels in striatum decreased between 3h and 6h, but increased in other regions between 3h and 14 d. TNFα levels remained twofold higher in CA6 vs. shams across brain regions at 14 d (p<0.01). In contrast to pronounced TNFα response, other cytokines showed only a minimal increase in CA6 and CA8 groups vs. sham in all brain regions with the exception that IL-1β increased twofold in cerebellum and striatum (p<0.01). TNFα colocalized with neurons. In conclusion, CA produced a duration-dependent acute TNFα response, with dramatic increase in the striatum where TNFα colocalized with neurons. Increased TNFα levels persist for at least two weeks. This TNFα surge contrasts the lack of an acute increase in other cytokines in brain after CA. Given that striatum is a selectively vulnerable brain region, our data suggest possible role of neuronal TNFα in striatum after CA and identify therapeutic targets for future experiments. This study was approved by the University of Pittsburgh IACUC 1002340A-3. |
12,146 | β-Blockers and atrial fibrillation: hypertension and other medical conditions influencing their use. | β-Blockers are among the most frequently used drugs in patients with atrial fibrillation. They are often used for ventricular rate control, acutely in emergency situations and chronically, in patients with persistent or permanent atrial fibrillation. They are also used, with less evidence of benefit, to prevent the first occurrence or recurrence of atrial fibrillation, particularly in patients with hypertension. They are effective in reducing ventricular rate, potentially leading to an improvement in symptoms and well-being. They are particularly indicated in patients with heart failure and atrial fibrillation; the choice of β-blockers in this condition should be guided by tolerability and effects on symptoms and well-being. |
12,147 | Vagal control of cardiac electrical activity and wall motion during ventricular fibrillation in large animals. | Vagal inputs control pacemaking and conduction systems in the heart. Anatomical evidence suggests a direct ventricular action, but functional evidence that separates direct and indirect (via the conduction system) vagal actions is less well established. We studied vagus nerve stimulation (VNS) during sinus rhythm and ventricular fibrillation (VF) in pigs and sheep to determine: 1) the range of unilateral and bilateral actions (inotropic and chronotropic) and 2) whether VNS alters left ventricular motion and/or electrical activity during VF, a model of abnormal electrical conduction of the left ventricle that excludes sinus and atrioventricular nodal function. Adult pigs (N=8) and sheep (N=10) were anesthetized with urethane and mechanically ventilated. VNS was performed in animals at 1, 2, 5, 10, 20, 50, and 100Hz for 20s. VF was induced with direct current to the ventricles or occlusion of the left anterior descending coronary artery. In 4 pigs and 3 sheep, left ventricular wall motion was assessed from endocardial excursion in epicardial echocardiography. In sheep and pigs, the best frequency among those tested for VNS during sinus rhythm to produce sustained electrical and mechanical ventricular standstill was 50Hz for unilateral or bilateral stimulation. When applied during VF, bilateral VNS increased the variability of the dominant VF frequency, indicating a direct impact on the excitability of ventricular myocytes, and decreased endocardial excursion by more than 50% during VF. We conclude that the vagus nerve directly modulates left ventricular function independently from its effects on the conduction system. |
12,148 | Association between survival and early versus later rhythm analysis in out-of-hospital cardiac arrest: do agency-level factors influence outcomes? | Effectiveness of a resuscitation strategy may vary across communities. We hypothesize that a strategy that prioritizes initial emergency medical services (EMS) rhythm analysis (analyze early) will be associated with survival advantage among EMS systems with lower baseline (pretrial) ventricular fibrillation survival, whereas a strategy that prioritizes initial EMS cardiopulmonary resuscitation (analyze late) will be associated with survival advantage among systems with higher ventricular fibrillation baseline survival.</AbstractText>We conducted a secondary, post hoc study of a randomized trial of out-of-hospital cardiac arrest. Subjects were stratified according to randomization status (analyze early versus analyze late) and EMS agency baseline ventricular fibrillation survival. We used a mixed-effects model to determine whether the association between favorable functional survival to hospital discharge and trial intervention (analyze late versus analyze early) differed according to EMS agency baseline ventricular fibrillation survival (<20% or >20%).</AbstractText>Characteristics were similar among patients randomized to analyze early (n=4,964) versus analyze late (n=4,426). For EMS agencies with baseline ventricular fibrillation survival less than 20%, analyze late compared with analyze early was associated with a lower likelihood of favorable functional survival (3.8% versus 5.5%; odds ratio [OR]=0.67 [95% CI 0.50, 0.90]). Conversely, among agencies with a ventricular fibrillation survival greater than 20%, analyze late compared with analyze early was associated with higher likelihood of favorable functional survival (7.5% versus 6.1%; OR=1.22 [95% CI 0.98, 1.52]). In the multivariable-adjusted model, for every 10% increase in baseline ventricular fibrillation survival, analyze late versus analyze early was associated with a 34% increase in odds of favorable functional survival (OR=1.34 [95% CI 1.07 to 1.66]).</AbstractText>The findings suggest that system-level characteristics may influence resuscitation outcomes.</AbstractText>Copyright © 2014 American College of Emergency Physicians. Published by Mosby, Inc. All rights reserved.</CopyrightInformation> |
12,149 | Beyond auscultation: acoustic cardiography in clinical practice. | Cardiac auscultation by stethoscope is widely used but limited by low sensitivity and accuracy. Phonocardiogram was developed in an attempt to provide quantitative and qualitative information of heart sounds and murmurs by transforming acoustic signal into visual wavelet. Although phonocardiogram provides objective heart sound information and holds diagnostic potentials of different heart problems, its examination procedure is time-consuming and it requires specially trained technicians to operate the device. Acoustic cardiography (AUDICOR, Inovise Medical, Inc., Portland, OR, USA) is a major recent advance in the evolution of cardiac auscultation technology. The technique is more efficient and less operator-dependent. It synchronizes cardiac auscultation with ECG recording and provides a comprehensive assessment of both mechanical and electronic function of the heart. The application of acoustic cardiography is far beyond auscultation only. It generates various parameters which have been proven to correlate with gold standards in heart failure diagnosis and ischemic heart disease detection. Its application can be extended to other diseases, including LV hypertrophy, constrictive pericarditis, sleep apnea and ventricular fibrillation. The newly developed ambulatory acoustic cardiography is potentially used in heart failure follow-up in both home and hospital setting. This review comprehensively summarizes acoustic cardiographic research, including the most recent development. |
12,150 | Long-term prognostic value and serial changes of plasma N-terminal prohormone B-type natriuretic peptide in patients undergoing transcatheter aortic valve implantation. | Little is known about the usefulness of evaluating cardiac neurohormones in patients undergoing transcatheter aortic valve implantation (TAVI). The objectives of this study were to evaluate the baseline values and serial changes of N-terminal prohormone B-type natriuretic peptide (NT-proBNP) after TAVI, its related factors, and prognostic value. A total of 333 consecutive patients were included, and baseline, procedural, and follow-up (median 20 months, interquartile range 9 to 36) data were prospectively collected. Systematic NT-proBNP measurements were performed at baseline, hospital discharge, 1, 6, and 12 months, and yearly thereafter. Baseline NT-proBNP values were elevated in 86% of the patients (median 1,692 pg/ml); lower left ventricular ejection fraction and stroke volume index, greater left ventricular mass, and renal dysfunction were associated with greater baseline values (p <0.01 for all). Higher NT-proBNP levels were independently associated with increased long-term overall and cardiovascular mortalities (p <0.001 for both), with a baseline cut-off level of ∼2,000 pg/ml best predicting worse outcomes (p <0.001). At 6- to 12-month follow-up, NT-proBNP levels had decreased (p <0.001) by 23% and remained stable up to 4-year follow-up. In 39% of the patients, however, there was a lack of NT-proBNP improvement, mainly related to preprocedural chronic atrial fibrillation, lower mean transaortic gradient, and moderate-to-severe mitral regurgitation (p <0.01 for all). In conclusion, most patients undergoing TAVI presented high NT-proBNP levels, and a lack of improvement was observed in >1/3 of the patients after TAVI. Also, higher NT-proBNP levels predicted greater overall and cardiac mortalities at a median follow-up of 2 years. These findings support the implementation of NT-proBNP measurements for the clinical decision-making process and follow-up of patients undergoing TAVI. |
12,151 | Deep accidental hypothermia with core temperature below 24°c presenting with vital signs. | According to the Swiss hypothermia clinical staging, patients with stage III are unconscious with preserved vital signs, with core temperature usually between 24° and 28°C. With stage IV, vital signs are absent with core temperature <24°C.</AbstractText>To describe a patient presenting with HT stage III with vital signs but a core temperature of <24°C, and to search for similar patients in the medical literature.</AbstractText>MEDLINE was used to search for cases of deep accidental hypothermia (<24°C) and preserved vital signs.</AbstractText>We found 22 cases in addition to our case (n=23). Median age was 44 years (IQR 36; range 4-83) and median core temperature 22°C (IQR 1.7; 17-23.8). Vital signs were often minimal. Seven patients developed ventricular fibrillation (VF). Twenty patients survived with excellent neurological outcome.</AbstractText>Vital signs can be present in hypothermic patients with core temperature <24°C. In deeply hypothermic patients, a careful check and prolonged check of vital functions should be made, as vital signs may be minimal. The clinical Swiss staging remains valuable in the prehospital evaluation of hypothermic patients; its correlation with core temperature should be better defined.</AbstractText> |
12,152 | Performance of an automatic arrhythmia classification algorithm: comparison to the ALTITUDE electrophysiologist panel adjudications. | Adjudication of thousands of implantable cardioverter defibrillator (ICD)-treated arrhythmia episodes is labor intensive and, as a result, is most often left undone. The objective of this study was to evaluate an automatic classification algorithm for adjudication of ICD-treated arrhythmia episodes.</AbstractText>The algorithm uses a machine learning algorithm and was developed using 776 arrhythmia episodes. The algorithm was validated on 131 dual-chamber ICD shock episodes from 127 patients adjudicated by seven electrophysiologists (EPs). Episodes were classified by panel consensus as ventricular tachycardia/ventricular fibrillation (VT/VF) or non-VT/VF, with the resulting classifications used as the reference. Subsequently, each episode electrogram (EGM) data was randomly assigned to three EPs without the atrial lead information, and to three EPs with the atrial lead information. Those episodes were also classified by the automatic algorithm with and without atrial information. Agreement with the reference was compared between the three EPs consensus group and the algorithm.</AbstractText>The overall agreement with the reference was similar between three-EP consensus and the algorithm for both with atrial EGM (94% vs 95%, P = 0.87) and without atrial EGM (90% vs 91%, P = 0.91). The odds of accurate adjudication, after adjusting for covariates, did not significantly differ between the algorithm and EP consensus (odds ratio 1.02, 95% confidence interval: 0.97-1.06).</AbstractText>This algorithm performs at a level comparable to an EP panel in the adjudication of arrhythmia episodes treated by both dual- and single-chamber ICDs. This type of algorithm has the potential for automated analysis of clinical ICD episodes, and adjudication of EGMs for research studies and quality analyses.</AbstractText>©2014 Wiley Periodicals, Inc.</CopyrightInformation> |
12,153 | Management of atrial fibrillation in critically ill patients. | Atrial fibrillation (AF) is common in ICU patients and is associated with a two- to fivefold increase in mortality. This paper provides a reappraisal of the management of AF with a special focus on critically ill patients with haemodynamic instability. AF can cause hypotension and heart failure with subsequent organ dysfunction. The underlying mechanisms are the loss of atrial contraction and the high ventricular rate. In unstable patients, sinus rhythm must be rapidly restored by synchronised electrical cardioversion (ECV). If pharmacological treatment is indicated, clinicians can choose between the rate control and the rhythm control strategy. The optimal substance should be selected depending on its potential adverse effects. A beta-1 antagonist with a very short half-life (e.g., esmolol) is an advantage for ICU patients because the effect of beta-blockade on cardiovascular stability is unpredictable in those patients. Amiodarone is commonly used in the ICU setting but has potentially severe cardiac and noncardiac side effects. Digoxin controls the ventricular response at rest, but its benefit decreases in the presence of adrenergic stress. Vernakalant converts new-onset AF to sinus rhythm in approximately 50% of patients, but data on its efficacy and safety in critically ill patients are lacking. |
12,154 | MicroRNA regulation and cardiac calcium signaling: role in cardiac disease and therapeutic potential. | MicroRNAs (miRNAs) are emerging as key control molecules in the regulation of gene expression, and their role in heart disease is becoming increasingly evident. Given the critical role of Ca(2+) handling and signaling proteins in the maintenance of cardiac function, the targeting of such proteins by miRNAs would be expected to have important consequences. miRNAs have indeed been shown to control the expression of genes encoding important Ca(2+) handling and signaling proteins, and are themselves regulated by Ca(2+)-dependent processes. Ca(2+)-related miRNAs have been found to be significant pathophysiological contributors in conditions like myocardial ischemic injury, cardiac hypertrophy, heart failure, ventricular arrhythmogenesis, and atrial fibrillation. This review is a comprehensive analysis of the present knowledge concerning miRNA regulation of Ca(2+) handling processes, the participation of Ca(2+)-regulating miRNAs in the evolution of heart disease, the mutual relationship between Ca(2+) signaling and miRNAs in the control of cardiac function, and the potential value of miRNA-control of Ca(2+) handling as a therapeutic target. |
12,155 | Long-term follow-up of DDD pacing mode. | The aim of this study was to determine the long-term survival of DDD pacing and identify the main reasons for its loss.</AbstractText>The study group consisted of 496 patients in whom a DDD pacing system was implanted between October 1984 and March 2002 and who were followed up until July 2010. The follow-up period was 152.1 ± 35.5 months. The patients' mean age at the time of implantation was 59.5 ± 12.5 years, and 53.5% were male; 58% had sick sinus syndrome (SSS), 26% had atrioventricular block (AVB), 15% had both of these indications simultaneously, and 1% had other indications. The incidence of lead malfunction, progression to chronic atrial fibrillation (AF), and the rate of infective complications was analysed.</AbstractText>During the follow-up, 369 patients remained in DDD mode stimulation. DDD mode survival rate at one, five, ten and 15 years was, respectively, 96%, 86%, 77% and 72%. The most common reason for reprogramming out of DDD mode was the development of permanent AF in 65 (13.1%) patients. The occurrence of chronic AF was associated with a prior history of paroxysmal AF (p = 0.0001), SSS (p = 0.0215), and older age at time of implantation (p = 0.0068) compared to patients who remained in sinus rhythm. Lead malfunction caused loss of DDD mode pacing in 56 (11.3%) patients. Atrial leads were damaged in 37 patients, ventricular in 12 patients, and both leads in seven patients. The subclavian vein puncture was correlated with the mechanical damage of the atrial lead (p = 0.02935) compared to cephalic vein access. At the moment of complication, the patients with a dysfunctional lead were significantly younger than those who progressed to chronic AF(p = 0.0019). Infective complications which caused temporary loss of DDD pacing were observed in six patients: five had pocket infection and one had lead-dependent infective endocarditis.</AbstractText>1. Effective DDD pacing from the originally implanted system was noted in a high percentage (72%) of patients in long-term observation (15 years). 2. Progression to permanent AF is the most common reason for loss of DDD pacing;a history of paroxysmal AF and old age are the risk factors. 3. Subclavian vein puncture is associated with a higher rate of atrial lead damage.</AbstractText> |
12,156 | Incidence, predictors, and evolution of conduction disorders and atrial arrhythmias after contemporary mitral valve repair. | Conduction disorders (CD) and atrial arrhythmias (AA) in the postoperative period of cardiac surgery impede prompt clinical recovery and prolong hospitalization. Mitral valve repair (MVR) has become the treatment of choice for patients with significant valvular regurgitation, but information on CD and AA in this population is scarce.</AbstractText>Records of consecutive patients undergoing MVR at a single center were reviewed. Patients with a preoperative pacemaker, CD, prior cardiac surgery or concomitant MVR were excluded. A total of 290 patients were included in the final analysis. Electrocardiograms pre andpost-operatively were analyzed for CD and AA.</AbstractText>CD occurred in 69 (23.7%) patients: 47 (16.2%) had first degree atrio-ventricular block (AVB), 10 (3.4%) had Mobitz I, 3 (1.03%) had Mobitz II, and 9 (3.1%) complete AVB. Only 6 (2.0%) patients required pacemakers. Univariate predictors of AVB were age, preexisting right bundle branch block (RBBB), mitral valve ring size, and bypass time. The only multivariate predictors of AVB were bypass time and preexisting RBBB (OR 3.23 and 1.98, respectively). The most common AA was atrial fibrillation 13.1% (38 patients) followed by atrial flutter 2.7% (8 patients). Multivariate predictors of AA were age and left atrial size (OR 1.85 and 4.2, respectively). Length of stay in patients with CD or AA was prolonged 2.2 ± 2 days compared to controls (p < 0.05).</AbstractText>In this large sample of patients undergoing MVR, we found that bypass time and preexisting RBBB were independent predictors of CD; age and left atrial size were independent predictors of AA.</AbstractText> |
12,157 | Outcomes after atrioventricular node ablation and biventricular pacing in patients with refractory atrial fibrillation and heart failure: a comparison between non-ischaemic and ischaemic cardiomyopathy. | Atrioventricular junction ablation (AVJA) combined with biventricular (BiV) pacing (AVJA/BiV) is an effective treatment for refractory atrial fibrillation (AF) and rapid ventricular response (RVR) associated with heart failure (HF). This study compared the outcomes between patients with non-ischaemic (DCM) and ischaemic cardiomyopathy (ICM) following AVJA/BiV for AF/RVR.</AbstractText>This was a retrospective study of 45 patients, comparing the response to AVJA/BiV in patients with ICM to those with DCM. The study compared (a) the change in echocardiographic parameters of HF (ejection fraction (EF) and left ventricular dimensions) prior to, and at least 6 months post AVJA/BiV; and (b) HF hospitalizations (HFH) and appropriate implantable cardioverter defibrillator (ICD) therapies occurring post-procedure. Ejection fraction improved significantly in the DCM group (ΔEF 11.2% ± 11.9; P< 0.01); however, EF remained unchanged (ΔEF 0.5% ± 9.9; P = NS) in the ICM group post-AVJA/BiV. Post-procedurely, HFH were significantly more common (15/18 vs. 4/25; P < 0.0001), and there were significantly more appropriate ICD therapies (9.4 ± 12.3 vs. 2.3 ± 6.1; P = 0.01) in the ICM compared with the DCM group.</AbstractText>After AVJA/BiV, there was significantly less post-procedural echocardiographic reverse remodelling, and more HFH in the ICM compared with the DCM group. In addition, significantly more appropriate ICD therapies occurred in ICM patients post-procedure. These differences may be due to the presence of more extensive discrete myocardial scar in patients with ICM. Furthermore, it is possible that tachycardia-induced cardiomyopathy plays more of a causative role in HF in patients with AF and DCM than those with ICM.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
12,158 | Surgical management of giant fibroelastoma of the aortic valve with repair through valve sparing technique. | Fibroelastomas account for less than 10% of all cardiac tumors, representing the most common valvular and the second most common cardiac benign tumor, following myxomas.Fibroelastomas are histologically benign, but they can result in life-threatening complications such as stroke, acute valvular dysfunction, embolism, ventricular fibrillation, and sudden death.</AbstractText>A valve-sparing technique with simple shave excision of the tumor was undertaken with success.</AbstractText>Surgical resection should be offered to all patients who have symptoms and to asymptomatic patients who have pedunculated lesions or tumors larger than 1 cm in diameter. Valve-sparing excision produces good long-term results in most instances.</AbstractText>We report our surgical experience of a giant fibroelastoma in the aortic valve.<Learning objective:</b> Medical and surgical management of giant fibroelastoma of aortic valve.>.</AbstractText> |
12,159 | Quantification of the functional consequences of atrial fibrillation and surgical ablation on the left atrium using cardiac magnetic resonance imaging. | The effect of atrial fibrillation (AF) on left atrial (LA) function has not been well defined and has been largely based on limited echocardiographic evaluation. This study examined the effect of AF and a subsequent Cox-Maze IV (CMIV) procedure on atrial function.</AbstractText>Cardiac magnetic resonance imaging (cMRI) was performed in 20 healthy volunteers, 8 patients with paroxysmal atrial fibrillation (PAF) and 7 patients with persistent or long-standing persistent atrial fibrillation (LSP AF). Six of the PAF patients underwent surgical ablation with the CMIV procedure and 5 underwent both pre- and postoperative cMRIs. The persistent or LSP AF patients underwent only postoperative cMRIs because all scans were performed with patients in normal sinus rhythm. Volume-time curves throughout the cardiac cycle and regional wall shortening were evaluated using the cine images and compared across groups.</AbstractText>Compared with normal volunteers, patients with PAF had significantly decreased reservoir contribution to left ventricular (LV) filling (P = 0.0010), an increased conduit function contribution (P = 0.04) and preserved booster pump function (P = 0.14). Following the CMIV procedure, significant reductions were noted with respect to reservoir and booster pump function, with corresponding increases in conduit function. These differences were more drastic in patients with persistent/LSP AF. Regional wall motion was significantly reduced by PAF in all wall segments (P < 0.05), but was not further reduced by the CMIV. Despite changes in LA function, LV function was preserved following surgery.</AbstractText>PAF significantly altered LA function and has a detrimental effect on regional wall motion. Surgical intervention further altered LA function, but the reasons for this are likely multifactorial and not entirely related to the lesion set itself.</AbstractText>© The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.</CopyrightInformation> |
12,160 | Complex left atrial appendage morphology and left atrial appendage thrombus formation in patients with atrial fibrillation. | In patients with atrial fibrillation (AF), most thrombus forms in the left atrial appendage (LAA). However, the relation of LAA morphology with LAA thrombus is unknown.</AbstractText>We prospectively enrolled 633 consecutive patients who were candidates for catheter ablation for symptomatic drug-resistant AF. Transesophageal echocardiography (TEE) was performed to assess LAA thrombus. LAA structure was assessed by 3-dimensional TEE. LAA orifice area, depth, volume, and number of lobes were measured on reconstructed 3-dimensional images. Clinical characteristics and echocardiographic measures were compared to determine variables predicting LAA thrombus. Excluded were 69 (10.9%) patients who met the exclusion criteria. Finally, this study comprised 564 patients, of whom LAA thrombus was observed in 36 (6.4%) patients. Multivariate analysis revealed CHADS2 (Congestive heart failure, Hypertension Age>75, Diabetes mellitus and prior Stroke or transient ischemic attack) score (P=0.002), left ventricular ejection fraction (P=0.01), degree of spontaneous echo contrast (P=0.02), left atrial volume (P=0.02), and number of LAA lobes (P<0.001) to be independently associated with thrombus formation. Most patients with LAA thrombus (32/34, 94.4%) had ≥3 LAA lobes, whereas LAA thrombus was observed in only 2 (0.7%) of 296 patients with 1 or 2 lobes. LAA volume significantly decreased in patients maintaining sinus rhythm after catheter ablation (P=0.0009). Number of LAA lobes did not change in any patient.</AbstractText>Complex LAA morphology characterized by an increased number of LAA lobes was associated with the presence of LAA thrombus independently of clinical risk and blood stasis. This study suggests that LAA morphology might be a congenital risk factor for LAA thrombus formation in patients with AF.</AbstractText> |
12,161 | [Electrical storm in Brugada syndrome successfully treated with isoproterenol. Report of a case]. | We report a 22-year-old male who experienced several episodes of syncope within a timeframe of few hours. In the emergency room, multiple ventricular fibrillation episodes where documented along with a type 1 Brugada ECG pattern. Isoproterenol in continuous infusion was started, normalizing the ECG and avoiding further arrhythmia recurrences. The patient was implanted with an automated defibrillator and discharged 3 days after admission. |
12,162 | Early subclinical ventricular dysfunction in patients with insulin resistance. | The aim of our study was to evaluate the relationship between insulin resistance and the detection of precocious echocardiographic signs of heart failure in patients with cardiovascular risk factors.</AbstractText>We enrolled 34 consecutive patients with cardiovascular risk factors. All patients underwent coronary angiography, echocardiography, and laboratory tests. Exclusion criteria were diabetes (fasting glucose greater than 126 mg/dl or treatment with insulin or oral hypoglycemic agents), coronary artery disease, creatinine above 1.5 mg/dl, left-ventricular hypertrophy, valvular heart disease, ejection fraction below 50%, atrial fibrillation, or other severe arrhythmia. The presence of insulin resistance was assessed by using the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR). Ventricular function was investigated by echocardiography.</AbstractText>Distinguishing patients with insulin resistance, based on the median value of HOMA-IR (<4.06 and >4.06), we observed that in the group with higher levels of HOMA-IR, there were echocardiographic signs of subclinical ventricular dysfunction statistically more frequent (E/A in group with HOMA <4.06: 1.159 + 0.33 vs. group with HOMA >4.06: 0.87 + 0.29, P = 0.0136; E/E': 6.42 + 4 vs. 15.52 + 3.26, P = 0.001; Tei index: 0.393 + 0.088 vs. 0.489 + 0.079, P = 0.0029; S wave: 0112 + 0.015 vs. 0.114 + 0.027, P = 0.0001; ejection fraction 59.11 + 4.75 vs. 58.88 + 6.81, P = 0.9078). Grade II diastolic dysfunction was observed in 5 patients, grade I in 12 patients, and 17 patients had normal diastolic function. On multivariate analysis, HOMA-IR (P = 0.0092), hypertension (P = 0.0287), waist circumference (P = 0.0009), high-density lipoprotein (P = 0.0004), and fasting blood glucose (P = 0.0003) were variables independently associated with diastolic dysfunction. On analysis of covariance, we found that the variables that influence diastolic dysfunction are HOMA-IR, waist circumference, BMI, and age, and that the only variable that influences Tei index is HOMA-IR.</AbstractText>Insulin resistance is frequently associated with subclinical left-ventricular dysfunction. Patients with cardiovascular risk factors and increased HOMA-IR levels, although without diabetes mellitus, overt coronary artery disease, or hypertensive cardiomyopathy, may represent a target population for screening programs, recommended changes in lifestyle, and possibly the use of pharmacological interventions to prevent the onset of heart failure.</AbstractText> |
12,163 | Prognostic value of late gadolinium enhancement on cardiac magnetic resonance imaging in Japanese hypertrophic cardiomyopathy patients. |  The prognostic value of late gadolinium enhancement (LGE) on contrast-enhanced cardiovascular magnetic resonance (CMR) in Japanese hypertrophic cardiomyopathy (HCM) patients in a large, single-center cohort was investigated.</AbstractText> A total of 345 HCM patients (mean age, 59±17 years; 214 male) underwent CMR with gadolinium enhancement, and were followed (mean duration, 21.8 months) for cardiovascular events. Patients were divided into event-positive and event-negative groups. The clinical and CMR characteristics were compared between the 2 groups, and predictors of cardiovascular events assessed on multivariate analysis. LGE was positive in 252 patients (73%). The annual cardiovascular events rate was significantly higher in patients with LGE than in those without (6.2%/year vs. 0.6%/year, P=0.003). On multivariate analysis, LGE (hazard ratio [HR], 7.436; 95% confidence interval [CI]: 1.001-55.228, P=0.050), increased myocardial mass index (HR, 1.013; 95% CI: 1.002-1.023, P=0.018), reduced left ventricular ejection fraction (HR, 0.965; 95% CI: 0.945-0.985, P=0.001), and atrial fibrillation (HR, 2.257; 95% CI: 1.024-4.976, P=0.043) were significantly associated with cardiovascular events.</AbstractText> The presence of LGE, increased myocardial mass index, reduced left ventricular ejection fraction and atrial fibrillation were independent predictors of adverse prognosis in Japanese HCM patients.  </AbstractText> |
12,164 | Physical activity measured with implanted devices predicts patient outcome in chronic heart failure. | Physical activity (PA) predicts cardiovascular mortality in the population at large. Less is known about its prognostic value in patients with chronic heart failure (HF).</AbstractText>Data from 836 patients with implantable cardioverter defibrillator without or with cardiac resynchronization therapy enrolled in the Sensitivity of the InSync Sentry OptiVol feature for the prediction of Heart Failure (SENSE-HF)(1) study and the Diagnostic Outcome Trial in Heart Failure (DOT-HF) were pooled. The devices continuously measured and stored total daily active time (single-axis accelerometer). Early PA (average daily activity over the earliest 30-day study period) was studied as a predictor of time to death or HF-related hospital admission (primary end point). Data from 781 patients were analyzed (65±10 years; 85% men; left ventricular ejection fraction, 26±7%). Older age, shorter height, ischemic cause, peripheral artery disease, atrial fibrillation, diabetes mellitus, rales, peripheral edema, higher New York Heart Association class, lower diastolic blood pressure, and no angiotensin II receptor blocker/angiotensin-converting enzyme inhibitor use were associated with reduced early PA. The primary end point occurred in 135 patients (15±7 months of follow-up). In multivariable analysis including baseline variables, early PA predicted death or HF hospitalization, with a 4% reduction in risk for each 10 minutes per day additional activity (hazard ratio [HR], 0.96; confidence interval [CI], 0.94-0.98; P=0.0002 compared with a model with the same baseline variables but without PA). PA also predicted death (HR, 0.93; CI, 0.90-0.96; P<0.0001) and HF hospitalization (HR, 0.97; CI, 0.95-0.99; P=0.011).</AbstractText>Early PA, averaged over a 30-day window early after defibrillator implantation or cardiac resynchronization therapy in patients with chronic HF, predicted death or HF hospitalization, as well as mortality and HF hospitalization separately, accounting for baseline HF severity. Clinical Trial Registration Information- URL: http://www.clinicaltrials.gov. Unique identifiers: NCT00400985, NCT00480077.</AbstractText> |
12,165 | Left ventricular thrombus development during ventricular fibrillation and resolution during resuscitation in a swine model of sudden cardiac arrest. | Intracardiac thrombus is a well-known complication of low-flow cardiac states including acute myocardial infarction and atrial fibrillation. Little is known, however, about the formation of intracardiac (left ventricular [LV]) thrombus during the extreme low-flow state of cardiac arrest.</AbstractText>Using a swine model of sudden cardiac arrest, we examined the sonographic development of LV thrombus over time after induction of ventricular fibrillation (VF) and resolution of thrombus with cardiopulmonary resuscitation (CPR).</AbstractText>This observational study was IACUC approved. Forty-five Yorkshire swine were sedated, intubated, and instrumented under general anesthesia before VF was electrically induced. Sonographic data was collected immediately after VF induction and at 2-min intervals thereafter. Following 12min of untreated VF, resuscitation was initiated with closed chest compressions using an oxygen-powered mechanical resuscitation device. Observations were continued during attempted resuscitation. At the end of the experiment, the animals were euthanized while still at a surgical depth of anesthesia. The data was analyzed descriptively.</AbstractText>Sonographic evidence of LV thrombus was observed in 43/45 animals (95.6% [95%CI: 85.2%, 98.8%]). Thrombus was detected within 6min in 39/45 (86.7% [95%CI: 73.8%, 93.8%]) animals that developed thrombus. Thrombus resolved within 2min after initiation of chest compressions in 31/43 (72.1% [95%CI: 57.3%, 83.3%]) animals.</AbstractText>Similar to other low-flow cardiac states, LV thrombus develops early in the natural history of VF arrest and resolves quickly once forward flow is re-established by chest compressions. Institutional protocol number: 154600-8.</AbstractText>Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
12,166 | The role of Purkinje-myocardial coupling during ventricular arrhythmia: a modeling study. | The Purkinje system is the fast conduction network of the heart which couples to the myocardium at discrete sites called Purkinje-Myocyte Junctions (PMJs). However, the distribution and number of PMJs remains elusive, as does whether a particular PMJ is functional. We hypothesized that the Purkinje system plays a role during reentry and that the number of functional PMJs affect reentry dynamics. We used a computer finite element model of rabbit ventricles in which we varied the number of PMJs. Sustained, complex reentry was induced by applying an electric shock and the role of the Purkinje system in maintaining the arrhythmia was assessed by analyzing phase singularities, frequency of activation, and bidirectional propagation at PMJs. For larger junctional resistances, increasing PMJ density increased the mean firing rate in the Purkinje system, the percentage of successful retrograde conduction at PMJs, and the incidence of wave break on the epicardium. However, the mean firing of the ventricles was not affected. Furthermore, increasing PMJ density above 13/[Formula: see text] did not alter reentry dynamics. For lower junctional resistances, the trend was not as clear. We conclude that Purkinje system topology affects reentry dynamics and conditions which alter PMJ density can alter reentry dynamics. |
12,167 | Different prognostic value of functional right ventricular parameters in arrhythmogenic right ventricular cardiomyopathy/dysplasia. | The value of standard 2-dimensional transthoracic echocardiographic parameters for risk stratification in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is controversial.</AbstractText>We investigated the impact of RV fractional area change (FAC) and tricuspid annulus plane systolic excursion (TAPSE) for the prediction of major adverse cardiovascular events (MACE) defined as the occurrence of cardiac death, heart transplantation, survived sudden cardiac death, ventricular fibrillation, sustained ventricular tachycardia, or arrhythmogenic syncope. Among 70 patients who fulfilled the 2010 ARVC/D Revised Task Force Criteria and underwent baseline transthoracic echocardiography, 37 (53%) patients experienced MACE during a median follow-up period of 5.3 (interquartile range, 1.8-9.8) years. Average values for FAC, TAPSE, and TAPSE indexed to body surface area (BSA) decreased over time (P=0.03 for FAC, P=0.03 for TAPSE, and P=0.01 for TAPSE/BSA, each versus baseline). In contrast, median RV end-diastolic area increased (P=0.001 versus baseline). Based on the results of Kaplan-Meier estimates, the time between baseline transthoracic echocardiography and experiencing MACE was significantly shorter for patients with FAC <23% (P<0.001), TAPSE <17 mm (P=0.02), or right atrial short axis/BSA ≥25 mm/m(2) (P=0.04) at baseline. A reduced FAC constituted the strongest predictor of MACE (hazard ratio, 1.08 per 1% decrease; 95% confidence interval, 1.04-1.12; P<0.001) on bivariable analysis.</AbstractText>This long-term observational study indicates that TAPSE and dilation of right-sided cardiac chambers are associated with an increased risk for MACE in patients with ARVC/D with advanced disease and a high risk for adverse events. However, FAC is the strongest echocardiographic predictor of adverse outcome in these patients. Our data advocate a role for transthoracic echocardiography in risk stratification in patients with ARVC/D, although our results may not be generalizable to lower-risk ARVC/D cohorts.</AbstractText> |
12,168 | Atrial fibrillation in a large population with Brugada electrocardiographic pattern: prevalence, management, and correlation with prognosis. | A high prevalence of atrial fibrillation/atrial flutter (AF/AFl) has been reported in small series of Brugada patients, with discordant data.</AbstractText>The purpose of this study was to analyze, in a large population of Brugada patients, the prevalence of AF/AFl, its correlation with prognosis, and the efficacy of hydroquinidine (HQ) treatment.</AbstractText>Among 560 patients with Brugada type 1 ECG (BrECG), 48 (9%) had AF/AFl. Three groups were considered: 23 patients with BrECG pattern recognized before AF/AFl (group 1); 25 patients first diagnosed with AF/AFl in whom Class IC antiarrhythmic drugs administered for cardioversion/prophylaxis unmasked BrECG (group 2); and 512 patients without AF/AFl (group 3). Recurrence of AF/AFl and occurrence of ventricular arrhythmias were evaluated at follow-up.</AbstractText>Mean age was 47 ± 15 years, 59 ± 11 years, and 44 ± 14 years in groups 1, 2, and 3, respectively. Seven subjects (32%) in group 1 had syncope/aborted sudden death, 1 (4%) in group 2, and 122 (24%) in group 3. Ventricular arrhythmia occurred in three patients in group 1, none in group 2, and 10 in group 3 at median follow-up of 51, 68, and 41 months, respectively. Nine patients in group 1 and nine in group 2 received HQ for AF/AFl prophylaxis; on therapy, none had AF/AFl recurrence.</AbstractText>Prevalence of AF/AFl in Brugada patients is higher than in the general population of the same age. Patients in group 1 are younger than those in group 2 and have a worse prognosis compared to both groups 2 and 3. HQ therapy has proved useful and safe in patients with AF/AFl and BrECG.</AbstractText> |
12,169 | Extensive fatal intracoronary thrombosis during percutaneous coronary intervention with bivalirudin. | The authors describe 2 cases of extensive intracoronary thrombus formation leading to acute closure of the left main where bivalirudin (Angiomax) was used as the anticoagulant during percutaneous coronary intervention leading to mortality. Both cases had similarity in the cascade of complications of coronary dissection leading to slow flow and prolonged procedure time with compromise of antegrade flow in the coronary artery and a final catastrophic development of extensive intracoronary thrombosis extending into the left main and nonintervened vessel (left anterior descending or circumflex) followed by ventricular fibrillation and death. Bivalirudin has reversible anticoagulant pharmacodynamics because the bivalirudin molecule is cleaved by the thrombin molecule. In situations when the antegrade flow is compromised, delivery of fresh circulating bivalirudin to replenish the catalysis of bivalirudin by thrombin is diminished, allowing thrombin activity to regenerate, thereby creating a prothrombotic milieu in these coronary segments. This can lead to extensive intracoronary thrombus formation in situations of slow flow precipitated by coronary dissection and prolonged dwell time with intracoronary hardware (wires, balloons, and stents). Interventionalists should be aware of the potential risk of this fatal complication and should be proactive in recognizing the scenarios where this is likely to occur. In such anticipated circumstances, the interventionalist may judiciously switch the anticoagulant to heparin and/or use additional glycoprotein IIb/IIIa inhibitor because freshly formed intracoronary thrombus is susceptible to lysis by glycoprotein IIb/IIIa inhibitors. |
12,170 | Influencing factors for early acute cerebrovascular accidents in patients with stroke history following off-pump coronary artery bypass grafting. | To analyse risk factors for early acute cerebrovascular accidents following off-pump coronary artery bypass grafting (OPCAB) in patients with stroke history, and to propose preventive measures to reduce the incidence of these events.</AbstractText>A total of 468 patients with a history of stroke underwent OPCAB surgery in Beijing Anzhen Hospital of China from January 2010 to September 2012. They were retrospectively divided into two groups according to the occurrence of early acute cerebrovascular accidents within 48 hours following OPCAB. Multivariate logistic regression analysis was used to find risk or protective factors for early acute cerebrovascular accidents following the OPCAB.</AbstractText>Fifty-two patients (11.1%) suffered from early acute cerebrovascular accidents in 468 patients, including 39 cases of cerebral infarction, two cases of cerebral haemorrhage, 11 cases of transient ischaemic attack (TIA). There were significant differences between the two groups in preoperative left ventricular ejection fraction ≤ 35%, severe bilateral carotid artery stenosis, poorly controlled hypertension, intraoperative application of Enclose® II proximal anastomotic device, postoperative acute myocardial infarction, atrial fibrillation, hypotension, ventilation time > 48h, ICU duration >48h and mortality. Multivariate logistic regression analysis showed that preoperative severe bilateral carotid stenosis (OR=6.378, 95%CI: 2.278-20.987) and preoperative left ventricular ejection fraction ≤ 35% (OR=2.737, 95%CI: 1.267-6.389), postoperative acute myocardial infarction (OR=3.644, 95%CI: 1.928-6.876), postoperative atrial fibrillation (OR=3.104, 95%CI:1.135∼8.016) and postoperative hypotension (OR=4.173, 95%CI: 1.836∼9.701) were independent risk factors for early acute cerebrovascular accidents in patients with a history of stroke following OPCAB procedures, while intraoperative application of Enclose® II proximal anastomotic device was protective factor (OR=0.556, 95%CI: 0.337-0.925).</AbstractText>This study indicated that patients with severe bilateral carotid stenosis, the left ventricular ejection fraction ≤35%, the postoperative acute myocardial infarction, postoperative atrial fibrillation and postoperative hypotension were more likely to suffer from early acute cerebrovascular accidents when they received OPCAB. Application of Enclose® II proximal anastomotic device may decrease the incidence of early acute cerebrovascular accidents during OPCAB.</AbstractText>Copyright © 2014 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.</CopyrightInformation> |
12,171 | Clinical significance of late gadolinium enhancement in patients<20 years of age with hypertrophic cardiomyopathy. | Late gadolinium enhancement (LGE) on cardiovascular magnetic resonance imaging is associated with adverse events in adults with hypertrophic cardiomyopathy (HC). However, limited data exist on the extent and clinical significance of LGE in the pediatric population. In 30 patients (aged 14.1±3.2 years) with clinically diagnosed HC who underwent cardiovascular magnetic resonance imaging from 2007 to 2012, segments with hypertrophy and LGE were identified by 2 experienced readers blinded to outcome. Radial, circumferential, and longitudinal strains were evaluated using feature tracking software. The composite outcome was defined as cardiac death, nonsustained ventricular tachycardia, ventricular fibrillation, or appropriate implantable cardioverter-defibrillator discharge. LGE was present in 17 of 30 patients (57%), all in a midmyocardial pattern, with median 3 segments per patient (interquartile range [IQR] 2 to 5). No LGE was detected in patients without phenotypic hypertrophy. Segments with LGE had decreased radial (basal segments 20.7% vs 70.9%, p=0.01), circumferential (basal segments -23.2% vs -29.3%, p=0.04), and longitudinal strains (basal segments -13.8% vs -20.9%, p=0.04). After median follow-up of 26.9 months (IQR 7.5 to 34.3), 7 patients who had an adverse outcome (5 ventricular tachycardia, 1 appropriate implantable cardioverter-defibrillator discharge, and 1 death) had more segments of LGE (median 4, IQR 2 to 7 vs 0, IQR 0 to 2, p=0.01). One patient without LGE had ventricular tachycardia on exercise test. In conclusion, LGE occurs in a similar pattern in pediatric patients with HC as in adults, associated with hypertrophy, decreased myocardial strain, and adverse clinical outcomes. Further longitudinal studies are necessary to evaluate the rate of development of LGE and relation to outcomes in a larger cohort. |
12,172 | Inappropriate implantable cardioverter-defibrillator shocks attributed to alternating-current leak in a swimming pool. | Implantable cardioverter-defibrillators (ICDs) are the standard of care for preventing sudden cardiac death in patients who are predisposed to malignant ventricular arrhythmias. Causes of inappropriate ICD shock include equipment malfunction, improper arrhythmia evaluation, misinterpretation of myopotentials, and electromagnetic interference. As the number of implanted ICDs has increased, other contributors to inappropriate therapy have become known, such as minimal electrical current leaks that mimic ventricular fibrillation. We present the case of a 63-year-old man with a biventricular ICD who received 2 inappropriate shocks, probably attributable to alternating-current leaks in a swimming pool. In addition, we discuss ICD sensitivity and offer recommendations to avoid similar occurrences. |
12,173 | Postoperative arrhythmias after cardiac surgery: incidence, risk factors, and therapeutic management. | Arrhythmias are a known complication after cardiac surgery and represent a major cause of morbidity, increased length of hospital stay, and economic costs. However, little is known about incidence, risk factors, and treatment of early postoperative arrhythmias. Both tachyarrhythmias and bradyarrhythmias can present in the postoperative period. In this setting, atrial fibrillation is the most common heart rhythm disorder. Postoperative atrial fibrillation is often self-limiting, but it may require anticoagulation therapy and either a rate or rhythm control strategy. However, ventricular arrhythmias and conduction disturbances can also occur. Sustained ventricular arrhythmias in the recovery period after cardiac surgery may warrant acute treatment and long-term preventive strategy in the absence of reversible causes. Transient bradyarrhythmias may be managed with temporary pacing wires placed at surgery, but significant and persistent atrioventricular block or sinus node dysfunction can occur with the need for permanent pacing. We provide a complete and updated review about mechanisms, risk factors, and treatment strategies for the main postoperative arrhythmias. |
12,174 | An unusual case of flecainide-induced QT prolongation leading to cardiac arrest. | Flecainide is recommended as a first-line antiarrhythmic drug to maintain normal sinus rhythm in patients with atrial fibrillation (AF) who have structurally normal hearts or hypertension without left ventricular hypertrophy. Flecainide is a sodium channel blocker with minimal effects expected on ventricular repolarization. We describe the case of a 32-year-old man with a structurally normal heart and persistent AF who was started on diltiazem and flecainide 50 mg twice/day approximately a year prior to presentation. Due to persistent and bothersome symptoms, his dose was increased to 150 mg twice/day, which was associated with a progressive lengthening of his corrected QT interval. On the day of presentation, he underwent an exercise test as part of his job requirements. While running, he felt lightheaded and experienced a syncopal event and cardiac arrest. An automated external defibrillator was available that displayed polymorphic ventricular tachycardia. The patient was successfully resuscitated. Although rare, this case suggests that flecainide can induce QT prolongation leading to torsades de pointes. Clinicians should be aware and consider periodic evaluations with electrocardiograms. |
12,175 | Electrocardiographic abnormalities in elderly Chagas disease patients: 10-year follow-up of the Bambui Cohort Study of Aging. | Electrocardiography has been considered an important tool in the management of Chagas disease (ChD) patients, although its value in elderly infected patients is unknown. This study was designed to investigate the prevalence and prognostic value of electrocardiographic abnormalities in Trypanosoma cruzi infected and noninfected older adults.</AbstractText>We studied 1462 participants in Bambuí City, Brazil, with electrocardiogram (ECG) records classified by the Minnesota Code. Follow-up time was 10 years; the endpoint was mortality. Adjustment for potential confounding variables included age, gender, conventional risk factors, and B-type natriuretic peptide (BNP). The mean age was 69 years (60.9% women). The prevalence of ChD was 38.1% (n=557). ECG abnormalities were more frequent in ChD patients (87.6% versus 77.7%, P<0.001). Right bundle branch block (RBBB) with left anterior hemiblock (LAH) was strongly related to ChD (OR: 11.99 [5.60 to 25.69]). During the mean follow-up time of 8.7 years, 556 participants died (253 with ChD), and only 89 were lost to follow-up. ECG variables of independent prognostic value for death in ChD included absence of sinus rhythm, frequent ventricular and supraventricular premature beats, atrial fibrillation, RBBB, old and possible old myocardial infarction, and left ventricular hypertrophy. The presence of any major ECG abnormalities doubled the risk of death in ChD patients (HR: 2.18 [1.35 to 3.53]), but it also increased the risk in non-ChD subjects (HR: 1.50 [1.07 to 2.10]); the risk of death increased with the number of major abnormalities in the same patient.</AbstractText>ECG abnormalities are more common among elderly Chagas disease patients and strongly predict adverse outcomes.</AbstractText> |
12,176 | Smoking is associated with an increased risk of first and recurrent ventricular tachyarrhythmias in ischemic and nonischemic patients with mild heart failure: a MADIT-CRT substudy. | Limited data exist regarding the proarrhythmic effects of smoking.</AbstractText>To evaluate the relationship between smoking and the risk of first and recurrent ventricular tachyarrhythmias (VTAs) in patients with mild heart failure.</AbstractText>The risk of a first and recurrent appropriate implantable cardioverter-defibrillator therapy for VTAs or death was compared between nonsmokers (n = 465), past smokers (n = 780), and current smokers (n = 197) in patients with ischemic and nonischemic cardiomyopathy who were enrolled in the Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy study.</AbstractText>The cumulative probability of a first VTA or death was significantly higher in current smokers than in past and nonsmokers (P < .001). Multivariate analysis showed that current smokers had a significantly higher risk of first ventricular tachycardia/ventricular fibrillation or death (hazard ratio [HR] 1.51; 95% confidence interval [CI] 1.14-2.01; P = .005) and a higher risk for first ventricular tachycardia/ventricular fibrillation episode (HR 1.54, 95% CI 1.12-2.13, P = .008) than did nonsmokers. Past smokers had a risk of first VTAs or death similar to that of nonsmokers (HR 1.01; 95% CI 0.80-1.27; P = .953). In comparison to nonsmokers, the risk of recurrent VTAs was significantly higher in the total cohort of patients (HR 1.54; 95% CI 1.21-1.95; P < .001) and in the subgroups of patients with ischemic and nonischemic cardiomyopathy (HR 1.48; 95% CI 1.03-2.13; P = .035).</AbstractText>Current smokers with left ventricular dysfunction and mild heart failure are at a significantly higher risk of VTAs or death than are past smokers and nonsmokers. Smoking is associated with a significant increase in the risk of recurrent VTAs in both patients with ischemic and nonischemic cardiomyopathy.</AbstractText>Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,177 | Presence of early repolarization on admission electrocardiography is associated with long-term mortality and MACE in patients with STEMI undergoing primary percutaneous intervention. | Early repolarization (ER) is associated with increased risk of sudden cardiac death and ventricular fibrillation (VF) in patients with/without structural heart disease. In this trial we examined the short- and long-term prognostic value of ER on admission electrocardiogram (ECG) in patients with ST-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI).</AbstractText>Consecutive 521 patients with acute STEMI who underwent primary PCI were enrolled prospectively. Twelve-lead ECGs obtained during the initial diagnosis were scanned and stored digitally. The leads showing the typical ST segment elevation due to the acute infarction were excluded and the remaining ECG leads were included in the analysis for the presence of ER.</AbstractText>The study group included 61 STEMI patients (55 male; mean age 57.6±12.6 years) with ER and 460 STEMI patients (378 male; mean age 57.1±12.5) without ER on ECG. In the ER group, 14 patients (22.9%) had notching, 10 patients (16.4%) had slurring, and 37 patients (60.7%) had only J-point elevation. When analyzing regional leads, ER was observed mostly in inferior leads (n=40, 65.6%). During the hospitalization period, ventricular tachycardia or VF occurred more frequently in the ER group (19.6% vs. 10.9%; p=0.04) and 6 patients (6.9%) from the ER group and 14 patients (3%) from the control group died (p=0.01). During a follow-up period of 21.1±10.2 months, mortality was significantly higher in the ER group (12.7% vs. 4.2%; p=0.01). When total mortality rates were considered, highest mortality was observed in patients with notching pattern (5/14 subjects; 35.7%) when compared to patients with slurring (3/10 subjects; 30%), patients with only J-point elevation patterns (5/37subjects; 13.5%) and the control group (33/460 subjects; 7.1%). Presence of notching and slurring pattern on admission ECG was found as independent predictors of long-term mortality; whereas presence of only J-point elevation was not.</AbstractText>Presence of ER pattern in admission ECG in patients with STEMI is associated with both in-hospital and long-term mortality.</AbstractText>Copyright © 2014 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.</CopyrightInformation> |
12,178 | Concomitant aortic and mitral surgery: to replace or repair the mitral valve? | The study objectives were to evaluate the perioperative outcomes of concomitant mitral and aortic valve surgery and to determine the influence of mitral valve repair versus replacement on survival and adverse events.</AbstractText>The study population comprised 261 patients with a mean age of 61.3±11.2 (19-82) years; 57.5% were male, and 73% were in New York Heart Association class III or IV. Mitral valve repair was performed in 209 patients (80%), and mitral valve replacement was performed in 52 patients (20%). Follow-up was complete for 95% of the patients (1395 patient-years). We specifically examined the impact of mitral valve repair versus replacement by comparing 2 propensity-matched subgroups.</AbstractText>Degenerative and functional mitral regurgitation, and left ventricular dilation and dysfunction were associated with mitral valve repair (P<.05). Rheumatic disease, chronic obstructive pulmonary disease, redo surgery, mitral calcification, and atrial fibrillation were more frequently related to mitral valve replacement (P<.05). Overall 30-day mortality was 1.1% (3 patients). Overall 1-, 5-, and 8-year survival were 98.0%±2.0%, 85.9%±6.1%, and 79.8%±8.2%, respectively, for the mitral valve replacement group and 95.3%±1.5%, 87.4%±2.6%, and 75.2%±4.0%, respectively, for the mitral valve repair group (P=.906). This was confirmed by comparable survival in propensity-matched analyses. Mitral valve repair showed a survival advantage in older patients (aged ≥65 years) and patients with nonrheumatic mitral valves (P=.017 and P=.034, respectively). Bleeding events (83% vs 60%), endocarditis (97.6% vs 84.6%), and reoperation (97.6% vs 86.9%) were higher in those undergoing mitral valve replacement. Freedom from major adverse valve-related events was higher for the mitral valve repair group (P=.002). Mitral valve replacement was identified as an independent risk factor for major adverse valve-related events (hazard ratio, 1.99; P=.018).</AbstractText>Concomitant mitral and aortic valve surgery carries a low surgical risk. The choice of the mitral procedure did not significantly affect survival. However, mitral valve replacement was associated with an increased incidence of adverse events. Thus, valve repair, whenever feasible, is a better option.</AbstractText>Copyright © 2014 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,179 | False tendons may be associated with the genesis of J-waves: prospective study in young healthy male. | Recent studies showed that J-waves are associated with vulnerability to ventricular fibrillation. Recently we reported the association between false tendons (FTs) and J-waves in a retrospective study.</AbstractText>We prospectively studied 50 young healthy men (mean age 24.6±2.7 years). FTs were detected echocardiographically and classified based on their points of attachment as type 1 (longitudinal type), type 2 (diagonal type), and type 3 (transverse type). J-waves were defined as terminal QRS notching or slurring with ≥0.1 mV. The filtered QRS duration (fQRSd), RMS40, and LAS40 were measured on signal-averaged ECGs. FTs were detected in 37 of the 50 subjects (74%). The incidence of J-waves was significantly higher in subjects with type 1 or type 2 FTs than those with no- or type 3 FTs (61% vs. 26%, p<0.05). The leads with J-waves were closely associated with the location of the FT. While no late potential was recorded in any study subjects, fQRSd and LAS40 were significantly longer in subjects with type 1 or type 2 FTs (p<0.05). Univariate and multivariate logistic regression analysis revealed that only the existence of FTs (type 1 or 2) was an independent predictor of the presence of J-waves.</AbstractText>Our results suggest that FTs were related to the genesis of J-waves with conduction delay.</AbstractText>Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
12,180 | Association of CHADS2, CHA2DS2-VASc, and R2CHADS2 scores with left atrial dysfunction in patients with coronary heart disease (from the Heart and Soul study). | The predictive ability of the CHADS2 index to stratify stroke risk may be mechanistically linked to severity of left atrial (LA) dysfunction. This study investigated the association between the CHADS2 score and LA function. We performed resting transthoracic echocardiography in 970 patients with stable coronary heart disease and normal ejection fraction and calculated baseline LA functional index (LAFI) using a validated formula: (LA emptying fraction×left ventricular outflow tract velocity time integral)/LA end-systolic volume indexed to body surface area. We performed regression analyses to evaluate the association between risk scores and LAFI. Among 970 subjects, mean CHADS2 was 1.7±1.2. Mean LAFI decreased across tertiles of CHADS2 (42.8±18.1, 37.8±19.1, 36.7±19.4, p<0.001). After adjustment for age, sex, race, systolic blood pressure, hyperlipidemia, myocardial infarction, revascularization, body mass index, smoking, and alcohol use, high CHADS2 remained associated with the lowest quartile of LAFI (odds ratio 2.34, p=0.001). In multivariable analysis of component co-morbidities, heart failure, age, and creatinine clearance<60 ml/min were strongly associated with LA dysfunction. For every point increase in CHADS2, the LAFI decreased by 4.0%. Secondary analyses using CHA2DS2-VASc and R2CHADS2 scores replicated these results. Findings were consistent when excluding patients with baseline atrial fibrillation. In conclusion, CHADS2, CHA2DS2-VASc, and R2CHADS2 scores are associated with LA dysfunction, even in patients without baseline atrial fibrillation. These findings merit further study to determine the role of LA dysfunction in cardioembolic stroke and the value of LAFI for risk stratification. |
12,181 | Outcomes in atrial fibrillation patients with and without left ventricular hypertrophy when treated with a lenient rate-control or rhythm-control strategy. | Although left ventricular (LV) hypertrophy has been proposed as a factor predisposing to atrial fibrillation (AF), its relevance to prognosis and selection of therapeutic strategies is unclear. We identified 2,105 patients with echocardiographic data on LV mass enrolled in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial. LV hypertrophy was defined as increased LV mass, stratified by American Society of Echocardiography criteria. The primary end point was all-cause mortality, secondary end point was as per AFFIRM trial definition, and tertiary end point was cardiovascular hospitalizations. We compared "strict" versus "lenient" rate control in patients with increased LV mass, and studied association of heart failure (HF) with preserved and decreased systolic function in patients with increased LV mass. Over 6 years, 332 deaths (15.7%) were reported. Adjusted hazard ratio (HR) of severely increased LV mass for all-cause mortality was 1.34 (95% confidence interval [CI] 1.01 to 1.79, p=0.045) for the overall population and 1.61 (95% CI 1.09 to 2.37, p=0.016) for the rhythm-control arm. Increased LV mass was a predictor of cardiovascular hospitalizations in the lenient rate-control group (HR 1.72, 95% CI 1.05 to 2.82, p=0.03) but not in the strict rate-control group. Severely increased LV mass was predictive of cardiovascular hospitalizations in patients with HF with preserved (HR 1.8, 95% CI 1.0 to 3.2, p=0.03) and decreased LV systolic function (HR 2.4, 95% CI 1.1 to 5.2, p=0.02). Thus, LV hypertrophy is a significant independent predictor of mortality in patients with AF, especially those managed with rhythm control. In patients with LV hypertrophy, strict rate control may be associated with better outcomes than lenient rate control. LV hypertrophy portends higher cardiovascular morbidity in patients with AF and HF. |
12,182 | Prognosis in patients hospitalized with permanent and nonpermanent atrial fibrillation in heart failure. | Atrial fibrillation (AF) and heart failure (HF) frequently coexist and are associated with an increased mortality. This study evaluated the prognosis of permanent and nonpermanent AF in patients with both AF and HF. All AF patients seen in our institution were identified and followed up. We included 1,906 patients suffering from AF and HF: 839 patients (44%) had preserved left ventricular ejection fraction (LVEF) and 1,067 patients (56%) had decreased LVEF; 1,056 patients (55%) had nonpermanent AF and 850 patients (45%) had permanent AF. During a median follow-up of 1.9 years (interquartile range 0.3 to 5.0), 377 patients died, 462 were readmitted for HF, and 200 had stroke or thromboembolic events. In patients with decreased LVEF, the rate of death was similar in patients with permanent or nonpermanent AF. In patients with preserved LVEF, permanent AF was associated with a higher risk of death and a higher risk of HF hospitalization. Stroke risk did not differ with permanent AF whatever the LVEF. NYHA functional class was an independent predictor of death (risk ratio [RR]=1.33, 95% confidence interval [CI] 1.12 to 1.59, p=0.001), as was permanent AF (RR=1.79, 95%CI 1.32 to 2.42, p=0.0002). Permanent AF (RR=1.52, 95% CI 1.20 to 1.93, p=0.0006) was also an independent predictor of readmission for HF. In conclusion, in patients with AF and HF, the risk of admission for HF and risk of death were higher when AF was permanent, particularly in patients with preserved LVEF. Stroke risk did not differ according to the pattern of AF, whatever the LVEF. |
12,183 | Factors predicting long-term mortality in patients with hypertrophic cardiomyopathy. | In this study, we aimed to elucidate the factors affecting long-term all-cause mortality in patients with hypertrophic cardiomyopathy (HCM).</AbstractText>We retrospectively examined 31 patients (22 males and 9 females) diagnosed with HCM from 1999 to 2013. All subjects had sinus rhythm at the time of evaluation. Four patients had history of paroxysmal atrial fibrillation (PAF). In addition to echocardiographic examination plasma angiotensin-converting enzyme (ACE) activity and gene polymorphism were determined. The variables that were found to be significant in mortality were then included in multivariate analysis.</AbstractText>At the final follow-up examination, 12 patients had died, including 2 due to congestive heart failure and 10 due to sudden cardiac death. Patients with PAF had significantly higher mortality (P = 0.008). Moreover, left ventricular (LV) end-diastolic diameter (P = 0.04), LV systolic diameter (P = 0.001), LV mass index (P = 0.01), and left atrium diameter (P = 0.003) were found to be significantly correlated with mortality. However, no significant correlation was noted between mortality and age, type of HCM (familial/nonfamilial and obstructive/nonobstructive), ACE gene polymorphism, and plasma ACE level. In the multivariate analysis, left atrial (LA) diameter was still significantly associated with mortality. The LA diameter with a cutoff value of 4.1 cm predicted 13-year mortality with a sensitivity of 82% and specificity of 78%.</AbstractText>Instead of the ACE genotype and activity, echocardiographic evaluation findings such as LV systolic and diastolic diameters, LV mass index, and particularly LA dimension may predict long-term mortality in patients with HCM. PAF has also significant importance in the long-term mortality in patients with HCM.</AbstractText>© 2014, Wiley Periodicals, Inc.</CopyrightInformation> |
12,184 | Heart rate and its variability in response to running-associations with troponin. | The objective of this study is to investigate the time course of autonomic tone changes after a first-time endurance running race participation and associations with postexertional high-sensitivity troponin (hsTnT) levels in middle-aged males.</AbstractText>Male (n = 42) first-time long-distance running race (Lidingöloppet 30 km) participants ≥45 yr (50.5 ± 5) were examined. HR and HR variability (HRV) in the time domain (SDANN) was measured continuously from 2 d before to 4 d after the race using a wireless cardiovascular monitor that also recorded arrhythmia episodes. In addition, subjects were assessed pre- and postrace by medical history and physical examination, 12-lead ECG, blood tests including hsTnT, and echocardiography.</AbstractText>Compared with corresponding prerace values, nighttime (2:00-4:00 a.m.) HR was significantly elevated (63.6 ± 9.4 vs 53.9 ± 8.3 bpm, P < 0.001) on the first night postrace, whereas HRV remained reduced for a median of 64 h (interquartile range, 51-102 h). A prolonged HR recovery period (r = 0.48, P = 0.005) and a larger reduction in postrace HRV (r = -0.49, P = 0.003) correlated with higher postrace hsTnT levels. The association between reduced HRV and higher hsTnT remained significant after multivariate analysis (β = -0.48, P = 0.01). No sustained ventricular arrhythmias were recorded, but atrial fibrillation occurred in two subjects.</AbstractText>Endurance running race participation caused a prolonged alteration of autonomic tone. More marked and prolonged changes were associated with higher levels of hsTnT, suggesting that the magnitude of troponin increase after strenuous exercise may reflect the magnitude of exercise-induced cardiovascular stress.</AbstractText> |
12,185 | Fuzzy logic-based diagnostic algorithm for implantable cardioverter defibrillators. | The paper presents a diagnostic algorithm for classifying cardiac tachyarrhythmias for implantable cardioverter defibrillators (ICDs). The main aim was to develop an algorithm that could reduce the rate of occurrence of inappropriate therapies, which are often observed in existing ICDs. To achieve low energy consumption, which is a critical factor for implantable medical devices, very low computational complexity of the algorithm was crucial. The study describes and validates such an algorithm and estimates its clinical value.</AbstractText>The algorithm was based on the heart rate variability (HRV) analysis. The input data for our algorithm were: RR-interval (I), as extracted from raw intracardiac electrogram (EGM), and in addition two other features of HRV called here onset (ONS) and instability (INST). 6 diagnostic categories were considered: ventricular fibrillation (VF), ventricular tachycardia (VT), sinus tachycardia (ST), detection artifacts and irregularities (including extrasystoles) (DAI), atrial tachyarrhythmias (ATF) and no tachycardia (i.e. normal sinus rhythm) (NT). The initial set of fuzzy rules based on the distributions of I, ONS and INST in the 6 categories was optimized by means of a software tool for automatic rule assessment using simulated annealing. A training data set with 74 EGM recordings was used during optimization, and the algorithm was validated with a validation data set with 58 EGM recordings. Real life recordings stored in defibrillator memories were used. Additionally the algorithm was tested on 2 sets of recordings from the PhysioBank databases: MIT-BIH Arrhythmia Database and MIT-BIH Supraventricular Arrhythmia Database. A custom CMOS integrated circuit implementing the diagnostic algorithm was designed in order to estimate the power consumption. A dedicated Web site, which provides public online access to the algorithm, has been created and is available for testing it.</AbstractText>The total number of events in our training and validation sets was 132. In total 57 shocks and 28 antitachycardia pacing (ATP) therapies were delivered by ICDs. 25 out of 57 shocks were unjustified: 7 for ST, 12 for DAI, 6 for ATF. Our fuzzy rule-based diagnostic algorithm correctly recognized all episodes of VF and VT, except for one case where VT was recognized as VF. In four cases short lasting, spontaneously ending VT episodes were not detected (in these cases no therapy was needed and they were not detected by ICDs either). In other words, a fuzzy logic algorithm driven ICD would deliver one unjustified shock and deliver correct therapies in all other cases. In the tests, no adjustments of our algorithm to individual patients were needed. The sensitivity and specificity calculated from the results were 100% and 98%, respectively. In 126 ECG recordings from PhysioBank (about 30min each) our algorithm incorrectly detected 4 episodes of VT, which should rather be classified as fast supraventricular tachycardias. The estimated power consumption of the dedicated integrated circuit implementing the algorithm was below 120nW.</AbstractText>The paper presents a fuzzy logic-based control algorithm for ICD. Its main advantages are: simplicity and ability to decrease the rate of occurrence of inappropriate therapies. The algorithm can work in real time (i.e. update the diagnosis after every RR-interval) with very limited computational resources.</AbstractText>Copyright © 2013 Elsevier B.V. All rights reserved.</CopyrightInformation> |
12,186 | Cardiac resynchronization therapy is associated with reductions in left atrial volume and inappropriate implantable cardioverter-defibrillator therapy in MADIT-CRT. | There are no prior studies assessing the relationship between left atrial volume (LAV) and inappropriate implantable cardioverter-defibrillator (ICD) therapy following treatment with cardiac resynchronization therapy.</AbstractText>The purpose of this study was to investigate the hypothesis that patients randomized to cardiac resynchronization therapy with defibrillator (CRT-D) in the Multicenter Automatic Defibrillator Trial-Cardiac Resynchronization Therapy (MADIT-CRT) who had significant LAV reductions would have reduced risks of inappropriate ICD therapy.</AbstractText>Cardiac resynchronization remodeling was assessed by measuring LAV change between baseline and 12-month echocardiograms in 751 CRT-D treated patients. Patients were stratified into quartiles based on percent reduction of LAV change. High LAV responders were those in the highest 3 quartiles of LAV reduction (LAV reduction ≥21%). Low LAV responders were those in the lowest quartile of LAV reduction (LAV reduction <21%). Clinical factors associated with ≥21% reduction in LAV were evaluated by linear regression analysis.</AbstractText>In Cox proportional hazards regression analyses, high LAV responders had a 39% reduction in the risk of inappropriate therapy (hazard ratio 0.61, P = .04) and left bundle branch block patients exhibited an even greater risk reduction in inappropriate therapy (hazard ratio 0.51, P = .02) compared to low LAV responders during follow-up extending up to 3 years after the 12-month echocardiogram. High LAV responders also had a significantly lower risk of heart failure or death during follow-up than did low LAV responders.</AbstractText>A ≥21% reduction in LAV with cardiac resynchronization therapy is associated with significant reductions in inappropriate ICD therapy and in heart failure or death during a 3-year follow-up.</AbstractText>Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,187 | The OPTI-MIND study: a prospective, observational study of pacemaker patients according to pacing modality and primary indications. | The OPTI-MIND study aims to collect 2-year clinical outcomes of pacemaker patients in real-world clinical practice, overall and according to patient characteristics and pacemaker settings.</AbstractText>The present analysis of the OPTI-MIND study describes the programmed device settings after discharge from the pacemaker implant. The objective was to determine whether these settings fit recent guidelines for device-programmed physiological pacing based on the preservation of atrioventricular synchrony, avoiding unnecessary pacing, ensuring rate increase during exercise or preventing neurally mediated symptoms. A total of 1740 patients were enroled at 68 centres worldwide. Baseline patient characteristics and device programming settings are available in 1674 of 1740 patients (96%). Guidelines to ensure physiological pacing were followed in 41% of patients: in patients with sinus node disease (SND), and without atrioventricular block (AVB), device programming could have led to unnecessary right ventricular pacing in 38% of patients. In SND patients with chronotropic incompetence, assisted rate increase during exercise was not programmed in 42% of patients. In 11% of patients with AVB, atrioventricular (AV) synchrony was not pursued; the main drivers being advanced age and history of atrial fibrillation. Patients with both SND and AVB were generally programmed physiologically (87%).</AbstractText>The present analysis showed that frequent deviations occurred when comparing the device settings at discharge from the pacemaker implant in clinical practice to the available guidelines on pacing mode selection. Analysis of 2-year outcomes in the OPTI-MIND study will provide an insight into whether specific physiological settings could improve the quality of pacing with a positive effect on patient outcome.</AbstractText> |
12,188 | Cardiovascular magnetic resonance of total and atrial pericardial adipose tissue: a validation study and development of a 3 dimensional pericardial adipose tissue model. | Recently pericardial adipose tissue (PAT) has been shown to be an independent predictor of atrial fibrillation (AF). Atrial PAT may influence underlying atrial musculature creating a substrate for AF. This study sought to validate the assessment of total and atrial PAT by standard cardiovascular magnetic resonance (CMR) measures and describe and validate a three dimensional atrial PAT model.</AbstractText>10 merino cross sheep underwent CMR using a 1.5 Tesla system (Siemens, Sonata, Erlangen, Germany). Atrial and ventricular short axis (SA) images were acquired, using ECG -gated steady state free precession sequences. In order to quantify total volume of adipose tissue, a three dimensional model was constructed from consecutive end-diastolic images using semi-automated software. Regions of adipose tissue were marked in each slice followed by linear interpolation of pixel intensities in spaces between consecutive image slices. Total volume of adipose tissue was calculated as a total volume of the three dimensional model and the mass estimated from volume measurements. The sheep were euthanized and pericardial adipose tissue was removed and weighed for comparison to the corresponding CMR measurements.</AbstractText>All CMR adipose tissue estimates significantly correlated with autopsy measurements (ICC > 0.80; p < 0.03). Intra- observer reliability in CMR measures was high, with 95% levels of agreement within 5.5% (ICC = 0.995) for total fat mass and its individual atrial (95% CI ± 8.3%, ICC = 0.993) and ventricular components (95% CI ± 6.6%, ICC = 0.989). Inter- observer 95% limits of agreement were within ± 10.7% (ICC = 0.979), 7.4% (ICC = 0.991) and 7.2% (ICC = 0.991) for atrial, ventricular and total pericardial adipose tissue, respectively.</AbstractText>This study validates the use of a semi-automated three dimensional atrial PAT model utilizing standard (clinical) CMR sequences for accurate and reproducible assessment of atrial PAT. The measurement of local cardiac fat stores via this methodology could provide a sensitive tool to examine the regional effect of fat deposition on atrial substrate which potentially may influence AF ablation strategies in obese patients.</AbstractText> |
12,189 | [Cardiac sarcoidosis: diagnostic and therapeutic algorithms]. | Sarcoidosis is a multisystemic granulomatous disorder which affects the respiratory system in the majority of the cases. Cardiac manifestations are found in up to 10 % of the affected cohort and show a large heterogeneity based on the ethnic background. Cardiac sarcoidosis are not only found in patients with rhythmogenic heart disease such as atrial and ventricular fibrillation but also in all phenotypes of cardiomyopathies. The overall morbidity and mortality caused by cardiac sarcoidois in Germany is unclear and no large prospective international studies are published on this topic. This consensus paper on diagnostic and therapeutic algorithms in cardiac sarcoidosis is based on a current literature search and forms a expert opinion statement under the hospices of the "Deutsche Gesellschaft für Pneumologie" and "Deutsche Gesellschaft für Kardiologie". It is the rationale of this statement to offer algorithms to facilitate clinical decision-making based on the individual case. |
12,190 | Deterioration of the circadian variation of heart rate variability in Brugada syndrome may contribute to the pathogenesis of ventricular fibrillation. | Abnormal sympathetic innervation triggers ventricular fibrillation (VF). We examined the circadian variation of autonomic nervous system and its relevance to risk stratification of VF in patients with Brugada syndrome (Brs).</AbstractText>We enrolled 12 male Brs patients with documented VF (Brs-S; mean age, 42±4 years), 17 without documented VF (Brs-N; mean age 48±4 years), and 16 age- and gender-matched controls. The clinical data, 12-lead electrocardiography (ECG), signal-averaged ECG, electrophysiological study (EPS), and heart rate variability from 24h Holter ECG were compared between the groups.</AbstractText>The low frequency components (LF) in Brs-S and Brs-N and high frequency components (HF) in Brs-S patients were significantly lower than in the controls (409.8±128.6ms(2), 329.5±108ms(2) vs. 945.3±111.3ms(2); 135.1±73.8ms(2) vs. 391.8±63.9ms(2), respectively). The circadian variation of the LF and LF/HF decreased in the Brs patients, the standard deviation (SD) of LF/HF (<2.5) and SD of LF (<400ms(2)) had sufficiently high sensitivity (96.6%) and specificity (92.9%) for the diagnosis of Brs. Most of the Brs-S patients (83.3%) were located under the line formed by the SD/mean of HF=SD/mean of LF in the scatter plots.</AbstractText>Lack of the circadian variation of autonomic function occurs in Brs, and this may contribute to the pathogenesis of VF.</AbstractText>Copyright © 2013 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.</CopyrightInformation> |
12,191 | Suppression of spontaneous ca elevations prevents atrial fibrillation in calsequestrin 2-null hearts. | Atrial fibrillation (AF) risk has been associated with leaky ryanodine receptor 2 (RyR2) Ca release channels. Patients with mutations in RyR2 or in the sarcoplasmic reticulum Ca-binding protein calsequestrin 2 (Casq2) display an increased risk for AF. Here, we examine the underlying mechanisms of AF associated with loss of Casq2 and test mechanism-based drug therapy.</AbstractText>Compared with wild-type Casq2+/+ mice, atrial burst pacing consistently induced atrial flutter or AF in Casq2-/- mice and in isolated Casq2-/- hearts. Atrial optical voltage maps obtained from isolated hearts revealed multiple independent activation sites arising predominantly from the pulmonary vein region. Ca and voltage mapping demonstrated diastolic subthreshold spontaneous Ca elevations (SCaEs) and delayed afterdepolarizations whenever the pacing train failed to induce AF. The dual RyR2 and Na channel inhibitor R-propafenone (3 μmol/L) significantly reduced frequency and amplitude of SCaEs and delayed afterdepolarizations in atrial myocytes and intact atria and prevented induction of AF. In contrast, the S-enantiomer of propafenone, an equipotent Na channel blocker but much weaker RyR2 inhibitor, did not reduce SCaEs and delayed afterdepolarizations and failed to prevent AF.</AbstractText>Loss of Casq2 increases risk of AF by promoting regional SCaEs and delayed afterdepolarizations in atrial tissue, which can be prevented by RyR2 inhibition with R-propafenone. Targeting AF caused by leaky RyR2 Ca channels with R-propafenone may be a more mechanism-based approach to treating this common arrhythmia.</AbstractText> |
12,192 | In vivo left-ventricular contact force analysis: comparison of antegrade transseptal with retrograde transaortic mapping strategies and correlation of impedance and electrical amplitude with contact force. | Clinical outcomes following radiofrequency ablation of ventricular tachycardias (VTs) depend on catheter tip-to-tissue contact force (CF). Left-ventricular (LV) mapping is performed via antegrade-transseptal or retrograde-transaortic approaches, and the applied CF may depend on the approach used. This study evaluated (i) the impact of antegrade-transseptal vs. retrograde-transaortic LV-mapping approaches on CF and catheter stability and (ii) the clinical value of the commonly used surrogate markers of catheter-myocardial contact-impedance, unipolar, and bipolar electrogram amplitudes.</AbstractText>An antegrade-transseptal and a retrograde-transaortic LV-mapping approach was performed in 10 patients undergoing VT ablation by using CF-sensing catheters. Operators were blinded to CF data and data were analysed according to 11 predefined LV segments. Three thousand three hundred and twenty-four mapping points (1577 antegrade, 1747 retrograde) were analysed, including 80 (2.4%) points with maximum CF > 100 g. Median antegrade and retrograde CF were 16.0 g (q1-q3; 8.4-26.2) and 15.3 g (9.8-23.4), respectively. Contact force was significantly higher antegradely in mid-anteroseptum, mid-lateral, and apical segments, and significantly higher retrogradely in basal-anteroseptum, basal-inferoseptum, basal-inferior, and basal-lateral segments. Contact force did correlate with impedance, unipolar, and bipolar electrogram amplitudes; however, there were large overlaps.</AbstractText>Antegrade vs. retrograde LV-mapping approaches result in different CF. A combined approach to the LV mapping may improve the overall LV mapping, potentially resulting in better clinical outcomes for the left VT catheter ablation. The previous surrogate markers used to assess CF do correlate with in vivo CF; however, due to a larger overlap, their clinical value is limited.</AbstractText>© The Author 2014. Published by Oxford University Press on behalf of the European Society of Cardiology.</CopyrightInformation> |
12,193 | Ventricular fibrillation due to coronary vasospasm. | A 43-year-old woman developed a sudden-onset severe chest pain and breathlessness at home. She collapsed within minutes and received bystander cardiopulmonary resuscitation from her husband. On arrival, the paramedics identified ventricular fibrillation requiring defibrillation. She was admitted to the intensive care unit for observation. A coronary angiogram performed at our hospital demonstrated non-obstructive disease of the right coronary artery. Her antidepressant medications were discontinued and she was discharged. No specific cause was found for the arrhythmia and collapse. One week later, she developed similar chest pain. An ECG showed transient ST-elevation in the inferior leads. Symptoms and ECG changes resolved with sublingual nitroglycerin. During the course of a repeat coronary angiogram the patient developed severe spasm of the right coronary artery associated with typical chest pain and ST-elevation in the inferior leads. She was treated with insertion of a drug-eluting stent and a cardiac defibrillator. |
12,194 | Complement C3c as a biomarker in heart failure. | Experimental data indicates an important role of the innate immune system in cardiac remodeling and heart failure (HF). Complement is a central effector pathway of the innate immune system. Animals lacking parts of the complement system are protected from adverse remodeling. Based on these data, we hypothesized that peripheral complement levels could be a good marker for adverse remodeling and prognosis in patients with HF.</AbstractText>Since complement activation converges on the complement factor C3, we measured serum C3c, a stable C3-conversion product, in 197 patients with stable systolic HF. Subgroups with normal and elevated C3c levels were compared. C3c levels were elevated in 17% of the cohort. Patients with elevated C3c levels exhibited a trend to better survival, slightly higher LVEF, and lower NTpro-BNP values in comparison to patients with normal C3c values. No differences were found regarding NYHA functional class. Significantly more patients with elevated C3c had preexisting diabetes. The prevalence of CAD, arterial hypertension, and atrial fibrillation was not increased in patients with elevated C3c.</AbstractText>Elevated C3c levels are associated with less adverse remodeling and improved survival in patients with stable systolic heart failure.</AbstractText> |
12,195 | Does change in device detected frequency of non-sustained or diverted episodes serve as a marker for inappropriate shock therapy? Analyses from the INTRINSIC RV and ALTITUDE-REDUCES Trials. | Implantable cardioverter-defibrillators (ICDs) treat ventricular tachycardia or fibrillation but may also deliver unnecessary shocks. We sought to determine if the frequency of ICD-detected non-sustained or diverted (NSD) episodes increases before appropriate or inappropriate ICD shocks.</AbstractText>We evaluated NSD episodes in the INTRINSIC RV Trial and their relationship to ICD shocks (appropriate and inappropriate). Time from NSD to shock was analysed. Results were validated by utilizing 1495 adjudicated ICD and cardiac resynchronization therapy-defibrillator shocks following NSD episodes collected through the LATITUDE remote monitoring system as part of the ALTITUDE-REDUCES Study. In INTRINSIC RV, 185 participants received 373 shocks; 148 had at least 1 NSD episode. Non-sustained or diverted frequency increased 24 h before the first shock for those receiving an inappropriate (P < 0.01) but not an appropriate shock (P = 0.17). Patients with NSD episodes within 24 h of a shock were significantly more likely to receive inappropriate therapy [odds ratio (OR) = 3.12, P < 0.01]. At the receiver operator curve determined optimal cutoff, an NSD episode within 14 min before shock strongly predicted inappropriate therapy (sensitivity 48%, specificity 91%; OR = 8.8, and P < 0.001). The 14 min cut-off evaluated on an independent dataset of 1495 shock episodes preceded by an NSD in the ALTITUDE-REDUCES Study confirmed these results (sensitivity = 47%, specificity = 85%, OR = 5.0, and P < 0.001).</AbstractText>Device-detected NSD episodes increase before inappropriate but not appropriate shocks. Novel alerts or automated algorithms based on NSD episodes may reduce inappropriate shocks.</AbstractText> |
12,196 | P-wave dispersion: a possible warning sign of hypertension in children. | Hypertension and obesity in adults have been linked to increased EKG P-wave dispersion; the association has been shown in relation to hypertension, left ventricular hypertrophy and atrial enlargement. Though studies in children have linked P-wave dispersion to left ventricular hypertrophy, scant pediatric literature relates P-wave dispersion to hypertension and obesity.</AbstractText>Assess the association of P-wave dispersion with blood pressure and nutritional status in a pediatric population.</AbstractText>This cross-sectional study is part of the PROCDEC II project for pediatric hypertension diagnosis and control in Santa Clara, Cuba. Twelve-lead EKG and four blood pressure readings were conducted on a sample of 656 children aged 8-11 years. Blood pressure <90th percentile for age, sex and height was considered normal; 90th-95th percentile, prehypertension; and >95th percentile, hypertension. The main study variables were P-wave dispersion and systolic, diastolic and mean arterial pressure (MAP). Secondary variables were sex, height, weight, and body mass index. Comparisons of means, analysis of variance and linear correlations were done.</AbstractText>Mean P-wave dispersion differed significantly (p ≤0.05) among normotensive (30.10 ms), prehypertensive (32.99 ms) and hypertensive children (39.14 ms), as did mean MAP (p <0.05). P-wave dispersion and MAP were significantly correlated in prehypertensive and hypertensive children. Most overweight and obese children with high P-wave dispersion were prehypertensive or hypertensive.</AbstractText>Associations observed between P-wave dispersion and MAP in normotensive, prehypertensive and hypertensive children suggest potential for early detection of EKG patterns showing vulnerability. Given the relationship between increased P-wave dispersion and hypertension already described in adults, use of P-wave dispersion could be a simple, economical and noninvasive method of predicting risk of hypertensive cardiomyopathy in prehypertensive and hypertensive children; this in turn could guide timely, effective treatment and secondary prevention. Similar studies on a larger sample are needed to corroborate these results.</AbstractText> |
12,197 | The atrial fibrillation ablation pilot study: a European Survey on Methodology and results of catheter ablation for atrial fibrillation conducted by the European Heart Rhythm Association. | The Atrial Fibrillation Ablation Pilot Study is a prospective registry designed to describe the clinical epidemiology of patients undergoing an atrial fibrillation (AFib) ablation, and the diagnostic/therapeutic processes applied across Europe. The aims of the 1-year follow-up were to analyse how centres assess in routine clinical practice the success of the procedure and to evaluate the success rate and long-term safety/complications.</AbstractText>Seventy-two centres in 10 European countries were asked to enrol 20 consecutive patients undergoing a first AFib ablation procedure. A web-based case report form captured information on pre-procedural, procedural, and 1-year follow-up data. Between October 2010 and May 2011, 1410 patients were included and 1391 underwent an AFib ablation (98.7%). A total of 1300 patients (93.5%) completed a follow-up control 367 ± 42 days after the procedure. Arrhythmia documentation was done by an electrocardiogram in 76%, Holter-monitoring in 52%, transtelephonic monitoring in 8%, and/or implanted systems in 4.5%. Over 50% became asymptomatic. Twenty-one per cent were re-admitted due to post-ablation arrhythmias. Success without antiarrhythmic drugs was achieved in 40.7% of patients (43.7% in paroxysmal AF; 30.2% in persistent AF; 36.7% in long-lasting persistent AF). A second ablation was required in 18% of the cases and 43.4% were under antiarrhythmic treatment. Thirty-three patients (2.5%) suffered an adverse event, 272 (21%) experienced a left atrial tachycardia, and 4 patients died (1 haemorrhagic stroke, 1 ventricular fibrillation in a patient with ischaemic heart disease, 1 cancer, and 1 of unknown cause).</AbstractText>The AFib Ablation Pilot Study provided crucial information on the epidemiology, management, and outcomes of catheter ablation of AFib in a real-world setting. The methods used to assess the success of the procedure appeared at least suboptimal. Even in this context, the 12-month success rate appears to be somewhat lower to the one reported clinical trials.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
12,198 | Role of defibrillation threshold testing during implantable cardioverter-defibrillator placement: data from the Israeli ICD Registry. | Defibrillation threshold (DFT) testing during placement of an implantable cardioverter-defibrillator (ICD) has been considered mandatory. Accumulating data suggest a more limited role for DFT.</AbstractText>The purpose of this study was to compare the outcome of ICD recipients who underwent DFT testing compared with those who did not.</AbstractText>In this prospective cohort analysis of patients who received an ICD between July 2010 and March 2013, we compared patients who underwent DFT testing and those who did not. Primary end-points were death and malignant ventricular arrhythmias. Secondary end-points included the composite end-points and inappropriate ICD discharges.</AbstractText>Of the 3596 patients in the registry, 614 patients (17%) underwent DFT testing during ICD placement vs 2982 (83%) who did not. Variables associated with ICD testing were implantation for secondary prevention (relative risk [RR] 1.87), prior ventricular arrhythmias (RR 1.81), use of antiarrhythmic medication (RR 1.59), and sinus rhythm (RR 2.05). Factors predisposing against testing were cardiac resynchronization therapy defibrillator implantation (RR 0.56) and concomitant diuretic use (RR 0.71). ICD testing was not associated with 1-year mortality (5.3% vs 5.1%, P = .74), delivery of appropriate shocks (8.6% vs 5.6%, P = .16), combined outcomes of ventricular arrhythmias and death (12.9% vs 11.3%, P = .45), or inappropriate ICD discharges (3.9% vs 2.1%, P = .2) compared to no DFT testing.</AbstractText>No significant differences in the incidence of mortality, malignant ventricular arrhythmias, or inappropriate ICD discharges were observed between patients who underwent DFT testing compared to those who did not. Our results may support avoiding DFT testing during ICD placement, but this requires confirmation by additional prospective studies.</AbstractText>Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,199 | Ventricular tachyarrhythmias during acute myocardial infarction: the role of endothelin-1. | Ventricular arrhythmogenesis during acute coronary syndromes is a common cause of sudden cardiac death, but the underlying mechanisms remain incompletely understood. Recent evidence indicates an emerging pathophysiologic role of endothelin-1 during myocardial ischaemia and evolving infarction. At the early stages post-coronary occlusion, endothelin-1 enhances sympathetic activation, an effect mediated via the ETA receptor, whereas the ETB receptor exerts protective actions. The importance of this interaction is clearly decreased during subsequent stages, during which endothelin-1 may participate in the genesis of ventricular tachycardia or fibrillation via other mechanisms; of these, the effects of endothelin-1 on repolarizing potassium currents and electrical conduction via gap junctions merit further research. The relative roles of ETA and ETB receptors during this phase are unclear. Evaluation of the arrhythmogenic effects of endothelin-1 during acute coronary syndromes may provide the tools towards lowering sudden cardiac death rates. |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.