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13,900 | Graves' disease--familiar foe, unfamiliar face. | A 38-year-old man from a remote tribal area of South India presented with right heart failure. On evaluation, he was found to have untreated Graves' disease (GD) with atrial fibrillation and pulmonary hypertension. The left ventricular function was normal. Secondary causes for pulmonary hypertension were ruled out. He was treated with carbimazole and low-dose propranolol. Post 4 months medical therapy, his pulmonary hypertension completely reversed, thus establishing GD as a reversible cause of pulmonary hypertension and isolated right heart failure. |
13,901 | RECOVER evidence and knowledge gap analysis on veterinary CPR. Part 4: Advanced life support. | To systematically evaluate the evidence of the effect of advanced life support techniques on outcome in veterinary cardiopulmonary resuscitation (CPR) and to outline knowledge gaps.</AbstractText>Standardized, systematic evaluation of the literature, categorization of relevant articles according to level of evidence and quality, and development of consensus on conclusions for application of the concepts to clinical practice.</AbstractText>Academia, referral practice, and general practice</AbstractText>Sixteen population, intervention, control group, outcome questions were evaluated to determine if recommendations could be made concerning drug therapy, including vasopressors, vagolytics, corticosteroids, reversal agents, buffer therapy, and correction of electrolyte disturbances. Electrical defibrillation strategies as well as other advanced interventions such as open-chest CPR, impedance threshold devices, and special considerations regarding anesthesia-related cardiopulmonary arrest (CPA) were also investigated.</AbstractText>There is strong evidence supporting the use of standard-dose (0.01 mg/kg) epinephrine in CPR, as well as early electrical defibrillation for animals experiencing CPA due to ventricular fibrillation or pulseless ventricular tachycardia, preferentially using a biphasic defibrillator. For CPA due to certain causes and with the availability of advanced postcardiac arrest support, open chest CPR is preferred. Many knowledge gaps regarding other pharmacologic and advanced therapies were identified, and further studies are recommended to better systematically address these questions.</AbstractText>© Veterinary Emergency and Critical Care Society 2012.</CopyrightInformation> |
13,902 | High incidence of implantable cardioverter defibrillator malfunctions during radiation therapy: neutrons as a probable cause of soft errors. | To investigate the behaviour of the implantable cardioverter defibrillator (ICD) function during actual radiotherapy sessions.</AbstractText>Fifteen patients with an ICD underwent 17 radiation treatments for cancer [cumulative dose to the tumour was between 16 Gray (Gy) and 70 Gy; photon beams with maximum energies between 6 megaelectronvolt (MeV) and 18 MeV were employed]. During every session, the ICD was programmed to a monitoring mode to prevent inappropriate therapy delivery. Afterwards, the ICDs were interrogated to ensure proper function. Calculated radiation dose at the ICD site was <1 Gy in all patients. In 5 out of 17 radiation treatments (29%) the ICDs showed 6 malfunctions (35%). We noticed four disturbances in the memory data or device resets during radiation treatment and one case of inappropriate ventricular fibrillation detection due to external noise. In one case a late device data error was observed. All malfunctions occurred at 10 and 18 MeV beam energies.</AbstractText>Despite the fact that all recommended precautions were taken to minimize the damage to the ICDs during radiotherapy and the calculated dose to the ICDs was <1 Gy, in 29% of the treatments a malfunction occurred. We observed a possible correlation between the beam energy and the malfunctions. This correlation may be due to an interaction between neutrons produced in the head of the linear accelerator at beam energies ≥10 MeV, and boron-10 which is present in the integrated circuit.</AbstractText> |
13,903 | Global longitudinal strain predicts left ventricular dysfunction after mitral valve repair. | Despite a successful surgical procedure and adherence to current recommendations, postoperative left ventricular (LV) dysfunction after mitral valve repair (MVr) for organic mitral regurgitation (MR) may still occur. New approaches are therefore needed to detect subclinical preoperative LV dysfunction. LV global longitudinal strain (GLS), assessed with speckle-tracking echocardiographic analysis, has been proposed as a novel measure to better depict latent LV dysfunction. The aim of this study was to investigate the value of GLS to predict long-term LV dysfunction after MVr.</AbstractText>A total of 233 patients (61% men, 61 ± 12 years) with moderate-severe organic MR who underwent successful MVr between 2000 and 2009 were included. Echocardiography was performed at baseline and long-term follow-up (34 ± 20 months) after MVr. LV dysfunction at follow-up was defined as LV ejection fraction (EF) <50% and was present in 29 (12%) patients. A cut-off value of -19.9% of GLS showed a sensitivity and specificity of 90 and 79% to predict long-term LV dysfunction. By univariate logistic regression analysis, baseline LVEF ≤60%, LV end-systolic diameter (ESD) ≥40 mm, atrial fibrillation, presence of symptoms, and GLS >-19.9% were predictors of long-term LV dysfunction. By multivariate analysis, GLS remained an independent predictor of LV dysfunction (odds ratio 23.16, 95% confidence interval: 6.53-82.10, P < 0.001), together with LVESD.</AbstractText>In a large series of patients operated within the last decade, MVr resulted in a low incidence of long-term LV dysfunction. A GLS of >-19.9% demonstrated to be a major independent predictor of long-term LV dysfunction after adjustment for parameters currently implemented into guidelines.</AbstractText> |
13,904 | Expanding indications for resynchronization therapy. | Cardiac resynchronization therapy (CRT) is one of the major advances in the treatment of patients with chronic heart failure due to impaired left ventricular ejection fraction. Current guidelines recommend with the highest levels of recommendation and evidence CRT in patients with low ejection fraction wide QRS, LBBB, and mild to severe heart failure (New York Heart Association class II to IV). However, other patients might benefit from CRT. This is the case for patients with permanent atrial fibrillation, patients conventional pacemaker indication, patients with mildly impaired left ventricular function (>35 %), or asymptomatic patients (NYHA I). We will discuss in this manuscript each new potential indication for CRT. |
13,905 | Intermittent capture of the right ventricular outflow tract by atrial pacing in a patient with a dual-chamber pacemaker. | We describe a previously unreported phenomenon of intermittent outflow right ventricular tract capture from the atrial lead of a dual-chamber pacemaker. This was more obvious at slower paced atrial rates and disappeared by decreasing the atrial pulses voltage. Electroanatomical mapping showed that the onset of activation was nearly simultaneous at the insertion site of the atrial lead and at an intermediate level of the right ventricular outflow tract. This exceptional finding might be erroneously diagnosed as due to pseudo-pseudo fusion beats. |
13,906 | Improved survival of patients with coronary artery disease and low ejection fraction with ICD implantation versus conventional therapy in a real world survey. | Coronary artery disease (CAD) is associated with an increased risk for sudden cardiac death. Randomized controlled trials have shown that implantable cardioverter defibrillators (ICD) improve life expectancy unless they are implanted within the first days after an acute myocardial infarction and guidelines recommend their use. We aimed to validate that these results also apply to patients of a typical community hospital in Germany.</AbstractText>This was a retrospective analysis of patients undergoing coronary angiography in the Lippe-Detmold Hospital between 2003 and 2006. They had to have significant CAD and an ejection fraction (EF) ≤ 35% and no acute myocardial infarction within 28 days of implantation and no history of ventricular fibrillation.</AbstractText>213 patients were included; 70 of which received an ICD. Patients with an ICD implantation were younger (64.8 ± 9.9 vs. 67.9 ± 9.8 years; p = 0.034), had single vessel CAD more frequently (22.9 vs. 11.2%; p = 0.025) and a lower EF (26.7 ± 6.3 vs. 29.1 ± 4.6%; p = 0.006). Hospital readmissions were comparable between the ICD and the control group (68.6 vs. 72.0%; p = 0.602). ICD therapy was associated with a considerable survival benefit compared to conventional therapy (HR 0.52; 95%CI 0.29-0.93; p = 0.027) in a Cox-Proportional Hazards Regression analysis.</AbstractText>Appreciating the potential limitations of retrospective studies, we found that ICD use was associated with improved survival in patients with significant CAD and an EF <= 35% typical for a large tertiary hospital.</AbstractText> |
13,907 | [Asymptomatic ventricular pre-excitation in children: a 17 year follow-up study]. | Results of long term clinic-electrophysiological follow-up of a large group of children with Wolf-Parkinson-White (WPW) phenomenon are present. From 1993 to 2011 we examined 176 children - 117 boys (66,5%) and 59 girls (33,5%) - with manifesting type of WPW. Age at first examination was 12.5+/-3.2 ( 0.1 18 ). In 66.5% of children WPW phenomenon was present in the age from 10 to 18 . Hundred fifty nine children (104 [65.4%] boys and 55 [34.6%] girls) were followed up for 0.5-17 years (mean 7.4+/-4.5 years). During follow-up spontaneous attacs of atrioventricular reciprocal tachycardia appeared in 13 children (8.2%, 95% confidence interval [CI] 4.4-13.6%). Spontaneous disappearance of signs of ventricular pre-excitation on electrocardiogram and transition to intermittent form of WPW were registered in 14(8.8%, 95%CI 4.9-14.3%) and 12 children (7.5%, 95% CI 3.9-12.8%). Short lasting syncopal states were observed in 15 children (8.4%). In 3 of them atrial fibrillation with high rate of venricular rhytm was induced during transesophageal electrophysiological study. Two (1.3%) children had history of clinical death. In one of them WPW phenomenon was combined with hypertrophic cardiomyopathy and polymorphic ventricular tachycardia. This child died at the age of 11 years. One (0.6%) boy with WPW phenomenon died suddenly in 3 years after initial examination. Thus, children with WPW phenomenon are at risk of development of life threatening states and sudden cardiac death. Stratification of risk of sudden death is necessary at examination of such children. |
13,908 | [Clinico-economical aspects of cardioversion of paroxysmal atrial fibrillation at phehospital stage and during hospitalization]. | We carried out clinico-economical analysis of 2 tactics of rhythm restoration in patients with paroxysmal atrial fibrillation (AF) lasting less than 48 hours: cardioversion at prehospital stage with intravenous procainamide and inhospital cardioversion with any method. This retrospective study was based on the data from department of urgent aid of an outpatient clinic. The results showed that within 48 hours inhospital was a was more effective, safe, and more economically profitable compared with administration of procainamide at prehospital stage. Intravenous procainamide resulted in effective cardioversion in 70.6% of patients. It was associated with arterial hypotension and proarrhythmogenic action in 14,7% of cases. Patients with effective cardioversion with procainamide had lesser mean values of left ventricular anterior-posterior dimension (echocardiography) and shorter duration of arrhythmia. |
13,909 | Increased pulse pressure independently predicts incident atrial fibrillation in patients with type 2 diabetes. | To examine whether baseline pulse pressure (PP), a marker of arterial stiffness, is associated with subsequent development of atrial fibrillation (AF) in type 2 diabetes.</AbstractText>A total of 350 type 2 diabetic patients, who were free from AF at baseline, were followed for 10 years. A standard electrocardiogram was performed annually and a diagnosis of incident AF was confirmed in affected participants by a single cardiologist.</AbstractText>During the follow-up, 32 patients (9.1% of total) developed incident AF. After adjustments for age, sex, BMI, diabetes duration, presence of left ventricular hypertrophy, hypertension treatment, kidney dysfunction, and pre-existing history of coronary heart disease, heart failure, and mild valvular disease, baseline PP was associated with an increased incidence of AF (adjusted odds ratio 1.76 for each SD increment [95% CI 1.1-2.8]; P < 0.01).</AbstractText>Our findings suggest that increased PP independently predicts incident AF in patients with type 2 diabetes.</AbstractText> |
13,910 | A dynamic risk score to identify increased risk for heart failure decompensation. | A method for combining heart failure (HF) diagnostic information in a Bayesian belief network (BBN) framework to improve the ability to identify when patients are at risk for HF hospitalization (HFH) is investigated in this paper. Implantable devices collect HF related diagnostics, such as intrathoracic impedance, atrial fibrillation (AF) burden, ventricular rate during AF, night heart rate, heart rate variability, and patient activity, on a daily basis. Features were extracted that encoded information regarding out of normal range values as well as temporal changes at weekly and monthly time scales. A BBN is used to combine the features to generate a risk score defined as the probability of a HFH given the diagnostic evidence. Patients with a very high risk score at follow-up are 15 times more likely to have a HFH in the next 30 days compared to patients with a low-risk score. The combined score has improved ability to identify patients at risk for HFH compared to the individual diagnostic parameters. A score of this nature allows clinicians to manage patients by exception; a patient with higher risk score needs more attention than a patient with lower risk score. |
13,911 | Persistent angina pectoris, cardiac mortality and myocardial infarction during a 12 year follow-up in 273 variant angina patients without significant fixed coronary stenosis. | The incidence of cardiac events in patients with variant angina pectoris without significant coronary stenosis and ST-segment elevation was analyzed during a 12-year follow-up period in 273 consecutive patients (82% men) admitted from 1986 through 2010. Among the 252 patients who underwent electrocardiography during pain, 205 had ST-segment elevation (82%) and 45 had ST-segment depression (18%). During index hospitalization, angina occurred in 179 patients (66%), ventricular tachycardia or fibrillation in 28 (10%), and complete atrioventricular block in 3 (1%), but there were no deaths or myocardial infarctions (MIs). At 140 months, angina was still present in 129 patients (47%), but frequent angina (>10 episodes/year) occurred in only 6%. Total mortality, cardiac mortality, and MI rates were 24%, 7.0%, and 6%, respectively. Cardiac death or MI occurred in 28 patients (10%), associated with tobacco smoking (p = 0.004), antecedent "first-wind" angina (p = 0.020), and angina during hospitalization (p = 0.044) and with continued smoking (p = 0.056) and recurrent angina during follow-up (p <0.001). Multivariate analysis identified age (p = 0.001), antecedent infarction (p = 0.005), first-wind angina (p = 0.009), and smoking at index hospitalization (p = 0.027) as predictors of total mortality and treatment with calcium antagonists (p = 0.047) and smoking during follow-up (p = 0.110) for cardiac mortality and MI. In conclusion, during 12-year follow-up, patients with variant angina pectoris, mostly with ST-segment elevation during pain, had a reduced incidence of cardiac mortality and MI, associated with first-wind angina, persistent angina, and continued smoking. |
13,912 | Interference of low frequency magnetic fields with implantable cardioverter-defibrillators. | The aim of this study was to find the electromagnetic interference (EMI) thresholds for several commonly used implantable cardioverter-defibrillators (ICD).</AbstractText>Seventeen ICDs were exposed to magnetic fields with different intensities produced by the Helmholtz coil system. Sinusoidal, pulse, ramp, and square-waveforms with a frequency range of 2 Hz to 1 kHz were used.</AbstractText>ICD malfunctions occurred in 11 of the 17 ICDs tested. The ICD malfunctions that occurred were false detections of ventricular tachycardia (6/17 ICDs) and ventricular fibrillation (3/17 ICDs), false detection of atrial tachycardia (4/6 dual chamber ICDs) and tachycardia sensing occurring during atrial or ventricular refractory periods (1/17 ICD). In most cases, no interference occurred at magnetic field levels below the occupational safety limits of the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Nevertheless, some frequencies using sine, ramp or square waveforms did interfere with certain ICDs at levels below these limits. No EMI occurred with any of the ICDs below the ICNIRP limits for public exposure.</AbstractText>Evaluation of EMI should be part of the risk assessment of an employee returning to work after an ICD implantation. The risk assessment should consider magnetic field intensities, frequencies and waveforms.</AbstractText> |
13,913 | Left ventricular mass predicts left atrial appendage thrombus in persistent atrial fibrillation. | Atrial fibrillation (AF) can result in the development of left atrial appendage (LAA) thrombi. We sought to examine demographic and echocardiographic predictors of LAA thrombus in patients with persistent AF.</AbstractText>One hundred and sixty-five patients in persistent AF (36 with LAA thrombus and 129 without thrombus) were studied. Demographic and cardiovascular risk factors were retrospectively examined. Transthoracic (TTE) and transoesophageal echocardiography (TOE) were performed to assess the size and function of the left ventricle (LV), left atrium (LA), LAA, and spontaneous echo contrast (SEC) in the LA and right atrium (RA). Univariate demographic predictors of LA thrombus included systolic blood pressure, ischaemic heart disease and congestive heart failure. Indexed LV mass and septal E' velocity on TTE and mean LAA emptying velocity and the presence of SEC in both the LA and RA on TOE were predictors of thrombus. In a multiple logistic regression analysis the only independent predictor of thrombus was indexed LV mass (P < 0.001). Receiver operator characteristic curve analysis also demonstrated that indexed LV mass had the highest area under the curve (AUC: 0.98).</AbstractText>In the present study, increased LV mass was the strongest predictor of LAA thrombus in persistent AF. LA SEC and RA SEC were univariate predictors of LAA thrombus but did not add predictive value to a multivariate model including LV mass. This study highlights the importance of diagnosing and treating LV hypertrophy associated with persistent AF, which may reduce the risk of LAA thrombus and thrombo-embolic stroke.</AbstractText> |
13,914 | Negative tension of scroll wave filaments and turbulence in three-dimensional excitable media and application in cardiac dynamics. | Scroll waves are vortices that occur in three-dimensional excitable media. Scroll waves have been observed in a variety of systems including cardiac tissue, where they are associated with cardiac arrhythmias. The disorganization of scroll waves into chaotic behavior is thought to be the mechanism of ventricular fibrillation, whose lethality is widely known. One possible mechanism for this process of scroll wave instability is negative filament tension. It was discovered in 1987 in a simple two variables model of an excitable medium. Since that time, negative filament tension of scroll waves and the resulting complex, often turbulent dynamics was studied in many generic models of excitable media as well as in physiologically realistic models of cardiac tissue. In this article, we review the work in this area from the first simulations in FitzHugh-Nagumo type models to recent studies involving detailed ionic models of cardiac tissue. We discuss the relation of negative filament tension and tissue excitability and the effects of discreteness in the tissue on the filament tension. Finally, we consider the application of the negative tension mechanism to computational cardiology, where it may be regarded as a fundamental mechanism that explains differences in the onset of arrhythmias in thin and thick tissue. |
13,915 | Calcium leak through ryanodine receptors leads to atrial fibrillation in 3 mouse models of catecholaminergic polymorphic ventricular tachycardia. | Atrial fibrillation (AF) is the most common cardiac arrhythmia, however the mechanism(s) causing AF remain poorly understood and therapy is suboptimal. The ryanodine receptor (RyR2) is the major calcium (Ca2+) release channel on the sarcoplasmic reticulum (SR) required for excitation-contraction coupling in cardiac muscle.</AbstractText>In the present study, we sought to determine whether intracellular diastolic SR Ca2+ leak via RyR2 plays a role in triggering AF and whether inhibiting this leak can prevent AF.</AbstractText>We generated 3 knock-in mice with mutations introduced into RyR2 that result in leaky channels and cause exercise induced polymorphic ventricular tachycardia in humans [catecholaminergic polymorphic ventricular tachycardia (CPVT)]. We examined AF susceptibility in these three CPVT mouse models harboring RyR2 mutations to explore the role of diastolic SR Ca2+ leak in AF. AF was stimulated with an intra-esophageal burst pacing protocol in the 3 CPVT mouse models (RyR2-R2474S+/-, 70%; RyR2-N2386I+/-, 60%; RyR2-L433P+/-, 35.71%) but not in wild-type (WT) mice (P<0.05). Consistent with these in vivo results, there was a significant diastolic SR Ca2+ leak in atrial myocytes isolated from the CPVT mouse models. Calstabin2 (FKBP12.6) is an RyR2 subunit that stabilizes the closed state of RyR2 and prevents a Ca2+ leak through the channel. Atrial RyR2 from RyR2-R2474S+/- mice were oxidized, and the RyR2 macromolecular complex was depleted of calstabin2. The Rycal drug S107 stabilizes the closed state of RyR2 by inhibiting the oxidation/phosphorylation induced dissociation of calstabin2 from the channel. S107 reduced the diastolic SR Ca2+ leak in atrial myocytes and decreased burst pacing-induced AF in vivo. S107 did not reduce the increased prevalence of burst pacing-induced AF in calstabin2-deficient mice, confirming that calstabin2 is required for the mechanism of action of the drug.</AbstractText>The present study demonstrates that RyR2-mediated diastolic SR Ca2+ leak in atrial myocytes is associated with AF in CPVT mice. Moreover, the Rycal S107 inhibited diastolic SR Ca2+ leak through RyR2 and pacing-induced AF associated with CPVT mutations.</AbstractText> |
13,916 | Preprocedural imaging for patients with atrial fibrillation and heart failure. | Various electrophysiological procedures and device implantation has been shown to improve morbidity and mortality in patients with atrial fibrillation (AF) and patients with heart failure (HF). Noninvasive cardiac imaging is used extensively in the preprocedural patient selection and for procedural guidance. In this review, we will discuss the application of preprocedural cardiac imaging in patients with AF prior to pulmonary vein and left atrial ablation as well as insertion of left atrial occluder device. We also discuss the role of noninvasive cardiac imaging in the selection of appropriate HF patients for device therapy as well as their use in guiding implantation of biventricular pacemaker for cardiac resynchronization therapy by assessing left ventricular ejection fraction, coronary venous anatomy, mechanical dyssynchrony and myocardial scar. We describe new research associated with preprocedural imaging in these patient cohorts. |
13,917 | Long-term survival in an un-operated single ventricle. | Single ventricle is a rare and complex congenital heart disease. Neonates with single ventricle have a high mortality. Survival into adulthood is rare without surgical intervention. A case of single ventricle with double inlet and double outlet combined with severe valvular pulmonary stenosis and mitral regurgitation (Grade II) is being reported here. A 36 years old man was admitted for bluish discoloration of lips, tongue and fingers; shortness of breath and recurrent palpitation. His ECG showed atrial fibrillation with fast ventricular rate. Chest X-Ray depicted an enlarged cardiac shadow and right sided pleural effusion. Final diagnosis was made by echocardiogram which demonstrated single ventricle with double inlet and double outlet, severe valvular pulmonary stenosis and mitral regurgitation (Grade II) with good ventricular systolic function. |
13,918 | Transthoracic impedance for the monitoring of quality of manual chest compression during cardiopulmonary resuscitation. | The quality of cardiopulmonary resuscitation (CPR), especially adequate compression depth, is associated with return of spontaneous circulation (ROSC) and is therefore recommended to be measured routinely. In the current study, we investigated the relationship between changes of transthoracic impedance (TTI) measured through the defibrillation electrodes, chest compression depth and coronary perfusion pressure (CPP) in a porcine model of cardiac arrest.</AbstractText>In 14 male pigs weighing between 28 and 34 kg, ventricular fibrillation (VF) was electrically induced and untreated for 6 min. Animals were randomized to either optimal or suboptimal chest compression group. Optimal depth of manual compression in 7 pigs was defined as a decrease of 25% (50 mm) in anterior posterior diameter of the chest, while suboptimal compression was defined as 70% of the optimal depth (35 mm). After 2 min of chest compression, defibrillation was attempted with a 120-J rectilinear biphasic shock.</AbstractText>There were no differences in baseline measurements between groups. All animals had ROSC after optimal compressions; this contrasted with suboptimal compressions, after which only 2 of the animals had ROSC (100% vs. 28.57%, p=0.021). The correlation coefficient was 0.89 between TTI amplitude and compression depth (p<0.001), 0.83 between TTI amplitude and CPP (p<0.001).</AbstractText>Amplitude change of TTI was correlated with compression depth and CPP in this porcine model of cardiac arrest. The TTI measured from defibrillator electrodes, therefore has the potential to serve as an indicator to monitor the quality of chest compression and estimate CPP during CPR.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
13,919 | Electrocardiographic diagnosis of biventricular pacing in patients with nonapical right ventricular leads. | Assessment of left ventricular (LV) capture is of paramount importance in patients with biventricular (BiV) pacing. Our goal was to identify electrocardiographic features that differentiate between BiV and right ventricular (RV)-only pacing in patients with nonapical RV leads.</AbstractText>The study enrolled 300 consecutive patients with BiV devices and nonapical RV leads, and obtained from them 558 electrocardiograms with either BiV pacing (n = 300) or RV-only pacing (n = 258). RV pacing served as a surrogate for loss of LV capture. Electrocardiograms from the first 150 patients were used to identify BiV-specific features, and to construct an algorithm to differentiate between BiV and RV-only pacing. Electrocardiograms from the second 150 patients were used to validate the algorithm.</AbstractText>The following electrocardiographic features typical of BiV pacing were identified: QS in lead V6 (specificity = 98.7%, sensitivity = 54.7%), dominant R in lead V1 (specificity = 100%, sensitivity = 23.3%), q in lead V6 (specificity = 96%, sensitivity = 22.7%), and a QRS < 160 ms (specificity = 100%, sensitivity = 66.0%). The algorithm based on those features was found to have an overall diagnostic accuracy of 95.0%, a specificity of 96.0%, and a sensitivity of 93.5%.</AbstractText>The study identified QRS features that were very specific for BiV pacing in patients with nonapical RV leads. Sequential arrangement of those features resulted in an algorithm that was very accurate for differentiating between BiV pacing and loss of LV capture.</AbstractText>©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,920 | Mobile telemonitoring for arrhythmias in outpatients in the Republic of Georgia: a brief report of a pilot study. | As the very first trial of mobile telemedicine in the Republic of Georgia, in June-December 2010 we investigated 35 outpatients with different types of arrhythmia (male/female ratio=16/19; 12-80 years old), among them 5 patients with concomitant epilepsy. The control group comprised 7 clinically healthy sportsmen (soccer players, all men; 15-17 years old), during a 30-min velo ergometer stress test. A three-lead electrocardiogram (ECG) loop recorder (Vitaphone BT 3300; Vitasystems GmbH, Mannheim, Germany) was used in automatic mode, using special LRMA software (MDT, Lázně Bohdaneč, Czech Republic) and a Nokia (Espoo, Finland) model 6730 Symbian phone. Automatically recorded arrhythmia events were transmitted from the loop recorder by Bluetooth(®) (Bluetooth SIG, Inc., Kirkland, WA) to a phone and then by 3G (through our partner mobile operator, MagtiCom Ltd. [Tbilsi, Georgia]) to the Vitasystems server in Germany and were available to Georgian physicians via e-mail/Internet. Arrhythmias were recorded/monitored during 7-68 h of observation. The number of automatically recorded ECG events varied between 3 and 170 per observation, or 0.4-10.7 hourly. Cases of sinus brady- and tachyarrhythmia, sinus node weakness syndrome, atrial fibrillation, supraventricular tachycardia, supraventricular premature complexes, and ventricular premature complexes were correctly recognized by automatic recognition software and recorded. In 3 patients and 1 sportsman previously unspecified (despite multiple investigations), arrhythmias were recorded: paroxysmal tachycardia (n=1), sinus node weakness syndrome (n=1), and ventricular premature complexes (n=2). In 3 cases (all women) light insomnia and nervousness were reported. In 2 patients with neurosis (both elderly men, 1 with epilepsy) we had to stop investigation prematurely because of anxiety/agitation. Mobile telecardiology represents feasible methodology to monitor arrhythmias in outpatients in Georgia, promoting earlier discharge of non-life-threatening cases, improving patients' comfort of life, and increasing their mobility with enhanced safety. Mobile telehealth might also represent significant cost-saving for insurance companies (this is an ongoing study). Finally, in remote areas mobile telemonitoring of patients will improve quality of care by timely provision of a second opinion in cases when local expertise is not sufficient. |
13,921 | Vernakalant. Too dangerous in atrial fibrillation. | The usual aim of treatment for patients with symptomatic paroxysmal or recent-onset atrial fibrillation, including after cardiac surgery, is to slow the heart rate. Electrical and drug (amiodarone) cardioversion are other options. Vernakalant, an antiarrhythmic drug, has been authorised in the European Union for rapid reduction of recent-onset atrial fibrillation. It is only available in an injectable form. Vernakalant has not been compared in clinical trials with treatments slowing the heart rate, or with electrical cardioversion. The only available comparison with another antiarrhythmic agent is a clinical pharmacology study versus amiodarone, a slow-acting drug, based on the rate of cardioversion at 90 minutes in 240 patients. As expected, given the brief observation period, the rate was significantly higher with vernakalant (51.7% versus 5.2%). During clinical evaluation, 6 deaths occurred in the vernakalant groups versus none in the other groups (placebo or amiodarone). The main adverse effects of vernakalant are cardiac arrhythmias (ventricular arrhythmia, torsades de pointes, bradycardia) and severe hypotension. Altered taste, sneezing, paraesthesia, nausea and pruritus were frequent, and respiratory and neuropsychological effects were also reported. A trial in atrial flutter was interrupted when cases of cardiogenic shock occurred. Interactions are to be expected with drugs that prolong the QT interval, and also with drugs that lower the heart rate or the blood potassium concentration. In practice, it is better to continue to use amiodarone for drug cardioversion and to avoid using vernakalant. |
13,922 | Ventricular fibrillation during coronary angiography in a patient with left dominant coronary artery ectasia. | The presence of coronary ectasias in otherwise normal epicardial coronary arteries are an infrequent angiographic finding. Coronary ectasia is not a benign condition and has been associated with a high risk of coronary events. In the present case, a patient with left dominant coronary artery ectasia who developed ventricular fibrillation during coronary angiography is described. This event was unexpected, and has not been previously reported. |
13,923 | [Cardioverter-defibrillator in the treatment of arrhythmia induced by trastuzumab used in the adjuvant setting in a patient with positive human epidermal growth factor receptor type-2 breast cancer]. | A case of a 36-year old woman with HER2-positive early breast cancer treated with adjuvant trastuzumab left ventricle dysfunction and cardiac arrest in ventricular fibrillation mechanism is presented. After having been successfully resuscitated, trastuzumab therapy was withheld, pharmacotherapy (beta-blocker, ACE-I) implemented and ICD was implanted. Echocardiography performed 6 months later, revealed normal systolic function of the left ventricle. The patient died despite further oncologic treatment due to progression of the disease. The authors discuss the approach to this dramatic but lone cardiac side effect of trastuzumab treatment. |
13,924 | A primer on arrhythmias in patients with hypertrophic cardiomyopathy. | Patients with hypertrophic cardiomyopathy are at risk of atrial and ventricular arrhythmias, yet treatment options for these patients are made almost solely by extrapolation from patients with other diseases. Heart block may be seen spontaneously but is especially prevalent following septal reduction strategies. Atrial fibrillation is the most common arrhythmia in patients with hypertrophic cardiomyopathy. The onset of atrial fibrillation often represents a turning point clinically for patients, marked by substantial functional deterioration and morbidity. Sudden cardiac death is the most common cause of death in the young patient, but still contributes to mortality in older patients. Major risk factors for sudden cardiac death include resuscitated sudden cardiac death, marked hypertrophy, syncope, and family history of sudden cardiac death due to hypertrophic cardiomyopathy. Minor risk factors for sudden cardiac death include nonsustained ventricular tachycardia, and hypotensive response to exercise. Emerging possible risk factors include atrial fibrillation, myocardial ischemia, left ventricular outflow tract obstruction, genetic mutations, left ventricular apical aneurysms, myocardial fibrosis, and end stage disease. |
13,925 | "Benign" early repolarization versus malignant early abnormalities: clinical-electrocardiographic distinction and genetic basis. | In the great majority of cases the ECG pattern of early repolarization (ERP) is a benign phenomenon observed predominantly in teenagers, young adults, male athletes and the black race. The universally accepted criterion for its diagnosis is the presence, in at least two adjoining leads, of ≥ 1 mm or 0.1 mV ST segment elevation. In benign ERP reciprocal ST segment changes are possible only in lead aVR. In contrast, reciprocal ST segment changes can be observed in several leads in idiopathic ventricular fibrillation (IVF) and acute coronary syndrome. In benign ERP the ST segment and T wave patterns have a relative temporal stability. IVF is an entity with low prevalence, possibly familiar, and characterized by the occurrence of VF events in a young person. More frequently this occurs in male subjects without structural heart disease and with otherwise with normal ECG even using high right accessory leads and/or after ajmaline injection. Several clinical entities cause ST segment elevation include asthenic habitus, acute pericarditis, ST segment elevation myocardial infarction, Brugada syndrome, congenital short QT syndrome, and idiopathic VF. In these circumstances clinical and ECG data are most important for differential diagnosis. In IVF the modifications could be dramatic and predominantly at night during vagotonic predominance when J waves > 2 mm in amplitude. The ST/T abnormalities are dynamic, inconstant, and reversed with isoproterenol. Convex upward J waves, with horizontal/descending ST segments or "lambda-wave" ST shape are suggestive of IVF with early repolarization abnormalities. Premature ventricular contractions with very short coupling and "R on T" phenomenon are characteristics with two pattern: When originate from right ventricular outflow tract left bundle branch block morphology and from peripheral Purkinje network, left bundle branch block pattern. The inherited-familial forms are not frequent in IVF; however mutations were identified in the genes KCNJ8, DPP6, SCN5A, SCN3B, CACNA1C, CACNB2, and CACNA2D1. The management of IVF has class I indication for ICD implantation. Ablation therapy is considered additional to ICD implantation in those patients with repetitive ventricular arrhythmia. Quinidine is a highly efficient drug that prevents recurrence. |
13,926 | Prolonged spasm of the left anterior descending coronary artery. | Coronary artery spasm is one of the well-known causes of anginal chest pain. We presented the case of prolonged spasm of the left anterior descending coronary artery which happened during coronary angiography leading to pulse less state and low blood pressure with syncope and appearing of ventricular fibrillation on ECG. During one hour of successful cardiopulmonary resuscitation, the patient had again normal pulse and blood pressure. Coronary angiography performed immediately after DC's showed normal coronary angiogram. After two days the patient left the hospital without brain disorders. |
13,927 | Left ventricular and left atrial thrombi in sinus rhythm patients with dilated ischemic cardiomyopathy.<Pagination><StartPage>155</StartPage><EndPage>158</EndPage><MedlinePgn>155-8</MedlinePgn></Pagination><Abstract><AbstractText Label="INTRODUCTION" NlmCategory="BACKGROUND">Ischemic dilated cardiomyopathy offers a favorable terrain for left ventricular (LV) thrombus formation; however, left artial appendage (LAA) may be an additional source of thrombi in patients with dilated heart. The main objectives of this study were to determine the prevalence of LV and LAA thrombi in patients with chronic ischemic dilated cardiomyopathy in sinus rhythm, as well as to reveal echocardiographic predictors for thrombus formation.</AbstractText><AbstractText Label="METHODS" NlmCategory="METHODS">The study included 57 patients with chronic dilated ischemic cardiomyopathy in sinus rhythm, who were not under oral anticoagulation therapy. Exclusion criteria included patients with: swallowing problems, acute myocardial infarction, idiopathic and/or non-ischemic dilated cardiomyopathy, atrial fibrillation/flatter, severe systolic dysfunction. Transthoracic echocardiography and transesophageal echocardiography were obtained for each patient.</AbstractText><AbstractText Label="RESULTS" NlmCategory="RESULTS">Mean patient age was 62 +/- 10.5 years, mean LV end diastolic diameter was 67.2 +/- 5.8 mm, whereas mean LV ejection fraction (EF) was 37.1 +/- 4.3%. LV thrombus was detected in 11 (19.3%) patients; while 23 (40.3%) patients had LAA thrombus. In a multiple regression analysis LV size (p = 0.05) and lack of aspirin therapy (p = 0.02) showed to be independent LV thrombus predictors, whereas lower LV EF (p = 0.02) and larger LAA maximal area (p = 0.004) demonstrated to be independent predictors of LAA thrombus.</AbstractText><AbstractText Label="CONCLUSIONS" NlmCategory="CONCLUSIONS">We consider that our study sheds light to the high possibility of LAA thrombi formation in addition to LV thrombi in patients with chronic dilated ischemic cardiomyopathy in sinus rhythm. LV size, LV EF, LAA maximal area and lack of aspirin therapy are shown to be independent predictors of left heart chamber thrombi in this patient category.</AbstractText></Abstract><AuthorList CompleteYN="Y"><Author ValidYN="Y"><LastName>Bakalli</LastName><ForeName>Aurora</ForeName><Initials>A</Initials><AffiliationInfo><Affiliation>Department of Cardiology, Clinic of Internal Medicine, University Clinical Center of Kosova, Prishtine, Kosovo. abakalli@hotmail.com</Affiliation></AffiliationInfo></Author><Author ValidYN="Y"><LastName>Georgievska-Ismail</LastName><ForeName>Ljubica</ForeName><Initials>L</Initials></Author><Author ValidYN="Y"><LastName>Koçinaj</LastName><ForeName>Dardan</ForeName><Initials>D</Initials></Author><Author ValidYN="Y"><LastName>Musliu</LastName><ForeName>Nebi</ForeName><Initials>N</Initials></Author><Author ValidYN="Y"><LastName>Zahiti</LastName><ForeName>Bedri</ForeName><Initials>B</Initials></Author><Author ValidYN="Y"><LastName>Krasniqi</LastName><ForeName>Agim</ForeName><Initials>A</Initials></Author><Author ValidYN="Y"><LastName>Bekteshi</LastName><ForeName>Tefik</ForeName><Initials>T</Initials></Author><Author ValidYN="Y"><LastName>Sejdiu</LastName><ForeName>Basri</ForeName><Initials>B</Initials></Author></AuthorList><Language>eng</Language><PublicationTypeList><PublicationType UI="D016428">Journal Article</PublicationType></PublicationTypeList></Article><MedlineJournalInfo><Country>Bosnia and Herzegovina</Country><MedlineTA>Med Arch</MedlineTA><NlmUniqueID>101635337</NlmUniqueID><ISSNLinking>0350-199X</ISSNLinking></MedlineJournalInfo><CitationSubset>IM</CitationSubset><MeshHeadingList><MeshHeading><DescriptorName UI="D002311" MajorTopicYN="N">Cardiomyopathy, Dilated</DescriptorName><QualifierName UI="Q000150" MajorTopicYN="Y">complications</QualifierName><QualifierName UI="Q000503" MajorTopicYN="N">physiopathology</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D004452" MajorTopicYN="N">Echocardiography</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D017548" MajorTopicYN="N">Echocardiography, Transesophageal</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D005260" MajorTopicYN="N">Female</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D006331" MajorTopicYN="N">Heart Diseases</DescriptorName><QualifierName UI="Q000150" MajorTopicYN="Y">complications</QualifierName><QualifierName UI="Q000000981" MajorTopicYN="N">diagnostic imaging</QualifierName><QualifierName UI="Q000209" MajorTopicYN="N">etiology</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D006339" MajorTopicYN="N">Heart Rate</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D006801" MajorTopicYN="N">Humans</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D008297" MajorTopicYN="N">Male</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D008875" MajorTopicYN="N">Middle Aged</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D017202" MajorTopicYN="N">Myocardial Ischemia</DescriptorName><QualifierName UI="Q000150" MajorTopicYN="Y">complications</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D013927" MajorTopicYN="N">Thrombosis</DescriptorName><QualifierName UI="Q000000981" MajorTopicYN="N">diagnostic imaging</QualifierName><QualifierName UI="Q000209" MajorTopicYN="Y">etiology</QualifierName></MeshHeading></MeshHeadingList></MedlineCitation><PubmedData><History><PubMedPubDate PubStatus="entrez"><Year>2012</Year><Month>7</Month><Day>25</Day><Hour>6</Hour><Minute>0</Minute></PubMedPubDate><PubMedPubDate PubStatus="pubmed"><Year>2012</Year><Month>7</Month><Day>25</Day><Hour>6</Hour><Minute>0</Minute></PubMedPubDate><PubMedPubDate PubStatus="medline"><Year>2012</Year><Month>8</Month><Day>17</Day><Hour>6</Hour><Minute>0</Minute></PubMedPubDate></History><PublicationStatus>ppublish</PublicationStatus><ArticleIdList><ArticleId IdType="pubmed">22822612</ArticleId><ArticleId IdType="doi">10.5455/medarh.2012.66.155-158</ArticleId></ArticleIdList></PubmedData></PubmedArticle><PubmedArticle><MedlineCitation Status="MEDLINE" Owner="NLM"><PMID Version="1">22822564</PMID><DateCompleted><Year>2012</Year><Month>08</Month><Day>28</Day></DateCompleted><DateRevised><Year>2022</Year><Month>04</Month><Day>10</Day></DateRevised><Article PubModel="Print"><Journal><ISSN IssnType="Print">0037-9247</ISSN><JournalIssue CitedMedium="Print"><Issue>1</Issue><PubDate><Year>2012</Year></PubDate></JournalIssue><Title>Bulletin de la Societe des sciences medicales du Grand-Duche de Luxembourg</Title><ISOAbbreviation>Bull Soc Sci Med Grand Duche Luxemb</ISOAbbreviation></Journal>Impact of initial intervention on long-term neurological recovey after cardiac arrest: data from the Luxembourg "North Pole" cohort. | Ischemic dilated cardiomyopathy offers a favorable terrain for left ventricular (LV) thrombus formation; however, left artial appendage (LAA) may be an additional source of thrombi in patients with dilated heart. The main objectives of this study were to determine the prevalence of LV and LAA thrombi in patients with chronic ischemic dilated cardiomyopathy in sinus rhythm, as well as to reveal echocardiographic predictors for thrombus formation.</AbstractText>The study included 57 patients with chronic dilated ischemic cardiomyopathy in sinus rhythm, who were not under oral anticoagulation therapy. Exclusion criteria included patients with: swallowing problems, acute myocardial infarction, idiopathic and/or non-ischemic dilated cardiomyopathy, atrial fibrillation/flatter, severe systolic dysfunction. Transthoracic echocardiography and transesophageal echocardiography were obtained for each patient.</AbstractText>Mean patient age was 62 +/- 10.5 years, mean LV end diastolic diameter was 67.2 +/- 5.8 mm, whereas mean LV ejection fraction (EF) was 37.1 +/- 4.3%. LV thrombus was detected in 11 (19.3%) patients; while 23 (40.3%) patients had LAA thrombus. In a multiple regression analysis LV size (p = 0.05) and lack of aspirin therapy (p = 0.02) showed to be independent LV thrombus predictors, whereas lower LV EF (p = 0.02) and larger LAA maximal area (p = 0.004) demonstrated to be independent predictors of LAA thrombus.</AbstractText>We consider that our study sheds light to the high possibility of LAA thrombi formation in addition to LV thrombi in patients with chronic dilated ischemic cardiomyopathy in sinus rhythm. LV size, LV EF, LAA maximal area and lack of aspirin therapy are shown to be independent predictors of left heart chamber thrombi in this patient category.</AbstractText> |
13,928 | Wolff-Parkinson-White syndrome concomitant with idiopathic ventricular fibrillation associated with inferior early repolarization. | We encountered a 39-year-old man with documented ventricular fibrillation (VF). His ECGs showed intermittent Wolff-Parkinson-White (WPW) syndrome pattern. During electrophysiological study, no ventricular preexcitation was observed. An accessory pathway located at the posterior mitral annulus was identified, and successfully eliminated by radiofrequency catheter ablation. VF was not induced. His ECGs in the absence of delta waves demonstrated early repolarization in the inferior leads. This case raises the possibility that patients with manifest WPW syndrome may have an arrhythmogenic substrate associated with early repolarization, and the characteristic J waves can be masked by the presence of ventricular preexcitation. |
13,929 | Accelerated late gadolinium enhancement cardiac MR imaging with isotropic spatial resolution using compressed sensing: initial experience. | To evaluate the use of low-dimensional-structure self-learning and thresholding (LOST) compressed sensing acquisition and reconstruction in the assessment of left atrial (LA) and left ventricular (LV) scar by using late gadolinium enhancement (LGE) magnetic resonance (MR) imaging with isotropic spatial resolution.</AbstractText>The study was approved by the local institutional review board and was compliant with HIPAA. All subjects provided written informed consent. Twenty-eight patients (eight women; mean age, 58.0 years ± 10.1) with a history of atrial fibrillation were recruited for the LA LGE study, and 14 patients (five women; mean age, 54.2 years ± 18.6) were recruited for assessment of LV myocardial infarction. With use of a pseudorandom k-space undersampling pattern, threefold accelerated three-dimensional (3D) LGE data were acquired with isotropic spatial resolution and reconstructed off-line by using LOST. For comparison, subjects were also imaged by using standard 3D LGE protocols with nonisotropic spatial resolution. Images were compared qualitatively by three cardiologists with regard to diagnostic value, presence of enhancement, and image quality. The signed rank test and Wilcoxon unpaired two-sample test were used to test the hypothesis that there would be no significant difference in image quality ratings with different resolutions.</AbstractText>Interpretable images were obtained in 26 of the 28 patients (93%) in the LA LGE study. LGE was seen in 17 of 30 cases (57%) with nonisotropic resolution and in 18 cases (60%) with isotropic resolution. Diagnostic quality scores of isotropic images were significantly higher than those of nonisotropic images with coronal views (median, 3 vs 2, respectively [25th and 75th percentiles: 3, 3 vs 2, 3]; P < .001) and sagittal views (median, 3 vs 2 [25th and 75th percentiles: 3, 4 vs 2, 3]; P < .001) but lower with axial views (median, 4 vs 3 [25th and 75th percentiles: 3, 4 vs 3, 3]; P < .001). For the LV LGE study, all patients had interpretable images. LGE was seen in six of 14 patients (43%), with 100% agreement between both data sets. Diagnostic quality scores of high-isotropic-resolution LV images were higher than those of nonisotropic images with short-axis views (median, 4 vs 3 [25th and 75th percentiles: 3, 4 vs 2, 3]; P = .014) and two-chamber views (median, 4 vs 3 [25th and 75th percentiles: 3, 4 vs 2, 3]; P = .001).</AbstractText>An accelerated LGE acquisition with LOST enables imaging with high isotropic spatial resolution for improved assessment of LV, LA, and pulmonary vein scar.</AbstractText>© RSNA, 2012</CopyrightInformation> |
13,930 | Evaluation of shock waveform configuration on the defibrillation capacity of implantable cardioverter defibrillators in dogs. | Implantable cardioverter defibrillators (ICD) are programmed to detect ventricular arrhythmias and terminate them by delivering an electrical shock. A defibrillation threshold (DFT) at least 10 J below the maximum device output is recommended for successful therapy. Shock waveform configuration is a programmable parameter used to achieve a low DFT. It is hypothesized that a fixed-pulse configuration results in lower defibrillation energy requirements than a fixed-tilt configuration.</AbstractText>10 mongrel dogs.</AbstractText>ICD generator and transvenous lead were surgically implanted. Defibrillation threshold was determined using a protocol guided by the upper limit of vulnerability. Fixed-pulse and fixed-tilt (50%/50%) waveform configurations were tested in a random order. Plasma cardiac troponin I (cTnI) was measured for signs of myocardial injury.</AbstractText>The experiment was completed in 9 dogs. Overall mean DFT value was 424 ± 88 V (9.2 ± 3.9 J). Mean differences among voltage, energy and impedance at the DFT for fixed-pulse (422 ± 97 V, 9.1 ± 4.2 J, 62.6 ± 13.8 Ω) and fixed-tilt (426 ± 83 V, 9.3 ± 3.8 J, 62.8 ± 18.5 Ω) configurations were not statistically significant (All P > 0.21). Cardiac TnI concentration changed from 0.03 ng/mL (95% CI: 0.02-0.04) at baseline to 0.11 ng/mL (95 CI: 0.08-0.16) after DFT was obtained with the first waveform configuration and 0.19 ng/mL (95% CI: 0.13-0.28) at the end of the study period. There were no significant changes in heart rate, end-tidal CO2 and blood pressure over time (all P > 0.09).</AbstractText>The tested ICD device and lead placement reliably produced acceptable DFT values, based on a 10-J safety margin below the maximum device output. A benefit of fixed-pulse configuration could not be demonstrated over the standard fixed-tilt waveform. Signs of acute myocardial damage from repeated high-voltage shocks and episodes of ventricular fibrillation seemed of limited clinical significance.</AbstractText>Copyright © 2012 Elsevier B.V. All rights reserved.</CopyrightInformation> |
13,931 | Prevalence, prognosis, and identification of the malignant form of early repolarization pattern in a population-based study. | Early repolarization pattern (ERP) has recently been associated with idiopathic ventricular fibrillation and with cardiovascular mortality in the general population. We aimed to identify electrocardiographic tools to differentiate the "malignant" form of ERP from benign ERP in a population-based study. We retrospectively assessed the prevalence of ERP by recording electrocardiograms in 1,161 southwestern French subjects 35 to 64 years old. ERP was defined by an elevation of the J point ≥1 mm in 2 consecutive leads excluding leads V(1) through V(3). We categorized ERP as notching or slurring pattern as located in inferior and/or lateral leads and measured the J-point elevation amplitude. ST segment after ERP was categorized as ascendant or horizontal/nonascendant and T waves as negative or positive. Association of ERP with all-cause and cardiovascular mortalities was assessed by adjusted Cox proportional hazard models. ERP was found in 157 subjects (13.3%). During a mean follow-up of 14.2 ± 2 years, 77 subjects died (6.6%), of whom 24 (2.1%) died from cardiovascular causes. Subjects with ERP had an increased hazard ratios for all-cause mortality (2.45, 95% confidence interval [CI] 1.44 to 4.15, p = 0.001) and cardiovascular mortality (5.60, 95% CI 2.27 to 11.8, p = 0.001). The highest risk was found for notching ERP and ERP with a nonascendant/horizontal ST segment, yielding when associated increased hazard ratios of 3.84 (95% CI 2.14 to 6.92, p = 0.001) and 8.75 (95% CI 3.48 to 22.0, p = 0.001) for all-cause and cardiovascular mortalities, respectively. Conversely, a slurring ERP or ascendant ST segment was not associated with increased mortality. ERP localization, J-point elevation amplitude, or T-wave morphology did not distinguish benign from malignant forms of ERP. In conclusion, ERP with notching pattern and horizontal/descendant ST segments was associated with the highest risk of all-cause and cardiovascular deaths. These electrocardiographic patterns may be used for risk stratification in subjects with ERP. |
13,932 | Cardiac involvement in leptospirosis. | Leptospirosis is a neglected global disease with significant morbidity and mortality. Cardiac complications such as chest pain, arrhythmias, pulmonary oedema and refractory shock have been reported in patients with severe disease. However, the frequency and extent of cardiac involvement in leptospirosis, are under-reported and poorly understood. Multiple factors may contribute to clinical manifestations that suggest cardiac involvement, causing diagnostic confusion. A variety of electrocardiographic changes occur in leptospirosis, with atrial fibrillation, atrioventricular conduction blocks and non-specific ventricular repolarization abnormalities being the most common. Electrolyte abnormalities are likely to contribute to electrocardiographic changes; direct effects on Na(+)-K(+)-Cl(-) transporters in the renal tubules have been postulated. Echocardiographic evidence of myocardial dysfunction has not been adequately demonstrated. The diagnostic value of cardiac biomarkers is unknown. Histopathological changes in the myocardium have been clearly shown, with myocardial inflammation and vasculitis present in postmortem studies. Nonetheless, the pathophysiology of cardiac involvement in leptospirosis is poorly understood. Cardiac involvement, demonstrated electrocardiographically or clinically, tends to predict poor outcome. No specific therapies are available to prevent or treat cardiac involvement in leptospirosis; current management is based on correction of deranged homeostasis and supportive therapy. Evidence suggests that direct myocardial damage occurs in patients with severe leptospirosis, and further studies are recommended to elucidate its pathophysiology, clinical features and contribution to overall prognosis, and to identify appropriate diagnostic investigations and specific therapies. |
13,933 | Development of rapid preexcited ventricular response to atrial fibrillation in a patient with intermittent preexcitation. | Intermittent preexcitation during sinus rhythm is indicative of an accessory pathway at a very low risk for sudden death. We present the case of a 49-year-old man with intermittent preexcitation who subsequently developed rapid atrial fibrillation with a shortest preexcited R-R interval of 230 milliseconds. Electrophysiology study showed intermittent preexcitation at baseline and 1:1 anterograde accessory pathway conduction to 220 milliseconds in the presence of 1 mcg/min isoproterenol infusion. The pathway was successfully ablated at the lateral mitral annulus. Accessory pathways highly sensitive to catecholamines may show intermittent preexcitation at baseline with potential for rapid conduction during atrial fibrillation and sudden death. |
13,934 | Safety of the open-irrigated ablation catheter for radiofrequency ablation: safety analysis from six clinical studies. | The open-irrigated catheter is used most frequently for atrial and ventricular radiofrequency ablation (RFA), and is often considered as the standard by which new ablation systems are compared. But few data have been published concerning its safety. This report provides a comprehensive safety analysis of the use of an open-irrigated catheter for RFA of atrial flutter, ventricular tachycardia, and atrial fibrillation in 1,275 patients in six rigorously monitored, prospective, multicenter studies.</AbstractText>This analysis is of data from six studies conducted as part of both Food and Drug Administration-mandated investigational device exemption studies and postapproval studies. The six studies span a period of more than 10 years. All serious RFA complications and vascular access complications that occurred within seven days postprocedure were included.</AbstractText>The number of patients who experienced any acute serious RFA complication in these studies combined was 4.9% (63/1,275). The two earliest studies were conducted when the open-irrigated catheter was first introduced, and accounted for 55.6% of the complications. In the first atrial flutter ablation study, RFA complications decreased by 60% (15.4%-6.2%) after a proctoring program was initiated during the study. For all studies, vascular access complications ranged between from 0.5%-4.7%, and no stroke or transient ischemic attack was reported within 7 days postprocedure. No significant pulmonary vein stenosis was reported from the atrial fibrillation studies.</AbstractText>A proctoring program, careful fluid management, and absence of char and coagulum contributed to the safe use of the open-irrigated RFA catheter.</AbstractText>©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,935 | Preprocedural ventricular rate predicts subsequent sick sinus syndrome after ablation for long-standing persistent atrial fibrillation. | Concealed sick sinus syndrome may become manifest after restoration of sinus rhythm by ablation in patients with long-standing persistent atrial fibrillation (AF). The purpose of this study was to investigate the association between the preprocedural ventricular rate during AF and sinus node function in patients with long-standing persistent AF.</AbstractText>Consecutive patients (n = 102) who underwent ablation for long-standing persistent AF were enrolled. We measured the ventricular rate during AF before ablation in the absence of antiarrhythmic drugs. Sinus node function was assessed by electrophysiological study and serial Holter recordings after ablation.</AbstractText>Patients in the lowest quartile of ventricular rate during AF had longer corrected sinus node recovery time (1.06 ± 1.39 seconds) than those in the other quartiles (0.54 ± 0.31 seconds; P = 0.006) and lower mean heart rate on 24-hour Holter recording 3 months after ablation (68 ± 9 beats/min vs 75 ± 10 beats/min, P = 0.01). During a mean follow-up of 23 ± 10 months, sick sinus syndrome necessitating permanent pacemaker implantation developed in five (5%) patients, and multivariate analysis revealed that a low ventricular rate during AF rate was an independent risk factor for sick sinus syndrome (odds ratio = 0.90 for a 1 beat/min increase in AF rate, P = 0.04).</AbstractText>A low preprocedural ventricular rate during AF indicates the existence of sinus node dysfunction after restoration of sinus rhythm by ablation in patients with long-standing persistent AF.</AbstractText>©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,936 | Significant reduction of fluoroscopy in pediatric catheter ablation procedures: long-term experience from a single center. | Traditionally fluoroscopy has been used for navigation of catheters during electrophysiological procedures. Recent advances in electroanatomic mapping technologies resulted in a decrease and even in elimination of fluoroscopy exposure during these procedures.</AbstractText>Electrophysiological procedures were performed with the use EnSite NavX™ or Velocity™ (St. Jude Medical, St. Paul, MN, USA) systems. Following construction of the right atrial geometry, other relevant geometries were formed (right ventricle, coronary sinus, or left atrium). Fluoroscopy was used in patients with complex congenital heart disease, in younger children, and during transseptal punctures. Cryoablation or radiofrequency was used for catheter ablation.</AbstractText>A total of 305 patients underwent catheter ablation for various supraventricular and ventricular tachyarrhythmia substrates using EnSite system guidance. No fluoroscopy was used in 191 (63%) of these cases. The mean fluoroscopy time in the rest of the procedures was 13.9 ± 11.6 minutes (0.2-60 minutes). The mean procedure time was 184 ± 71 minutes. No complications were noted except for temporary diaphragmatic paralysis in one patient and temporary AV block in another patient following cryoablation. Acute success rate in achieving complete elimination of arrhythmia substrates was 95% (290/305). The recurrence rate was (31/271) 11.4% at a mean follow-up time of 42 ± 23 months.</AbstractText>Fluoroscopy can be significantly decreased or even eliminated in the majority of catheter ablation procedures. Long-term results demonstrate that this can be done efficiently and safely.</AbstractText>©2012, The Author. Journal compilation ©2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,937 | Vasospastic angina with J-wave pattern and polymorphic ventricular tachycardia effectively treated with quinidine. | Myocardial ischemia during coronary spasm may generate malignant ventricular arrhythmias. The J-wave pattern was suggested to be a marker of a disorder associated with life-threatening arrhythmias.</AbstractText>We report the case of a patient with vasospastic angina and J-wave pattern in inferior and lateral leads associated with polymorphic ventricular tachycardia which was effectively treated only with quinidine-vasodilating drugs were not able to prevent the arrhythmia although they were effective in preventing ischemic events.</AbstractText>The J-wave pattern in inferolateral leads may be a sign of electrical vulnerability to lethal ventricular arrhythmia in patients suffering from vasospastic angina--quinidine can effectively prevent such arrhythmias in these patients.</AbstractText>©2012, Wiley Periodicals, Inc.</CopyrightInformation> |
13,938 | Complete heart block following a blow on the chest by a soccer ball: a rare manifestation of commotio cordis. | Commotio cordis is a rare type of blunt cardiac injury in which low impact chest trauma causes sudden cardiac arrest, usually occurs from being struck by a projectile during sports. The most common arrhythmia during commotio cordis is ventricular fibrillation, although complete heart block and an idioventricular rhythm have also been reported. We describe a case of a young patient who presented with a persistent third-degree atrioventricular block and a left bundle branch block, following blunt chest trauma, as a result of blow by soccer ball and subsequently needed a permanent pacemaker. |
13,939 | Therapeutic effect of surfactant inhalation during warm ischemia in an isolated rat lung perfusion model. | Warm ischemia-reperfusion injury related to donation after cardiac death donors is a crucial and inevitable issue. As surfactant function is known to deteriorate during warm ischemia, we hypothesized that surfactant inhalation during warm ischemia would mitigate warm ischemia-reperfusion injury. We used an isolated rat lung perfusion model. The rats were divided into three groups: sham, control, and surfactant. In the control and surfactant groups, cardiac arrest was induced by ventricular fibrillation. Ventilation was restarted 110 min later; subsequently, the lungs were flushed, and heart and lung block was recovered. In the surfactant group, a natural bovine surfactant Surfacten(®) was inhaled for 3 min at the end of warm ischemia. Then, the lungs were reperfused for 80 min. Surfactant inhalation significantly improved graft functions, effectively increased lung tissue ATP levels, and significantly decreased mRNA levels of IL-6 and IL-6/IL-10 ratio at the end of reperfusion. Histologically, lungs in the surfactant group showed fewer signs of interstitial edema and hemorrhage, and significantly less neutrophilic infiltration than those in the control group. Our results indicated that surfactant inhalation in the last phase of warm ischemia maintained lung tissue energy levels and prevented cytokine production, resulting in the alleviation of warm ischemia-reperfusion injury. |
13,940 | A review of literature on the adverse effects of hyperthyroidism on the heart functional behavior. | Thyroid hormones play an important role on the physiological chemistry of heart and vascular systems in healthy subjects. Any thyroid disorders accompanied with alteration of effective concentration of thyroid hormones cause heart dysfunctions. Thyrotoxicosis is a term given for the clinical manifestation of hyperthyroidism which can invoke heart and vascular abnormalities through the mechanism at heart muscle cells nuclear level. Thyrotoxicosis can play positive roles for heart disorders including atrial fibrillation, left ventricular hypertrophy and right ventricular systolic dysfunction, which are considered as major risk factors for heart abnormalities. Miscalculation of heart dysfunctions related thyrotoxicosis in cardiovascular patients might be avoided through careful laboratory measurements of T4 and T3 to exclude any possible thyroid hormone-related heart diseases. |
13,941 | A case of Prinzmetal angina diagnosed by Holter monitoring who survived a sudden cardiac death: Case report. | A 47-year-old female patient was admitted to our hospital after a syncope. She reported episodes of angina in previous weeks. On admission, there were no electrocardiographic changes but elevated troponin. Coronary angiogram showed minimal arteriosclerosis and normal left ventricle. Holter monitoring showed severe ST-segment changes during an anginal episode.With calcium antagonists, the patient experienced no further episodes of angina or ST changes during telemetry.Six weeks later, calcium antagonist was stopped for unknown reason. After that, the patient experienced a second prolonged syncope with cardiopulmonary resuscitation and defibrillation of ventricular fibrillation.</AbstractText>"A variant form of angina pectoris" was first described by Myron Prinzmetal. He postulated coronary vasospasm as the underlying cause, however, after 50 years the exact pathophysiology is still not known.Patients with "variant angina" usually present with "spontaneous" attacks of typical retrosternal anginal pain during rest or normal activities, but not with physical exercise.Sudden cardiac deaths were reported in patients with Prinzmetal angina in only a few case reports.</AbstractText>In cases of variant angina accompanied by syncope, a provocation test and an electrophysiological study should be considered.</AbstractText> |
13,942 | A mutation in TNNC1-encoded cardiac troponin C, TNNC1-A31S, predisposes to hypertrophic cardiomyopathy and ventricular fibrillation. | Defined as clinically unexplained hypertrophy of the left ventricle, hypertrophic cardiomyopathy (HCM) is traditionally understood as a disease of the cardiac sarcomere. Mutations in TNNC1-encoded cardiac troponin C (cTnC) are a relatively rare cause of HCM. Here, we report clinical and functional characterization of a novel TNNC1 mutation, A31S, identified in a pediatric HCM proband with multiple episodes of ventricular fibrillation and aborted sudden cardiac death. Diagnosed at age 5, the proband is family history-negative for HCM or sudden cardiac death, suggesting a de novo mutation. TnC-extracted cardiac skinned fibers were reconstituted with the cTnC-A31S mutant, which increased Ca(2+) sensitivity with no effect on the maximal contractile force generation. Reconstituted actomyosin ATPase assays with 50% cTnC-A31S:50% cTnC-WT demonstrated Ca(2+) sensitivity that was intermediate between 100% cTnC-A31S and 100% cTnC-WT, whereas the mutant increased the activation of the actomyosin ATPase without affecting the inhibitory qualities of the ATPase. The secondary structure of the cTnC mutant was evaluated by circular dichroism, which did not indicate global changes in structure. Fluorescence studies demonstrated increased Ca(2+) affinity in isolated cTnC, the troponin complex, thin filament, and to a lesser degree, thin filament with myosin subfragment 1. These results suggest that this mutation has a direct effect on the Ca(2+) sensitivity of the myofilament, which may alter Ca(2+) handling and contribute to the arrhythmogenesis observed in the proband. In summary, we report a novel mutation in the TNNC1 gene that is associated with HCM pathogenesis and may predispose to the pathogenesis of a fatal arrhythmogenic subtype of HCM. |
13,943 | Modeling serum biomarkers S100 beta and neuron-specific enolase as predictors of outcome after out-of-hospital cardiac arrest: an aid to clinical decision making. | The aim of this study was to determine the added value of the serum biomarkers S100 and neuron-specific enolase to clinical characteristics for predicting outcome after out-of-hospital cardiac arrest.</AbstractText>Serum S100 beta (S100B) and neuron-specific enolase concentrations rise after brain injury.</AbstractText>A prolective observational study was conducted among all adult survivors of nontraumatic out-of-hospital cardiac arrest admitted to 1 hospital (April 3, 2008 to April 3, 2011). Three blood samples (on arrival and on days 1 and 3) were drawn for biomarkers, contingent on survival. Follow-up continued until in-hospital death or discharge. Outcomes were defined as good (Cerebral Performance Category score 1 or 2) or poor (Cerebral performance category score 3 to 5).</AbstractText>A total of 195 patients were included (65.6% men, mean age 73 ± 16 years), with presenting rhythms of asystole in 61.5% and ventricular tachycardia or ventricular fibrillation in 24.1%. Only 43 patients (22.0%) survived to hospital discharge, 26 (13.3%) with good outcomes. Patients with good outcomes had significantly lower S100B levels at all time points and lower neuron-specific enolase levels on days 1 and 3 compared with those with poor outcomes. Independent predictors at admission of a good outcome were younger age, a presenting rhythm of ventricular tachycardia or ventricular fibrillation, and lower S100B level. Predictors on day 3 were younger age and lower day 3 S100B level. The area under the receiver-operating characteristic curve of the admission-day model was 0.932 with and 0.880 without biomarker data (p = 0.027 for the difference).</AbstractText>Risk stratification after out-of-hospital cardiac arrest using both clinical and biomarker data is feasible. The biomarkers, although adding an ostensibly modest 5.2% to the area under the receiver-operating characteristic curve, substantially reduced the level of uncertainty in decision making. Nevertheless, current biomarkers cannot replace societal considerations in determining acceptable levels of uncertainty. (Protein S100 Beta as a Predictor of Resuscitation Outcome; NCT00814814).</AbstractText>Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
13,944 | Defining abnormal electrocardiography in adult emergency department syncope patients: the Ottawa Electrocardiographic Criteria. | Previous studies have indicated that the suboptimal performance of the San Francisco Syncope Rule (SFSR) is likely due to the misclassification of the "abnormal electrocardiogram (ECG)" variable. We sought to identify specific emergency department (ED) ECG and cardiac monitor abnormalities that better predict cardiac outcomes within 30 days in adult ED syncope patients.</AbstractText>This health records review included patients 16 years or older with syncope and excluded patients with ongoing altered mental status, alcohol or illicit drug use, seizure, head injury leading to loss of consciousness, or severe trauma requiring admission. We collected patient characteristics, 22 ECG variables, cardiac monitoring abnormalities, SFSR "abnormal ECG" criteria, and outcome (death, myocardial infarction, arrhythmias, or cardiac procedures) data. Recursive partitioning was used to develop the "Ottawa Electrocardiographic Criteria."</AbstractText>Among 505 included patient visits, 27 (5.3%) had serious cardiac outcomes. We found that patients were at risk for cardiac outcomes within 30 days if any of the following were present: second-degree Mobitz type 2 or third-degree atrioventricular (AV) block, bundle branch block with first-degree AV block, right bundle branch with left anterior or posterior fascicular block, new ischemic changes, nonsinus rhythm, left axis deviation, or ED cardiac monitor abnormalities. The sensitivity and specificity of the Ottawa Electrocardiographic Criteria were 96% (95% CI 80-100) and 76% (95% CI 75-76), respectively.</AbstractText>We successfully identified specific ED ECG and cardiac monitor abnormalities, which we termed the Ottawa Electrocardiographic Criteria, that predict serious cardiac outcomes in adult ED syncope patients. Further studies are required to identify which adult ED syncope patients require cardiac monitoring in the ED and the optimal duration of monitoring and to confirm the accuracy of these criteria.</AbstractText> |
13,945 | Spray cryotherapy is effective for bronchoscopic, endoscopic and open ablation of thoracic tissues. | Spray cryotherapy (SCT) delivers a liquid nitrogen spray via a catheter to produce cellular death. This study seeks to determine the histological changes after bronchoscopic, endoscopic and open SCT on tissues in the thoracic cavity.</AbstractText>Yorkshire pigs underwent flexible bronchoscopy, endoscopy and thoracotomy for SCT of the airway, oesophagus and other intrathoracic structures, respectively. Variations in the duration and number of spray cycles for the same dosimetry were compared.</AbstractText>Bronchoscopic SCT of the airway resulted in cellular death up to the cartilage layer. Endoscopic SCT of the oesophagus led to cell death up to the adventitial layer. Tissue necrosis was severe in the lung, of full thickness in the pleura, but very superficial in the great vessels. The extracellular matrix (ECM) of treated tissues remained well-preserved. Having shorter but more cycles of SCT decreased the depth of the cellular necrosis. One pig developed ventricular fibrillation during the surgery and expired.</AbstractText>SCT causes reproducible tissue injury with the preserved ECM of most tissues within the thoracic cavity, making it enticing for ablation around vital structures like the great vessels with a decreased long-term risk. Further study is warranted to investigate the adverse events during SCT.</AbstractText> |
13,946 | [ECG changes in patients with chronic non-cancer pain: a prospective observational study]. | Patients with chronic non-cancer pain not only show reduced quality of life, but also chronic morbidity and increased mortality. However, little is known about prevalence and type of abnormal electrocardiogram (ECG) recordings in these individuals.</AbstractText>A total of 100 consecutive patients (≥ 18 years) with chronic (≥ 3 months) non-cancer pain were examined prospectively using ECG recordings and a questionnaire [German Pain Society (DGSS); further questions]. Data were collected at the first and next two follow-up outpatients' clinic appointments.</AbstractText>Participation rate was 98%. Of all patients, 26% had an abnormal ECG, while 5% of these patients had an abnormal ECG first at the follow-up when consuming a different analgesic regimen. Findings were QTc prolongation (16%), ventricular block (7%), artrioventricular block (6%), and atrial fibrillation (4%).</AbstractText>The prevalence of abnormal ECG recordings should be considered in the pain management of these patients. General ECG screening in this population should be discussed. Future studies should examine a larger population to identify potential risk factors (e.g., medication).</AbstractText> |
13,947 | Hypoxic-ischemic brain injury and prognosis after cardiac arrest. | : Cardiac death is the leading cause of death in the United States, and patients who have out-of-hospital cardiac arrest have only a 1% to 10% survival rate, despite improvements in advanced life support. The neurologic sequelae of hypoxic-ischemic brain injury after cardiac arrest vary from subtle cognitive impairment to coma, persistent vegetative state, and brain death. Neurologists are commonly asked to prognosticate neurologic outcome after cardiac arrest.</AbstractText>: In 2002, two randomized controlled trials demonstrated that therapeutic hypothermia (32°C to 34°C [89.6°F to 93.2°F]) increases the odds of improved neurologic outcome and reduces the risk of death compared with normothermia when applied for the initial 12 to 24 hours after ventricular fibrillation or tachycardia cardiac arrest. Considerable research continues into neurologic prognostication after hypoxic-ischemic brain injury, especially with the advent of therapeutic hypothermia and its effects on the clinical examination, neurophysiologic studies, and serum biomarkers of brain injury. Recent reports indicate that poor motor response 72 hours after cardiac arrest, absent cortical responses on median nerve somatosensory-evoked potentials, and elevated neuron-specific enolase may not necessarily indicate poor prognosis in patients treated with therapeutic hypothermia compared with historical populations not treated with hypothermia, perhaps because of sedation and neuromuscular blockade.</AbstractText>: Neurologic prognostication after cardiac arrest remains challenging because of the sedation and neuromuscular blocking agents given to patients who undergo therapeutic hypothermia. A multimodal algorithmic approach (clinical, electrophysiologic, and possibly serum biomarker testing) is suggested for cardiac arrest patients treated with hypothermia, but further research is needed to determine more accurate prognostic predictors.</AbstractText> |
13,948 | Effects of prolonged mild hypothermia on cerebral blood flow after cardiac arrest. | The aim of the present study was to assess the cerebral blood flow and cerebral oxygen extraction in adult patients after pulseless electrical activity/asystole or resistant ventricular fibrillation who were treated with mild therapeutic hypothermia for 72 hrs.</AbstractText>Observational study.</AbstractText>Tertiary care university hospital.</AbstractText>Ten comatose patients with return of spontaneous circulation after pulseless electrical activity/asystole or prolonged ventricular fibrillation.</AbstractText>Treatment with mild therapeutic hypothermia for 72 hrs.</AbstractText>Mean flow velocity in the middle cerebral artery was measured by transcranial Doppler at 12, 24, 36, 48, 60, 72, 84, 96, and 108 hrs after admission. Jugular bulb oxygenation was measured at the same intervals. Mean flow velocity in the middle cerebral artery was low (26.5 (18.7-48.0) cm/sec) at admission and significantly increased to 63.9 (45.6-65.6) cm/sec at 72 hrs (p=.002). Upon rewarming, the mean flow velocity in the middle cerebral artery remained relatively constant with a mean flow velocity in the middle cerebral artery of 71.5 (56.0-78.5) at 108 hrs (p=.381). Jugular bulb oxygenation at the start of the study was 57.0 (51.0-61.3)% and gradually increased to 81.0 (78.5-88.0)% at 72 hrs (p=.003). Upon rewarming, the jugular bulb oxygenation remained constant with a jugular bulb oxygenation of 84.0 (77.3-86.3)% at 108 hrs (p=.919). There were no differences in mean flow velocity in the middle cerebral artery, pulsatility index, and jugular bulb oxygenation between survivors and nonsurvivors.</AbstractText>Temperature by itself is probably not a major determinant in regulation of cerebral blood flow after cardiac arrest. The relatively low mean flow velocity in the middle cerebral artery in combination with normal jugular bulb oxygenation values suggests a reduction in cerebral metabolic activity that may contribute to the neuroprotective effect of (prolonged) mild therapeutic hypothermia in the delayed hypoperfusion phase.</AbstractText> |
13,949 | Intracellular calcium dynamics, shortened action potential duration, and late-phase 3 early afterdepolarization in Langendorff-perfused rabbit ventricles. | To elucidate the mechanism of late-phase 3 early after depolarization (EAD) in ventricular arrhythmogenesis, we hypothesized that intracellular calcium (Ca(i) ) overloading and action potential duration (APD) shortening may promote late-phase 3 EAD and triggered activity, leading to development of ventricular fibrillation (VF).</AbstractText>In isolated rabbit hearts, we performed microelectrode recording and simultaneous dual optical mapping of transmembrane potential (V(m) ) and Ca(i) transient on left ventricular endocardium. An I(KATP) channel opener, pinacidil, was used to abbreviate APD. Rapid pacing was then performed. Upon abrupt cessation of rapid pacing with cycle lengths of 60-200 milliseconds, there were APD(90) prolongation and the corresponding Ca(i) overloading in the first postpacing beats. The duration of Ca(i) transient recovered to 50% (DCaT(50) ) and 90% (DCaT(90) ) in the first postpacing beats was significantly longer than baseline. Abnormal Ca(i) elevation coupled with shortened APD produced late-phase 3 EAD induced triggered activity and VF. In additional 6 preparations, the heart tissues were treated with BAPTA-AM, a calcium chelator. BAPTA-AM significantly reduced the maximal Ca(i) amplitude (26.4 ± 3.5% of the control; P < 0.001) and the duration of Ca(i) transients in the mapped region, preventing the development of EAD and triggered activity that initiated VF.</AbstractText>I (KATP) channel activation along with Ca(i) overloading are associated with the development of late-phase 3 EAD and VF. Because acute myocardial ischemia activates the I(KATP) channel, late-phase 3 EADs may be a mechanism for VF initiation during acute myocardial ischemia.</AbstractText>© 2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,950 | PPAR-alpha activation as a preconditioning-like intervention in rats in vivo confers myocardial protection against acute ischaemia-reperfusion injury: involvement of PI3K-Akt. | Peroxisome proliferator-activated receptors (PPAR) regulate the expression of genes involved in lipid metabolism, energy production, and inflammation. Their role in ischaemia-reperfusion (I/R) is less clear, although research indicates involvement of PPARs in some forms of preconditioning. This study aimed to explore the effects of PPAR-α activation on the I/R injury and potential cardioprotective downstream mechanisms involved. Langendorff-perfused hearts of rats pretreated with the selective PPAR-α agonist WY-14643 (WY, pirinixic acid; 3 mg·(kg body mass)·day(-1); 5 days) were subjected to 30 min ischaemia - 2 h reperfusion with or without the phosphatidylinositol 3-kinase (PI3K)-Akt inhibitor wortmannin for the evaluation of functional (left ventricular developed pressure, LVDP) recovery, infarct size (IS), and reperfusion-induced arrhythmias. A 2-fold increase in baseline PPAR-α mRNA levels (qPCR) in the WY-treated group and higher post-I/R PPAR-α levels compared with those in untreated controls were accompanied by similar changes in the expression of PPAR-α target genes PDK4 and mCPT-1, regulating glucose and fatty acid metabolism, and by enhanced Akt phosphorylation. Post-ischaemic LVDP restoration in WY-treated hearts reached 60% ± 9% of the pre-ischaemic values compared with 24% ± 3% in the control hearts (P < 0.05), coupled with reduced IS and incidence of ventricular fibrillation that was blunted by wortmannin. Results indicate that PPAR-α up-regulation may confer preconditioning-like protection via metabolic effects. Downstream mechanisms of PPAR-α-mediated cardioprotection may involve PI3K-Akt activation. |
13,951 | ECG changes in octogenarians. | Numerous studies have been done about the Electrocardiogram (ECG) in the elderly but just a few regarding the changes in ECG in octogenarians. Ageing is definitely associated with changes in the cardiac conduction and physiology. This study attempts to evaluate the ECG in octogenarians. ECG recordings from 165 octogenarian subjects were obtained from subjects aged 80-89 years, mean age was 82.75 +/- 2.41 years. ECG's were normal in 27.27 % of the study population. The major abnormalities noted were right bundle branch block 15.15%, left ventricular hypertrophy in 13.93%, Poor R-wave progression in precordial leads in 10.91%, atrial fibrillation in 8.48%, ST changes in 8.48%, sinus tachycardia in 6.66% and sinus bradycardia in 4.84% of the study population. The mean QTc was 0.41s. Because of its non-invasive nature, ECG is a least expensive, readily available diagnostic tool for evaluating cardiac health issues in the growing elderly population. We hope the observations will be helpful in future studies, in evaluating cardiac health in octogenarians and in clinical practice. |
13,952 | Postoperative tetralogy of fallot with concomitant atrial fibrillation and ventricular tachycardia. | Postoperative tetralogy of Fallot patients, since the first corrective surgical correction in the 1960s, have borne a burden of postoperation arrhythmias and sudden death. This is confirmed to be secondary to supraventricular arrhythmias and predominantly ventricular arrhythmias. It is rare to have both types of arrhythmias in the same patient, which the index case developed. Attempts to stratify patients in groups to predict which patients are susceptible to sudden death and arrhythmias have not been unanimous, despite multiple retrospective and prospective analysis of this group of patients. |
13,953 | Acute ventricular fibrillation during primary HIV infection. | Primary HIV infection normally shows an asymptomatic presentation or symptoms resembling infectious mononucleosis. However, severe unusual presentations have been reported. We report a case of acute ventricular fibrillation during primary HIV infection. Moreover, the rapid development of symptoms, the profound pancytopaenia and the marked elevation of liver enzymes make this case rather unique. Therefore, acute ventricular fibrillation should be added to the list of complications of primary HIV infection. |
13,954 | The usefulness of the consensus clinical diagnostic criteria in Brugada syndrome. | Consensus statements were proposed for the diagnosis of Brugada syndrome (BS). The clinical diagnostic criteria were defined as documented ventricular fibrillation or ventricular tachycardia (VT), family history of sudden cardiac death at <45 years, diagnostic ECGs of family members, inducibility of VT during electrophysiological study, syncope or nocturnal agonal respiration. The clinical validation of these criteria is still missing. Methods and results 280 patients (41 ± 18 years, male: 168 pts) with diagnostic coved type I ECG were included. Consensus clinical diagnostic criteria were present in 244 (87%) patients (40 ± 18 y, 142 males). In 36 pts (13% of the 280 pts, 51 ± 12 years, 27 males) consensus clinical diagnostic criteria were not met. Nine patients (25%) presented with spontaneous type I ECG. Ten of the 36 patients (28%) had a history of atrial fibrillation and 13 (36%) had conduction disease on the baseline ECG. In 23 patients (64%) family screening was not performed. Two of the 36 patients had undocumented syncope during follow-up. Univariate analysis showed no significant difference in event free survival between patients with or without consensus clinical diagnostic criteria.</AbstractText>In a significant number of patients with diagnostic ECG pattern the current diagnostic criteria for BS are not met. These patients have frequently spontaneous type I ECG and clinical signs of Brugada syndrome as paroxysmal atrial fibrillation or conduction disturbances. Our results suggest that in patients with a diagnostic type I ECG pattern the current clinical consensus diagnostic criteria have limited added diagnostic value.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
13,955 | Increased comorbidities in heart failure patients ≥ 85 years but declined from >90 years: data from the Swedish Heart Failure Registry. | Epidemiological studies of elderly heart failure (HF) patients (≥ 85 years) are limited with inconsistent findings. Our objective is to confirm and extend epidemiological study in elderly (≥ 85 years) patients using the Swedish Heart Failure Registry database.</AbstractText>This retrospective study included 8,347 HF patients aged ≤ 65 years and 15,889 HF patients aged ≥ 85 years. Elderly population was further divided into two subgroups: 11,412 patients were 85-90 years and 4,477 patients were >90 years.</AbstractText>The ≥ 85 year group was characterized by more women, higher systolic blood pressure (SBP), lower body-mass index (BMI), more than twice as many HF with normal left ventricular ejection fraction (HFNEF), higher incidence of cardiovascular and non-cardiovascular comorbidities and less use of proven therapeutics compared with the ≤ 65 year group. Compared with the 85-90 year subgroup, the > 90 year subgroup had a decline in cardiovascular and non-cardiovascular comorbidities except renal insufficiency and anaemia which continued to increase with ageing (p<0.01). Tendency was the same regardless of gender but slightly different between systolic HF (SHF) and HFNEF. In the group with HFNEF, there were more women, higher SBP, lower N-terminal pro-B-type natriuretic peptide levels, less ischaemic heart disease, more hypertension and left bundle branch block regardless of age. Atrial fibrillation was more frequent in patients with HFNEF than with SHF in the elderly group (p<0.01). Patients with HFNEF in the > 90 year subgroup had increasing incidence of ischaemic heart disease compared to 85-90 year group (p<0.01).</AbstractText>HF patients ≥ 85 years had increased cardiovascular and non-cardiovascular comorbidities but with a decline from >90 years.</AbstractText>Crown Copyright © 2012. Published by Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
13,956 | Fragmented QRS may predict postoperative atrial fibrillation in patients undergoing isolated coronary artery bypass graft surgery. | Fragmented QRS complexes (fQRS) are defined as various RSR' patterns in 2 contiguous leads corresponding to a major coronary artery territory. Although the reason of association between fQRS and cardiac events was documented as cardiac fibrosis, the predictive role of fQRS was not studied for postoperative atrial fibrillation (POAF) which is a frequent and serious complication in patients undergoing isolated coronary artery bypass graft (CABG) surgery. Therefore, this issue was investigated in the present study.</AbstractText>The current study has a prospective observational design. Two hundred and seventy two eligible patients who underwent isolated CABG surgery were enrolled consecutively. The patients were divided in two groups with post-op atrial fibrillation (AF) and non-AF. The occurrence of new-onset AF following CABG and the relationship with fQRS were searched. The logistic regression analysis was used to determine independent predictors for POAF. The sensitivity and specificity of study variables in predicting POAF were calculated using a receiver-operating characteristic curve (ROC).</AbstractText>POAF occurred in 62 of 272 patients (22.8%). Patients with POAF were generally older (p<0.001) and female (p=0.006), with preexisting hypertension (p=0.008), lower hemoglobin levels (p=0.011), chronic obstructive lung disease (p=0.003), prolonged QRS time (p=0.004), and higher EUROSCORE (p<0.001) compared to non-AF patients. Patients with POAF had lower left ventricular ejection fraction (p<0.001) and high fQRS rate (p<0.001), but similar left atrial size (LA, p=NS). Interestingly, LA size was significantly enlarged in patients with fQRS (3.8±0.6 vs. 4.1±0.5 cm, p=0.002). In addition, the patients with POAF had prolonged stay in the cardiac surgery intensive-care unit (p<0.001) and extended in-hospital care (p=0.001). New-onset POAF was significantly related to the presence and number of fQRS. In the logistic regression analysis, only age (OR: 1.044, 95% CI: 1.008-1.082, p=0.016), female gender (OR: 2.347, 95% CI: 1.079-5.106, p=0.031), the presence and number of fQRS (OR: 6.020, 95% CI: 3.152-11.5 and OR: 1.522, 95% CI: 1.282-1.807, both of, p<0.001) were independent predictors of POAF. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and the diagnostic accuracy (DA) of presence of fQRS on pre-op electrocardiogram to predict POAF were 66%, 76%, 45%, 88% and 74%, respectively. The area under ROC was found as 0.733 (p<0.001, 95% CI: 0.657-0.810).</AbstractText>In our study, we found that new-onset POAF was independently related to the presence and number of fQRS in patients undergoing CABG surgery. In addition, fQRS on pre-op surface ECG had high predictive values for new-onset POAF.</AbstractText> |
13,957 | Emergency cardio-pulmonary bypass in cardiac arrest: seventeen years of experience. | Emergency cardiopulmonary bypass (E-CPB) is an advanced and rarely used procedure for patients in cardiac arrest that do not regain restoration of spontaneous circulation with standard resuscitation methods. The feasibility, safety and outcome of the intervention with E-CPB in cardiac arrest situations at our department have been evaluated.</AbstractText>Clinical presentation, time intervals, diagnosis and outcome of all patients who received E-CPB at an emergency department of a tertiary care university hospital were evaluated. Patient charts were reviewed regarding cardiac arrest variables and treatment data of all patients from 1993 to 2010.</AbstractText>E-CPB was performed in 55 patients. Of all patients, 33 (60%) were male and the median age was 32 years (IQR 24-44). In all cases cardiac arrest was witnessed. The first recorded ECG rhythm showed pulseless electric activity in 23 (42%), ventricular fibrillation in 21 (38%) and asystole in 11 (20%) patients. Cardiac arrest occurred out-of-hospital in 33 (60%) patients. The median duration of CPR before performing E-CPB was 86 min (IQR 69-121). The median 'cannulation'-time was 33 min (IQR 21-45) and the duration on bypass was 311 min (IQR 161-953). Cardiac causes of arrest were found in 19 (35%) patients. Eight patients (15%) survived to 6 months with good neurological outcome.</AbstractText>E-CPB for cardiac arrest is feasible and safe. In this seemingly desperate patient population after prolonged cardiac arrest, we observed a high survival rate of 15%. E-CPB is a meaningful treatment option, which should be considered more often and earlier.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
13,958 | Mineralocorticoid receptor antagonists and cardiovascular mortality in patients with atrial fibrillation and left ventricular dysfunction: insights from the Atrial Fibrillation and Congestive Heart Failure Trial. | Patients with heart failure (HF) and atrial fibrillation (AF) may differ from the larger HF population with respect to comorbidities, including renal impairment and overall prognosis. Associated cardiorenal interactions may mitigate the effects of pharmacological agents. Our primary objective was to assess the impact of mineralocorticoid receptor antagonists on cardiovascular mortality in patients with AF and HF enrolled in the Atrial Fibrillation and Congestive Heart Failure (AF-CHF) trial.</AbstractText>All 1376 patients randomized in the AF-CHF trial were included. The median baseline creatinine was 105.2 (Q1 88.4, Q3 125.0) μmol/L, and the median estimated glomerular filtration rate was 62.3 (Q1 49.0, Q3 77.2) mL/min per 1.73 m(2). The renal function was moderately or severely impaired (ie, estimated glomerular filtration rate <60 mL/min per 1.73 m(2)) in 46.5% of patients. In multivariable analyses, increased creatinine was associated with worsening HF but not mortality. Mineralocorticoid receptor antagonists were prescribed in 44.8% and were independently associated with a 1.4-fold increase in total mortality (hazard ratio, 1.4; 95% CI [1.1-1.8]; P=0.005) and a 1.4-fold increase in cardiovascular mortality (hazard ratio, 1.4; 95% CI [1.1-1.9]; P=0.009). This was driven by an increased incidence of sudden cardiac death (hazard ratio, 2.0; 95% CI [1.3, 3.0]; P=0.001).</AbstractText>Renal dysfunction was highly prevalent in patients with AF and HF. Mineralocorticoid receptor antagonists were independently associated with an increased incidence of cardiovascular deaths, predominantly of presumed arrhythmic cause. Although these provocative findings merit prospective validation, they underscore the importance of careful monitoring of renal function and electrolytes in patients with AF and HF receiving mineralocorticoid receptor antagonists.</AbstractText> |
13,959 | Implantable cardioverter defibrillator shock embolizes an atrial septal occluder device in Brugada syndrome. | Implantable cardioverter defibrillators (ICDs) are indicated in patients with Brugada syndrome with resuscitated ventricular arrhythmias. When these patients have atrial septal defects, they also need closure to prevent paradoxic embolism of thrombus from the defibrillator leads. A 15-year-old boy with Brugada syndrome had transvenous ICD placement along with device closure of a large atrial septal defect. When the defibrillation threshold was checked during device testing, a shock was delivered to terminate the induced ventricular fibrillation. The sudden jerk during this shock resulted in device embolization into the left atrium. The device was successfully retrieved and the defect closed with a larger device. This report discusses this extremely rare association of Brugada syndrome with atrial septal defect, unreported complications after device closure, and successful management of the problem. |
13,960 | Pacing-facilitated proarrhythmia. | The implantable cardioverter-defibrillator (ICD) has been proven to reduce the mortality of patients with life-threatening ventricular arrhythmias, and has become the therapy of choice for patients with aborted sudden cardiac death or poorly tolerated ventricular tachycardias. Abrupt changes in ventricular cycle lengths or short-long-short (S-L-S) sequences might precede the initiation of ventricular tachycardia and ventricular fibrillation. The S-L-S sequences might be passively permitted or actively facilitated by pacing. We present a case of ICD-facilitated ventricular tachycardia. |
13,961 | The quality of cardiopulmonary resuscitation using supraglottic airways and intraosseous devices: a simulation trial. | To assess whether using interventions such as laryngeal mask airways (LMA) and IO lines lead to improved resuscitation in a simulated cardiac arrest when compared to standard methods of endotracheal intubation (ETI) and central line placement.</AbstractText>Emergency Medicine residents at a single academic center were grouped into teams of four. Each team participated in two simulated ventricular fibrillation cardiac arrests using a high fidelity simulator. Peripheral IV access was unobtainable. Only ETI supplies and a central line kit were available in one case (control) and in the other case those supplies were replaced by an LMA and an EZ-IO drill kit (experimental). Groups were randomized to which set up they were given first. Data examined included time to airway placement, duration and success rate of airway placement, time to vascular access, time to defibrillation, and percent hands off time.</AbstractText>44 residents in 11 teams participated. Mean time to airway was shorter in the experimental group (122.8 seconds (s) vs. 265.6 s, p=0.001). Mean duration of airway attempt was also shorter (7.6 s vs. 22.7 s, p=0.002). Time to access was shorter in the experimental group (49.0 s vs. 194.6 s, p=<0.001). Time to defibrillation and percent hands off time did not significantly differ between the two groups.</AbstractText>Use of an LMA and an IO device led to significantly faster establishment of an airway and vascular access in a simulated cardiac arrest. The variation in devices did not affect time to defibrillation or percent hands off time.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
13,962 | Mapping cardiac surface mechanics with structured light imaging. | Cardiovascular disease often manifests as a combination of pathological electrical and structural heart remodeling. The relationship between mechanics and electrophysiology is crucial to our understanding of mechanisms of cardiac arrhythmias and the treatment of cardiac disease. While several technologies exist for describing whole heart electrophysiology, studies of cardiac mechanics are often limited to rhythmic patterns or small sections of tissue. Here, we present a comprehensive system based on ultrafast three-dimensional (3-D) structured light imaging to map surface dynamics of whole heart cardiac motion. Additionally, we introduce a novel nonrigid motion-tracking algorithm based on an isometry-maximizing optimization framework that forms correspondences between consecutive 3-D frames without the use of any fiducial markers. By combining our 3-D imaging system with nonrigid surface registration, we are able to measure cardiac surface mechanics at unprecedented spatial and temporal resolution. In conclusion, we demonstrate accurate cardiac deformation at over 200,000 surface points of a rabbit heart recorded at 200 frames/s and validate our results on highly contrasting heart motions during normal sinus rhythm, ventricular pacing, and ventricular fibrillation. |
13,963 | Pulseless electrical activity after myocardial infarction: not always a left ventricular free wall rupture. | Pulseless electrical activity (PEA) after acute myocardial infarction is classically caused by ventricular free wall rupture. We report the case of a 76-year-old woman who presented a cardiac arrest with PEA 5 days after an embolic acute myocardial infarction. Transthoracic echocardiogram showed a massive mitral regurgitation due to posterior papillary muscle rupture. This case demonstrates that other causes potentially treatable than cardiac tamponade must be sought in patients with PEA after myocardial infarction. |
13,964 | Passive leg raising during cardiopulmonary resuscitation results in improved neurological outcome in a swine model of prolonged ventricular fibrillation. | The objective was to evaluate whether passive leg raising during cardiopulmonary resuscitation in a porcine model of prolonged ventricular fibrillation improves hemodynamics, return of spontaneous circulation, 24-hour survival, and neurological outcome.</AbstractText>Ventricular fibrillation was induced in 20 healthy Landrace/Large White piglets, which were subsequently left untreated for 8 minutes. Ten animals were randomly assigned into the control group and were resuscitated according to the 2005 European Resuscitation Council guidelines, and 10 piglets were assigned into the passive leg raising group and were resuscitated with the legs passively raised at 45° with the aid of a special purpose-made metallic device. End points were either return of spontaneous circulation or asystole.</AbstractText>Return of spontaneous circulation was observed in 6 and 9 animals from the control and the passive leg raising group, respectively (P = .121; odds ratio = 0.16; 95% confidence interval, 0.01-1.87). Just prior to the first defibrillation attempt, coronary perfusion pressure was significantly higher in the passive leg raising group (22.8 ± 9.5 vs 10.6 ± 6.5 mm Hg, P < .004); but no subsequent significant differences were observed. Although all animals that restored spontaneous circulation survived for 24 hours, neurologic alertness score was significantly better in the animals treated with passive leg raising (90 ± 10 vs 76.6 ± 12.1, P = .037).</AbstractText>Passive leg raising during cardiopulmonary resuscitation significantly increased coronary perfusion pressure in the minute prior to the first shock. Return of spontaneous circulation and 24-hour survival rate were comparable between groups. However, the animals in the passive leg raising group exhibited significantly higher neurological scores.</AbstractText>Copyright © 2012 Elsevier Inc. All rights reserved.</CopyrightInformation> |
13,965 | Cross-sectional study of cardiac resynchronization therapy in Spain. Indications, implant techniques, optimization and follow-up. | A cross-sectional study of cardiac resynchronization therapy use in Spain was performed to analyze problems with indications, implantation, and patient follow-up.</AbstractText>Spanish cardiac resynchronization therapy implanter centers were identified, then the department members were surveyed and the data were recorded by each implantation team.</AbstractText>Eighty-eight implanter centers were identified; of these, 85 (96.6%) answered the survey. A total of 2147 device implantations were reported, comprising 85.6% of the overall number of 2518 implantations estimated by the European Confederation of Medical Suppliers Associations for the same period. The reported implantation rate was 46 per million inhabitants versus an estimated implantation rate of 51 per million (European average, 131). Cardiac resynchronization therapy devices accounted for 84% of implantations, and upgrades to previously implanted devices, 16%. The majority of cardiac resynchronization therapy devices were implanted in men (70.7%). The mean age was 68 (12) years, and the mean left ventricular ejection fraction was 26.4% (5%). Most patients (67%) were in New York Heart Association functional class III. The group of patients for whom cardiac resynchronization therapy was indicated according to the latest update of the guidelines was significant: 17.3% among New York Heart Association class II patients and more than 21.6% among patients with atrial fibrillation. In all, electrophysiologists accounted for 73.8% of implanters, followed by surgeons, accounting for 21.4%.</AbstractText>The latest update of the guidelines is being progressively implemented in Spain, according to data obtained in patients in New York Heart Association class II or with atrial fibrillation. Nevertheless, the number of cardiac resynchronization therapy device implants is still well below the European average.</AbstractText>Copyright © 2012 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.</CopyrightInformation> |
13,966 | Oscillation in cycle length induces transient discordant and steady-state concordant alternans in the heart. | Alternans is a beat-to-beat alternation of the cardiac action potential duration (APD) or intracellular calcium (Ca(i)) transient. In cardiac tissue, alternans can be spatially concordant or discordant, of which the latter has been shown to increase dispersion of repolarization and promote a substrate for initiation of ventricular fibrillation. Alternans has been studied almost exclusively under constant cycle length pacing conditions. However, heart rate varies greatly on a beat-by-beat basis in normal and pathological conditions. The purpose of this study was to determine if applying a repetitive but non-constant pacing pattern, specifically cycle length oscillation (CLO), promotes or suppresses a proarrhythmic substrate. We performed computational simulations and optical mapping experiments to investigate the potential consequences of CLO. In a single cell computational model, CLO induced APD and Ca(i) alternans, which became "phase-matched" with the applied oscillation. As a consequence of the phase-matching, in one-dimensional cable simulations, neonatal rat ventricular myocyte monolayers, and isolated adult guinea pig hearts CLO could transiently induce spatial and electromechanical discordant alternans followed by a steady-state of concordance. Our results demonstrated that under certain conditions, CLO can initiate ventricular fibrillation in the isolated hearts. On the other hand, CLO can also exert an antiarrhythmic effect by converting an existing state of discordant alternans to concordant alternans. |
13,967 | Brugada syndrome 2012. | Brugada syndrome (BS) is a cardiac disorder characterized by typical ECG alterations, and it is associated with a high risk for sudden cardiac death (SCD), affecting young subjects with structurally normal hearts. The prevalence of this disorder is still uncertain, presenting marked geographical differences. The syndrome has a genetic basis, and several mutations have been identified in genes encoding subunits of cardiac sodium, potassium, and calcium channels, as well as in genes involved in the trafficking or regulation of these channels. Most BS patients are asymptomatic, but those who develop symptoms present with syncope and/or SCD secondary to polymorphic ventricular tachycardia and/or ventricular fibrillation. Risk stratification is still challenging, especially in cases of asymptomatic BS patients. This is a brief review of recent advances in our understanding of the genetic and molecular bases of BS, arrhythmogenic mechanisms and clinical course, as well as an update of the tools for risk stratification and treatment of the condition. |
13,968 | Adenosine facilitates dormant conduction across cavotricuspid isthmus following catheter ablation. | Recurrence of trans-isthmus conduction following catheter ablation of common right atrial flutter (AFL) has been reported to be as high as 15%-31% at 3 months with invasive follow-up. Intravenous adenosine has previously been shown to facilitate acute, transient reconnection of pulmonary veins following catheter ablation of atrial fibrillation.</AbstractText>To determine whether intravenous adenosine can facilitate dormant trans-isthmus conduction after achieving bidirectional conduction block (BDB) with catheter ablation.</AbstractText>Thirty-two patients underwent radiofrequency catheter ablation of cavotricuspid isthmus (CTI) for common right AFL at 2 institutions. Once persistent BDB was achieved for 30 minutes and during isoproterenol infusion, 18 mg of intravenous adenosine was injected during coronary sinus pacing. Evidence for transient reconduction across the isthmus was observed. Additional ablation lesions were performed, and adenosine infusion was repeated to reassess for dormant conduction.</AbstractText>Thirty-two (men 81%, hypertension 72%, coronary artery disease 15%, congestive heart failure 25%, diabetes mellitus 30%, left atrial size 42 ± 11 mm, left ventricular ejection fraction 51% ± 10%) patients underwent ablation of CTI. BDB was achieved in 30 of the 32 patients. Following adenosine infusion, transient reconduction was observed in 7 of the 30 patients (23%) for 10-45 seconds. Following additional ablation lesions, persistent BDB could be achieved in all 7 patients without evidence for reconduction with repeat adenosine infusion. During a mean follow-up of 19 ± 12 months, only 1 of 30 patients (3%) had clinical recurrence of AFL. None of the patients with transient reconduction after adenosine developed symptomatic recurrence of AFL.</AbstractText>Adenosine infusion can facilitate dormant conduction across CTI following catheter ablation. Persistent BDB can be achieved with additional ablation. Adenosine challenge with additional ablation may improve long-term clinical outcome.</AbstractText>Copyright © 2012. Published by Elsevier Inc.</CopyrightInformation> |
13,969 | A randomized-controlled pilot study comparing ICD implantation with and without intraoperative defibrillation testing in patients with heart failure and severe left ventricular dysfunction: a substudy of the RAFT trial. | The need to perform defibrillation testing (DT) at the time of implantable cardioverter defibrillator (ICD) insertion is controversial. In the absence of randomized trials, some regions now perform more than half of ICD implants without DT.</AbstractText>During the last year of enrolment in the Resynchronization for Ambulatory Heart Failure Trial, a substudy randomized patients to ICD implantation with versus without DT.</AbstractText>Among 252 patients screened, 145 were enrolled; 75 randomized to DT and 70 to no DT. Patients were similar in terms of age (65.9 ± 9.3 years vs 67.9 ± 8.9 years); LVEF (24.7 ± 4.6% vs 23.6 ± 4.6%), QRS width (154.8 ± 23.5 vs 155.8 ± 23.6 ms), and history of atrial fibrillation (5% vs 6%). All 68 patients in the DT arm tested according to the protocol achieved a successful DT (≤25 J); 96% without requiring any system modification. No patient experienced perioperative stroke, myocardial infarction, heart failure (HF), intubation or unplanned ICU stay. The length of hospital stay was not prolonged in the DT group: 20.2 ± 26.3 hours versus 21.3 ± 23.0 hours, P = 0.79. One patient in the DT arm had a failed appropriate shock and no patient suffered an arrhythmic death. The composite of HF hospitalization or all-cause mortality occurred in 10% of patients in the no-DT arm and 19% of patients in the DT arm (HR = 0.53, 95% CI: 0.21-1.31, P = 0.14).</AbstractText>In this randomized trial, perioperative complications, failed appropriate shocks, and arrhythmic death were all uncommon regardless of DT. There was a nonsignificant increase in the risk of death or HF hospitalization with DT.</AbstractText>© 2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,970 | Prognostic value at 5 years of microvascular obstruction after acute myocardial infarction assessed by cardiovascular magnetic resonance. | Early and late microvascular obstruction (MVO) assessed by cardiovascular magnetic resonance (CMR) are prognostic markers for short-term clinical endpoints after acute ST-elevation myocardial infarction (STEMI). However, there is a lack of studies with long-term follow-up periods (>24 months).</AbstractText>STEMI patients reperfused by primary angioplasty (n = 129) underwent MRI at a median of 2 days after the index event. Early MVO was determined on dynamic Gd first-pass images directly after the administration of 0.1 mmol/kg bodyweight Gd-based contrast agent. Furthermore, ejection fraction (EF, %), left ventricular myocardial mass (LVMM) and total infarct size (% of LVMM) were determined with CMR. Clinical follow-up was conducted after a median of 52 months. The primary endpoint was defined as a composite of death, myocardial re-infarction, stroke, repeat revascularization, recurrence of ischemic symptoms, atrial fibrillation, congestive heart failure and hospitalization.</AbstractText>Follow-up was completed by 107 patients. 63 pre-defined events occurred during follow-up. Initially, 74 patients showed early MVO. Patients with early MVO had larger infarcts (mean: 24.9 g vs. 15.5 g, p = 0.002) and a lower EF (mean: 39% vs. 46%, p = 0.006). The primary endpoint occurred in 66.2% of patients with MVO and in 42.4% of patients without MVO (p < 0.05). The presence of early MVO was associated with a reduced event-free survival (log-rank p < 0.05). Early MVO was identified as the strongest independent predictor for the occurrence of the primary endpoint in the multivariable Cox regression analysis adjusting for age, ejection fraction and infarct size (hazard ratio: 2.79, 95%-CI 1.25-6.25, p = 0.012).</AbstractText>Early MVO, as assessed by first-pass CMR, is an independent long-term prognosticator for morbidity after AMI.</AbstractText> |
13,971 | Extracorporeal Life Support After Prolonged Resuscitation for In-Hospital Cardiac Arrest due to Refractory Ventricular Fibrillation: Two Cases Resulting in a Full Recovery. | Extracorporeal life support (ECLS) has well demonstrated its efficacy in treating in-hospital cardiac arrest and is being used for broader indications. However, ECLS after prolonged cardiopulmonary resuscitation (CPR) has been traditionally contraindicated and is now challenging. Here, we introduce two cases of successful ECLS after prolonged CPR, resulting in a immediate and full recovery. Both these acute ST elevation myocardial infarction patients waiting for primary percutaneous coronary intervention (PCI) suddenly collapsed due to ventricular fibrillation (VF), which was refractory to conventional treatment. After 2 hours of conventional CPR, the ECLS had been implemented and primary PCI could be performed. Subsequent to successful revascularization, the VF was stopped with a single electric shock. In our second case, normal sinus rhythm was spontaneously restored after ECLS implementation, which was completed after 45 minutes of conventional resuscitation. Both patients made a full neurological recovery on the day of the event and were discharged with only minor complications. |
13,972 | Videoscopic left cardiac sympathetic denervation for patients with recurrent ventricular fibrillation/malignant ventricular arrhythmia syndromes besides congenital long-QT syndrome. | Treatment options for patients with recurrent ventricular arrhythmias refractory to pharmacotherapy and ablation are minimal. Although left cardiac sympathetic denervation (LCSD) is well established in long-QT syndrome, its role in non-long-QT syndrome arrhythmogenic channelopathies and cardiomyopathies is less clear. Here, we report our single-center experience in performing LCSD in this setting.</AbstractText>In this institutional review board-approved study, we retrospectively reviewed the electronic medical records of all patients (N=91) who had videoscopic LCSD at our institution from 2005 to 2011. Data were analyzed for the subset (n=27) who were denervated for an underlying diagnosis other than autosomal dominant or sporadic long-QT syndrome. The spectrum of arrhythmogenic disease included catecholaminergic polymorphic ventricular tachycardia (n=13), Jervell and Lange-Nielsen syndrome (n=5), idiopathic ventricular fibrillation (n=4), left ventricular noncompaction (n=2), hypertrophic cardiomyopathy (n=1), ischemic cardiomyopathy (n=1), and arrhythmogenic right ventricular cardiomyopathy (n=1). Five patients had LCSD because of high-risk assessment and β-blocker intolerance, none of whom had a sentinel breakthrough cardiac event at early follow-up. Among the remaining 22 previously symptomatic patients who had LCSD as secondary prevention, all had an attenuation in cardiac events, with 18 having no breakthrough cardiac events so far and 4 having experienced ≥1 post-LCSD breakthrough cardiac event.</AbstractText>LCSD may represent a substrate-independent antifibrillatory treatment option for patients with life-threatening ventricular arrhythmia syndromes other than long-QT syndrome. The early follow-up seems promising, with a marked reduction in the frequency of cardiac events postdenervation.</AbstractText> |
13,973 | Predictors of sustained ventricular arrhythmias in cardiac resynchronization therapy. | Patients undergoing cardiac resynchronization therapy (CRT) are at high risk for ventricular arrhythmias (VAs), and risk stratification in this population remains poor.</AbstractText>This study followed 269 patients (left ventricular ejection fraction <35%; QRS >120 ms; New York Heart Association class III/IV) undergoing CRT with a defibrillator for 553±464 days after CRT with defibrillator implantation to assess for independent predictors of appropriate device therapy for VAs. Baseline medication use, medical comorbidities, and echocardiographic parameters were considered. The 4-year incidence of appropriate device therapy was 36%. A Cox proportional hazard model identified left ventricular end-systolic diameter >61 mm as an independent predictor in the entire population (hazard ratio [HR], 2.66; P=0.001). Those with left ventricular end-systolic diameter >61 mm had a 51% 3-year incidence of VA compared with a 26% incidence among those with a less dilated ventricle (P=0.001). Among patients with left ventricular end-systolic diameter ≤61 mm, multivariate predictors of appropriate therapy were absence of β-blocker therapy (HR, 6.34; P<0.001), left ventricular ejection fraction <20% (HR, 4.22; P<0.001), and history of sustained VA (HR, 2.97; P=0.013). Early (<180 days after implant) shock therapy was found to be a robust predictor of hospitalization for heart failure (HR, 3.41; P<0.004) and mortality (HR, 5.16; P<0.001.)</AbstractText>Among patients with CRT and a defibrillator, left ventricular end-systolic diameter >61 mm is a powerful predictor of VAs, and further risk stratification of those with less dilated ventricles can be achieved based on assessment of ejection fraction, history of sustained VA, and absence of β-blocker therapy.</AbstractText> |
13,974 | Use of antiarrhythmic drugs in elderly patients. | Human aging is a global issue with important implications for current and future incidence and prevalence of health conditions and disability. Cardiac arrhythmias, including atrial fibrillation, sudden cardiac death, and bradycardia requiring pacemaker placement, all increase exponentially after the age of 60. It is important to distinguish between the normal, physiological consequences of aging on cardiac electrophysiology and the abnormal, pathological alterations. The age-related cardiac changes include ventricular hypertrophy, senile amyloidosis, cardiac valvular degenerative changes and annular calcification, fibrous infiltration of the conduction system, and loss of natural pacemaker cells and these changes could have a profound effect on the development of arrhythmias. The age-related cardiac electrophysiological changes include up- and down-regulation of specific ion channel expression and intracellular Ca(2+) overload which promote the development of cardiac arrhythmias. As ion channels are the substrates of antiarrhythmic drugs, it follows that the pharmacokinetics and pharmacodynamics of these drugs will also change with age. Aging alters the absorption, distribution, metabolism, and elimination of antiarrhythmic drugs, so liver and kidney function must be monitored to avoid potential adverse drug effects, and antiarrhythmic dosing may need to be adjusted for age. Elderly patients are also more susceptible to the side effects of many antiarrhythmics, including bradycardia, orthostatic hypotension, urinary retention, and falls. Moreover, the choice of antiarrhythmic drugs in the elderly patient is frequently complicated by the presence of co-morbid conditions and by polypharmacy, and the astute physician must pay careful attention to potential drug-drug interactions. Finally, it is important to remember that the use of antiarrhythmic drugs in elderly patients must be individualized and tailored to each patient's physiology, disease processes, and medication regimen. |
13,975 | Oxidative Stress and Microcirculatory Flow Abnormalities in the Ventricles during Atrial Fibrillation. | Patients with atrial fibrillation (AF) often present with typical angina pectoris and mildly elevated levels of cardiac troponin (non-ST-segment elevation myocardial infarction) during an acute episode of AF. However, in a large proportion of these patients, significant coronary artery disease is excluded by coronary angiography, which suggests that AF itself influences myocardial blood flow. The present review summarizes the effect of AF on the occurrence of ventricular oxidative stress, redox-sensitive signaling pathways and gene expression, and microcirculatory flow abnormalities in the left ventricle. |
13,976 | The occurrence of cardiovascular disease during 5-year follow-up in patients with idiopathic atrial fibrillation. | Idiopathic atrial fibrillation (AF) may be an expression of as yet undetected underlying heart disease. We found it useful for clinical practice to study the long-term development of cardiovascular disease (CVD) in patients diagnosed with idiopathic AF.</AbstractText>Forty-one consecutive idiopathic AF patients (56 ± 10 years, 66% male) were compared with 45 healthy control patients in permanent sinus rhythm. Patients were free of hypertension, antihypertensive and antiarrhythmic drugs, diabetes, congestive heart failure, coronary artery or peripheral vascular disease, previous stroke, thyroid, pulmonary and renal disease, and structural abnormalities on echocardiography. Baseline characteristics and echocardiographic parameters were equal in AF cases and controls. During a mean follow-up of 66 ± 11 months, CVD occurred significantly more often in idiopathic AF patients compared with controls (49 vs. 20%, P= 0.006). Patients with idiopathic AF were significantly younger at the time of their first CV event compared with controls (59 ± 9 vs. 64 ± 5 years, P= 0.027), and had more severe disease. Multivariable Cox regression analysis revealed that age, a history of AF, and echocardiographic left ventricular wall width were significant predictors of CVD development.</AbstractText>Patients originally diagnosed with idiopathic AF develop CVD more often, at younger age, and with a more severe disease profile compared with healthy sinus rhythm control patients. The detection and treatment of CVD in an early stage could improve the prognosis of these patients. At present it seems prudent to regularly check idiopathic AF patients for the insidious development of CVD.</AbstractText> |
13,977 | Clinical implications of provocation tests for coronary artery spasm: safety, arrhythmic complications, and prognostic impact: multicentre registry study of the Japanese Coronary Spasm Association. | Provocation tests of coronary artery spasm are useful for the diagnosis of vasospastic angina (VSA). However, these tests are thought to have a potential risk of arrhythmic complications, including ventricular tachycardia (VT), ventricular fibrillation (VF), and brady-arrhythmias. We aimed to elucidate the safety and the clinical implications of the spasm provocation tests in the nationwide multicentre registry study by the Japanese Coronary Spasm Association.</AbstractText>A total of 1244 VSA patients (M/F, 938/306; median 66 years) who underwent the spasm provocation tests were enrolled from 47 institutes. The primary endpoint was defined as major adverse cardiac events (MACEs). The provocation tests were performed with either acetylcholine (ACh, 57%) or ergonovine (40%). During the provocation tests, VT/VF and brady-arrhythmias developed at a rate of 3.2 and 2.7%, respectively. Overall incidence of arrhythmic complications was 6.8%, a comparable incidence of those during spontaneous angina attack (7.0%). Multivariable logistic regression analysis demonstrated that diffuse right coronary artery spasm (P < 0.01) and the use of ACh (P < 0.05) had a significant correlation with provocation-related VT/VF. During the median follow-up of 32 months, 69 patients (5.5%) reached the primary endpoint. The multivariable Cox proportional hazard model revealed that mixed (focal plus diffuse) type multivessel spasm had an important association with MACEs (adjusted hazard ratio, 2.84; 95% confidence interval, 1.34-6.03; P < 0.01), whereas provocation-related arrhythmias did not.</AbstractText>The spasm provocation tests have an acceptable level of safety and the evaluation of spasm type may provide useful information for the risk prediction of VSA patients.</AbstractText> |
13,978 | Current issues in atrial fibrillation. | Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. It places an enormous burden on the patients, caregivers, and the society at large. While the main themes in the care of an AF patient have not changed over the years and continue to focus on stroke prevention, control of the ventricular, rate and rhythm maintenance, there have been a number of new developments in each of these realms. This paper will discuss the "hot" topics in AF in 2012 including new and upcoming medical and invasive management strategies for this condition. |
13,979 | Ankyrin-B protein in heart failure: identification of a new component of metazoan cardioprotection. | Ankyrins (ankyrin-R, -B, and -G) are adapter proteins linked with defects in metazoan physiology. Ankyrin-B (encoded by ANK2) loss-of-function mutations are directly associated with human cardiovascular phenotypes including sinus node disease, atrial fibrillation, ventricular tachycardia, and sudden cardiac death. Despite the link between ankyrin-B dysfunction and monogenic disease, there are no data linking ankyrin-B regulation with common forms of human heart failure. Here, we report that ankyrin-B levels are altered in both ischemic and non-ischemic human heart failure. Mechanistically, we demonstrate that cardiac ankyrin-B levels are tightly regulated downstream of reactive oxygen species, intracellular calcium, and the calcium-dependent protease calpain, all hallmarks of human myocardial injury and heart failure. Surprisingly, β(II)-spectrin, previously thought to mediate ankyrin-dependent modulation in the nervous system and heart, is not coordinately regulated with ankyrin-B or its downstream partners. Finally, our data implicate ankyrin-B expression as required for vertebrate myocardial protection as hearts deficient in ankyrin-B show increased cardiac damage and impaired function relative to wild-type mouse hearts following ischemia reperfusion. In summary, our findings provide the data of ankyrin-B regulation in human heart failure, provide insight into candidate pathways for ankyrin-B regulation in acquired human cardiovascular disease, and surprisingly, implicate ankyrin-B as a molecular component for cardioprotection following ischemia. |
13,980 | How to improve flow during cardiopulmonary bypass in an acardia experimental model. | OBJECTIVES In extreme scenarios, such as hyperacute rejection of heart transplant, an urgent heart explantation might be necessary. The aim of this experimental study was to determine the feasibility and to improve the haemodynamics of a venoarterial cardiopulmonary bypass after cardiectomy. METHODS A venoarterial cardiopulmonary bypass was established in seven calves (56.4 ± 7 kg) by the transjugular insertion to the caval axis of a self-expanding cannula, with a carotid artery return. After baseline measurements (A), ventricular fibrillation was induced (B), great arteries were clamped (C), the heart was excised and the right and left atria remnants, containing the pulmonary veins, were sutured together leaving an atrial septal defect over the cannula in the caval axis (D). Measurements were taken with the pulmonary artery clamped and declamped. RESULTS Initial pump flow was 4.16 ± 0.75 l/min dropping to 2.9 ± 0.63 l/min (P(AB )< 0.001) 10 min after induction of ventricular fibrillation. After cardiectomy with the pulmonary artery clamped, the pump flow increased non-significantly to 3.20 ± 0.78 l/min. After declamping, the flow significantly increased close to baseline levels (3.61 ± 0.73 l/min, P(DB )= 0.009, P(DC )= 0.017), supporting the notion that full cardiopulmonary bypass in acardia is feasible only if adequate drainage of pulmonary circulation is assured to avoid pulmonary congestion and loss of volume from the left-to-right shunt of bronchial vessels. |
13,981 | The effect of spironolactone on ventricular tachyarrhythmias in patients with implantable cardioverter-defibrillators. | Previous studies have suggested that aldosterone blockade can reduce the incidence of ventricular tachycardia (VT) or ventricular fibrillation (VF) in patients with heart failure. The SPIronolactone to Reduce ICD Therapy (SPIRIT) trial was designed to test the hypothesis that spironolactone reduces the incidence of VT/VF in patients with implantable cardioverter-defibrillators (ICDs) who are at moderately high risk for recurrent VT/VF.</AbstractText>Ninety patients who had ICDs who were at moderately high risk for recurrent VT/VF and who were not candidates for spironolactone by current heart failure guidelines were randomized to receive spironolactone 25 mg daily or placebo in a double-blind fashion. All patients had previously received ICD therapy (shock or antitachycardia pacing) for VT/VF within 2 years of randomization or an ICD for secondary prevention of VT/VF within 6 months of randomization. The primary end point was time to first recurrence of VT/VF requiring ICD therapy. After a median follow-up of 35 months, the Kaplan-Meier probability estimates for VT/VF requiring ICD therapy were 68.7% in the placebo group and 84.7% in the spironolactone group. Compared with placebo, spironolactone was associated with a similar risk of VT/VF (hazard ratio, 1.01; 95% CI, 0.64-1.83; P=0.71). There was no significant difference between the median times to first VT/VF recurrence requiring ICD therapy in the 2 groups.</AbstractText>In patients with ICDs who were at moderately high risk for recurrent VT/VF on account of a recent VT/VF event that was either sustained or treated by the ICD and who were not candidates for spironolactone by current heart failure guidelines, spironolactone did not delay the first recurrence of VT/VF or reduce the risk of recurrent VT/VF.</AbstractText> |
13,982 | Cardioprotective effect of δ-opioid receptor agonist vs. mild therapeutic hypothermia in a rat model of cardiac arrest with extracorporeal life support. | To compare the effect of δ-opioid receptor agonist, d-Ala2-d-Leu5 enkephalin (DADLE) with normothermic control and therapeutic hypothermia on post resuscitation myocardial function in a model of extracorporeal life support (ECLS).</AbstractText>Ventricular fibrillation (VF) was induced in male Wistar rats. After 10 min of untreated VF, venoarterial ECLS was instituted for 60 min. At the beginning of ECLS animals were randomized to three groups of ten: normothermia, hypothermia (32 °C) and DADLE intravenous infusion (1 mg/kg/h). Cooling to 32 °C or normothermia or drug infusion lasted for the entire ECLS. Plasma samples and myocardial biopsies were obtained and left-ventricular (LV) function was assessed by a conductance catheter at baseline and after weaning from ECLS.</AbstractText>DADLE administration resulted in a significantly enhanced recovery of LV systolic function expressed by slope of the LV end-systolic pressure volume relationship (Ees) and preload recruitable stroke work (PRSW) than hypothermia and normothermia. LV stiffness indicated by end-diastolic pressure volume relationship (EDPVR) was significantly lower after DADLE administration (P<0.01). LV relaxation described by Tau was preserved after DADLE treatment but not after normothermia or mild hypothermia (P<0.01). Plasma lactate concentrations were lower in DADLE group (P<0.05). DADLE and not conventional hypothermia significantly increased phosphorylation of the kinases ERK1 and 2 (3.9±0.3 and 3.1±0.5 vs. 0.4±0.1 and 0.3±0.1-fold of baseline levels) (P<0.001). Both DADLE and hypothermia but not normothermia increase phosphorylation of Akt.</AbstractText>DADLE was more effective than mild therapeutic hypothermia in recovering myocardial function and activation of the pro-survival kinases Akt and ERK after ECLS.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
13,983 | Comparison of shock-first strategy and cardiopulmonary resuscitation-first strategy in a porcine model of prolonged cardiac arrest. | The choice of a shock-first or a cardiopulmonary resuscitation (CPR)-first strategy in the treatment of prolonged cardiac arrest (CA) is still controversial. The purpose of this study was to compare the effects of these strategies on oxygen metabolism and resuscitation outcomes in a porcine model of 8min CA.</AbstractText>Ventricular fibrillation (VF) was electrically induced. After 8min of untreated VF, 24 male inbred Wu-Zhi-Shan miniature pigs were randomized to receive either defibrillation first (ID group) or chest compression first (IC group). In the ID group, a shock was delivered immediately. If the defibrillation attempt failed to attain restoration of spontaneous circulation (ROSC), manual chest compressions were rapidly initiated at a rate of 100compressionsmin(-1), and the compression-to-ventilation ratio was 30:2. If VF persisted after five cycles of CPR, a second defibrillation attempt was made. In the IC group, chest compressions were delivered first, followed by a shock.</AbstractText>Hemodynamic variables, the VF waveform and blood gas analysis outcomes were recorded. Oxygen metabolism parameters and the amplitude spectrum area (AMSA) of the VF waveform were computed. There were no significant differences in the rate of ROSC and 24h survival between two groups. The ID group had lower lactic acid levels, higher cardiac output, better oxygen consumption and better oxygen extraction ratio at 4 and 6h after ROSC than the IC group.</AbstractText>In a porcine model of prolonged CA, the choice of a shock-first or CPR-first strategy did not affect the rate of ROSC and 24h survival, but the shock-first strategy might result in better hemodynamic status and better oxygen metabolism than the CPR-first strategy at the first 6h after ROSC.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
13,984 | Amiodarone versus lidocaine and placebo for the prevention of ventricular fibrillation after aortic crossclamping: a randomized, double-blind, placebo-controlled trial. | Ventricular fibrillation occurs commonly after aortic crossclamping in patients undergoing cardiac surgery. Ventricular fibrillation increases myocardial oxygen consumption, and defibrillation may harm the myocardium. Thus, a pharmacologic approach to decreasing the incidence of ventricular fibrillation or the number of shocks required may be beneficial. The goal of this study was to evaluate whether amiodarone or lidocaine was superior to placebo for the prevention of ventricular fibrillation after aortic crossclamping in patients undergoing a variety of cardiac surgical procedures.</AbstractText>Patients undergoing cardiac surgery requiring aortic crossclamping were randomized to receive lidocaine 1.5 mg/kg, amiodarone 300 mg, or placebo before aortic crossclamp removal The primary outcomes were the incidence of ventricular fibrillation and the number of shocks required to terminate ventricular fibrillation.</AbstractText>A total of 342 patients completed the trial. On multivariate analysis, there was no difference in the incidence of ventricular fibrillation among treatment groups. The number of required shocks was categorized as 0, 1 to 3, and greater than 3. On multivariate analysis, patients receiving amiodarone required fewer shocks to terminate ventricular fibrillation (odds ratio, 0.51; 95% confidence interval, 0.31-0.83; P = .008 vs placebo). There was no difference between lidocaine and placebo in the number of required shocks (odds ratio, 0.86; 95% confidence interval, 0.52-1.41; P = .541).</AbstractText>In patients undergoing a variety of cardiac surgical procedures, neither amiodarone nor lidocaine reduced the incidence of ventricular fibrillation. Amiodarone decreased the number of shocks required to terminate ventricular fibrillation.</AbstractText>Copyright © 2012 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.</CopyrightInformation> |
13,985 | Early and simple detection of diastolic dysfunction during weaning from mechanical ventilation. | Weaning from mechanical ventilation imposes additional work on the cardiovascular system and can provoke or unmask left ventricular diastolic dysfunction with consecutive pulmonary edema or systolic dysfunction with inadequate increase of cardiac output and unsuccessful weaning. Echocardiography, which is increasingly used for hemodynamic assessment of critically ill patients, allows differentiation between systolic and diastolic failure. For various reasons, transthoracic echocardiographic assessment was limited to patients with good echo visibility and to those with sinus rhythm without excessive tachycardia. In these patients, often selected after unsuccessful weaning, echocardiographic findings were predictive for weaning failure of cardiac origin. In some studies, patients with various degrees of systolic dysfunction were included, making evaluation of the diastolic dysfunction to the weaning failure even more difficult. The recent study by Moschietto and coworkers included unselected patients and used very simple diastolic variables for assessment of diastolic function. They also included patients with atrial fibrillation and repeated echocardiographic examination only 10 minutes after starting a spontaneous breathing trial. The main finding was that weaning failure was not associated with systolic dysfunction but with diastolic dysfunction. By measuring simple and robust parameters for detection of diastolic dysfunction, the study was able to predict weaning failure in patients with sinus rhythm and atrial fibrillation as early as 10 minutes after beginning a spontaneous breathing trial. Further studies are necessary to determine whether appropriate treatment tailored according to the echocardiographic findings will result in successful weaning. |
13,986 | Antitachycardia pacing reduces appropriate and inappropriate shocks in children and congenital heart disease patients. | Antitachycardia pacing (ATP) can reduce implantable cardioverter-defibrillator shocks, but its use in children and patients with congenital heart disease (CHD) is not well described.</AbstractText>To review the efficacy of ATP in children and patients with CHD.</AbstractText>We reviewed implantable cardioverter-defibrillator therapies in children and patients with CHD (aged 2-52 years) at our institution. Appropriate therapies were defined as those delivered for true ventricular tachycardia (VT) or ventricular fibrillation; other therapies were defined as inappropriate.</AbstractText>During a median follow-up of 4 years (range 0.5-15 years), 17 of 79 patients (23%) received appropriate therapy and 14 received ATP for 100 episodes of VT. ATP was highly successful (88%) in terminating VT, and only 10 of 100 episodes required a shock. Shocks were effective in terminating VT/ventricular fibrillation in 21 of 24 episodes (87%). The outcomes of appropriate therapy were similar for ATP and shocks (success 88% vs 87%, failure 9% vs 8%, acceleration 3% vs 4% for ATP and shocks, respectively). Thirty-one patients (39%) received inappropriate therapy. Inappropriate ATP (without subsequent shocks) was delivered to 11 patients for the following: sinus tachycardia (19 episodes in 7 patients) with slowing of the rate after ATP, T-wave oversensing (2 episodes in 2 patients) with loss of oversensing after ATP, and reentrant supraventricular tachycardia (14 episodes in 2 patients) terminated with ventricular ATP.</AbstractText>ATP is highly efficacious for VT in children and patients with CHD. In addition to reducing appropriate shocks, inappropriate shocks due to sinus or supraventricular tachycardia can be significantly reduced with ATP.</AbstractText>Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
13,987 | Polymorphic ventricular tachycardia in a patient with hypertrophic cardiomyopathy and digitalis intoxication. | We report the case of a 74-year-old woman who presented with recurrent episodes of polymorphic ventricular tachycardia (PVT) with a normal QT interval due to digitalis intoxication (serum digoxin concentration, 5.0 ng/mL) and severe hyperkalemia (serum potassium level, 8.3 mEq/L). In addition, laboratory data showed elevated levels of blood urea nitrogen (54 mg/dL) and serum creatinine (1.57 mg/dL), suggesting dehydration. She had been treated with a combination of digoxin and eplerenone for atrial fibrillation and heart failure. The PVT resolved after treatment for hyperkalemia. Cardiac magnetic resonance imaging and left ventriculography showed left ventricular hypertrophy predominantly in the apex, suggesting apical hypertrophic cardiomyopathy (HCM). We presume that the presence of HCM was related to the occurrence of PVT in this patient with digitalis intoxication and hyperkalemia. <<b>Learning objective:</b> PVT with a normal QT interval caused by digitalis intoxication with hyperkalemia was observed in a patient with HCM treated with digoxin and eplerenone for atrial fibrillation and heart failure. The presence of HCM may be related to the occurrence of PVT. Combination therapy with digoxin and aldosterone receptor antagonist may predispose severe hyperkalemia, and monitoring of serum digitalis concentration and potassium level should be done strictly.>. |
13,988 | Effect of nebivolol on outcome in elderly patients with heart failure and atrial fibrillation: insights from SENIORS. | Beneficial effects of beta-blockade remain unclear in heart failure patients who have atrial fibrillation (AF), especially in the elderly. We evaluated the effect of nebivolol on cardiovascular outcomes in elderly patients with heart failure and AF.</AbstractText>The SENIORS trial showed an overall benefit of nebivolol compared with placebo in 2128 heart failure patients >70 years of age. At baseline, AF was present in 738 (34.7%) patients. The primary outcome was all-cause mortality or cardiovascular hospitalizations. After 21 months, the cumulative incidence of the primary outcome was significantly more common in patients with AF compared with those with sinus rhythm (38.5% vs. 30.4%, respectively, P < 0.001). In patients with AF, nebivolol had no beneficial effect on the primary outcome [nebivolol vs. placebo, 37.1% vs. 39.8%, hazard ratio (HR) 0.92, 95% confidence interval (CI), 0.73-1.17, P = 0.46], in contrast to patients with sinus rhythm (28.1% vs. 32.9%, in the nebivolol vs. placebo group, respectively, HR 0.82, 95% CI 0.67-0.99, P = 0.049). In patients with AF, the primary outcome was similar in the impaired and preserved left ventricular ejection fraction (LVEF) groups (39.0% with LVEF ≤ 35% vs. 37.3% in patients with LVEF > 35%). There was also no evidence of benefit of nebivolol in AF patients stratified by LVEF.</AbstractText>Nebivolol failed to improve outcomes in elderly patients with stable heart failure and co-existing AF, irrespective of LVEF. Furthermore, in patients with AF, outcome was comparable between patients with preserved and impaired LVEF.</AbstractText> |
13,989 | Sodium current deficit and arrhythmogenesis in a murine model of plakophilin-2 haploinsufficiency. | The shRNA-mediated loss of expression of the desmosomal protein plakophilin-2 leads to sodium current (I(Na)) dysfunction. Whether pkp2 gene haploinsufficiency leads to I(Na) deficit in vivo remains undefined. Mutations in pkp2 are detected in arrhythmogenic right ventricular cardiomyopathy (ARVC). Ventricular fibrillation and sudden death often occur in the 'concealed phase' of the disease, prior to overt structural damage. The mechanisms responsible for these arrhythmias remain poorly understood. We sought to characterize the morphology, histology, and ultrastructural features of PKP2-heterozygous-null (PKP2-Hz) murine hearts and explore the relation between PKP2 abundance, I(Na) function, and cardiac electrical synchrony.</AbstractText>Hearts of PKP2-Hz mice were characterized by multiple methods. We observed ultrastructural but not histological or gross anatomical differences in PKP2-Hz hearts compared with wild-type (WT) littermates. Yet, in myocytes, decreased amplitude and a shift in gating and kinetics of I(Na) were observed. To further unmask I(Na) deficiency, we exposed myocytes, Langendorff-perfused hearts, and anaesthetized animals to a pharmacological challenge (flecainide). In PKP2-Hz hearts, the extent of flecainide-induced I(Na) block, impaired ventricular conduction, and altered electrocardiographic parameters were larger than controls. Flecainide provoked ventricular arrhythmias and death in PKP2-Hz animals, but not in the WT.</AbstractText>PKP2 haploinsufficiency leads to I(Na) deficit in murine hearts. Our data support the notion of a cross-talk between desmosome and sodium channel complex. They also suggest that I(Na) dysfunction may contribute to generation and/or maintenance of arrhythmias in PKP2-deficient hearts. Whether pharmacological challenges could help unveil arrhythmia risk in patients with mutations or variants in PKP2 remains undefined.</AbstractText> |
13,990 | Increased left ventricular myocardial mass is associated with arrhythmias after cardiac surgery. | The purpose of this study was to investigate whether patients with an elevated left ventricular mass index undergoing cardiac surgery were more likely to experience postoperative atrial and ventricular arrhythmias.</AbstractText>A retrospective analysis.</AbstractText>A single tertiary care university hospital.</AbstractText>One thousand consecutive patients undergoing all types of adult cardiac surgery.</AbstractText>With institutional review board approval, intraoperative transesophageal echocardiographic images were reviewed by a single reviewer. The left ventricular mass index was calculated using the American Society of Echocardiography-recommended formula. Medical charts were reviewed for the occurrence and type of clinically significant postoperative arrhythmias.</AbstractText>Of the patients who had an elevated left ventricular mass index, 47.6% (225/473) developed clinically significant postoperative arrhythmias compared with 38.3% (142/371) of patients with a normal left ventricular mass index (odds ratio [OR] = 1.46; 95% confidence interval [CI], 1.11-1.93; p = 0.007). In the multivariate analysis, this finding remained statistically significant, controlling for the effects of age, weight, sex, surgery type, left ventricular function, functional status, left atrial dimensions, and a history of atrial fibrillation (OR = 1.40; 95% CI, 1.03-1.90 per 100-g/m(2) increase in the left ventricular mass index). An increased left ventricular mass index was also an independent predictor of the separate or combined occurrence of atrial or ventricular arrhythmias.</AbstractText>An elevated left ventricular mass index was a strong independent predictor of clinically significant postoperative atrial and ventricular arrhythmias after adult cardiac surgery. Although prospective validation is required, targeting patients for arrhythmia prophylaxis therapy may be justified in patients with a left ventricular mass index >188 g/m(2).</AbstractText>Copyright © 2013 Elsevier Inc. All rights reserved.</CopyrightInformation> |
13,991 | Index-beat assessment of left ventricular systolic and diastolic function during atrial fibrillation using myocardial strain and strain rate. | Accurate assessment of left ventricular (LV) function in patients with atrial fibrillation (AF) remains difficult, mainly because of the beat-to-beat variability of many echocardiographic parameters. The aim of this study was to assess the hypothesis that LV function can be estimated from an index-beat echocardiographic assessment in patients with AF using myocardial strain and strain rate.</AbstractText>A prospective study was conducted to assess 25 patients with AF (mean age, 66 ± 10 years). Peak systolic longitudinal strain (LS) and peak diastolic longitudinal strain rate (dSR) were measured using two different methods: (1) mean LS and dSR, the averages of instantaneous LS and dSR over 10 sec, and (2) index-beat LS and dSR, calculated when the ratio of the preceding (RR1) to the pre-preceding (RR2) interval was 1 (range, 0.96-1.04). These variables were compared with simultaneously measured LV pressure parameters using Millar catheters.</AbstractText>There was a positive linear relationship between mean LS and index-beat LS at RR1/RR2 = 1 (r = 0.94, P < .001) and a positive linear relationship between mean dSR and index-beat dSR (r = 0.69, P < .001). Index-beat LS was correlated with the maximal positive derivative of LV pressure (peak +dP/dt) (r = -0.73, P < .001). Index-beat dSR was correlated with the time constant of isovolumic LV pressure decay (τ) (r = -0.63, P < .001). To investigate the independent predictors of τ, a stepwise multilinear regression analysis showed that index-beat dSR was the best predictor of τ.</AbstractText>Index-beat parameters accurately reflect the mean values of parameters in patients with AF. These noninvasively obtained index-beat parameters are useful to assess surrogate LV function even in patients with AF.</AbstractText>Copyright © 2012 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.</CopyrightInformation> |
13,992 | Measuring left ventricular peak longitudinal systolic strain from a single beat in atrial fibrillation: validation of the index beat method. | It is traditionally difficult to estimate left ventricular (LV) systolic function in atrial fibrillation (AF). The aim of this study was to validate the use of an index beat, the beat after the nearly equal preceding (RR1) and pre-preceding (RR2) intervals, for the measurement of LV peak longitudinal systolic strain (PLSS). The difference between RR1 and RR2 intervals of the index beat must be <60 msec. LV PLSS measured from the index beat (PLSSindex) was compared with LV PLSS measured from the conventional but time-consuming method of averaging multiple cardiac cycles (PLSSavg).</AbstractText>Ninety-eight patients with persistent or permanent AF and resting ventricular rates ≤ 105 beats/min were prospectively included. LV PLSSindex and LV PLSSavg were obtained from two-dimensional speckle-tracking echocardiography.</AbstractText>LV PLSSindex had a highly significant correlation with LV PLSSavg (r = 0.970, P < .001). Bland-Altman analysis showed only small bias of 0.01%, and the 95% limits of agreement were +1.64% to -1.62%. Compared with those with lower risk scores of stroke indicated by CHADS(2) scores < 2 or CHA(2)DS(2)-VASc scores < 2, patients with higher risk scores of stroke indicated by CHADS(2) scores ≥ 2 or CHA(2)DS(2)-VASc scores ≥ 2 had lower PLSSavg and PLSSindex (P ≤ .012).</AbstractText>LV PLSSindex was a good alternative to LV PLSSavg in patients with AF. Use of the index beat to measure LV longitudinal systolic strain in patients with AF was as accurate as the time-consuming method of averaging multiple cardiac cycles.</AbstractText>Copyright © 2012 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.</CopyrightInformation> |
13,993 | Ventricular fibrillation as primary presentation of takotsubo cardiomyopathy after complicated cesarean delivery. | Takotsubo cardiomyopathy typically affects post-menopausal women under severe psychological or physical stress; it also has been reported to develop after medical procedures or surgery. We herein report the rare case of a 30-year-old woman who presented with an episode of ventricular fibrillation after a very complicated cesarean delivery and was successfully resuscitated. Subsequent electrocardiography and echocardiography showed a typical Takotsubo pattern. Within 3 wk, left ventricular systolic function returned to normal. |
13,994 | Heparin does not improve graft function in uncontrolled non-heart-beating lung donation: an experimental study in pigs. | Non-heart-beating donation (NHBD) has the potential to increase the number of patients treated with lung transplantation. Our study investigated, in a simulated clinical situation in the uncontrolled NHBD setting, whether or not heparin administration after death affects the donor lung function.</AbstractText>Twelve Swedish domestic pigs underwent ventricular fibrillation and were left untouched for 7 min followed by cardiopulmonary resuscitation with mechanical compressions for 20 min. The animals were declared dead after a 'hands-off' period of 10 min and randomized to heparin (300 IU/kg) or placebo given into a central venous catheter. In the animals receiving heparin, 2 more minutes of chest compression followed. Intrapleural cooling was initiated 1 h after death, and prevailed for 2 h. Ex vivo lung perfusion (EVLP) was performed with the Vivoline(®) system. Lung function was evaluated with blood gases at different oxygen levels, pulmonary vascular resistance (PVR), wet/dry weight ratio, macroscopic appearance and histology.</AbstractText>During EVLP, there were no significant differences between groups in PaO(2) or PVR at any investigated FiO(2) level (1.0, 0.5 or 0.21). At FiO(2) 1.0 the PaO(2) in the heparin group was 64 ± 2 (range 57-73) kPa and in the non-heparin group 63 ± 4 (range 51-71) kPa. The values for PVR were 592 ± 90 (range 402-1007) and 647 ± 97 (range 426-1044), respectively. There was no significant difference between groups in wet/dry ratio or histology.</AbstractText>The use of heparin is of no obvious benefit to the donor lungs in the uncontrolled NHBD situation. The exclusion of heparin will simplify lung donation from NHBDs.</AbstractText> |
13,995 | Comparison of intravenous and oral magnesium replacement in hospitalized patients with cardiovascular disease. | The results of an investigation of serum magnesium concentrations (SMCs) after i.v. versus oral delivery of magnesium in cardiovascular critical care are presented.</AbstractText>A retrospective case review was conducted to compare the net gain of magnesium after i.v. (n = 188) or oral (n = 164) magnesium therapy for the prevention of ventricular fibrillation and arrhythmias in patients hospitalized for serious cardiovascular disorders, as determined by assessing SMCs. The primary study outcome was the change from baseline SMC values 6-24 hours after the completion of magnesium courses; secondary outcomes included the impact of renal impairment, concomitant medication use, and other clinical variables on SMC changes.</AbstractText>Although consistent elevations in SMC were produced by oral magnesium delivery, i.v. administration resulted in greater and more rapid elevations relative to baseline SMC. The degree of change in SMC was significantly influenced by the timing of SMC measurement after a magnesium course, by renal function, and by concomitant use of i.v. loop diuretics.</AbstractText>A comparison of 24-hour courses of magnesium replacement therapy showed that magnesium sulfate 2 g i.v. was associated with larger changes in SMC than magnesium oxide 800, 1200, or 1600 mg orally when the baseline SMC was 1.4-1.8 mg/dL. At baseline SMCs of 1.4-1.8 mg/dL, oral magnesium oxide provided a consistent median increase in SMC of 0.1 mg/dL. The change in the number of bowel movements did not differ significantly between courses of i.v. magnesium sulfate and oral magnesium oxide.</AbstractText> |
13,996 | The role of fine-scale anatomical structure in the dynamics of reentry in computational models of the rabbit ventricles. | Fine-scale anatomical structures in the heart may play an important role in sustaining cardiac arrhythmias. However, the extent of this role and how it may differ between species are not fully understood. In this study we used computational modelling to assess the impact of anatomy upon arrhythmia maintenance in the rabbit ventricles. Specifically, we quantified the dynamics of excitation wavefronts during episodes of simulated tachyarrhythmias and fibrillatory arrhythmias, defined as being respectively characterised by relatively low and high spatio-temporal disorganisation.Two computational models were used: a highly anatomically detailed MR-derived rabbit ventricular model (representing vasculature, endocardial structures) and a simplified equivalent model, constructed from the same MR-data but lacking such fine-scale anatomical features. During tachyarrhythmias, anatomically complex and simplified models showed very similar dynamics; however, during fibrillatory arrhythmias, as activation wavelength decreased, the presence of fine-scale anatomical details appeared to marginally increase disorganisation of wavefronts during arrhythmias in the complex model. Although a small amount of clustering of reentrant rotor centres (filaments) around endocardial structures was witnessed in follow-up analysis (which slightly increased during fibrillation as rotor size decreased), this was significantly less than previously reported in large animals. Importantly, no anchoring of reentrant rotors was visibly identifiable in arrhythmia movies. These differences between tachy- and fibrillatory arrhythmias suggest that the relative size of reentrant rotors with respect to anatomical obstacles governs the influence of fine-scale anatomy in the maintenance of ventricular arrhythmias in the rabbit. In conclusion, our simulations suggest that fine-scale anatomical features play little apparent role in the maintenance of tachyarrhythmias in the rabbit ventricles and, contrary to experimental reports in larger animals, appear to play only a minor role in the maintenance of fibrillatory arrhythmias. These findings also have important implications in optimising the level of detail required in anatomical computational meshes frequently used in arrhythmia investigations. |
13,997 | Association of pulse pressure with new-onset atrial fibrillation in patients with hypertension and left ventricular hypertrophy: the Losartan Intervention For Endpoint (LIFE) reduction in hypertension study. | Previous studies have found pulse pressure (PP), a marker of arterial stiffness, to be an independent predictor of atrial fibrillation (AF) in general and hypertensive populations. We examined whether PP predicted new-onset AF in comparison with other blood pressure components in the Losartan Intervention For Endpoint reduction in hypertension study, a double-blind, randomized (losartan versus atenolol), parallel-group study, including 9193 patients with hypertension and electrocardiographic left ventricular hypertrophy. In 8810 patients with neither a history of AF nor AF at baseline, Minnesota coding of electrocardiograms confirmed new-onset AF in 353 patients (4.0%) during mean 4.9 years of follow-up. In multivariate Cox regression analyses, baseline and in-treatment PP and baseline and in-treatment systolic blood pressure predicted new-onset AF, independent of baseline age, height, weight, and Framingham Risk Score; sex, race, and treatment allocation; and in-treatment heart rate and Cornell product. PP was the strongest single blood pressure predictor of new-onset AF determined by the decrease in the -2 Log likelihood statistic, in comparison with systolic blood pressure, diastolic blood pressure, and mean arterial pressure. When evaluated in the same model, the predictive effect of systolic and diastolic blood pressures together was similar to that of PP. In this population of patients with hypertension and left ventricular hypertrophy, PP was the strongest single blood pressure predictor of new-onset AF, independent of other risk factors. |
13,998 | Quantification of not-dipolar components of atrial depolarization by principal component analysis of the P-wave. | Principal component analysis (PCA) of the T-wave has been demonstrated to quantify the dipolar and not-dipolar components of the ventricular activation, the latter reflecting repolarization heterogeneity. Accordingly, the PCA of the P-wave could help in analyzing the heterogeneous propagation of sinus impulses in the atria, which seems to predispose to fibrillation.</AbstractText>The aim of this study is to perform the PCA of the P-wave in patients prone to atrial fibrillation (AF).</AbstractText>PCA is performed on P-waves extracted by averaging technique from ECG recordings acquired using a 32-lead mapping system (2048 Hz, 24 bit, 0-400 Hz bandwidth). We extracted PCA parameters related to the dipolar and not dipolar components of the P-wave using the first 3 eigenvalues and the cumulative percent of variance explained by the first 3 PCs (explained variance EV).</AbstractText>We found that the EV associated to the low risk patients is higher than that associated to the high risk patients, and that, correspondingly, the first eigenvalue is significantly lower while the second one is significantly higher in the high risk patients respect to the low risk group. Factor loadings showed that on average all leads contribute to the first principal component.</AbstractText> |
13,999 | Decreased TSP-1 following percutaneous coronary intervention is associated with major adverse cardiac events in ST-elevation myocardial infarction. | TSP-1 is a vasoconstrictive protein, which is released from both endothelium and cardiomyocytes during ischemia and promotes platelet aggregation and adhesion to subendothelial layers in atherosclerotic lesions. During myocardial ischemia and reperfusion, TSP-1 disturbs local microcirculation by disrupting both NO-signaling as well as VEGF-pathways by activation of CD47 and CD36. Furthermore, activation of TGF-ß might induce excessive fibrosis after infarction. It was assumed that TSP-1 is washed out after successful coronary reperfusion. In this study, we examined circulating TSP-1 post emergency PCI as a risk factor for major adverse cardiac events after STEMI with and without ventricular fibrillation.</AbstractText>TSP-1 levels in platelet poor plasma were measured in 54 patients after ST-elevation myocardial infarction. Major adverse cardiac events were monitored for 426 days.</AbstractText>Patients with decreased TSP levels after coronary stenting showed a significantly higher risk for MACE than patient with higher TSP levels (TSP-1[d0]: n = 46, no MACE = 16.38 ± 1.98 ug/mL vs. MACE 7.11 ± 1.54 ug/mL; p = 0.003). Kaplan-Meyer-analysis for MACE showed a better outcome above 10 ug/mL (p = 0.02). For MACE later than 3 months post-STEMI, the corresponding Kaplan-Meier-analysis yielded a p-value of 0.01. The number needed to diagnose for late MACE was 2.158.</AbstractText>Low plasma levels of TSP1 after PCI are associated with MACE. Due to its procoagulant effects and dysregulation of microvascular tone, adequately powered prospective studies are warranted to test the impact of TSP-1 on cardiac microcirculation, endothelial function and remodeling. TSP-1 might serve as a new diagnostic and therapeutic approach in cardiovascular disease.</AbstractText> |
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