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11,000 | Early subcellular Ca2+ remodelling and increased propensity for Ca2+ alternans in left atrial myocytes from hypertensive rats. | Hypertension is a major risk factor for atrial fibrillation. We hypothesized that arterial hypertension would alter atrial myocyte calcium (Ca2+) handling and that these alterations would serve to trigger atrial tachyarrhythmias.</AbstractText>Left atria or left atrial (LA) myocytes were isolated from spontaneously hypertensive rats (SHR) or normotensive Wistar-Kyoto (WKY) controls. Early after the onset of hypertension, at 3 months of age, there were no differences in Ca2+ transients (CaTs) or expression and phosphorylation of Ca2+ handling proteins between SHR and WKY. At 7 months of age, when left ventricular (LV) hypertrophy had progressed and markers of fibrosis were increased in left atrium, CaTs (at 1 Hz stimulation) were still unchanged. Subcellular alterations in Ca2+ handling were observed, however, in SHR atrial myocytes including (i) reduced expression of the α1C subunit of and reduced Ca2+ influx through L-type Ca2+ channels, (ii) reduced expression of ryanodine receptors with increased phosphorylation at Ser2808, (iii) decreased activity of the Na+ / Ca2+ exchanger (at unaltered intracellular Na+ concentration), and (iv) increased SR Ca2+ load with reduced fractional release. These changes were associated with an increased propensity of SHR atrial myocytes to develop frequency-dependent, arrhythmogenic Ca2+ alternans.</AbstractText>In SHR, hypertension induces early subcellular LA myocyte Ca2+ remodelling during compensated LV hypertrophy. In basal conditions, atrial myocyte CaTs are not changed. At increased stimulation frequency, however, SHR atrial myocytes become more prone to arrhythmogenic Ca2+ alternans, suggesting a link between hypertension, atrial Ca2+ homeostasis, and development of atrial tachyarrhythmias.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
11,001 | Expanding the phenotype of Timothy syndrome type 2: an adolescent with ventricular fibrillation but normal development. | Timothy syndrome is a rare multiorgan disorder with prolonged QTc interval, congenital heart defects, syndactyly, typical facial features and neurodevelopmental problems. Ventricular tachyarrhythmia is the leading cause of death at early age. Classical Timothy syndrome type 1 (TS1) results from a recurrent de novo CACNA1C mutation, G406R in exon 8 A. An atypical form of Timothy syndrome type 2 (TS2) is caused by mutations in G406R and G402S in the alternatively spliced exon 8. Only one individual for each exon 8 mutations has been described. In contrast to multiorgan disease caused by the mutation in G406R either in exon 8 A or 8, the G402S carrier manifested only an isolated cardiac phenotype with LQTS and cardiac arrest. We describe a teenage patient resuscitated from ventricular fibrillation and treated with an implantable cardioverter defibrillator. She has no other organ manifestations, no syndactyly, normal neurodevelopment and her QTc has ranged between 440-480 ms. There is no family history of arrhythmias or sudden death. Targeted oligonucleotide-selective sequencing (OS-Seq) of channelopathy genes revealed a de novo substitution, G402S in exon 8 of CACNA1C. Direct sequencing of blood and saliva derived DNA showed an identical mutation peak suggesting ubiquitous expression in different tissues. The phenotype of our patient and the previously described patient show an isolated arrhythmia disease with no other organ manifestations of classical Timothy syndrome. |
11,002 | Development and validation of a risk score for predicting operative mortality in heart failure patients undergoing surgical ventricular reconstruction. | Different risk models have been introduced and refined in the past in order to improve standards of care. However, the predictive power of any risk algorithms can decline over time due to changes in surgical practice and the population's risk profile. The present study aimed to develop and validate a risk model for predicting operative mortality in patients with ischaemic heart failure (HF) undergoing surgical ventricular reconstruction (SVR).</AbstractText>The study population included 525 patients with previous myocardial infarction and left ventricular remodelling referred to our centre for SVR. All patients underwent surgical reshaping; coronary artery bypass grafting was performed in 489 (93%) patients and mitral valve (MV) repair in 142 (27%). Operative mortality was defined as death within 30 days after surgery. All patients received an operative risk assessment using the logistic EuroSCORE and the ACEF score.</AbstractText>Better accuracy was achieved by the ACEF score (0.771) compared with the EuroSCORE (0.747). On multivariable logistic regression analysis, forcing the ACEF score in the model, three additional factors remained as independent predictors of operative mortality: atrial fibrillation, NYHA Class 3-4 and MV surgery (odds ratio 2.2, 2.6 and 2.1, respectively) and were computed in the ACEF-SVR. The ACEF-SVR score demonstrated an improved accuracy in respect of the ACEF score (from 0.771 to 0.792) and a better calibration (Hosmer-Lemeshow χ(2) of 5.40, P = 0.714).</AbstractText>The ACEF-SVR score, starting from a simplified model of risk enabled improvement in the accuracy and calibration of the model, tailoring the risk to a specific population of patients with HF undergoing a specific surgical procedure.</AbstractText>© The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.</CopyrightInformation> |
11,003 | Multicentre comparison Of shock efficacy using single-vs. Dual-coil lead systems and Anodal vs. cathodaL polarITY defibrillation in patients undergoing transvenous cardioverter-defibrillator implantation. The MODALITY study. | An optimal active-can lead configuration during implantable cardioverter defibrillator (ICD) placement is important to obtain an adequate defibrillation safety margin. The purpose of this multicenter study was to evaluate the rate of the first shock success at defibrillation testing according to the type of lead implant (single vs. dual coil) and shock polarity (cathodal and anodal) in a large series of consecutive patients who received transvenous ICDs.</AbstractText>This was a multicenter study enrolling 469 consecutive patients. Single- versus dual-coil leads and cathodal versus anodal polarity were evaluated at defibrillation testing. In all cases, the value of the energy for the first shock was set to 20 J less than the maximum energy deliverable from the device.</AbstractText>A total of 469 patients underwent defibrillation testing: 158 (34 %) had dual-coil and 311 (66 %) had single-coil lead systems configuration, 254 (54 %) received anodal shock and 215 (46 %) received cathodal shock. In 35 (7.4 %) patients, the shock was unsuccessful. No significant differences in the outcome of defibrillation testing using single- versus dual-coil lead were observed but the multivariate analysis showed an increased risk of shock failure using cathodal shock polarity (OR 2.37, 95 % CI 1.12-5.03).</AbstractText>Both single- and dual-coil transvenous ICD lead systems were associated with high rates of successful ICD implantation, and we found no significant differences in ventricular arrhythmias interruption between the two ICD lead systems configuration. Instead, anodal defibrillation was more likely to be successful than cathodal defibrillation.</AbstractText> |
11,004 | Clinical course and prognostic relevance of antitachycardia pacing-terminated ventricular tachyarrhythmias in implantable cardioverter-defibrillator patients. | In patients with an implantable cardioverter-defibrillator (ICD), ICD shocks due to ventricular tachycardia (VT) or ventricular fibrillation (VF) have been associated with an increased mortality. It is not known whether patients with antitachycardia pacing (ATP)-terminated VT/VF episodes have a similar worse outcome. The aim of this study was to evaluate the clinical course and prognostic impact of ATP-terminated episodes on mortality in ICD patients.</AbstractText>A total of 1398 consecutive patients of the prospective single-centre ICD-registry Ludwigshafen who underwent an ICD implantation between 1992 and 2008 for primary or secondary prevention of sudden cardiac death were analysed. Patients treated with ATP were compared with patients with appropriate ICD shocks or patients without any appropriate ATP or ICD shock. During the median follow-up time of 6 years, 749 (54%) patients experienced 17 827 episodes of VT or VF which were terminated by ATP in 74% and by shock in 26% of patients. In approximately half (n = 321/749) of those patients with VT/VF, the first episode was terminated by ATP. In a multivariate analysis adjusted for different baseline confounding parameters, the occurrence of first ATP therapy was associated with a higher mortality rate [hazard ratio (HR) 2.60, 95% confidence interval (CI) 2.02-3.35]. When excluding all patients with appropriate ICD shocks first ATP therapy remained associated with a worse prognosis (HR 1.92, 95% CI 1.38-2.67).</AbstractText>In ICD patients, about three-fourths of ventricular arrhythmias are terminated by ATP. The occurrence of ATP-terminated episode is associated with an increased mortality rate.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
11,005 | Old And New Oral Anticoagulants In Management Of Atrial Fibrillation: A Double-Edged Sword For Women. | Atrial fibrillation (AF), one of the most prevalent supra-ventricular arrhythmia in adults, is related to a substantial increase in the risk of thromboembolic events requiring tailored preventive strategy. In AF, antithrombotic therapy should be individualized according to a careful decisionmaking process, taking in account the likely concomitant presence of risk factors for stroke and bleeding. Anticoagulation management is particularly challenging in women with AF, to the extent that female sex is incorporated in commonly used stratification schemes for both thromboembolic and bleeding risk evaluation. Nevertheless, gender- based differences on the efficacy and safety of either "old" (i.e. vitamin K antagonist) or "new" oral anticoagulants (i.e. direct thrombin inhibitors and activated factor X inhibitors) are not conclusive and not always reported. This review aims to analyse the literature on sex differences in AF anticoagulation management. We focus on safety data, bleeding complications and specific haemostatic mechanisms currently under investigation, which could account for observed disparities among sexes. Moreover, details on sex difference in response to anticoagulant treatment will be discussed. Comparing old and new antithrombotics, a need clearly emerges for differentiated and integrated strategies for the treatment of AF in female patients. |
11,006 | Modeling cardiac arrest and resuscitation in the domestic pig. | Cardiac arrest remains a leading cause of death and permanent disability worldwide. Although many victims are initially resuscitated, they often succumb to the extensive ischemia-reperfusion injury inflicted on the internal organs, especially the brain. Cardiac arrest initiates a complex cellular injury cascade encompassing reactive oxygen and nitrogen species, Ca(2+) overload, ATP depletion, pro- and anti-apoptotic proteins, mitochondrial dysfunction, and neuronal glutamate excitotoxity, which injures and kills cells, compromises function of internal organs and ignites a destructive systemic inflammatory response. The sheer complexity and scope of this cascade challenges the development of experimental models of and effective treatments for cardiac arrest. Many experimental animal preparations have been developed to decipher the mechanisms of damage to vital internal organs following cardiac arrest and cardiopulmonary resuscitation (CPR), and to develop treatments to interrupt the lethal injury cascades. Porcine models of cardiac arrest and resuscitation offer several important advantages over other species, and outcomes in this large animal are readily translated to the clinical setting. This review summarizes porcine cardiac arrest-CPR models reported in the literature, describes clinically relevant phenomena observed during cardiac arrest and resuscitation in pigs, and discusses numerous methodological considerations in modeling cardiac arrest/CPR. Collectively, published reports show the domestic pig to be a suitable large animal model of cardiac arrest which is responsive to CPR, defibrillatory countershocks and medications, and yields extensive information to foster advances in clinical treatment of cardiac arrest. |
11,007 | COR-ART: A multicenter, randomized, double-blind, placebo-controlled dose-ranging study to evaluate single oral doses of vanoxerine for conversion of recent-onset atrial fibrillation or flutter to normal sinus rhythm. | Restoration of sinus rhythm (SR) in patients with atrial fibrillation/atrial flutter (AF/AFL) is limited principally to direct current cardioversion. The multi-ion channel blocker vanoxerine may prove an effective alternative.</AbstractText>The purpose of this study was to assess vanoxerine, a 1,4-dialkylpiperazine derivative, for acute conversion of recent-onset, symptomatic AF and AFL.</AbstractText>One hundred four subjects with symptomatic AF/AFL for <7 days were randomized sequentially to single oral doses of vanoxerine 200, 300, and 400 mg or placebo. Holter monitors were examined for conversion to SR and proarrhythmia through ≥24 hours.</AbstractText>Conversion to SR was dose related: 18.2%, 44.0%, and 52.0% within 4 hours, and 59.1%, 64.0%, and 84.0% within 24 hours, for the 200-, 300-, and 400-mg groups, respectively. This was significantly higher than placebo for the 300- and 400-mg groups within 4 hours (12.5% for placebo; P = .0138 and P = .0028, respectively) and for all doses within 24 hours (31.3% for placebo; P = .0421, P = .0138, P = .0001 for 200-, 300-, and 400-mg vanoxerine groups, respectively). Although vanoxerine caused significant dose-dependent QTcF (QT correction by Fridericia) prolongation, monomorphic or polymorphic ventricular tachycardia did not occur. Adverse events were mild and self-limited, with only the highest dose having a greater frequency than placebo.</AbstractText>Oral vanoxerine converted AF/AFL to SR at a high rate, was well tolerated, and caused no ventricular proarrhythmia.</AbstractText>Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,008 | The Association of Serum Galectin-3 Levels with Atrial Electrical and Structural Remodeling. | Left atrial (LA) interstitial fibrosis is known to have a role in the initiation and maintenance of atrial fibrillation (AF). The role of galectin-3 in the pathogenesis of cardiac fibrosis has been demonstrated in previous studies. We aimed to determine whether serum galectin-3 level is associated with markers of atrial remodeling, including the extent of LA fibrosis detected by delayed enhancement magnetic resonance imaging (DE-MRI) and atrial electromechanical delay (AEMD) in paroxysmal AF patients with preserved left ventricular (LV) functions.</AbstractText>Thirty-three patients (58 [28-74] years, 51.5% male) with paroxysmal AF who underwent DE-MRI prior to cryoballoon-based AF ablation were included in the study. Serum galectin-3 levels were measured with ELISA. LA volume index (B ± SE: 0.424 ± 0.504, 95% CI: 0.560-2.627, P = 0.004) and serum galectin-3 levels (B ± SE: 0.549 ± 7.745, 95% CI: 16.874-47.550, P < 0.001) were found to be independently correlated with extent of LA fibrosis detected with DE-MRI in paroxysmal AF patients with preserved LV function. Correlation analysis between AEMD parameters and baseline characteristics showed that galectin-3 was significantly correlated with intra-left (ρ = 0.432, P = 0.012) and inter-AEMD (ρ = 0.395, P = 0.023). Duration of AF, LAD, and extent of LA fibrosis were also found to be significantly correlated with AEMD parameters.</AbstractText>This is a hypothesis-generating study pointing out that serum galectin-3 level is significantly associated with atrial remodeling in paroxysmal AF patients with preserved LV function. Further studies are necessary to provide exact pathophysiological mechanisms.</AbstractText>© 2015 Wiley Periodicals, Inc.</CopyrightInformation> |
11,009 | Short and medium term outcomes of surgery for patients with hypertrophic obstructive cardiomyopathy. | We report one surgeon's experience of corrective surgery for hypertrophic obstructive cardiomyopathy (HOCM) over a 10-year span and comment on factors that influence longer term outcomes. Septal myectomy (SM) and adjunctive procedures, including shortening of the aorta, a novel technique in HOCM patients, are described.</AbstractText>Perioperative data were obtained by retrospective review of institutional surgical databases between 2001 and 2011. Review of most recent echocardiogram and clinical status by telephone interview was performed.</AbstractText>A total of 211 patients underwent SM for HOCM. There was a bimodal age distribution related to sex; mean age for males and females was 46 ± 13 and 54 ± 14 years, respectively (p < 0.001). Functional New York Heart Association (NYHA) class improved significantly after surgery; 79% were in class III-IV preoperatively and 84% were in class I-II at follow-up (p < 0.001). Sixty percent had angina of Canadian Cardiovascular Society (CCS) grade III-IV preoperatively and 89% were in CCS I-II at follow-up (p < 0.001). There were significant improvements in resting left ventricular outflow tract gradient (64 ± 36 to 5 ± 5 mm Hg, p < 0.001), right ventricular systolic pressure (36 ± 7.3 to 32 ± 8 mm Hg, p < 0.001), left atrial size (4.6 ± 0.7 to 4.3 ± 0.6 cm, p < 0.001), and grade of mitral regurgitation (moderate to severe mitral regurgitation 28% to 3.5%, p < 0.001). In-hospital mortality was 0.5%, 1 year survival 98.6%, and 5-year survival 98.1%. Predictors of worse clinical outcomes were preoperative NYHA and CCS class III-IV (p < 0.001, p = 0.05), new onset atrial fibrillation (p < 0.001), and female sex (p = 0.03).</AbstractText>Septal myectomy in patients with obstructive HOCM offers excellent symptom relief and minimal operative risk.</AbstractText>Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,010 | Chronic pantoprazole administration and ischemia--reperfusion arrhythmias in vivo in rats--antiarrhythmic or arrhythmogenic? | The safety of all proton pump inhibitors (PPIs) in patients with intrinsic cardiac disease has not been well studied. In the present study, the effect of PPI pantoprazole on ventricular arrhythmias induced by either ischemia or ischemia-reperfusion (I/R) was studied.</AbstractText>The left main coronary artery (LAD) was ligated for 30 or 10 min followed by a 30-min reperfusion in anesthetized rats. Rats were pretreated with pantoprazole (1.3 mg/kg) or vehicle by gastric gavage (daily for 3 weeks) before ligation. Serum electrolytes levels were measured by the end of the third week before coronary ligation. Lactate dehydrogenase (LDH) activity and nitric oxide (NO) concentrations were measured at the end of the ischemia and IR injury.</AbstractText>Pantoprazole caused significant hyperkalemia by the end of third week compared with vehicle-treated rats. After LAD ligation (30 min), ventricular premature contractions (VPC), ventricular tachycardia (VT) and ventricular fibrillation (VF) were recorded in rats of the vehicle ischemia group. Pantoprazole pretreatment aggravate these arrhythmias and increased mortality. A 10-min period of ischemia followed by a 30-min reperfusion induced high incidence of VT (100%) and VF (80%) in the vehicle-treated group. The group of rats administered pantoprazole had significantly lower incidence and durations of VT and VF together with reduction of mortality rate. Pantoprazole significantly reduced serum LDH activity and NO release from myocardial tissue after both ischemia and I/R injury.</AbstractText>Pantoprazole aggravated ischemia-induced arrhythmias but had a significant antiarrhythmic effect on I/R-induced ventricular arrhythmias.</AbstractText>© 2015 John Wiley & Sons Ltd.</CopyrightInformation> |
11,011 | Update in cardiac arrhythmias and pacing. | This article discusses the main advances in cardiac arrhythmias and pacing published between 2013 and 2014. Special attention is given to the interventional treatment of atrial fibrillation and ventricular arrhythmias, and on advances in cardiac pacing and implantable cardioverter defibrillators, with particular reference to the elderly patient. |
11,012 | Out-of-hospital cardiac arrest survival improving over time: Results from the Resuscitation Outcomes Consortium (ROC). | Out-of-hospital cardiac arrest (OHCA) remains a leading cause of death and a 2010 meta-analysis concluded that outcomes have not improved over several decades. However, guidelines have changed to emphasize CPR quality, minimization of interruptions, and standardized post-resuscitation care. We sought to evaluate whether OHCA outcomes have improved over time among agencies participating in the Resuscitation Outcomes Consortium (ROC) cardiac arrest registry (Epistry) and randomized clinical trials (RCTs).</AbstractText>Observational cohort study of 47,148 EMS-treated OHCA cases in Epistry from 139 EMS agencies at 10 ROC sites that participated in at least one RCT between 1/1/2006 and 12/31/2010. We reviewed patient, scene, event characteristics, and outcomes of EMS-treated OHCA over time, including subgroups with initial rhythm of pulseless ventricular tachycardia or ventricular fibrillation (VT/VF).</AbstractText>Mean response interval, median age and male proportion remained similar over time. Unadjusted survival to discharge increased between 2006 and 2010 for treated OHCA (from 8.2% to 10.4%), as well as for subgroups of VT/VF (21.4% to 29.3%) and bystander witnessed VT/VF (23.5% to 30.3%). Compared with 2006, adjusted survival to discharge was significantly higher in 2010 for treated cases (OR = 1.72; 95% CI 1.53, 1.94), VT/VF cases (OR = 1.69; 95% CI 1.45, 1.98) and bystander witnessed VT/VF cases (OR = 1.65; 95% CI 1.36, 2.00). Tests for trend in each subgroup were significant (p < 0.001).</AbstractText>ROC-wide survival increased significantly between 2006 and 2010. Additional research efforts are warranted to identify specific factors associated with this improvement.</AbstractText>Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
11,013 | [Clinical practice of systemic lysis in prehospital resuscitation. Success and complication rates]. | Systemic thrombolysis was introduced as the sole prehospital treatment option in patients with cardiac arrest in the setting of acute myocardial ischemia or pulmonary embolism; however, it remains the subject of discussion.</AbstractText>A total of 194 patients with sudden prehospital cardiac arrest were included in this retrospective case control study. Of these patients, 96 in whom circulatory arrest due to cardiac disease (pulmonary artery embolism or myocardial ischemia) was suspected underwent thrombolytic treatment and were compared to the remaining 98 patients that did not undergo thrombolytic therapy. In addition to the circumstances of circulatory arrest, the course and success of resuscitation, as well as in-hospital course (including bleeding complications), overall survival and neurological outcomes were compared.</AbstractText>There were no significant differences between patients with or without thrombolysis in terms of the circumstances of cardiac arrest. Patients that received thrombolytic treatment were significantly younger and were more frequently treated with anticoagulants, platelet aggregation inhibitors and amiodarone. They also received higher doses of epinephrine and arrived at hospital under ongoing resuscitation significantly more frequently. A trend toward more prehospital return of spontaneous circulation (ROSC) following thrombolytic treatment was seen in the entire cohort. However, patients pre-treated with acetylsalicylic acid and heparin did not show better prehospital ROSC rates as a result of additional thrombolytic therapy. Significant differences in terms of bleeding complications or the need for blood transfusion could not be seen due to the small number of patients.</AbstractText>The indication for systemic thrombolysis in the context of prehospital resuscitation should remain restricted to patients with clear symptoms of acute pulmonary embolism or recurrent episodes of ventricular fibrillation in the setting of acute myocardial infarction. Due to a lack of evidence, systemic thrombolysis should not be used as a treatment of last resort in younger patients with persistent ventricular fibrillation.</AbstractText> |
11,014 | Impact of duration of mitral regurgitation on outcomes in asymptomatic patients with myxomatous mitral valve undergoing exercise stress echocardiography. | Significant mitral regurgitation (MR) typically occurs as holosystolic (HS) or mid-late systolic (MLS), with differences in volumetric impact on the left ventricle (LV). We sought to assess outcomes of degenerative MR patients undergoing exercise echocardiography, separated based on MR duration (MLS versus HS).</AbstractText>We included 609 consecutive patients with ≥III+myxomatous MR undergoing exercise echocardiography: HS (n=487) and MLS (n=122). MLS MR was defined as delayed appearance of MR signal during mid-late systole on continuous-wave Doppler while HS MR occurred throughout systole. Composite events of death and congestive heart failure were recorded. Compared to MLS MR, HS MR patients were older (60±14 versus 53±14 years), more were males (72% versus 53%), and had greater prevalence of atrial fibrillation (16% versus 7%; all P<0.01). HS MR patients had higher right ventricular systolic pressure (RVSP) at rest (33±11 versus 27±9 mm Hg), more flail leaflets (36% versus 6%), and a lower number of metabolic equivalents (METs) achieved (9.5±3 versus 10.5±3), compared to the MLS MR group (all P<0.05). There were 54 events during 7.1±3 years of follow-up. On step-wise multivariable analysis, HS versus MLS MR (HR 4.99 [1.21 to 20.14]), higher LV ejection fraction (hazard ratio [HR], 0.94 [0.89 to 0.98]), atrial fibrillation (HR, 2.59 [1.33 to 5.11]), higher RVSP (HR, 1.05 [1.03 to 1.09]), and higher percentage of age- and gender-predicted METs (HR, 0.98 [0.97 to 0.99]) were independently associated with adverse outcomes (all P<0.05).</AbstractText>In patients with ≥III+myxomatous MR undergoing exercise echocardiography, holosystolic MR is associated with adverse outcomes, independent of other predictors.</AbstractText>© 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.</CopyrightInformation> |
11,015 | Detection of paroxysmal atrial fibrillation by prolonged electrocardiographic recording after ischaemic stroke in patients aged<60years: a study with 21-day recording using the SpiderFlash(®) monitor. | Many studies have suggested that longer duration of cardiac monitoring is suitable for the detection of occult paroxysmal atrial fibrillation (AF) after stroke; however, most studies involved patients aged≥65years - a population with a high stroke rate.</AbstractText>To assess the incidence of paroxysmal AF in unselected young patients presenting with stroke.</AbstractText>We included consecutive patients aged<60years with a stroke diagnosis on magnetic resonance imaging. Aetiological screening included clinical history and examination, and biological and cardiac tests. Patients were included if they had no history of AF and if a 24-hour electrocardiogram recording detected no AF or atrial flutter. Patients wore the SpiderFlash(®) monitor for 21days after discharge from hospital. The primary outcome was detection of paroxysmal AF episodes lasting>30seconds during monitoring. The secondary outcome was detection of paroxysmal AF episodes lasting<30seconds and any arrhythmia during monitoring.</AbstractText>Among the 56 patients included (mean age 48±9years), 39 had cryptogenic stroke (CS) and 17 had stroke of known cause (SKC). Cardiac monitoring was achieved in 54 patients (37 CS, 17 SKC); one CS patient had a paroxysmal AF episode lasting>30seconds and one CS patient had a paroxysmal AF episode lasting<30seconds (versus no patients in the SKC group). Two CS patients and one SKC patient presented numerous premature atrial complexes. Non-sustained ventricular tachycardia was detected in one CS patient.</AbstractText>This prospective observational study showed a low rate of paroxysmal AF among young patients presenting with stroke, on the basis of 21-day cardiac monitoring. This result highlights the need to identify patients who would benefit from such long monitoring.</AbstractText>Copyright © 2015 Elsevier Masson SAS. All rights reserved.</CopyrightInformation> |
11,016 | Masked hypertension and cardiac remodeling in middle-aged endurance athletes. | Extensive endurance training and arterial hypertension are established risk factors for atrial fibrillation. We aimed to assess the proportion of masked hypertension in endurance athletes and the impact on cardiac remodeling, mechanics, and supraventricular tachycardias (SVT).</AbstractText>Male participants of a 10-mile race were recruited and included if office blood pressure was normal (<140/90 mmHg). Athletes were stratified into a masked hypertension and normotension group by ambulatory blood pressure. Primary endpoint was diastolic function, expressed as peak early diastolic mitral annulus velocity (E'). Left ventricular global strain, left ventricular mass/volume ratio, left atrial volume index, signal-averaged P-wave duration (SAPWD), and SVT during 24-h Holter monitoring were recorded.</AbstractText>From 108 runners recruited, 87 were included in the final analysis. Thirty-three (38%) had masked hypertension. The mean age was 42 ± 8 years. Groups did not differ with respect to age, body composition, cumulative training hours, and 10-mile race time. Athletes with masked hypertension had a lower E' and a higher left ventricular mass/volume ratio. Left ventricular global strain, left atrial volume index, SAPWD, and SVT showed no significant differences between the groups. In multiple linear regression analysis, masked hypertension was independently associated with E' (beta = -0.270, P = 0.004) and left ventricular mass/volume ratio (beta = 0.206, P = 0.049). Cumulative training hours was the only independent predictor for left atrial volume index (beta = 0.474, P < 0.001) and SAPWD (beta = 0.481, P < 0.001).</AbstractText>In our study, a relevant proportion of middle-aged athletes had masked hypertension, associated with a lower diastolic function and a higher left ventricular mass/volume ratio, but unrelated to left ventricular systolic function, atrial remodeling, or SVT.</AbstractText> |
11,017 | New strategies for ventricular tachycardia and ventricular fibrillation ablation. | Patients with ventricular tachycardia (VT) and ventricular fibrillation (VF) and no reversible cause are difficult to treat. While implantable defibrillators prolong survival, many patients remain symptomatic due to device shocks and syncope. To address this, there have been recent advances in the catheter ablation of VT and VF. For example, non-invasive imaging has improved arrhythmia substrate characterisation, 3D catheter navigation tools have facilitated mapping of arrhythmia and substrate and ablation catheters have advanced in their ability to deliver effective lesions. However, the long-term success rates of ablation for VT and VF remain modest, with nearly half of treated patients developing recurrence within 2-3 years, and this drives the ongoing innovation in the field. This review focuses on the challenges particular to ablation of life-threatening ventricular arrhythmia, and the strategies that have been recently developed to improve procedural efficacy. Patient sub-groups that illustrate the use of new strategies are described. |
11,018 | Renal dysfunction and the risk of postoperative atrial fibrillation after cardiac surgery: role beyond the CHA2DS2-VASc score. | To investigate whether renal dysfunction is a useful predictor of postoperative atrial fibrillation (POAF) after cardiac surgery. We also aimed to determine whether the addition of renal dysfunction into the scoring system could improve diagnostic accuracy of the CHA2DS2-VASc score to predict POAF.</AbstractText>The study prospectively enrolled 350 consecutive patients who underwent cardiac surgery. Echocardiography was performed before cardiac surgery. Renal dysfunction was defined as estimated glomerular filtration rate < 60 mL min(-1) 1.73 m(-2). All patients were monitored with continuous electrocardiographic telemetry for the occurrence of POAF until the day of hospital dismissal. Postoperative atrial fibrillation occurred in 103 of 350 patients (29%). Patients with POAF was associated with longer intensive care unit stay compared with those without POAF (3.7 ± 2.2 vs. 3.1 ± 1.4 days, P = 0.002). Both the CHA2DS2-VASc score and renal dysfunction were independent predictors of POAF in multivariate analysis. Renal dysfunction can further stratify patients with a CHA2DS2-VASc score of 0 or 1 into two groups with different POAF rates (3.1% vs. 68.8%, P < 0.001). A new scoring system (R-CHA2DS2-VASc score) derived by assigning an additional point representing renal dysfunction to the CHA2DS2-VASc score could improve its predictive accuracy. The area under the receiver operating characteristic curve increased from 0.68 to 0.71 (P < 0.001). Furthermore, the rate of left ventricular diastolic dysfunction also increased with increasing renal dysfunction.</AbstractText>Renal dysfunction, associated with left ventricular diastolic dysfunction, was a significant risk factor for POAF after cardiac surgery and may improve the diagnostic accuracy of the CHA2DS2-VASc score.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
11,019 | Late cardiac death in patients undergoing transcatheter aortic valve replacement: incidence and predictors of advanced heart failure and sudden cardiac death. | Little evidence exists of the burden and predictors of cardiac death after transcatheter aortic valve replacement (TAVR).</AbstractText>The purpose of this study was to assess the incidence and predictors of cardiac death from advanced heart failure (HF) and sudden cardiac death (SCD) in a large patient cohort undergoing TAVR.</AbstractText>The study included a total of 3,726 patients who underwent TAVR using balloon (57%) or self-expandable (43%) valves. Causes of death were defined according to the Valve Academic Research Consortium-2.</AbstractText>At a mean follow-up of 22 ± 18 months, 155 patients had died due to advanced HF (15.2% of total deaths, 46.1% of deaths from cardiac causes) and 57 had died due to SCD (5.6% of deaths, 16.9% of cardiac deaths). Baseline comorbidities (chronic obstructive pulmonary disease, atrial fibrillation, left ventricular ejection fraction ≤40%, lower mean transaortic gradient, pulmonary artery systolic pressure >60 mm Hg; p < 0.05 for all) and 2 procedural factors (transapical approach, hazard ratio [HR]: 2.38, 95% confidence interval [CI]: 1.60 to 3.54; p < 0.001; presence of moderate or severe aortic regurgitation after TAVR, HR: 2.79, 95% CI: 1.82 to 4.27; p < 0.001) independently predicted death from advanced HF. Left ventricular ejection fraction ≤40% (HR: 1.93, 95% CI: 1.05 to 3.55; p = 0.033) and new-onset persistent left bundle-branch block following TAVR (HR: 2.26, 95% CI: 1.23 to 4.14; p = 0.009) were independently associated with an increased risk of SCD. Patients with new-onset persistent left bundle-branch block and a QRS duration >160 ms had a greater SCD risk (HR: 4.78, 95% CI: 1.56 to 14.63; p = 0.006).</AbstractText>Advanced HF and SCD accounted for two-thirds of cardiac deaths in patients after TAVR. Potentially modifiable or treatable factors leading to increased risk of mortality for HF and SCD were identified. Future studies should determine whether targeting these factors decreases the risk of cardiac death.</AbstractText>Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,020 | The effect of carvedilol on B-type natriuretic peptide and cardiac function in patients with heart failure and persistent atrial fibrillation. | We sought to determine the relationship between changes in natriuretic peptides and symptoms as a consequence of introducing beta-blocker therapy, in patients with chronic heart failure (CHF) and persistent atrial fibrillation (AF).</AbstractText>In a randomised, double-blind, placebo-controlled study involving 47 patients with CHF and persistent AF (mean age 68 years and 62% men), we analysed the individual change (Δ) in B-type natriuretic peptide (BNP) level to the introduction of carvedilol (titrated to a target dose of 25 mg twice daily, group A) or placebo (group B) in addition to background treatment with digoxin. Symptoms score, 6-min walk distance, New York Heart Association (NYHA) class, left ventricular ejection fraction (LVEF), heart rate (24-hour ECG) and BNP were measured at baseline and at 4 months.</AbstractText>LVEF (Δ median +5 vs. +0.4, p = 0.048), symptoms score (Δ median -4 vs. 0, p = 0.04), NYHA class (Δ median -33% vs. +3% in NYHA class 3-4, p = 0.046) and heart rate [Δ median 24-hour ventricular rate (VR) -19 vs. -2, p < 0.0001] improved with combination therapy of digoxin and carvedilol compared to digoxin alone, but BNP (Δ median +28 vs. -6 , p = 0.11) trended in the opposite direction. There was no relationship between the degree of symptomatic improvement or VR control and BNP response.</AbstractText>After the introduction of carvedilol, clinical outcome appears unrelated to BNP changes in patients with CHF and AF. Changes in BNP cannot be used as a marker of clinical response in terms of symptoms or cardiac function in this setting.</AbstractText>© 2015 S. Karger AG, Basel.</CopyrightInformation> |
11,021 | Health care resource utilization and costs during episodes of care for type 2 diabetes mellitus-related comorbidities. | To obtain costs of episodes of care for type 2 diabetes mellitus (T2DM)-related comorbidities.</AbstractText>Data from the MarketScan Commercial Claims and Encounters Database were analyzed with the Medical Episode Grouper software, which uses proprietary algorithms to identify episodes of care. Episodes relevant to the T2DM population were examined, including: coronary artery disease with acute myocardial infarction, ventricular fibrillation, shock, and/or cardiac arrest (CAD episodes); cerebrovascular disease with stroke (CVD episodes); hypoglycemia; T2DM with complications (complication episodes); and renal failure.</AbstractText>45,350 CAD; 85,287 CVD; 29,886 hypoglycemia; 40,339 complication; and 211,673 renal failure episodes were identified. Mean (SD) episode durations were 15.2 (39.1), 25.5 (55.0), 5.9 (24.0), 21.2 (54.6), and 364.0 (0.0) days, respectively. Inpatient visits were the largest component of unadjusted costs for CAD, CVD, and complication episodes (93.4%, 78.3%, and 91.9%, respectively). Other ancillary care represented the largest component of unadjusted costs for hypoglycemia (53.3%) and renal failure (80.5%) episodes. Mean adjusted total costs were $16,435; $4558; $445; $5675; and $8765 for CAD, CVD, hypoglycemia, complication, and renal failure episodes, respectively.</AbstractText>This study adds important information to the literature regarding costs of episodes of care for patients with T2DM in the US.</AbstractText>Copyright © 2015 Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,022 | Life-threatening ventricular arrhythmia due to silent coronary artery spasm: usefulness of I-123 metaiodobenzylguanidine scintigraphy for detecting coronary artery spasm in the era of automated external defibrillators: a case report. | Cardiac arrhythmia is sometimes life-threatening, and automated external defibrillators are presently used in some countries. Coronary artery spasm is one of the primary causes of life-threatening arrhythmia. In general, chest symptoms are key indicators of possible coronary artery spasm; however, if chest symptoms are not present, clinicians may not suspect this disease. We encountered a patient who had recovered from ventricular fibrillation treated by using an automated external defibrillator, and silent coronary artery spasm was considered to be the cause of this life-threatening arrhythmia. In this case, I-123 metaiodobenzylguanidine scintigraphy was a useful screening tool for a silent coronary artery spasm.</AbstractText>A 72-year-old Japanese man was transferred to our hospital after recovering from ventricular fibrillation treated by using an automated external defibrillator. He had never complained of chest symptoms previously. Decreased uptake of I-123 metaiodobenzylguanidine was observed in the inferolateral and anteroseptal walls of the left ventricle. A spasm provocation test of the coronary artery was performed, and silent coronary artery spasm was diagnosed as the underlying disease.</AbstractText>Non-invasive I-123 metaiodobenzylguanidine scintigraphy was a useful screening tool for silent coronary artery spasm as a possible cause of cardiopulmonary arrest in a patient with no chest symptoms.</AbstractText> |
11,023 | Reliability of blood color and blood gases in discriminating arterial from venous puncture during cardiopulmonary resuscitation. | We investigated the use of blood color brightness and blood gas variables for discriminating arterial from venous puncture during cardiopulmonary resuscitation (CPR). The study's aims were to determine if discrimination using Po2 is superior to using blood color brightness, and if blood color brightness, Po2, and acid-base variables derived from blood gas analysis accurately discriminate arterial from venous blood during CPR.</AbstractText>Fifteen pigs underwent ventricular fibrillation followed by CPR. During CPR, paired femoral arterial and venous blood samples were obtained, and 2 blinded observers were asked to identify the blood's origin. Blood color brightness was measured using a blood brightness scale (BBS). The discriminatory performances of the BBS and blood gas variables were evaluated by calculating the area under receiver operating characteristic curves (AUC).</AbstractText>The observers accurately discriminated arterial from venous blood with a sensitivity of 97.0% (84.7%-99.5%) and specificity of 84.9% (69.1%-93.4%). The BBS (AUC = 0.983) and Po2 (AUC = 0.981) methods both showed comparable and excellent discriminatory performances. pH, Pco2, and HCO3(-) all discriminated arterial from venous blood (AUC = 0.831, 0.971, and 0.652, respectively). The AUC for Pco2 was comparable to that for Po2 but significantly larger than that for pH (P = .002) or HCO3(-) (P < .001).</AbstractText>The BBS and Po2 methods showed comparable and excellent discrimination performances. Using pH, Pco2, and HCO3(-) levels also discriminated arterial from venous blood during CPR with statistical significance.</AbstractText>Copyright © 2015 Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,024 | Neurologic outcomes and postresuscitation care of patients with myoclonus following cardiac arrest. | To evaluate the outcomes of cardiac arrest survivors with myoclonus receiving modern postresuscitation care.</AbstractText>Retrospective review of registry data.</AbstractText>Cardiac arrest receiving centers in Europe and the United States from 2002 to 2012.</AbstractText>Two thousand five hundred thirty-two cardiac arrest survivors 18 years or older enrolled in the International Cardiac Arrest Registry.</AbstractText>None.</AbstractText>Eighty-eight percent of patients underwent therapeutic hypothermia and 471 (18%) exhibited myoclonus. Patients with myoclonus had longer time to professional cardiopulmonary resuscitation (8.6 vs 7.0 min; p < 0.001) and total ischemic time (25.6 vs 22.3 min; p < 0.001) and less often presented with ventricular tachycardia/ventricular fibrillation, a witnessed arrest, or had bystander cardiopulmonary resuscitation. Electroencephalography demonstrated myoclonus with epileptiform activity in 209 of 374 (55%), including status epilepticus in 102 of 374 (27%). Good outcome (Cerebral Performance Category 1-2) at hospital discharge was noted in 9% of patients with myoclonus, less frequently in myoclonus with epileptiform activity (2% vs 15%; p < 0.001). Patients with myoclonus with good outcome were younger (53.7 vs 62.7 yr; p < 0.001), had more ventricular tachycardia/ventricular fibrillation (81% vs 46%; p < 0.001), shorter ischemic time (18.9 vs 26.4 min; p = 0.003), more witnessed arrests (91% vs 77%; p = 0.02), and fewer "do-not-resuscitate" orders (7% vs 78%; p < 0.001). Life support was withdrawn in 330 of 427 patients (78%) with myoclonus and poor outcome, due to neurological futility in 293 of 330 (89%), at 5 days (3-8 d) after resuscitation. With myoclonus and good outcome, median ICU length of stay was 8 days (5-11 d) and hospital length of stay was 14.5 days (9-22 d).</AbstractText>Nine percent of cardiac arrest survivors with myoclonus after cardiac arrest had good functional outcomes, usually in patients without associated epileptiform activity and after prolonged hospitalization. Deaths occurred early and primarily after withdrawal of life support. It is uncertain whether prolonged care would yield a higher percentage of good outcomes, but myoclonus of itself should not be considered a sign of futility.</AbstractText> |
11,025 | Case of Recurrent Ventricular Fibrillations with Osborn Wave Developed during Therapeutic Hypothermia. | Therapeutic hypothermia (TH) has been used to protect neurological functions in cardiac arrest patient. Although Osborn wave is not pathognomonic of hypothermia, it is a well-known electrocardiogram finding of hypothermic patients. The cellular and ionic mechanisms of the Osborn wave have been suggested, and its relationship to tachyarrhythmias, such as ventricular tachycardia and ventricular fibrillation, is being explored. This case highlights the arrhythmogenic potential of Osborn wave and individual difference in response of TH. |
11,026 | Functional outcome, cognition and quality of life after out-of-hospital cardiac arrest and therapeutic hypothermia: data from a randomized controlled trial. | To study functional neurologic and cognitive outcome and health-related quality of life (HRQoL) in a cohort of patients included in a randomised controlled trial on glucose control following out-of-hospital cardiac arrest (OHCA) from ventricular fibrillation (VF) treated with therapeutic hypothermia.</AbstractText>Patients alive at 6 months after being discharged from the hospital underwent clinical neurological and extensive neuropsychological examinations. Functional outcome was evaluated with the Cerebral Performance Category scale, the modified Rankin scale and the Barthel Index. Cognitive outcome was evaluated by neuropsychological test battery including two measures of each cognitive function: cognitive speed, execution, memory, verbal skills and visuospatial performance. We also assessed quality of life with a HRQoL 15D questionnaire.</AbstractText>Of 90 OHCA-VF patients included in the original trial, 57 were alive at 6 months. Of these, 52 (91%) were functionally independent and 54 (95%) lived at their previous home. Focal neurological deficits were scarce. Intact cognitive performance was observed in 20 (49%), mild to moderate deficits in 14 (34%) and severe cognitive deficits in 7 (17%) of 41 patients assessed by a neuropsychologist. Cognitive impairments were most frequently detected in executive and memory functions. HRQoL of the CA survivors was comparable to that of age- and gender matched population.</AbstractText>Functional outcome six months after OHCA and therapeutic hypothermia was good in the great majority of the survivors, and half of them were cognitively intact. Of note, the HRQoL of CA survivors did not differ from that of age- and gender matched population.</AbstractText> |
11,027 | Testing the burden of rare variation in arrhythmia-susceptibility genes provides new insights into molecular diagnosis for Brugada syndrome. | The Brugada syndrome (BrS) is a rare heritable cardiac arrhythmia disorder associated with ventricular fibrillation and sudden cardiac death. Mutations in the SCN5A gene have been causally related to BrS in 20-30% of cases. Twenty other genes have been described as involved in BrS, but their overall contribution to disease prevalence is still unclear. This study aims to estimate the burden of rare coding variation in arrhythmia-susceptibility genes among a large group of patients with BrS. We have developed a custom kit to capture and sequence the coding regions of 45 previously reported arrhythmia-susceptibility genes and applied this kit to 167 index cases presenting with a Brugada pattern on the electrocardiogram as well as 167 individuals aged over 65-year old and showing no history of cardiac arrhythmia. By applying burden tests, a significant enrichment in rare coding variation (with a minor allele frequency below 0.1%) was observed only for SCN5A, with rare coding variants carried by 20.4% of cases with BrS versus 2.4% of control individuals (P = 1.4 × 10(-7)). No significant enrichment was observed for any other arrhythmia-susceptibility gene, including SCN10A and CACNA1C. These results indicate that, except for SCN5A, rare coding variation in previously reported arrhythmia-susceptibility genes do not contribute significantly to the occurrence of BrS in a population with European ancestry. Extreme caution should thus be taken when interpreting genetic variation in molecular diagnostic setting, since rare coding variants were observed in a similar extent among cases versus controls, for most previously reported BrS-susceptibility genes. |
11,028 | Predictors for outcome among cardiac arrest patients: the importance of initial cardiac arrest rhythm versus time to return of spontaneous circulation, a retrospective cohort study. | In the past decade, early treatment of cardiac arrest (CA) victims has been improved in several ways, leading to more optimistic over all prognoses. However, the global survival rate after out-of-hospital CA (OHCA) is still not more than 5-10%. With a better knowledge of the predictors for outcome among CA patients, we can improve the management of CA, in order to strengthen the leads in the chain of survival.</AbstractText>A retrospective cohort study including 172 CA patients admitted to the intensive care unit (ICU) in Odense University Hospital (OUH) in a three-year period was conducted. We determined the 90-day mortality and neurological outcome at discharge for CA patients treated with therapeutic hypothermia (TH), in regard to determine the importance of the predictors for mortality and neurological outcome, with emphasize on combining initial rhythm and time to return of spontaneous circulation (ROSC).</AbstractText>The overall mortality was 44% and a favorable neurological outcome was seen among 52%. Strong predictors for survival and favorable neurological outcome were ventricular tachycardia/ventricular fibrillation (VT/VF) as initial rhythm, cardiac etiology and time to ROSC < 20 minutes. Age < 60 years was a predictor for survival only. Patients with the combination of VT/VF and ROSC < 20 minutes had undeniably the best chance of both survival and a favorable neurological outcome.</AbstractText>We found significant predictors for both survival and neurological outcome, in which an initial rhythm of VT/VF and a cardiac etiology were the strongest.</AbstractText> |
11,029 | QRS Fragmentation and QTc Duration Relate to Malignant Ventricular Tachyarrhythmias and Sudden Cardiac Death in Patients with Hypertrophic Cardiomyopathy. | QRS fragmentation (fQRS) and prolonged QTc interval on surface ECG are prognostic in various cardiomyopathies other than hypertrophic cardiomyopathy (HCM). The association between fQRS and prolonged QTc duration with occurrence of ventricular tachyarrhythmias or sudden cardiac death (VTA/SCD) in patients with HCM was explored.</AbstractText>One hundred and ninety-five clinical HCM patients were studied. QTc duration was derived applying Bazett's formula; fQRS was defined as presence of various RSR' patterns, R or S notching and/or >1 additional R wave in any non-aVR lead in patients without pacing or (in)complete bundle branch block. The endpoints comprised SCD, ECG documented sustained VTA (tachycardia or fibrillation) or appropriate implantable cardioverter defibrillator (ICD) therapies (antitachycardia pacing [ATP] or shock) for VTA in ICD recipients (n = 58 [30%]). QT prolonging drugs recipients were excluded. After a median follow-up of 5.7 years (IQR 2.7-9.1), 26 (13%) patients experienced VTA or SCD. Patients with fQRS in ≥3 territories (inferior, lateral, septal, and/or anterior) (p = 0.004) or QTc ≥460 ms (p = 0.009) had worse cumulative survival free of VTA/SCD than patients with fQRS in <3 territories or QTc <460 ms. fQRS in ≥3 territories (ß 4.5, p = 0.020, 95%CI 1.41-14.1) and QTc ≥460 ms (ß 2.7, p = 0.037, 95%CI 1.12-6.33) were independently associated with VTA/SCD. Likelihood ratio test indicated assessment of fQRS and QTc on top of conventional SCD risk factors provides incremental predictive value for VTA/SCD (p = 0.035).</AbstractText>Both fQRS in ≥3 territories and QTc duration are associated with VTA/SCD in HCM patients, independently of and incremental to conventional SCD risk factors.</AbstractText>© 2015 Wiley Periodicals, Inc.</CopyrightInformation> |
11,030 | Development of ST Elevation Myocardial Infarction and Atrial Fibrillation after an Electrical Injury. | Electrical energy is a type of energy that is commonly used in daily life. Ventricular premature beats, ventricular tachycardia, ventricular fibrillation, atrial tachycardia, atrial fibrillation, bundle branch blocks, and AV block are arrhythmic complications that are encountered in case of electric shocks. Myocardial infarction is one of the rarely seen complications of electric shocks yet it has fatal outcomes. Coronary arteries were detected to be normal in most of the patients who had myocardial infarction following an electric shock. So, etiology of myocardial infarction is thought to be unrelated to coronary atherosclerosis in these cases. Coronary artery vasospasm is thought to be the primary etiological cause. In our case report, we presented a patient who developed ST elevation MI with atrial fibrillation after an electric shock. |
11,031 | Evidence of reversible bradycardia and arrhythmias caused by immunogenic proteins secreted by T. cruzi in isolated rat hearts. | Chagas cardiomyopathy, caused by the protozoan Trypanosoma cruzi, is characterized by alterations in intracellular ion, heart failure and arrhythmias. Arrhythmias have been related to sudden death, even in asymptomatic patients, and their molecular mechanisms have not been fully elucidated.</AbstractText>The aim of this study is to demonstrate the effect of proteins secreted by T. cruzi on healthy, isolated beating rat heart model under a non-damage-inducing protocol.</AbstractText>We established a non-damage-inducing recirculation-reoxygenation model where ultrafiltrate fractions of conditioned medium control or conditioned infected medium were perfused at a standard flow rate and under partial oxygenation. Western blotting with chagasic patient serum was performed to determine the antigenicity of the conditioned infected medium fractions. We observed bradycardia, ventricular fibrillation and complete atrioventricular block in hearts during perfusion with >50 kDa conditioned infected culture medium. The preincubation of conditioned infected medium with chagasic serum abolished the bradycardia and arrhythmias. The proteins present in the conditioned infected culture medium of >50 kDa fractions were recognized by the chagasic patient sera associated with arrhythmias.</AbstractText>These results suggest that proteins secreted by T. cruzi are involved in Chagas disease arrhythmias and may be a potential biomarker in chagasic patients.</AbstractText> |
11,032 | Surgical treatment of aberrant aortic origin of coronary arteries. | Aberrant origin of the coronary arteries is rare but can be life threatening. It is an important cause of sudden death in athletes and other young adults, and may be treated surgically. Consensus exists that interarterial left coronary artery (LCA) should be surgically repaired. For interarterial right coronary artery (RCA), the discussion remains open. The purpose of this study was to analyse our surgical experience.</AbstractText>From 2001 until 2014, 31 patients were operated for interarterial RCA, interarterial LCA or intraseptal course of the LCA. Twenty-six patients had interarterial RCA, 4 patients interarterial LCA and 1 patient an intraseptal course of the LCA. Median age at operation was 38 years (range 9-66 years). Twenty-eight patients had previous or current symptoms. The most important were a life-threatening event with resuscitation in 3 and myocardial infarction in 3 others. Surgical repair of interarterial RCA consisted of unroofing of the ostium with or without reimplantation in 25 patients and CABG on the RCA with a venous graft in 1 patient. Reconstruction of interarterial LCA consisted of ostium reconstruction of the LCA with a venous patch in 4 patients. The patient with an intraseptal course had a complete release of the LCA out of the septum and reimplantation in the correct coronary sinus. Follow-up was done by analysis of outpatient records, direct patient contact, echocardiography, electrocardiography, CT-angiography and an exercise test.</AbstractText>Median follow-up was 6 years (range 0-11 years). One patient was lost to follow-up. No early or late mortality occurred. Three patients had ischaemia with ventricular fibrillation or ventricular tachycardia shortly after surgery. Two were immediately reoperated, 1 had a stent implantation 1.5 months after release of intraseptal LCA. Two of these patients show a slight dysfunction of the left ventricle at follow-up. All other patients are asymptomatic.</AbstractText>Surgery for aberrant origin of coronary arteries is safe. There is a risk of cardiac ischaemia shortly after operation, especially in LCA reconstruction. We strongly believe that a slit-like coronary ostium and an intramural aortic course is an absolute indication for surgical repair, also in asymptomatic aberrant RCA.</AbstractText>© The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.</CopyrightInformation> |
11,033 | Atrial fibrillation recurrence predictors after conversion to sinus rhythm. | We aimed to identify predictors of atrial fibrillation recurrence after conversion to sinus rhythm.</AbstractText><AbstractText Label="MATERIAL/METHODS" NlmCategory="METHODS">We included 100 patients with a history of documented atrial fibrillation in the last 12 months that were assessed by transthoracic echocardiography, 12-lead electrocardiogram and signal averaged electrocardiogram of the P wave. Follow-up was 7.3 ± 2.2 months.</AbstractText>Atrial fibrillation recurrence was documented in 27 patients. It was more frequent in patients with longer duration of previous atrial fibrillation episode, with increased left atrium size and left ventricular mass, and it was correlated with the filtered P wave duration and Integral of the P wave.</AbstractText>Signal averaged ECG of the P wave, left atrium size and left ventricular mass determined by echocardiography could be helpful in predicting the risk of atrial fibrillation recurrence after conversion.</AbstractText> |
11,034 | Predictors of survival and favorable functional outcomes after an out-of-hospital cardiac arrest in patients systematically brought to a dedicated heart attack center (from the Harefield Cardiac Arrest Study). | Despite advances in cardiopulmonary resuscitation (CPR), survival remains low after out-of-hospital cardiac arrest (OOHCA). Acute coronary ischemia is the predominating precipitant, and prompt delivery of patients to dedicated facilities may improve outcomes. Since 2011, all patients experiencing OOHCA in London, where a cardiac etiology is suspected, are systematically brought to heart attack centers (HACs). We determined the predictors for survival and favorable functional outcomes in this setting. We analyzed 174 consecutive patients experiencing OOHCA from 2011 to 2013 brought to Harefield Hospital-a designated HAC in London. We analyzed (1) all-cause mortality and (2) functional status using a modified Rankin scale (mRS 0 to 6, where mRS0-3(+) = favorable functional status). The overall survival rates were 66.7% (30 days) and 62.1% (1 year); and 54.5% had mRS0-3(+) at discharge. Patients with mRS0-3(+) had reduced mortality compared to mRS0-3(-): 30 days (1.2% vs 72.2%, p <0.001) and 1 year (5.3% vs 77.2%, p <0.001). Multivariate analyses identified lower patient comorbidity, absence of cardiogenic shock, bystander CPR, ventricular tachycardia/ventricullar fibrillation as initial rhythm, shorter duration of resuscitation, prehospital advanced airway, absence of adrenaline and inotrope use, and intra-aortic balloon pump use as predictors of mRS0-3(+). Consistent predictors of increased mortality were the presence of cardiogenic shock, advanced airway use, increased duration of resuscitation, and absence of therapeutic hypothermia. A streamlined delivery of patients experiencing OOHCA to dedicated facilities is associated with improved functional status and survival. Our study supports the standardization of care for such patients with the widespread adoption of HACs. |
11,035 | Validation of the mapping accuracy of a novel non-invasive epicardial and endocardial electrophysiology system. | Use of a non-invasive electrocardiographic mapping system may aid in rapid diagnosis of atrial or ventricular arrhythmias or the detection of ventricular dyssynchrony. The aim of the present study was to validate the mapping accuracy of a novel non-invasive epi- and endocardial electrophysiology system (NEEES).</AbstractText>Patients underwent pre-procedural computed tomography or magnetic resonance imaging of the heart and torso. Radiographic data were merged with the data obtained from the NEEES during pacing from implanted pacemaker leads or pacing from endocardial sites using an electroanatomical mapping system (CARTO 3, Biosense Webster). The earliest activation as denoted on the NEEES three-dimensional heart model was compared with the true anatomic location of the tip of the pacemaker lead or the annotated pacing site on the CARTO 3 map. Twenty-nine patients [mean age: 62 ± 11 years, 6/29 (11%) female, 21/29 (72%) with ischaemic cardiomyopathy] were enrolled into the pacemaker verification group. The mean distance from the non-invasively predicted pacing site to the anatomic reference site was 10.8 ± 5.4 mm for the right atrium, 7.7 ± 5.8 mm for the right ventricle, and 7.9 ± 5.7 mm for the left ventricle activated via the coronary sinus lead. Five patients [mean age 65 ± 4 years, 2 (33%) females] underwent CARTO 3 verification study. The mean distance between non-invasively reconstructed pacing site and the reference pacing site was 7.4 ± 2.7 mm for the right atrium, 6.9 ± 2.3 mm for the left atrium, 6.5 ± 2.1 mm for the right ventricle, and 6.4 ± 2.2 for the left ventricle, respectively.</AbstractText>The novel NEEES was able to correctly identify the site of pacing from various endo- and epicardial sites with high accuracy.</AbstractText>© The Author 2015. Published by Oxford University Press on behalf of the European Society of Cardiology.</CopyrightInformation> |
11,036 | [The Mexican Registry of Atrial Fibrillation (ReMeFa)]. | The Mexican Registry of Atrial Fibrillation (ReMeFa) is the first national multicenter registry with one-year clinical follow-up on the treatment of atrial fibrillation (AF) in newly diagnosed patients.</AbstractText>To describe the demographics and treatment modalities for rhythm control (RC) strategy or heart rate (HR) control in patients with AF treated by cardiologists. A secondary objective was to prospectively evaluate the status of AF according to the chosen strategy; sinus rhythm in RC and mean ventricular rate at rest ≤ 80 bpm in HR, as well as the incidence of clinical outcomes at 12 month follow-up.</AbstractText>ReMeFa was a multicenter, prospective, descriptive study. We included adults with documented AF. We excluded those with AF secondary to reversible causes, undergoing pulmonary vein ablation, pacemaker or defibrillator users, with a life expectancy of less than one year, or with physical or mental impediments to meet the protocol objectives. Data were collected at baseline and at 6 and 12 months.</AbstractText>We registered 1,201 subjects and 1,193 were eligible for evaluation: 40% were on RC strategy and 60% on HR control. In the RC strategy, the drugs most commonly used were class III antiarrhythmics (64%), beta-blockers (25%), and digoxin (24%). In HR control strategy, the drugs used were digoxin (69%), class III antiarrhythmics (59%), and beta-blockers (56%). Compared with those on HR control, patients in RC strategy were younger (64 ± 14 years), in sinus rhythm (55%) and with paroxysmal AF (60%) at baseline. Patients in HR control were older (68 ± 13 years), with non-paroxysmal AF (91%), valvular disease (42%), heart failure (35%), left ventricular dysfunction (33%), and diabetes (25%). At one year follow-up, a 3% incidence of ischemic stroke was observed in the HR control group, significantly higher than the 1% observed in the RC strategy (p = 0.041).</AbstractText>ReMeFa registry results offer a current and comprehensive perspective on management strategies in Mexican patients with AF. The RC strategy provided better control of the arrhythmia as compared with the HR control strategy and it was associated with a lower rate of ischemic stroke. Nonetheless, current strategies of treatment of AF are not satisfactory.</AbstractText> |
11,037 | Cardiac fibrosis as a determinant of ventricular tachyarrhythmias. | Animal and emerging clinical studies have demonstrated that increased ventricular fibrosis in a setting of reduced repolarization reserve promotes early afterdepolarizations (EADs) and triggered activity that can initiate ventricular tachycardia and ventricular fibrillation (VT/VF). Increased ventricular fibrosis plays a key facilitatory role in allowing oxidative and metabolic stress-induced EADs to manifest as triggered activity causing VT/VF. The lack of such an arrhythmogenic effect by the same stressors in normal non-fibrotic hearts highlights the importance of fibrosis in the initiation of VT/VF. These findings suggest that antifibrotic therapy combined with therapy designed to increase ventricular repolarization reserve may act synergistically to reduce the risk of sudden cardiac death. |
11,038 | Impaired sinoatrial node function and increased susceptibility to atrial fibrillation in mice lacking natriuretic peptide receptor C. | Natriuretic peptides (NPs) are critical regulators of the cardiovascular system that are currently viewed as possible therapeutic targets for the treatment of heart disease. Recent work demonstrates potent NP effects on cardiac electrophysiology, including in the sinoatrial node (SAN) and atria. NPs elicit their effects via three NP receptors (NPR-A, NPR-B and NPR-C). Among these receptors, NPR-C is poorly understood. Accordingly, the goal of this study was to determine the effects of NPR-C ablation on cardiac structure and arrhythmogenesis. Cardiac structure and function were assessed in wild-type (NPR-C(+/+)) and NPR-C knockout (NPR-C(-/-)) mice using echocardiography, intracardiac programmed stimulation, patch clamping, high-resolution optical mapping, quantitative polymerase chain reaction and histology. These studies demonstrate that NPR-C(-/-) mice display SAN dysfunction, as indicated by a prolongation (30%) of corrected SAN recovery time, as well as an increased susceptibility to atrial fibrillation (6% in NPR-C(+/+) vs. 47% in NPR-C(-/-)). There were no differences in SAN or atrial action potential morphology in NPR-C(-/-) mice; however, increased atrial arrhythmogenesis in NPR-C(-/-) mice was associated with reductions in SAN (20%) and atrial (15%) conduction velocity, as well as increases in expression and deposition of collagen in the atrial myocardium. No differences were seen in ventricular arrhythmogenesis or fibrosis in NPR-C(-/-) mice. This study demonstrates that loss of NPR-C results in SAN dysfunction and increased susceptibility to atrial arrhythmias in association with structural remodelling and fibrosis in the atrial myocardium. These findings indicate a critical protective role for NPR-C in the heart. |
11,039 | Resveratrol, a red wine antioxidant, reduces atrial fibrillation susceptibility in the failing heart by PI3K/AKT/eNOS signaling pathway activation. | Resveratrol has shown benefits in reducing ventricular remodeling and arrhythmias.</AbstractText>This study aimed to assess the therapeutic efficacy of resveratrol in reducing atrial fibrillation (AF) in a heart failure (HF) model and to explore the underlying mechanisms.</AbstractText>HF rabbits were created 4 weeks after undergoing coronary ligation. Group 1 (n = 6) was divided into subgroups of (a) normal rabbits, (b) HF sham rabbits, and (c) HF rabbits treated for 1 week with intraperitoneal injections of resveratrol, (d) resveratrol plus wortmannin, or (e) resveratrol plus diphenyleneiodonium chloride (DPI). All rabbits underwent epicardial catheter stimulation. Collagen content, messenger RNA and protein expression in ion channels, and phosphoinositide 3-kinase (PI3K)/AKT/endothelial nitric oxide synthase (eNOS) signaling pathways were studied in left atrial appendage (LAA) preparations. To investigate acute drug effects on left atrial electrophysiology, groups 2 a through 2e (n = 6 per group) were subjected to Langendorff perfusion.</AbstractText>Higher AF inducibility was found in the HF group and groups that were given PI3K and eNOS inhibitors than in the normal and resveratrol-treated groups (P < .001). Histologic analysis of the LAA revealed a decrease in fibrosis in resveratrol-treated groups compared with the HF group (8.95% ± 1.53% vs 26.62% ± 2.19%, P < .001). In real-time polymerase chain reaction analysis, ion channels including Kv1.4, Kv1.5, KvLQT1, Kir2.1, Nav1.5, Cav1.2, NCX, SERCA2a, and phospholamban were upregulated by resveratrol. PI3K, AKT, and eNOS messenger RNA and protein expression were upregulated by resveratrol but were inhibited by the coadministration of wortmannin and DPI.</AbstractText>Resveratrol decreases left atrial fibrosis and regulates variation in ion channels to reduce AF through the PI3K/AKT/eNOS signaling pathway.</AbstractText>Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,040 | Cardiorenal axis and arrhythmias: Will renal sympathetic denervation provide additive value to the therapeutic arsenal? | Disruption of sympathetic tone may result in the occurrence or maintenance of cardiac arrhythmias. Multiple arrhythmic therapies that intervene by influencing cardiac sympathetic tone are common in clinical practice. These vary from pharmaceutical (β-blockers, angiotensin-converting enzyme inhibitors, and calcium antagonists) to percutaneous/surgical (cardiac sympathetic denervation) interventions. In some patients, however, these therapies have insufficient prophylactic and therapeutic capabilities. A safe and effective additional therapy wherein sympathetic drive is further attenuated would be expedient. Recently, renal sympathetic denervation (RSD) has been subject of research for various sympathetic nervous system-related diseases. By its presumed afferent and efferent sympatholytic effects, RSD might indirectly attenuate sympathetic outflow via the brain to the heart but might also reduce systemic catecholamine excretion and might therefore reduce catecholamine-sensitive arrhythmias. RSD is subject of research for various sympathetically driven arrhythmias, both supraventricular and ventricular. In this review, we give an overview of the rationale behind RSD as potential therapy in mediating arrhythmias that are triggered by a disrupted sympathetic nervous system and discuss the presently available results from animal and human studies. |
11,041 | Inhibition of nitric oxide synthases, but not inducible nitric oxide synthase, selectively worsens left ventricular function after successful resuscitation from cardiac arrest in swine. | Nitric oxide (NO) is a critical regulator of vascular tone and signal transduction in the cardiovascular system. NO is synthesized by three unique enzymes (nitric oxide synthases [NOS]): endothelial and neuronal NOS, both constitutively expressed, and inducible NOS (iNOS), which is induced by proinflammatory stimuli and subsequently produces a burst of NO. NO has been implicated as both an injurious and a beneficial mediator after cardiac arrest and resuscitation. A previous study in swine found that iNOS expression is absent in the myocardium prior to cardiac arrest and that it increases after 10 minutes of untreated ventricular fibrillation (VF), decreases somewhat during the early postresuscitation period, and then steadily increases up to 6 hours postresuscitation. Because this time course of iNOS expression mirrors that of postresuscitation myocardial dysfunction, this study was designed to test the hypothesis that selective inhibition of iNOS improves postresuscitation outcomes in swine.</AbstractText>Thirty-two domestic swine of either sex were randomly assigned to receive one of the following treatments 15 minutes after return of spontaneous circulation (ROSC): (1) N(G) -nitro-l-arginine methyl ester (l-NAME), a global NO inhibitor; (2) aminoguanidine (AG), a selective iNOS inhibitor; or (3) saline as control. After 10 minutes of untreated VF, swine received a standard resuscitation protocol. Twenty-four-hour survival, neurological status, left ventricular (LV) function, and hemodynamic measurements were obtained.</AbstractText>Return of spontaneous circulation occurred in 28 of 32 animals (88%). Only successfully resuscitated animals were assigned to treatment groups and completed the study. There were no differences in survival or neurological outcomes between groups. There were also no differences in LV function or hemodynamic variables found between the control group and the AG group. Global inhibition of NOS with l-NAME post-ROSC increased aortic pressure and transiently decreased pulse pressure. Treatment with l-NAME also increased LV end diastolic pressure and decreased cardiac output within 30 minutes post-ROSC, which was sustained throughout the 4-hour measurements, compared to both the control and the AG groups. In addition, LV ejection fraction recovered to baseline measurements in both the control and AG groups, but failed to recover in the l-NAME group.</AbstractText>Global inhibition of NOS after cardiac arrest and resuscitation markedly worsens hemodynamic variables. Selective inhibition of iNOS after cardiac arrest and resuscitation does not prevent postresuscitation myocardial stunning. There were no significant differences in neurological outcome or survival between treatment groups.</AbstractText>© 2015 by the Society for Academic Emergency Medicine.</CopyrightInformation> |
11,042 | Reverse cardiac remodeling after renal denervation: Atrial electrophysiologic and structural changes associated with blood pressure lowering. | Hypertension is the most common modifiable risk factor associated with atrial fibrillation.</AbstractText>The purpose of this study was to determine the effects of blood pressure (BP) lowering after renal denervation on atrial electrophysiologic and structural remodeling in humans.</AbstractText>Fourteen patients (mean age 64 ± 9 years, duration of hypertension 16 ± 11 years, on 5 ± 2 antihypertensive medications) with treatment-resistant hypertension underwent baseline 24-hour ambulatory BP monitoring, echocardiography, cardiac magnetic resonance imaging, and electrophysiologic study. Electrophysiologic study included measurements of P-wave duration, effective refractory periods, and conduction times. Electroanatomic mapping of the right atrium was completed using CARTO3 to determine local and regional conduction velocity and tissue voltage. Bilateral renal denervation was performed, and all measurements repeated after 6 months.</AbstractText>After renal denervation, mean 24-hour BP reduced from 152/84 mm Hg to 141/80 mm Hg at 6-month follow-up (P < .01). Global conduction velocity increased significantly (0.98 ± 0.13 m/s to 1.2 ± 0.16 m/s at 6 months, P < .01), conduction time shortened (32 ± 5 ms to 27 ± 6 ms, P < .01), and complex fractionated activity was reduced (37% ± 14% to 19% ± 12%, P = .02). Changes in conduction velocity correlated positively with changes in 24-hour mean systolic BP (R(2) = 0.55, P = .01). There was a significant reduction in left ventricular mass (139 ± 37 g to 120 ± 29 g, P < .01) and diffuse ventricular fibrosis (T1 partition coefficient 0.39 ± 0.07 to 0.31 ± 0.09, P = .01) on cardiac magnetic resonance imaging.</AbstractText>BP reduction after renal denervation is associated with improvements in regional and global atrial conduction and reductions in ventricular mass and fibrosis. Whether changes in electrical and structural remodeling are solely due to BP lowering or are due in part to intrinsic effects of renal denervation remains to be determined.</AbstractText>Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,043 | Autologous dermal fibroblast injections slow atrioventricular conduction and ventricular rate in atrial fibrillation in swine. | Nonpharmacological ventricular rate control in atrial fibrillation (AF) without producing atrioventricular (AV) block remains a clinical challenge. We investigated the hypothesis that autologous dermal fibroblast (ADF) injection into the AV nodal area would reduce ventricular response during AF without causing AV block.</AbstractText>Fourteen pigs underwent electrophysiology study before, immediately, and 28 days after ≈ 200 million cultured ADFs (n = 8) or saline (n = 6) were injected under electroanatomical guidance in the AV nodal area, with continuous 28-day ECG recording. In the ADF group at 28 days postinjection, there were prolongations of PR interval (after versus before: 130 ± 13 versus 113 ± 14 ms, P = 0.04), of AH interval during both sinus rhythm (92 ± 13 versus 76.8 ± 8 ms, P < 0.01) and atrial pacing at 400 ms (102 ± 13 versus 91 ± 9 ms, P < 0.01), and of AV node Wenckebach cycle length (230 ± 19 versus 213 ± 24 ms, P < 0.01), with no changes in the control group. The RR interval during induced AF 28 days after injections was 24% longer in ADF-treated group compared with controls (488 ± 120 versus 386 ± 116 ms, P < 0.001). Histological analysis revealed presence of ADF-labeled cells in the AV nodal area at 28 days. Transient accelerated junctional rhythm during injections, and transient nocturnal Mobitz I AV conduction occurred early postinjection in both groups.</AbstractText>Cells survived for 4 weeks and significantly slowed AV conduction and ventricular rate in acutely induced AF. Critically, despite a large number of injections in the AV nodal area and marked effects on AV conduction, AV block did not occur. Further studies are necessary to determine the clinical feasibility and safety of this strategy for ventricular rate control in AF.</AbstractText>© 2015 American Heart Association, Inc.</CopyrightInformation> |
11,044 | [Characteristics and clinical course of patients with acute heart failure and the therapeutic measures applied in Spanish emergency departments: based on the EAHFE registry (Epidemiology of Acute Heart Failure in Emergency Departments)]. | To analyze data recorded in the EAHFE registry (Epidemiology of Acute Heart Failure in Emergency Departments), which collects information on the clinical characteristics and laboratory findings of patients with acute heart failure (AHF) treated in 29 Spanish hospital emergency departments (EDs) as well as therapies used and clinical course. We analyzed changes in management observed over time and compared the results with data recorded in other AHF registries.</AbstractText>Prospective multicenter cohort study of consecutive patients treated in 3 different years: 2007, 2009, and 2011. We collected demographic, clinical, and laboratory data; medications taken prior to the emergency and in the ED; and outcome variables (in-hospital and 30-day and 1-year mortality rates, readmissions within 30 days). Changes in therapy and course in the 3 years were analyzed. The literature was reviewed to find other national and international AHF registries.</AbstractText>A total of 5845 patients were included (2007, 948; 2009, 1483; 2011, 3414). The mean age was 79 years and 56% were women. The AHF episode registered was the first experienced by 34.6% of the patients. Comorbidity was high: 82% had hypertension, 42.3% had diabetes mellitus, and 47.7% had atrial fibrillation. Severe or total functional dependence was observed in 21.9%, and 57.3% had systolic dysfunction (left ventricular ejection fraction, 38.3%). The main treatments administered consisted in diuretics (96.8%), endovenous nitroglycerine (20.7%), noninvasive ventilation (6.4%), and inotropic agents or vasopressors (3.6%). The glomerular filtration rate was low in 57%. Troponin and natriuretic peptide levels were measured in the EDs in 49.1% and 42.4% of the cases, respectively. Patients presented as normotensive in 66.4% of the cases, hypertensive in 23.5%, and hypotensive in 4.6% (0.7% in shock); 76.1% were admitted (1.9% to the ICU). The median hospital stay was 7 days and 23.9% were discharged from the ED. In-hospital mortality was 7.6%; 30-day mortality was 9.4% and 1-year mortality 29.5%. Orders for troponin and natriuretic peptide determinations increased over the 3 study periods, and the intravenous infusion of diuretics and inotropic agents and vasoconstrictors decreased (P < 0.001, all comparisons). Revisits within 30 days also decreased (P = 0.004). No changes were observed in in-hospital or 30-day mortality rates between 2007 and 2011. We reviewed 14 previously published registry reports (8 compiled prospectively); only 2 of the registries included ED patients.</AbstractText>The EAHFE registry describes the characteristics of AHF in a cohort that resembles the universe of our patients with AHF. Significant changes were observed over time in some aspects of AHF management. Revisits decreased, but mortality rates remained unchanged. Only 2 other previously analyzed registries included patients with AHF treated in hospital EDs.</AbstractText> |
11,045 | Takotsubo Cardiomyopathy Occurring in the Postoperative Period. | Takotsubo cardiomyopathy simulates acute myocardial infarction, and it is characterised by reversible left ventricular failure. A case of Takotsubo cardiomyopathy diagnosed after emergency angiography performed in a patient with evidence of acute myocardial infarction in the postoperative period will be described in this report. Transurethral resection of a bladder tumour (TUR-BT) was performed in a 92-year-old male patient by the urology clinic. The patient was transferred to the post-anaesthesia care unit after the operation. An echocardiography was performed because of the sudden onset of dyspnoea, tachycardia (140-150 beats per minute, rhythm-atrial fibrillation) and ST-segment elevation on electrocardiography (ECG) at the first postoperative hour, and midapical dyskinesia was detected at the patient. An immediate angiography was performed due to suspicion of acute coronary syndrome. Patent coronary arteries and temporary aneurysmatic dilatation of the apex of the heart were revealed by angiography. As a result of these findings, the patient was diagnosed with Takotsubo cardiomyopathy by the cardiology service. The patient was discharged uneventfully following 10 days in the intensive care unit. Aneurysm of the apex of the left ventricle and normal anatomy of the coronary arteries in the angiography have diagnostic value for Takotsubo cardiomyopathy. Diuretics (furosemide) and beta-blockers (metoprolol) are commonly used for the treatment of Takotsubo cardiomyopathy. Even though Takotsubo cardiomyopathy is a rare and benign disease, it should be kept in mind in patients suspected for acute myocardial infarction in the postoperative period. |
11,046 | Transcatheter aortic valve implantation in the United Kingdom: temporal trends, predictors of outcome, and 6-year follow-up: a report from the UK Transcatheter Aortic Valve Implantation (TAVI) Registry, 2007 to 2012. | We assessed trends in the performance of transcatheter aortic valve implantation in the United Kingdom from the first case in 2007 to the end of 2012. We analyzed changes in case mix, complications, outcomes to 6 years, and predictors of mortality.</AbstractText>Annual cohorts were examined. Mortality outcomes were analyzed in the 92% of patients from England and Wales for whom independent mortality tracking was available. A total of 3980 transcatheter aortic valve implantation procedures were performed. In successive years, there was an increase in frequency of impaired left ventricular function, but there was no change in Logistic EuroSCORE. Overall 30-day mortality was 6.3%; it was highest in the first cohort (2007-2008), after which there were no further significant changes. One-year survival was 81.7%, falling to 37.3% at 6 years. Discharge by day 5 rose from 16.7% in 2007 and 2008 to 28% in 2012. The only multivariate preprocedural predictor of 30-day mortality was Logistic EuroSCORE ≥40. During long-term follow-up, multivariate predictors of mortality were preprocedural atrial fibrillation, chronic obstructive pulmonary disease, creatinine >200 μmol/L, diabetes mellitus, and coronary artery disease. The strongest independent procedural predictor of long-term mortality was periprocedural stroke (hazard ratio=3.00; P<0.0001). Nonfemoral access and postprocedural aortic regurgitation were also significant predictors of adverse outcome.</AbstractText>We analyzed transcatheter aortic valve implantation in an entire country, with follow-up over 6 years. Although clinical profiles of enrolled patients remained unchanged, longer-term outcomes improved, and patients were discharged earlier. Periprocedural stroke, nonfemoral access, and postprocedural aortic regurgitation are predictors of adverse outcome, along with intrinsic patient risk factors.</AbstractText>© 2015 American Heart Association, Inc.</CopyrightInformation> |
11,047 | Low inappropriate shock rates in patients with single- and dual/triple-chamber implantable cardioverter-defibrillators using a novel suite of detection algorithms: PainFree SST trial primary results. | The benefits of implantable cardioverter-defibrillators (ICDs) have been well demonstrated in many clinical trials, and ICD shocks for ventricular tachyarrhythmias save lives. However, inappropriate and unnecessary shock delivery remains a significant clinical issue with considerable consequences for patients and the healthcare system.</AbstractText>The purpose of the PainFree SmartShock Technology (SST) study was to investigate new-generation ICDs to reduce inappropriate and unnecessary shocks through novel discrimination algorithms with modern programming strategies.</AbstractText>This prospective, multicenter clinical trial enrolled 2790 patients with approved indication for ICD implantation (79% male, mean age 65 years; 69% primary prevention indication, 27% single-chamber ICD, 33% replacement or upgrade). Patients were followed for a minimum of 12 months, and mean follow-up was 22 months. The primary end-point of the study was the percentage of patients remaining free of inappropriate shocks at 1 year postimplant, analyzed separately for dual/triple-chamber ICDs (N = 2019) and single-chamber ICDs (N = 751).</AbstractText>The inappropriate shock rate at 1 year was 1.5% for patients with dual/triple-chamber ICDs and 2.5% for patients with single-chamber devices. Two years postimplant, the inappropriate shock rate was 2.8% for patients with dual-/triple chamber ICDs and 3.7% for those with single-chamber ICDs. The most common cause of an inappropriate shock in both groups was atrial fibrillation or flutter.</AbstractText>In a large patient cohort receiving ICDs for primary or secondary prevention, the adoption of novel enhanced detection algorithms in conjunction with routine implementation of modern programming strategies led to a very low inappropriate shock rate.</AbstractText>Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,048 | Characteristics of "malignant" vs. "benign" electrocardiographic patterns of early repolarization. | The electrocardiographic (ECG) pattern of early repolarization (ER) has historically been regarded as a benign ECG variant, but during the past few years, this concept has been challenged based on multiple reports linking the ER pattern with an increased risk of sudden cardiac death. Although the mechanistic basis of ventricular arrhythmogenesis in patients with ER pattern is still incompletely understood, there is increasing information about the ECG and phenotype characteristics of "malignant" vs. "benign" patterns of ER. This review presents the current evidence of markers of "benign" and a more severe nature of ER. |
11,049 | Dofetilide induced torsade de pointes: mechanism, risk factors and management strategies. | Dofetilide is an effective antiarrhythmic agent for conversion of atrial fibrillation and atrial flutter as well as maintenance of sinus rhythm in appropriately selected patients. However, as with other antiarrhythmic agents, proarrhythmia is a known adverse effect. The risk of dofetilide induced torsade de pointes (Tdp) is low when used with strict dosing criteria guided by renal function, QT interval and concomitant drug therapy. Benefit from dofetilide use must be individualized and weighed against the side effects and the role of other available treatment options. In this review, we discuss the underlying mechanism, risk factors and precautionary measures to avoid dofetilide induced QT prolongation and ventricular tachycardia/Tdp. We suggest a scheme for the management of QT prolongation, ventricular arrhythmia and Tdp as well. |
11,050 | Catheter ablation of atrial fibrillation in patients with severely impaired left ventricular systolic function. | Little is known about the outcome of catheter ablation of atrial fibrillation (AF) in patients with heart failure (HF) and a severely reduced left ventricular ejection fraction (LVEF). We aimed to clarify the effectiveness of catheter ablation of AF in patients with a severely low LVEF. This retrospective study included 18 consecutive patients with HF and an LVEF of ≤ 35 % who underwent catheter ablation of AF. We investigated the clinical parameters, echocardiographic parameters and the incidence of hospitalizations for HF. During a median follow-up of 21 months (IQR, 13-40) after the final procedure (9 with repeat procedures), 11 patients (61 %) maintained sinus rhythm (SR) (6 with amiodarone). The LVEF and NYHA class significantly improved at 6 months after the CA in 12 patients (67 %) who were in SR or had recurrent paroxysmal AF (from 25.8 ± 6.3 to 37.0 ± 11.7 %, P = 0.02, and from 2.3 ± 0.5 to 1.5 ± 0.7, P < 0.01, respectively) but not in patients who experienced recurrent persistent AF. The patients with SR or recurrent paroxysmal AF had significantly fewer hospitalizations for HF than those with recurrent persistent AF after the AF ablation (log-rank test; P < 0.01). Catheter ablation of AF improved the clinical status in patients with an LVEF of ≤ 35 %. A repeat ablation procedure and amiodarone were often necessary to obtain a favorable outcome. |
11,051 | Acute caffeine poisoning resulting in atrial fibrillation after guarana extract overdose. | Guarana (Paullinia cupana) is the climbing vine native to Amazon Basin, characterized by high caffeine content in its seeds. Guarana extract is a common ingredient of energy drinks used in order to boost energy and physical endurance and increase alertness. Severe caffeine intoxication is rare, but may be life-threatening mostly due to supraventricular and ventricular dysrhythmias.</AbstractText>We present the case of intentional caffeine poisoning after ingestion of tablets containing guarana extract, complicated by atrial fibrillation.</AbstractText>A44-year-old man with no significant medical history was admitted to hospital about 21 h after ingestion of guarana extract containing 1.6 g of caffeine. Typical symptoms of caffeine toxicity, i.e. nausea, vomiting, anxiety and palpitaions, occurred shortly after ingestion. On admission, he was conscious, with blood pressure of 136/86 mmHg, heart rate of 106-113 beats per minute, fever of 37.8 °C, and symmetrically increased deep tendon reflexes. QTc interval in electrocardiogram was prolonged to 0.542 s. Laboratory tests revealed hypokalemia, hyperglycemia, leukocytosis, as well as elevated creatinine and creatine phosphokinase levels. Approximately 45 h post ingestion, the patient developed atrial fibrillation with fast ventricular rhythm. Tachydysrythmia subsided after infusion of amiodarone and restoration of electrolyte balance. Echocardiogram revealed presence of asymmetrical hypertrophy of the left ventricle with the systolic anterior motion of the mitral valve and normal left ventricular outflow tract gradient suggesting non-obstructive hypertrophic cardiomyopathy.</AbstractText>Acute caffeine poisoning may result in atrial fibrillation, especially in predisposed patients with underlying hypertrophic cardiomyopathy.</AbstractText> |
11,052 | Changes in Global and Regional Mechanics Due to Atrial Fibrillation: Insights from a Coupled Finite-Element and Circulation Model. | Atrial fibrillation (AF) is a rhythm disorder with rapidly increasing prevalence due to the aging of the population. AF triggers structural remodeling and a gradual loss of function; however, the relative contributions of specific features of AF-induced remodeling to changes in atrial mechanical function are unclear. We constructed and validated a finite-element model (FEM) of the normal human left atrium using anatomic information from cardiac magnetic resonance imaging, material properties and fiber orientations from published studies, and an iterative algorithm to estimate unloaded geometry. We coupled the FEM to a circuit model to capture hemodynamic interactions between the atrium, pulmonary circulation, and left ventricle. The normal model reproduced measured volumes within 1 SD, as well as most metrics of regional mechanics. Using this validated human model as a starting point, we explored the impact of individual features of atrial remodeling on atrial mechanics and found that a combination of dilation, increased pressure, and fibrosis can explain most of the observed changes in mechanics in patients with paroxysmal AF. However, only impaired ventricular relaxation could reproduce the increased reliance on active emptying we observed in these patients. The resulting model provides new insight into the mechanics of AF and a platform for exploring future therapies. |
11,053 | Relationship between degree of left ventricular dysfunction, symptom status, and risk of embolic events in patients with atrial fibrillation and heart failure. | Limited data exists regarding the relationship between left ventricular systolic dysfunction (LVSD) and heart failure (HF) symptoms and embolic risk among patients with atrial fibrillation.</AbstractText>Participants in the Atrial Fibrillation Clopidogrel Trial With Irbesartan for Prevention of Vascular Events (ACTIVE) trials with HF, but not randomized to oral anticoagulation, were categorized as having preserved versus reduced ejection fraction. If reduced, LVSD was classified as mild, moderate, or severe. Symptoms were quantified using New York Heart Association class.The primary outcome was a composite of stroke, transient ischemic attack, and systemic embolism.</AbstractText>There were 3487 antiplatelet-treated patients with HF at baseline. Of these patients, 969 (46.8%) had HF with preserved ejection fraction and 1103 (53.2%) had HF with reduced ejection fraction. During 3.6 years of mean follow-up, first occurrence of stroke, transient ischemic attack, or systemic embolism occurred in 386 patients.The strongest independent predictors of embolic events were age ≥75 years (hazard ratio 2.55; confidence interval, 1.85-3.53), prior stroke or transient ischemic attack (hazard ratio 2.07; 95% confidence interval, 1.65-2.60), and female sex (hazard ratio 1.37; confidence interval, 1.11-1.69). However, ejection fraction <0.50, degree of LVSD, and New York Heart Association class did not predict embolic events. Patients with HF with preserved ejection fraction exhibited similar risk of embolic events as those with HR with reduced ejection fraction: 4.3% versus 4.4% per 100 person-years (hazard ration 1.01; 95% confidence interval, 0.78-1.31). Risk of embolic events was similar across categories of LVSD (P for trend =0.96) and New York Heart Association class (P for trend =0.57).</AbstractText>Among HF patients in ACTIVE, neither the presence of LVSD or degree of symptom severity influenced risk of embolic events.</AbstractText>© 2015 American Heart Association, Inc.</CopyrightInformation> |
11,054 | Evaluation of a novel pulsatile extracorporeal life support system synchronized to the cardiac cycle: effect of rhythm changes on hemodynamic performance. | Arrhythmias are a frequent complication during extracorporeal life support (ECLS). A new ECLS system can provide pulsatile flow synchronized to the patient's intrinsic cardiac cycle based upon the R wave of the electrocardiogram (ECG). It is unclear how the occurrence of arrhythmias may alter the hemodynamic performance of the system. This in vitro study evaluated the effect of simulated arrhythmias on hemodynamics during R wave-triggered pulsatile ECLS. The ECLS circuit with an i-cor diagonal pump and iLA membrane ventilator was primed with whole blood at room temperature. Flow and pressure data were collected at 2.5 and 4 L/min for each condition using a customized data acquisition system. Pulsatile ECLS flow was R wave synchronized to an ECG simulator using 1:1, 1:2, and 1:3 assist ratios. Conditions tested included sinus rhythm at 45 and 90 bpm, supraventricular tachycardia (SVT), ventricular tachycardia (VT), and irregular rhythms such as ventricular fibrillation. Pulsatile mode was successfully triggered by ECG signals of normal sinus rhythm, SVT, VT, atrial fibrillation, atrial flutter, and ventricular bigeminy with assist ratios 1:1, 1:2, and 1:3. Regular rhythm at 90 bpm generated the best surplus hemodynamic energy (SHE). For SVT and VT, an assist ratio of 1:2 resulted in maximum pulsatile flow waveforms with optimal SHE at 2.5 L/min flow rate. At 4 L/min, SHE declined and the pressure drop increased independent of arrhythmia condition. Irregular rhythms still produced adequate pulsatile wave forms at lower pulsatile frequency. This study demonstrated the feasibility of generating pulsatile ECLS flow with the novel ECG-synchronized i-cor system during various simulated rhythms. The optimal rate for pulsatile flow was 90 bpm. During irregular rhythms, the lower pulsatile frequency was the more reliable synchronization mode for generating pulsatile flow. |
11,055 | Risk prediction for adverse events during initiation of sotalol and dofetilide for the treatment of atrial fibrillation. | Inpatient antiarrhythmic drug initiation for atrial fibrillation is mandated for dofetilide (DF) and is often performed for sotalol (SL), particularly if proarrhythmia risk factors are present. Whether low-risk patients can be identified to safely allow outpatient initiation is unknown.</AbstractText>A single-center retrospective cohort study was performed on patients initiated with DF or SL. Risk factors for adverse events (AEs), defined as any arrhythmia or electrocardiogram change requiring dose reduction or cessation, were identified.</AbstractText>Of 329 patients, 227 (69%) received SL and 102 (31%) DF. The cohort had a mean age of 63 ± 13 years; 70% of patients were male and had a baseline QTc of 440 ± 37 ms. A total of 105 AEs occurred in 92 patients: QTc prolongation or ventricular tachyarrhythmia in 70 patients (67% of AEs), bradyarrhythmias in 35 patients (33% of AEs), with some experiencing both AE types. Ventricular arrhythmias were seen in 23 patients (7%) and torsades de pointes in one (0.3%). Total AE rates were similar between drugs (P = 0.09); however, DF patients had more QTc prolongation or ventricular arrhythmias (P = 0.001). In SL patients, there were no predictors for QTc prolongation or ventricular proarrhythmia. In DF patients, higher baseline QTc interval (odds ratio = 1.64/25 ms, P = 0.01) was an independent predictor of QTc prolongation or ventricular proarrhythmias. For patients without proarrhythmia risk factors, overall AE rate was 26%.</AbstractText>In conclusion, AEs are common during DF and SL initiation but rarely severe in hospitalized inpatients. Baseline QTc predicts AEs for DF patients only and AE are common even in "low-risk" patients. These results support in-hospital drug initiation for all DF and SL patients.</AbstractText>© 2015 Wiley Periodicals, Inc.</CopyrightInformation> |
11,056 | Milrinone for the Treatment of Acute Heart Failure After Acute Myocardial Infarction: A Systematic Review and Meta-Analysis. | Despite advancements in modern medicine, the treatment of acute heart failure (AHF) after acute myocardial infarction (AMI) remains challenging. Milrinone is effective in the treatment of chronic congestive heart failure, but its safety and efficacy in patients with AHF after AMI have not been systematically evaluated. This meta-analysis was performed to assess the safety and efficacy of milrinone in patients with AHF after AMI. We used a pre-designed protocol to search electronic databases for randomized trials assessing milrinone for the treatment of AHF after AMI. Data were abstracted from relevant studies. Heterogeneity was assessed qualitatively using a Q test and quantified using the I(2) statistic. Pooled risk estimates with 95% confidence intervals (CIs) were obtained using fixed-effects models unless substantial heterogeneity was observed (I(2) ≥ 50% and heterogeneity p ≤ 0.1). Four randomized trials met the inclusion criteria. However, there were no significant differences in deaths, blood pressure, premature ventricular contractions, gastrointestinal reactions, or ventricular tachycardia or fibrillation (all p > 0.05) between control group and milrinone treatment group. Pooled estimates showed that milrinone significantly increased the left ventricular ejection fraction (MD 5.69; 95% CI 4.27 to 7.10; p < 0.00001) and cardiac output (MD 0.35, 95% CI: 0.13 to 0.56; p = 0.002, I(2) = 24%). While studies to date are few and limited by small sample sizes and poor quality, they suggest that treatment with milrinone may be safe and effective for patients with AHF after AMI. However, this meta-analysis did not show that milrinone could improve prognosis or the survival rate. |
11,057 | [The 10-year stroke risk in hypertensive outpatients combined with diabetes in cardiovascular clinics of 36 tertiary hospitals in China]. | To assess the estimated 10-year risk of stroke among hypertensive outpatients known with diabetes from cardiovascular clinics of 36 tertiary hospitals in China and to analyze the characteristics of the risk factors and the 10-year risk of stroke between the southern and the northern patients.</AbstractText>A multi-center prevalence survey was conducted from October 2011 to June 2012. Hypertensive outpatients known with diabetes were enrolled from cardiovascular clinics of 36 tertiary hospitals in China. A total of 15 914 outpatients were included in the final analysis. The 10-year probability of stroke was evaluated by the Framingham stroke risk profile. According to the 10-year probability of stroke, patients were divided into low risk ( ≤ 5%), medium risk (6%∼9%) and high risk ( ≥ 10%).</AbstractText>(1) Of all the hypertensive outpatients known with diabetes, the mean age was (64.6 ± 10.1) years and the mean systolic pressure was (138.7 ± 19.3) mmHg (1 mmHg = 0.133 kPa). Among them, 7.4% with atrial fibrillation, 11.2% with left ventricular hypertrophy, 57.2% with cardiovascular diseases, 17.1% smokers and 37.0% using mono-hypoglycemic agent. The southern patients who were older with more smokers had higher proportions of men and left ventricular hypertrophy, lower levels of systolic blood pressure, and lower proportions of other cardiovascular diseases than those of the northern patients ( all P < 0.05). (2) The mean 10-year probability of stroke was (20.9 ± 16.2) %. The southern patients had a higher mean 10-year probability of stroke than that of the northern patients [(22.4 ± 17.1) % vs (19.7 ± 15.2) %] (P < 0.01) . After adjusted by age and sex, the southern patients still had a higher mean 10-year probability of stroke (P < 0.05) . (3) All the patients had 7.7% with low risk, 17.4% with medium risk, and 74.9% with high risk. The southern patients had lower proportions of low and medium risk than those of the northern patients (6.7% vs 8.4%, 15.5% vs 18.9%), but had a higher proportion of high risk than that of the northern patients (77.7% vs 72.7%, all P < 0.01).</AbstractText>Among the hypertensive outpatients known with diabetes from the cardiovascular clinics of our study, most of them were at the 10-year high risk of stroke. The southern patients had a higher mean 10-year probability of stroke than that of the northern patients.</AbstractText> |
11,058 | Inflammation and the pathogenesis of atrial fibrillation. | Atrial fibrillation (AF) is the most common cardiac arrhythmia. However, the development of preventative therapies for AF has been disappointing. The infiltration of immune cells and proteins that mediate the inflammatory response in cardiac tissue and circulatory processes is associated with AF. Furthermore, the presence of inflammation in the heart or systemic circulation can predict the onset of AF and recurrence in the general population, as well as in patients after cardiac surgery, cardioversion, and catheter ablation. Mediators of the inflammatory response can alter atrial electrophysiology and structural substrates, thereby leading to increased vulnerability to AF. Inflammation also modulates calcium homeostasis and connexins, which are associated with triggers of AF and heterogeneous atrial conduction. Myolysis, cardiomyocyte apoptosis, and the activation of fibrotic pathways via fibroblasts, transforming growth factor-β and matrix metalloproteases are also mediated by inflammatory pathways, which can all contribute to structural remodelling of the atria. The development of thromboembolism, a detrimental complication of AF, is also associated with inflammatory activity. Understanding the complex pathophysiological processes and dynamic changes of AF-associated inflammation might help to identify specific anti-inflammatory strategies for the prevention of AF. |
11,059 | Extracorporeal cardiopulmonary resuscitation for refractory ventricular fibrillation. A rescue bridge to reperfusion. | Accumulating evidence suggests benefit of extracorporeal cardiopulmonary resuscitation (E-CPR) in patients with refractory cardiac arrest by using venoarterial extracorporeal membrane oxygenation. Appropriate patient selection for E-CPR is cumbersome and still debated. We describe a 56-year-old male who developed refractory ventricular fibrillation upon arrival at the emergency department and was successfully treated by urgent E-CPR. Patient selection, complications and the need to adapt the chain of survival are discussed. |
11,060 | Inappropriate ICD shocks in pediatrics and congenital heart disease patients: Risk factors and programming strategies. | Inappropriate implantable cardioverter-defibrillator (ICD) shocks are a common and significant problem in pediatric patients and patients with congenital heart disease (CHD).</AbstractText>The purpose of this study was to evaluate the effect of programming high detection rates and long detection duration on inappropriate shocks in this population.</AbstractText>We performed a retrospective review of all patients with ICDs at a single pediatric center. Inappropriate shocks were defined as a shock for any rhythm except ventricular tachycardia or fibrillation.</AbstractText>A total of 144 patients were included, 63 (44%) with CHD. At implant, mean age and weight were 17 ± 10 years and 57 ± 23 kg. ICDs were single chamber in 35 (24%), dual chamber in 97 (67%), and biventricular in 12 (8%). The mean follow-up duration was 42 ± 39 months. Appropriate shocks occurred in 29 (20.1%) and inappropriate shocks in 14 (9.7%). Causes of inappropriate shocks were supraventricular tachycardia (n = 6), lead malfunction (n = 4), sinus tachycardia (n = 3), and T-wave oversensing (n = 1). The mean ventricular fibrillation detection rate was 222 ± 15 beats/min, and the detection duration was 18 ± 12 beats. Patients with shocks programmed in the ventricular tachycardia zone were more likely to receive an inappropriate shock (P = .03). There were no associations between inappropriate shocks and age or weight at implant, presence of CHD, dual-chamber vs single-chamber device, history of supraventricular tachycardia, or antiarrhythmic use. There were no adverse events as a result of programming.</AbstractText>Programming high detection rates and long detection duration resulted in a low rate of inappropriate shocks without associated adverse events in this large cohort of pediatric and CHD patients with ICDs.</AbstractText>Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,061 | Palmitoyl-carnitine increases RyR2 oxidation and sarcoplasmic reticulum Ca2+ leak in cardiomyocytes: Role of adenine nucleotide translocase. | Long chain fatty acids bind to carnitine and form long chain acyl carnitine (LCAC), to enter into the mitochondria. They are oxidized in the mitochondrial matrix. LCAC accumulates rapidly under metabolic disorders, such as acute cardiac ischemia, chronic heart failure or diabetic cardiomyopathy. LCAC accumulation is associated with severe cardiac arrhythmia including ventricular tachycardia or fibrillation. We thus hypothesized that palmitoyl-carnitine (PC), alters mitochondrial function leading to Ca(2+) dependent-arrhythmia. In isolated cardiac mitochondria from C57Bl/6 mice, application of 10μM PC decreased adenine nucleotide translocase (ANT) activity without affecting mitochondrial permeability transition pore (mPTP) opening. Mitochondrial reactive oxygen species (ROS) production, measured with MitoSOX Red dye in isolated ventricular cardiomyocytes, increased significantly under PC application. Inhibition of ANT by bongkrekic acid (20 μM) prevented PC-induced mitochondrial ROS production. In addition, PC increased type 2 ryanodine receptor (RyR2) oxidation, S-nitrosylation and dissociation of FKBP12.6 from RyR2, and therefore increased sarcoplasmic reticulum (SR) Ca(2+) leak. ANT inhibition or anti-oxidant strategy (N-acetylcysteine) prevented SR Ca(2+) leak, FKBP12.6 depletion and RyR2 oxidation/S-nitrosylation induced by PC. Finally, both bongkrekic acid and NAC significantly reduced spontaneous Ca(2+) wave occurrences under PC. Altogether, these results suggest that an elevation of PC disturbs ANT activity and alters Ca(2+) handling in a ROS-dependent pathway, demonstrating a new pathway whereby altered FA metabolism may contribute to the development of ventricular arrhythmia in pathophysiological conditions. |
11,062 | Protective effects of yindanxinnaotong capsule in a rat model of myocardial ischemia/reperfusion injury. | To investigate the effects of Yindanxinnaotong capsule (YDXNTC) and main components compatibility and ratios on myocardium against ischemia/reperfusion injury and the effect's underlying mechanism.</AbstractText>Myocardial ischemia/reperfusion injury (MIRI) was induced by ischemia for 30 min and reperfusion for 30 min. Electrocardiogram data and coronary flow were recorded, and superoxide dismutase (SOD), malondialdehyde (MDA), lactate dehydrogenase, creatine kinase-MB, cardiac troponin T and I (cTnT, cTnI) and interleukin-1β, interleukin-8, interleukin-18 (IL-1β, IL-8, IL-18) in myocardium were measured. Hypoxia/reoxygenation and hydrogen peroxide (H2O2) injury were induced by hypoxia for 3 h/reoxygenation for 2 h, and 100 μM H2O2 for 1 h, respectively, in vitro rat myocardial cells (H9c2). Cell viability, SOD, MDA, cTnT and inflammatory factors (IL-1β, IL-8 and IL-18) were determined, and Toll-like receptor 4 (TLR-4) expression was measured by western blotting.</AbstractText>In the isolated heart experiment, elevated heart function, coronary flow and SOD levels, and decreased MDA levels and inflammatory factors were noted in the YDXNTC, main components and main components compatibility groups. Ventricular tachycardia/ventricular fibrillation occurrence decreased in the ginkgo biloba extract (GBE), and GBE and salvia miltiorrhiza ethanol extract compatibility (SM-E, GSEC) groups. Lactic dehydrogenase levels decreased in the YDXNTC and aqueous extract of salvia miltiorrhiza (SM-H) groups. Creatine kinase-MB decreased with GBE, SM-E, SM-H and GSEC treatment, and cTnI and cTnT levels decreased with GSEC. In the in vitro cell study, YDXNTC and main components ratios improved cell viability and SOD levels, and suppressed MDA, cTnT and inflammatory factors. TLR-4 expression was down-regulated.</AbstractText>YDXNTC and main components compatibility showed protective effects on MIRI in this rat model and in vitro study. Regulating the Toll-like receptor signaling pathway may affect the mechanism.</AbstractText> |
11,063 | Noncompaction cardiomyopathy: a substrate for a thromboembolic event. | Noncompaction cardiomyopathy (NCC) is a rare genetic cardiomyopathy characterized by a thin, compacted epicardial layer and an extensive noncompacted endocardial layer. The clinical manifestations of this disease include ventricular arrhythmia, heart failure, and systemic thromboembolism.</AbstractText>A 43-year-old male was anticoagulated by pulmonary thromboembolism for 1 year when he developed progressive dyspnea. Cardiovascular magnetic resonance imaging showed severe biventricular trabeculation with an ejection fraction of 15%, ratio of maximum noncompacted/compacted diastolic myocardial thickness of 3.2 and the presence of exuberant biventricular apical thrombus.</AbstractText>Still under discussion is the issue of which patients and when they should be anticoagulated. It is generally recommended to those presenting ventricular systolic dysfunction, antecedent of systemic embolism, presence of cardiac thrombus and atrial fibrillation. In clinical practice the patients with NCC and ventricular dysfunction have been given oral anticoagulation, although there are no clinical trials showing the real safety and benefit of this treatment.</AbstractText> |
11,064 | Impact of genotype on clinical course in arrhythmogenic right ventricular dysplasia/cardiomyopathy-associated mutation carriers. | We sought to determine the influence of genotype on clinical course and arrhythmic outcome among arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C)-associated mutation carriers.</AbstractText>Pathogenic mutations in desmosomal and non-desmosomal genes were identified in 577 patients (241 families) from USA and Dutch ARVD/C cohorts. Patients with sudden cardiac death (SCD)/ventricular fibrillation (VF) at presentation (n = 36) were younger (median 23 vs. 36 years; P < 0.001) than those presenting with sustained monomorphic ventricular tachycardia (VT). Among 541 subjects presenting alive, over a mean follow-up of 6 ± 7 years, 12 (2%) patients died, 162 (30%) had sustained VT/VF, 78 (14%) manifested left ventricular dysfunction (EF < 55%), 28 (5%) experienced heart failure (HF), and 10 (2%) required cardiac transplantation. Patients (n = 22; 4%) with >1 mutation had significantly earlier occurrence of sustained VT/VF (mean age 28 ± 12 years), lower VT-/VF-free survival (P = 0.037), more frequent left ventricular dysfunction (29%), HF (19%) and cardiac transplantation (9%) when compared with those with only one mutation. Desmoplakin mutation carriers experienced more than four-fold occurrence of left ventricular dysfunction (40%) and HF (13%) than PKP2 carriers. Missense mutation carriers had similar death-/transplant-free survival and VT/VF penetrance (P = 0.137) when compared with those with truncating or splice site mutations. Men are more likely to be probands (P < 0.001), symptomatic (P < 0.001) and have earlier and more severe arrhythmic expression.</AbstractText>Presentation with SCD/VF occurs at a significantly younger age when compared with sustained monomorphic VT. The genotype of ARVD/C mutation carriers impacts clinical course and disease expression. Male sex negatively modifies phenotypic expression.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
11,065 | The first Latin American Catheter Ablation Registry. | To assess the results of transcatheter ablation of cardiac arrhythmias in Latin America and establish the first Latin American transcatheter ablation registry.</AbstractText>All ablation procedures performed between 1 January and 31 December 2012 were analysed retrospectively. Data were obtained on the characteristics and resources of participating centres (public or private institution, number of beds, cardiac surgery availability, type of room for the procedures, days per week assigned to electrophysiology procedures, type of fluoroscopy equipment, availability and type of electroanatomical mapping system, intracardiac echo, cryoablation, and number of electrophysiologists) and the results of 17 different ablation substrates: atrio-ventricular node reentrant tachycardia, typical atrial flutter, atypical atrial flutter, left free wall accessory pathway, right free wall accessory pathway, septal accessory pathway, right-sided focal atrial tachycardia, left-sided focal atrial tachycardia, paroxysmal atrial fibrillation, non-paroxysmal atrial fibrillation, atrio-ventricular node, premature ventricular complex, idiopathic ventricular tachycardia, post-myocardial infarction ventricular tachycardia, ventricular tachycardia in chronic chagasic cardiomyopathy, ventricular tachycardia in congenital heart disease, and ventricular tachycardias in other structural heart diseases. Data of 15 099 procedures were received from 120 centres in 13 participating countries (Argentina, Bolivia, Brazil, Chile, Colombia, Cuba, El Salvador, Guatemala, Mexico, Peru, Dominican Republic, Uruguay, and Venezuela). Accessory pathway was the group of arrhythmias most frequently ablated (31%), followed by atrio-ventricular node reentrant tachycardia (29%), typical atrial flutter (14%), and atrial fibrillation (11%). Overall success was 92% with the rate of global complications at 4% and mortality 0.05%.</AbstractText>Catheter ablation in Latin America can be considered effective and safe.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
11,066 | Cor triatriatum sinister identified after new onset atrial fibrillation in an elderly man. | A 73-year-old man with new onset atrial fibrillation with rapid ventricular response underwent transthoracic echocardiography that revealed an echogenic linear structure along the left atrium, suggestive of cor triatriatum sinister (CTS). CTS was confirmed with transesophageal echocardiography which demonstrated a proximal accessory atrium receiving pulmonary venous flow separated from a distal true atrium by a fibromuscular membrane with a large fenestration allowing flow between the chambers. In CTS, the left atrium is divided into proximal and distal chambers by a fenestrated fibromuscular septum. This cardiac anomaly accounts for 0.1% of cases of congenital heart disease and rarely presents in adults. CTS is primarily diagnosed with echocardiography and is associated with left atrial enlargement and development of atrial fibrillation. Treatment options depend on size of the communication between proximal and distal chambers, the gradient across the membrane, and the position of pulmonary veins. In some instances, surgical resection of the membrane that divides the left atrium is warranted. |
11,067 | Cardiac function changes with switching from the supine to prone position: analysis by quantitative semiconductor gated single-photon emission computed tomography. | Prone positioning is required in certain operations such as spinal surgery. Changes in cardiac function in the prone position have been studied with various methodologies. Few studies have investigated changes in left ventricular diastolic function and rhythm in subjects turned prone.</AbstractText>Cardiac function was evaluated in the supine and prone positions in 90 patients without atrial fibrillation who underwent (99m)Tc-tetrofosmin quantitative gated single-photon emission computed tomography. Three groups of 30 patients each were classified as "no history of myocardial ischemia or cardiomyopathy" (Group A), "history of myocardial infarction" (Group B), and "ischemic heart disease without myocardial infarction history" (Group C). Upon assuming the prone position, the cardiac index and any dyssynchrony worsened in all groups. Ejection fraction changes occurred only in Group B, and diastolic function changes occurred in Groups B and C, but not in Group A. The changes caused by prone positioning were more severe in the patients with poor cardiac function.</AbstractText>Prone positioning induces significant changes in systolic and diastolic function, as well as dyssynchrony. The negative effects of prone positioning are more severe in patients with poor baseline cardiac function.</AbstractText> |
11,068 | Dilated left atrium as a predictor of late outcome after pulmonary vein isolation concomitant with aortic valve replacement and/or coronary artery bypass grafting†. | Left atrial (LA) dimension can predict atrial fibrillation (AF) recurrence after catheter-based or surgical ablation. Pulmonary vein isolation (PVI) may be a surgical option during aortic valve replacement (AVR) and/or coronary artery bypass grafting (CABG), though consensus regarding patient selection and late outcome is lacking.</AbstractText>We studied 160 patients (mean age 70 ± 9 years) with paroxysmal AF who underwent radiofrequency-based PVI during AVR and/or CABG, and were followed up postoperatively for at least 6 months. Mean preoperative LA dimension was 44 ± 7 mm. Serial echocardiography was performed to evaluate left ventricular (LV) and LA dimensions, E/e', estimated systolic pulmonary artery (PA) pressure and degree of valvular regurgitation. Follow-up was completed with a mean duration of 47 ± 25 months.</AbstractText>At the latest follow-up, 133 patients (83%) remained in sinus rhythm. Preoperative LA dimension was independently associated with increased risk of AF recurrence at 6 months after surgery [adjusted odds ratio 1.3 per 1-mm increase in LA dimension, 95% confidence interval (CI) 1.1-1.6, P < 0.001]. Receiver-operating characteristic curve analysis demonstrated an optimal cut-off value for preoperative LA dimension of 45 mm to predict sinus rhythm restoration (98% for <45 mm vs 55% for ≥45 mm, P < 0.001). Patients with LA dimension ≥45 mm had a significantly lower 5-year survival rate (62 ± 7 vs 82 ± 7%, P = 0.025) and freedom from adverse events defined as cerebral infarction/haemorrhage, admission for heart failure, catheter ablation and permanent pacemaker implantation (58 ± 7 vs 91 ± 4%, P < 0.001). Multivariate analysis showed that preoperative LA dimension ≥45 mm was independently associated with adverse events (adjusted hazards ratio 2.4, 95% CI 1.2-5.1, P = 0.019). Serial echocardiography demonstrated improvement in LV systolic function irrespective of LA dimension, whereas patients with LA dimension ≥45 mm showed less improvement in LA dimension and systolic PA pressure (interaction effect P < 0.001) and persistent higher E/e' (group effect P < 0.001), along with aggravated tricuspid regurgitation.</AbstractText>In patients with paroxysmal AF related to aortic valve disease and/or coronary artery disease, a dilated left atrium (≥45 mm) was associated with inferior AF- and event-free survival after PVI, accompanied by persistent abnormalities in cardiac and haemodynamic function. These findings may assist patient selection for PVI during AVR and/or CABG.</AbstractText>© The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.</CopyrightInformation> |
11,069 | Update on management of cardiac arrhythmias in acute coronary syndromes. | This review summarizes different types of arrhythmias in patients with acute coronary syndromes and provides an overview of the available therapeutic options for acute care and management of critical arrhythmias. The different therapeutic options are depending on the origin and type of arrhythmia. The main common dominant mechanisms are intramural re-entry in ischemia and triggered activity in reperfusion. The different forms of arrhythmia were explained in detail. Atrial arrhythmias are mainly atrial fibrillation; other forms are rare and usually self-limited. As therapeutic options antiarrhythmic drug therapy with beta-blockers or amiodarone and direct current cardioversion are suitable. Ventricular arrhythmias can be divided in premature ventricular complexes, accelerated idioventricular rhythm, non-sustained ventricular tachycardia, sustained ventricular tachycardia (VT), ventricular fibrillation (VF) and electrical storm. As therapeutic options antiarrhythmic drug therapy, implantable cardioverter defibrillator therapy (ICD), radiofrequency catheter ablation (RFA) and stellate ganglion blockade are available. The treatment with antiarrhythmic drug is rather cautious recommended, with the exception of beta-blockers. An additional drug therapy with ranolazine may be considered. The advantage of ICD therapy for long-term primary or secondary prophylactic therapy has been well documented. ICD therapy is associated with significant reduction in mortality compared with antiarrhythmic drug therapy (mainly amiodarone), with the exception of beta-blockers. RFA and stellate ganglion blockade are rather intended as therapeutically options for incessant VT/VF or electrical storm. |
11,070 | Caring for a patient with unexpected pheochromocytoma complicated by medical fraud. | We report a case of a patient who used multiple aliases as part of a medical fraud scheme. As a consequence, the surgical team was unaware of a left-sided adrenal mass that had been documented for this patient under another name. In the operating room, severe hypertension from the undiagnosed pheochromocytoma led to a ventricular fibrillation cardiac arrest. This case demonstrates the importance of physician awareness of medical identity fraud and its potential consequences. |
11,071 | A new algorithm to diagnose atrial ectopic origin from multi lead ECG systems--insights from 3D virtual human atria and torso. | Rapid atrial arrhythmias such as atrial fibrillation (AF) predispose to ventricular arrhythmias, sudden cardiac death and stroke. Identifying the origin of atrial ectopic activity from the electrocardiogram (ECG) can help to diagnose the early onset of AF in a cost-effective manner. The complex and rapid atrial electrical activity during AF makes it difficult to obtain detailed information on atrial activation using the standard 12-lead ECG alone. Compared to conventional 12-lead ECG, more detailed ECG lead configurations may provide further information about spatio-temporal dynamics of the body surface potential (BSP) during atrial excitation. We apply a recently developed 3D human atrial model to simulate electrical activity during normal sinus rhythm and ectopic pacing. The atrial model is placed into a newly developed torso model which considers the presence of the lungs, liver and spinal cord. A boundary element method is used to compute the BSP resulting from atrial excitation. Elements of the torso mesh corresponding to the locations of the placement of the electrodes in the standard 12-lead and a more detailed 64-lead ECG configuration were selected. The ectopic focal activity was simulated at various origins across all the different regions of the atria. Simulated BSP maps during normal atrial excitation (i.e. sinoatrial node excitation) were compared to those observed experimentally (obtained from the 64-lead ECG system), showing a strong agreement between the evolution in time of the simulated and experimental data in the P-wave morphology of the ECG and dipole evolution. An algorithm to obtain the location of the stimulus from a 64-lead ECG system was developed. The algorithm presented had a success rate of 93%, meaning that it correctly identified the origin of atrial focus in 75/80 simulations, and involved a general approach relevant to any multi-lead ECG system. This represents a significant improvement over previously developed algorithms. |
11,072 | Determinants of Atrial Electromechanical Delay in Patients with Functional Mitral Regurgitation and Non-ischemic Dilated Cardiomyopathy. | Atrial conduction time has important hemodynamic effects on ventricular filling and is accepted as a predictor of atrial fibrillation. In this study we assessed atrial conduction time in patients with non ischemic dilated cardiomyopathy (NIDCMP) and functional mitral regurgitation (MR) and aimed to determine factors predicting atrial conduction time prolongation.</AbstractText>Sixty five patients with non ischemic dilated cardiomyopathy who have moderate to severe MR and 60 control subjects were included in the study. In addition to conventional echocardiographic measures used to asses left ventricle and MR, atrial electromechanical coupling (time interval from the onset of P wave on surface electrocardiogram [ECG] to the beginning of A wave interval with tissue Doppler echocardiography [PA]), intra- and interatrial electromechanical delay (intra and inter AEMD) were measured.</AbstractText>The correlations between inter AEMD and left atrial (LA) size, MR volume, isovolumetric relaxation time (IVRT), deceleration time (DT), systolic pulmonary artery pressure (PAPs), E/A ratio and E/e' were very poor. Similarly, intra AEMD was not correlated to LA size , MR volume, IVRT, DT, PAPs, E/A ratio and E/e'. However, both inter AEMD and intra AEMD had good correlation with left ventricular mass index, tenting area (TA), tenting distance (TD), coaptation septal distance (CSD), sphericity index (SI).</AbstractText>Prolongation of inter and intra AEMDs were found to be well correlated with parameters reflecting left ventricular and mitral annular remodeling.</AbstractText> |
11,073 | Atrioventricular node ablation in Langendorff-perfused porcine hearts using carbon ion particle therapy: methods and an in vivo feasibility investigation for catheter-free ablation of cardiac arrhythmias. | Particle therapy, with heavy ions such as carbon-12 ((12)C), delivered to arrhythmogenic locations of the heart could be a promising new means for catheter-free ablation. As a first investigation, we tested the feasibility of in vivo atrioventricular node ablation, in Langendorff-perfused porcine hearts, using a scanned 12C beam.</AbstractText>Intact hearts were explanted from 4 (30-40 kg) pigs and were perfused in a Langendorff organ bath. Computed tomographic scans (1 mm voxel and slice spacing) were acquired and (12)C ion beam treatment planning (optimal accelerator energies, beam positions, and particle numbers) for atrioventricular node ablation was conducted. Orthogonal x-rays with matching of 4 implanted clips were used for positioning. Ten Gray treatment plans were repeatedly administered, using pencil beam scanning. After delivery, positron emission tomography-computed tomographic scans for detection of β(+) ((11)C) activity were obtained. A (12)C beam with a full width at half maximum of 10 mm was delivered to the atrioventricular node. Delivery of 130 Gy caused disturbance of atrioventricular conduction with transition into complete heart block after 160 Gy. Positron emission computed tomography demonstrated dose delivery into the intended area. Application did not induce arrhythmias. Macroscopic inspection did not reveal damage to myocardium. Immunostaining revealed strong γH2AX signals in the target region, whereas no γH2AX signals were detected in the unirradiated control heart.</AbstractText>This is the first report of the application of a (12)C beam for ablation of cardiac tissue to treat arrhythmias. Catheter-free ablation using 12C beams is feasible and merits exploration in intact animal studies as an energy source for arrhythmia elimination.</AbstractText>© 2015 American Heart Association, Inc.</CopyrightInformation> |
11,074 | Fluoroscopy integrated 3D mapping significantly reduces radiation exposure during ablation for a wide spectrum of cardiac arrhythmias. | Despite the use of established 3D-mapping systems, invasive electrophysiological studies and catheter ablation require high radiation exposure of patients and medical staff. This study investigated whether electroanatomic catheter tracking in prerecorded X-ray images on top of an existing 3D-mapping system has any impact on radiation exposure.</AbstractText>Two hundred and ninety-five consecutive patients were either ablated with the guidance of the traditional CARTO-3 system (c3) or with help of the CARTO-UNIVU system (cU): [typical atrial flutter (AFL) n = 58, drug refractory atrial fibrillation (AF) n = 81, ectopic atrial tachycardia (EAT) n = 37, accessory pathways (APs) n = 22, symptomatic, idiopathic premature ventricular complexes (PVCs) n = 56, ventricular tachycardias (VTs) n = 41]. The CARTO-UNIVU allowed a reduction in radiation exposure: fluoroscopy time: AFL c3: 8.6 ± 0.8 min vs. cU: 2.9 ± 0.3 min, P < 0.001; AF c3: 16.0 ± 1.3 min vs. cU: 6.4 ± 0.9 min, P < 0.001; EAT c3: 23.4 ± 3.1 min vs. cU: 9.7 ± 1.7 min, P < 0.001; AP c3: 7.1 ± 1.2 min vs. cU: 6.0 ± 1.5 min, P = 0.59; PVCs c3: 17.6 ± 2.3 min vs. cU: 15.2 ± 2.8 min, P = 0.52; VT c3: 31.4 ± 3.4 min vs. cU: 17.5 ± 2.4 min, P = 0.003. Corresponding to the fluoroscopy time the fluoroscopy dose was also reduced significantly. These advantages were not at the cost of increased procedure times, periprocedural complications, or decreased acute ablation success rates.</AbstractText>In a wide spectrum of cardiac arrhythmias, and especially in AF and VT ablation, fluoroscopy integrated 3D mapping contributed to a dramatic reduction in radiation exposure without prolonging procedure times and compromising patient's safety. That effect, however, could not be maintained in patients with APs and PVCs.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
11,075 | Fibroblast inward-rectifier potassium current upregulation in profibrillatory atrial remodeling. | Fibroblasts are involved in cardiac arrhythmogenesis and contribute to the atrial fibrillation substrate in congestive heart failure (CHF) by generating tissue fibrosis. Fibroblasts display robust ion currents, but their functional importance is poorly understood.</AbstractText>To characterize atrial fibroblast inward-rectifier K(+) current (IK1) remodeling in CHF and its effects on fibroblast properties.</AbstractText>Freshly isolated left atrial fibroblasts were obtained from controls and dogs with CHF (ventricular tachypacing). Patch clamp was used to record resting membrane potential (RMP) and IK1. RMP was significantly increased by CHF (from -43.2±0.8 mV, control, to -55.5±0.9 mV). CHF upregulated IK1 (eg, at -90 mV from -1.1±0.2 to -2.7±0.5 pA/pF) and increased the expression of KCNJ2 mRNA (by 52%) and protein (by 80%). Ba(2+) (300 μmol/L) decreased the RMP and suppressed the RMP difference between controls and dogs with CHF. Store-operated Ca(2+) entry (Fura-2-acetoxymethyl ester) and fibroblast proliferation (flow cytometry) were enhanced by CHF. Lentivirus-mediated overexpression of KCNJ2 enhanced IK1 and hyperpolarized fibroblasts. Functional KCNJ2 suppression by lentivirus-mediated expression of a dominant negative KCNJ2 construct suppressed IK1 and depolarized RMP. Overexpression of KCNJ2 increased Ca(2+) entry and fibroblast proliferation, whereas the dominant negative KCNJ2 construct had opposite effects. Fibroblast hyperpolarization to mimic CHF effects on RMP enhanced the Ca(2+) entry. MicroRNA-26a, which targets KCNJ2, was downregulated in CHF fibroblasts. Knockdown of endogenous microRNA-26 to mimic CHF effects unregulated IK1.</AbstractText>CHF upregulates fibroblast KCNJ2 expression and currents, thereby hyperpolarizing RMP, increasing Ca(2+) entry, and enhancing atrial fibroblast proliferation. These effects are likely mediated by microRNA-26a downregulation. Remodeling-induced fibroblast KCNJ2 expression changes may play a role in atrial fibrillation promoting fibroblast remodeling and structural/arrhythmic consequences.</AbstractText>© 2015 American Heart Association, Inc.</CopyrightInformation> |
11,076 | Effects of persistent atrial fibrillation on serum galectin-3 levels. | Galectin-3 is known to play an important role in a number of fibrotic conditions, including cardiac fibrosis. Many studies have focused on the association between galectin-3 levels and cardiac fibrosis in heart failure. However, the role of galectin-3 in the pathogenesis of atrial fibrillation (AF) has not been evaluated thoroughly yet. The aim of this study was to determine whether serum galectin-3 levels were elevated in patients with AF and preserved left ventricular function. Seventy-six patients with paroxysmal or persistent AF and preserved left ventricular systolic function and 75 age- and gender-matched control subjects were enrolled in this observational study. Galectin-3 levels were measured by enzyme-linked immunosorbent assay. Serum galectin-3 (median 0.6 ng/ml [interquartile range 0.2 to 1.4] vs 0.5 ng/ml [interquartile range 0.1 to 0.7], p <0.001) and left atrial volume index (LAVI) (mean 29.5 ± 3.5 vs 26.5 ± 2.5 ml/m(2), p <0.001) were significantly greater in patients with AF compared with the control group. Serum galectin-3 levels were also significantly higher in patients with persistent AF than those with paroxysmal AF (median 0.8 ng/ml [interquartile range 0.4 to 1.4] vs 0.5 ng/ml [interquartile range 0.2 to 0.9], p <0.001). Multivariate regression analysis demonstrated that serum galectin-3 (odds ratio 87.53, 95% confidence interval 6.06 to 1,265.03, p = 0.001) and LAVI (odds ratio 1.38, 95% confidence interval 1.19 to 1.60, p <0.001) were independent predictors of AF. Only LAVI was independently correlated with serum galectin-3 levels in patients with AF in linear regression analysis. In conclusion, serum galectin-3 is significantly elevated and is also significantly correlated with LAVI in patients with AF with preserved left ventricular function. |
11,077 | The ratio of early transmitral flow velocity (E) to early mitral annular velocity (Em) predicts improvement in left ventricular systolic and diastolic function 1 year after catheter ablation for atrial fibrillation. | Successful rhythm control after atrial fibrillation catheter ablation is known to induce left atrial reverse remodelling and improve left ventricular (LV) function. We explored the clinical factors affecting LV systolic and diastolic function 1-year after catheter ablation for atrial fibrillation.</AbstractText>We compared pre-procedural and 1-year follow-up echocardiograms in 521 patients with atrial fibrillation who underwent catheter ablation. Left ventricular systolic function was estimated by the ejection fraction (EF); diastolic function was estimated by the ratio of early transmitral flow velocity (E) to early mitral annular velocity (Em). (i) Catheter ablation of atrial fibrillation significantly reduced left atrium volume index (P < 0.001) and improved LV EF both in patients with recurrent atrial fibrillation (n = 133, P = 0.008) and those without recurrence (n = 388, P < 0.001). (ii) Follow-up EF was significantly improved in patients with baseline E/Em < 15 (n = 454, P < 0.001), whereas E/Em was significantly reduced in patients with pre-procedural E/Em ≥ 15 (n = 67, P = 0.008). (iii) Baseline E/Em < 15 (β = -3.854, 95% CI -5.99 to -1.72, P < 0.001), baseline EF <50% (β = 10.586, 95% CI 7.55 to 13.63, P < 0.001), and female (β = -1.726, 95% CI -3.36 to -0.10, P = 0.038) were independently associated with improved EF. Baseline E/Em ≥ 15 (β = 4.896, 95% CI 3.45 to 6.34, P < 0.001) and younger age (β = -0.066, 95% CI -0.11 to -0.02, P = 0.003) were independent factors associated with improved E/Em.</AbstractText>Pre-procedural E/Em predicted improvement in LV systolic and diastolic functions 1 year after catheter ablation for atrial fibrillation. Low baseline E/Em was independently associated with improved EF, while high E/Em predicted improvement in LV diastolic function.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
11,078 | Coronary spasm during cardiac electrophysiological study following isoproterenol infusion. | Sudden cardiac death (SCD) remains the leading cause of death in industrialized world. The majority of SCD is caused by ventricular fibrillation associated with structural and/or ischemic heart disease. Ventricular fibrillation represents the final common pathway for SCD and, thus, is an attractive target for ablation. According to class I recommendation level of evidence A, an implantable cardioverter defibrillator (ICD) should be implanted for such patients [1]. Other than programmed electrical extrastimulus technique, isoproterenol infusion is commonly used in invasive cardiac electrophysiology labs for arrhythmia induction. We hereby report a rare case of transient coronary spasm during isoproterenol infusion for ventricular tachycardia induction testing. |
11,079 | The need to resume chest compressions immediately after defibrillation attempts: an analysis of post-shock rhythms and duration of pulselessness following out-of-hospital cardiac arrest. | Current consensus guidelines for cardiopulmonary resuscitation (CPR) recommend that chest compressions resume immediately after defibrillation attempts and that rhythm and pulse checks be deferred until completion of 5 compression:ventilation cycles or minimally for 2min. However, data specifically confirming the post-shock duration of asystole or pulseless electrical activity before return of spontaneous circulation (ROSC) are lacking. Our aim was to describe the frequency of the various post-shock cardiac rhythms and the duration of post-shock pulselessness in out-of-hospital non-traumatic cardiac arrest.</AbstractText>Using prospectively-collected data from the Resuscitation Outcomes Consortium (ROC) Epistry database, the investigators reviewed monitor-defibrillator recordings of 176 patients who received defibrillation attempts in the out-of-hospital setting for ventricular fibrillation (VF) or ventricular tachycardia (VT) with absent pulses,.</AbstractText>Among 376 different defibrillation attempts delivered in the 176 patients, there were 182 resulting episodes of post-shock asystole. The mean interval of asystole after defibrillation was 69±136s (median 20s; IQR 36) and the mean interval for return of an organized rhythm was 64±157s (median 7s; IQR 26). The mean time to ROSC was 280±320s (median 136s; IQR 445).</AbstractText>After defibrillation attempts, the majority of patients remain pulseless for over 2min and the duration of asystole before return of pulses is longer than 120s beyond the shock gap in as many as 25%. These data support the recommendation to immediately resume chest compressions for 2min following attempted defibrillation.</AbstractText>Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
11,080 | Medical devices and procedures in the hyperbaric chamber. | The aim of this paper is to present current controversies concerning the safety of medical devices and procedures under pressure in a hyperbaric chamber including: defibrillation in a multiplace chamber; implantable devices during hyperbaric oxygen treatment (HBOT) and the results of a recent European questionnaire on medical devices used inside hyperbaric chambers. Early electrical defibrillation is the only effective therapy for cardiac arrest caused by ventricular fibrillation or pulseless ventricular tachycardia. The procedure of defibrillation under hyperbaric conditions is inherently dangerous owing to the risk of fire, but it can be conducted safely if certain precautions are taken. Recently, new defibrillators have been introduced for hyperbaric medicine, which makes the procedure easier technically, but it must be noted that sparks and fire have been observed during defibrillation, even under normobaric conditions. Therefore, delivery of defibrillation shock in a hyperbaric environment must still be perceived as a hazardous procedure. Implantable devices are being seen with increasing frequency in patients referred for HBOT. These devices create a risk of malfunction when exposed to hyperbaric conditions. Some manufacturers support patients and medical practitioners with information on how their devices behave under increased pressure, but in some cases an individual risk-benefit analysis should be conducted on the patient and the specific implanted device, taking into consideration the patient's clinical condition, the indication for HBOT and the capability of the HBOT facility for monitoring and intervention in the chamber. The results of the recent survey on use of medical devices inside European hyperbaric chambers are also presented. A wide range of non-CE-certified equipment is used in European chambers. |
11,081 | Dynamic regulation of atrial coronary blood flow in healthy adult pigs. | There are several indications for a mismatch between atrial oxygen supply and demand during atrial fibrillation (AF), but atrial coronary flow regulation has not been investigated extensively.</AbstractText>The purpose of this study was to characterize the dynamic regulation of atrial coronary flow in pigs.</AbstractText>In anesthetized open-chest pigs, Doppler flow probes were placed around left atrial (LA) and left ventricular (LV) branches of the circumflex artery. Pressures and work indices were measured simultaneously. Systolic and diastolic flow contribution, flow response kinetics, and relationship between pressures, work, and flow were investigated during sinus rhythm, atrial pacing, and acute AF.</AbstractText>During atrial systole, LA flow decreased. Only 2% of total LA flow occurred during atrial systole. Pacing with 2:1 AV block and infusion of acetylcholine revealed that atrial contraction itself impeded atrial coronary flow. The response to sudden changes in heart rate was slower in LA compared to LV. Both LA and LV vascular conductance were positively correlated with work. After the cessation of acute AF, the LA showed a more pronounced phase of supranormal vascular conductance than the LV, indicating a period of atrial reactive hyperemia.</AbstractText>In healthy adult pigs, atrial coronary flow is impeded by atrial contraction. Although atrial coronary blood flow is positively correlated with atrial external work, it reacts more slowly to changes in rate than ventricular flow. The occurrence of a pronounced hyperemic phase after acute AF supports the notion of a significant supply-demand mismatch during AF.</AbstractText>Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,082 | The association of left atrial low-voltage regions on electroanatomic mapping with low attenuation regions on cardiac computed tomography perfusion imaging in patients with atrial fibrillation. | Previous studies have shown that contrast-enhanced multidetector computed tomography (CE-MDCT) could identify ventricular fibrosis after myocardial infarction. However, whether CE-MDCT can characterize atrial low-voltage regions remains unknown.</AbstractText>The purpose of this study was to examine the association of CE-MDCT image attenuation with left atrial (LA) low bipolar voltage regions in patients undergoing repeat ablation for atrial fibrillation recurrence.</AbstractText>We enrolled 20 patients undergoing repeat ablation for atrial fibrillation recurrence. All patients underwent preprocedural 3-dimensional CE-MDCT of the LA, followed by voltage mapping (>100 points) of the LA during the ablation procedure. Epicardial and endocardial contours were manually drawn around LA myocardium on multiplanar CE-MDCT axial images. Segmented 3-dimensional images of the LA myocardium were reconstructed. Electroanatomic map points were retrospectively registered to the corresponding CE-MDCT images.</AbstractText>A total of 2028 electroanatomic map points obtained in sinus rhythm from the LA endocardium were registered to the segmented LA wall CE-MDCT images. In a linear mixed model, each unit increase in the local image attenuation ratio was associated with 25.2% increase in log bipolar voltage (P = .046) after adjusting for age, sex, body mass index, and LA volume, as well as clustering of data by patient and LA regions.</AbstractText>We demonstrate that the image attenuation ratio derived from CE-MDCT is associated with LA bipolar voltage. The potential ability to image fibrosis via CE-MDCT may provide a useful alternative in patients with contraindications to magnetic resonance imaging.</AbstractText>Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,083 | Tolerance of rapid right ventricular pacing during thoracic endovascular aortic repair. | The objective of this retrospective study was to evaluate the tolerance of rapid right ventricular pacing (RRVP) compared with that of the traditional methods of hypotension used during thoracic endovascular aortic repair (TEVAR).</AbstractText>From January 2002 to December 2012, we retrospectively included all the patients treated with TEVAR by comparing the 2 groups: patients operated with RRVP (RRVP+) and those operated without RRVP (RRVP-). The characteristics of the population and the procedures were recorded. The rates of complications were compared up to 1 year.</AbstractText>Sixty-one patients were operated. Treated pathologies were multiple with 19 aneurysms, 14 false aneurysms, 12 isthmic ruptures, 11 dissections, 3 coarctations, and 2 endoleaks. Twenty-four patients were RRVP+ and 37 patients were RRVP-. Mortality rates at 1 month in groups RRVP+ and RRVP- were of 0% and 2.7%, respectively (P = 1), and reintervention rates were 0% and 13.5%, respectively (P = 0.15). Three peroperative rhythm disorders (12.5%) were observed in the RRVP+ group including 2 ventricular fibrillations and 1 atrial fibrillation, both reduced without complications. One pacemaker was implanted for atrioventricular block in the RRVP- group. In the RRVP+ group, 83.3% of the patients presented a rise in troponin Ic (TnI) >0.04 ng/mL in 72 hours compared with 40.5% of the patients in the RRVP- group (P = 0.0013), with a spontaneously favorable evolution. No coronary syndrome was observed at 1 year with a mortality rate of 10.8% in the RRVP- group vs. 0% in the RRVP+ (P = 0.15).</AbstractText>In spite of a frequent moderate rise of TnI at the time of RRVP, this technique does not present more complications at 1 year than the use of a chemical hypotension. It thus seems an interesting alternative for selected patients, in trained teams.</AbstractText>Copyright © 2015 Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,084 | How long should resuscitative efforts be continued in adult out-of-hospital cardiac arrest? | The neurological prognosis of out-of-hospital cardiac arrest (OHCA) is extremely poor, particularly in patients who require prolonged cardiopulmonary resuscitation (CPR). However, the upper limit of CPR duration is unclear. We present a case of a 51-year-old man with nonhypothermic OHCA. He was discharged without neurological sequelae despite long duration CPR lasting 143 minutes, which is the longest duration among adult nonhypothermic OHCA cases reported. There are some patients for whom CPR duration might not be associated with prognosis. To determine when to terminate resuscitative efforts or whether more lifesaving medical resources should be provided, a prognostic indicator other than CPR duration is needed. |
11,085 | "Vasovagal" response during ventricular fibrillation: incidence and implications. | The purpose of this study was to assess the relationship between changes in sinus node cycle length (SNCL) during ventricular fibrillation (VF) and the peripheral changes in blood pressure (BP) and sympathetic nerve activity (SNA) in human subjects. We hypothesized that patients with no SNCL shortening during VF have a vasovagal-like response with a greater decrease in BP and SNA when compared to patients with SNCL shortening.</AbstractText>SNCL, BP, and SNA recordings were attempted in 24 patients undergoing the implantation of a dual-chamber implantable defibrillator. Changes were measured during the first 5 seconds of VF and compared with the 5 seconds prior to VF induction.</AbstractText>SNCL shortened during VF in nine patients (mean%∆SNCL = -12 ± 8%) and remained unchanged or lengthened in seven patients (mean%∆SNCL = 7 ± 7%). Eight patients had ventriculoatrial (VA) conduction prohibiting assessment of SNCL changes. In patients with SNCL shortening, the %∆MBP (mean BP) was -47 ± 6% compared to -58 ± 8% in patients with no SNCL shortening (P < 0.01). In patients with VA conduction, the %∆MBP was -54 ± 3%. SNA recordings were successfully obtained in four patients. When compared to baseline, SNA increased by 34 ± 30% in two patients with SNCL shortening, decreased by 25% in one patient with SNCL lengthening, and by 90% in the fourth patient with VA conduction.</AbstractText>We have shown that patients with no SNCL shortening have a significantly greater decrease in MBP during VF when compared to patients with SNCL shortening. The underlying mechanism appears to be reflex mediated with a vasovagal-like response in patients with no SNCL shortening.</AbstractText>© 2015 Wiley Periodicals, Inc.</CopyrightInformation> |
11,086 | Left atrial remodeling and function in advanced heart failure with preserved or reduced ejection fraction. | Left atrial (LA) structure and function are altered in most heart failure (HF) patients, but there may be fundamental differences in LA properties between HF with preserved (HFpEF) and reduced ejection fraction (HFrEF).</AbstractText>One hundred ninety-eight HF patients (51% HFpEF, New York Heart Association 3.1±0.7) and 40 HF-free controls underwent catheterization, echocardiography, and follow-up. Compared with controls, HF patients had larger and more dysfunctional left atria. At identical mean LA pressure (20 versus 20 mm Hg; P=0.9), HFrEF patients had larger LA volumes (LA volume index 50 versus 41 mL/m(2); P<0.001), whereas HFpEF patients had higher LA peak pressures, lower LA minimal pressures, higher LA stiffness (0.79 versus 0.48 mm Hg/mL; P<0.001), greater LA pulsatility (19 versus 13 mm Hg; P<0.001), and higher wall stress variations. Despite smaller LA volumes, better function, and less mitral regurgitation, HFpEF patients had more atrial fibrillation (42 versus 26%; P=0.02). LA dysfunction was associated with increased pulmonary vascular resistance and right ventricular dysfunction in both HF phenotypes. After a median follow-up of 350 days, 31 HFpEF and 28 HFrEF patients died. LA function (total LA EF) was associated with lower mortality in HFpEF (hazard ratio 0.43; 95% confidence interval, 0.2-0.9; P<0.05), but not in HFrEF.</AbstractText>HFrEF is characterized by greater eccentric LA remodeling, whereas HFpEF by increased LA stiffness, which might contribute to greater atrial fibrillation burden. LA function is associated with pulmonary vascular disease and right HF in both HF phenotypes, but is associated with outcome more closely in HFpEF, supporting efforts to improve LA function in this cohort.</AbstractText>© 2015 American Heart Association, Inc.</CopyrightInformation> |
11,087 | Role of electrophysiological studies in predicting risk of ventricular arrhythmia in early repolarization syndrome. | The early repolarization (ER) pattern is associated with an increased risk of arrhythmogenic sudden death. However, strategies for risk stratification of patients with the ER pattern are not fully defined.</AbstractText>This study sought to determine the role of electrophysiology studies (EPS) in risk stratification of patients with ER syndrome.</AbstractText>In a multicenter study, 81 patients with ER syndrome (age 36 ± 13 years, 60 males) and aborted sudden death due to ventricular fibrillation (VF) were included. EPS were performed following the index VF episode using a standard protocol. Inducibility was defined by the provocation of sustained VF. Patients were followed up by serial implantable cardioverter-defibrillator interrogations.</AbstractText>Despite a recent history of aborted sudden death, VF was inducible in only 18 of 81 (22%) patients. During follow-up of 7.0 ± 4.9 years, 6 of 18 (33%) patients with inducible VF during EPS experienced VF recurrences, whereas 21 of 63 (33%) patients who were noninducible experienced recurrent VF (p = 0.93). VF storm occurred in 3 patients from the inducible VF group and in 4 patients in the noninducible group. VF inducibility was not associated with maximum J-wave amplitude (VF inducible vs. VF noninducible; 0.23 ± 0.11 mV vs. 0.21 ± 0.11 mV; p = 0.42) or J-wave distribution (inferior, odds ratio [OR]: 0.96 [95% confidence interval (CI): 0.33 to 2.81]; p = 0.95; lateral, OR: 1.57 [95% CI: 0.35 to 7.04]; p = 0.56; inferior and lateral, OR: 0.83 [95% CI: 0.27 to 2.55]; p = 0.74), which have previously been demonstrated to predict outcome in patients with an ER pattern.</AbstractText>Our findings indicate that current programmed stimulation protocols do not enhance risk stratification in ER syndrome.</AbstractText>Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,088 | Ambulatory arterial stiffness index is associated with impaired left atrial mechanical functions in hypertensive diabetic patients: A speckle tracking study. | The ambulatory arterial stiffness index has been proposed as an indicator of arterial stiffness. The aim of this study was to test the hypothesis that increased ambulatory arterial stiffness index might be related with impaired left atrial function in hypertensive diabetic patients with no previous history of cardiovascular disease.</AbstractText>Inclusion criteria included office systolic BP> 130 mm Hg or diastolic BP> 80 mm Hg and absence of secondary causes of HT, whereas exclusion criteria LV ejection fraction <50%, history of significant coronary artery disease, chronic renal failure, atrial fibrillation/ flutter, second or third-degree atrioventricular block, moderate to severe valvular heart disease, history of cerebrovascular disease, non-dipper hypertensive pattern and sleep apnea. The study was composed of 121 hypertensive diabetic patients. Twenty-four-hour ambulatory blood pressure monitoring and echocardiography were performed in each patient. The relationship between ambulatory arterial stiffness index and left atrial functions was analyzed. AASI was calculated as 1 minus the regression slope of diastolic BP plotted against systolic BP obtained through individual 24-h ABPM.</AbstractText>The univariate analysis showed that ambulatory arterial stiffness index was positively correlated with age (r=:0.287, p=:0.001), hypertension duration (r=:0.388, p<0.001), fasting plasma glucose (r=:0.224, p=:0.014), HbA1c (r=:0.206, p=:0.023), LDL cholesterol (r=:0.254, p=:0.005), and also overall pulse pressure (r=:0.195, p=:0.002), office- pulse pressure (r=:0.188, p=:0.039), carotid intima-media thickness (r=:0.198, p=:0.029), E/E' (r=:0.248, p=:0.006), and left atrial volume index (r=:0.237, p=:0.009). Moreover, ambulatory arterial stiffness index was negatively correlated with eGFR (r=:(-) 0.242, p=:0.008), peak left atrial strain during ventricular systole [S-LAs (r=:(-) 0.654, p<0.001)], peak left atrial strain at early diastole [S-LAe (r=:(-)0.215, p=:0.018)], and peak left atrial strain rate during ventricular systole [SR-LAs (r=:(-) 0.607, p<0.001)]. The multiple linear regression analysis showed that ambulatory arterial stiffness index was independently associated with peak left atrial strain rate during ventricular systole (SR-LAs) (p<0.001).</AbstractText>In hypertensive diabetic patients, increased ambulatory arterial stiffness index is associated with impaired left atrial functions, independent of left ventricular diastolic dysfunction.</AbstractText> |
11,089 | Renal denervation decreases effective refractory period but not inducibility of ventricular fibrillation in a healthy porcine biomodel: a case control study. | Ventricular arrhythmias play an important role in cardiovascular mortality especially in patients with impaired cardiac and autonomic function. The aim of this experimental study was to determine, if renal denervation (RDN) could decrease the inducibility of ventricular fibrillation (VF) in a healthy porcine biomodel.</AbstractText>Controlled electrophysiological study was performed in 6 biomodels 40 days after RDN (RDN group) and in 6 healthy animals (control group). The inducibility of VF was tested by programmed ventricular stimulation from the apex of right ventricle (8 basal stimuli coupled with up to 4 extrastimuli) always three times in each biomodel using peripheral extracorporeal oxygenation for hemodynamic support. Further, basal heart rate (HR), PQ and QT intervals and effective refractory period of ventricles (ERP) were measured. Technical success of RDN was evaluated by histological examination.</AbstractText>According to histological findings, RDN procedure was successfully performed in all biomodels. Comparing the groups, basal HR was lower in RDN group: 79 (IQR 58; 88) vs. 93 (72; 95) beats per minute (p = 0.003); PQ interval was longer in RDN group: 145 (133; 153) vs. 115 (113; 120) ms (p < 0.0001) and QTc intervals were comparable: 402 (382; 422) ms in RDN vs. 386 (356; 437) ms in control group (p = 0.1). ERP was prolonged significantly in RDN group: 159 (150; 169) vs. 140 (133; 150) ms (p = 0.001), but VF inducibility was the same (18/18 vs. 18/18 attempts).</AbstractText>RDN decreased the influence of sympathetic nerve system on the heart conduction system in healthy porcine biomodel. However, the electrophysiological study was not associated with a decrease of VF inducibility after RDN.</AbstractText> |
11,090 | Ventricular fibrillation: are swine a sensitive species? | Legislation and sentiment have pushed large-animal electrophysiological research from the canine to the swine model. Anecdotal experience suggests that the swine is particularly sensitive to ventricular fibrillation (VF) induction, and radiofrequency ablation studies are consistent with this. Currently, no data exist directly comparing the VF threshold (VFT) in humans to swine. Because of the perceived difference in vulnerability to VF induction, we hypothesized that the VFT would be lower in swine compared to humans.</AbstractText>Six anesthetized open-chested swine, 31 ± 2 kg, were studied that were part of an ongoing study with up to 6 h of previous closed-chest percutaneous pacing with repeated VF cycles. Similar to the human study of Horowitz et al., 24 pulses of 4 ms each were applied at a rate of 100 Hz during the ST segment to the epicardium via a pair of 7-mm diameter platinum electrodes whose centers were 15 mm apart. Current was increased until VF was induced.</AbstractText>The swine right ventricle (RV) VFT was 9.7 ± 2.1 mA [median = 9.0, interquartile range (IQR) = 7.8-12.0], and the left ventricle (LV) VFT was 10.7 ± 2.2 mA [median = 10.5, IQR = 8.8-12.5] (p = NS). Horowitz reported the RV VFT in six patients as 24.3 ± 5.2 mA [median = 24.5, IQR = 19.0-29.3] and the LV VFT in ten patients as 33.6 ± 9.5 mA [median = 36.5, IQR = 27.3-42.3] (p = .11). Both the RV and LV VFTs were lower for swine (p < 0.003), and each of the mean and median VFTs for the ventricles together was one third that of the humans.</AbstractText>Swine are about three times as sensitive to the electrical induction of VF as are humans.</AbstractText> |
11,091 | Diagnosis and management of inherited cardiomyopathies. | Inherited heart conditions are the most common cause of sudden cardiac death in those under the age of 35 and the leading cause of non-traumatic death in young athletes. Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease affecting 1 in 500 of the population. Some patients may exhibit severe left ventricular hypertrophy, others may show nothing more than an abnormal ECG. Left ventricular hypertrophy most commonly manifests in the second decade of life. Sudden death is rare and usually affects patients in the first three decades whereas older patients present with heart failure, atrial fibrillation and stroke. Arrhythmogenic right ventricular cardiomyopathy is a rare, autosomal dominant heart muscle disorder which affects between 1 in 1,000 and 1 in 5,000 of the population. Dilated cardiomyopathy (DCM) is characterised by a dilated left ventricle with impaired function that cannot be explained by ischaemic heart disease, hypertension or valvular heart disease. At least 25% of cases of DCM are familial. DCM may be associated with multisystem conditions such as muscular dystrophy. Chemotherapy and certain other drugs, alcohol abuse and myocarditis may also lead to a dilated and poorly contracting left ventricle. In many cases the first manifestation of an inherited cardiomyopathy can be a sudden cardiac arrest. Other presentations include chest pain or breathlessness during exertion, palpitations and syncope. In many of the cardiomyopathies, the diagnosis can be made with a standard ECG and echocardiogram. However if the diagnosis is not certain or the cardiologist wishes to look at the heart structure in greater detail, a cardiac MRI may be performed. |
11,092 | Impact of atrial fibrillation ablation on left ventricular filling pressure and left atrial remodeling. | Left ventricular (LV) diastolic dysfunction is associated with new-onset atrial fibrillation (AF), and the estimation of elevated LV filling pressures by E/e' ratio is related to worse outcomes in patients with AF. However, it is unknown if restoring sinus rhythm reverses this process.</AbstractText>To evaluate the impact of AF ablation on estimated LV filling pressure.</AbstractText>A total of 141 patients underwent radiofrequency (RF) ablation to treat drug-refractory AF. Transthoracic echocardiography was performed 30 days before and 12 months after ablation. LV functional parameters, left atrial volume index (LAVind), and transmitral pulsed and mitral annulus tissue Doppler (e' and E/e') were assessed. Paroxysmal AF was present in 18 patients, persistent AF was present in 102 patients, and long-standing persistent AF in 21 patients. Follow-up included electrocardiographic examination and 24-h Holter monitoring at 3, 6, and 12 months after ablation.</AbstractText>One hundred seventeen patients (82.9%) were free of AF during the follow-up (average, 18 ± 5 months). LAVind reduced in the successful group (30.2 mL/m(2) ± 10.6 mL/m(2) to 22.6 mL/m(2) ± 1.1 mL/m(2), p < 0.001) compared to the non-successful group (37.7 mL/m(2) ± 14.3 mL/m(2) to 37.5 mL/m(2) ± 14.5 mL/m(2), p = ns). Improvement of LV filling pressure assessed by a reduction in the E/e' ratio was observed only after successful ablation (11.5 ± 4.5 vs. 7.1 ± 3.7, p < 0.001) but not in patients with recurrent AF (12.7 ± 4.4 vs. 12 ± 3.3, p = ns). The success rate was lower in the long-standing persistent AF patient group (57% vs. 87%, p = 0.001).</AbstractText>Successful AF ablation is associated with LA reverse remodeling and an improvement in LV filling pressure.</AbstractText> |
11,093 | Value of the Qrs-T angle in predicting the induction of ventricular tachyarrhythmias in patients with Chagas disease. | The QRS-T angle correlates with prognosis in patients with heart failure and coronary artery disease, reflected by an increase in mortality proportional to an increase in the difference between the axes of the QRS complex and T wave in the frontal plane. The value of this correlation in patients with Chagas heart disease is currently unknown.</AbstractText>Determine the correlation of the QRS-T angle and the risk of induction of ventricular tachycardia / ventricular fibrillation (VT / VF) during electrophysiological study (EPS) in patients with Chagas disease.</AbstractText>Case-control study at a tertiary center. Patients without induction of VT / VF on EPS were used as controls. The QRS-T angle was categorized as normal (0-105º), borderline (105-135º) or abnormal (135-180º). Differences between groups for continuous variables were analyzed with the t test or Mann-Whitney test, and for categorical variables with Fisher's exact test. P values < 0.05 were considered significant.</AbstractText>Of 116 patients undergoing EPS, 37.9% were excluded due to incomplete information / inactive records or due to the impossibility to correctly calculate the QRS-T angle (presence of left bundle branch block and atrial fibrillation). Of 72 patients included in the study, 31 induced VT / VF on EPS. Of these, the QRS-T angle was normal in 41.9%, borderline in 12.9% and abnormal in 45.2%. Among patients without induction of VT / VF on EPS, the QRS-T angle was normal in 63.4%, borderline in 14.6% and abnormal in 17.1% (p = 0.04). When compared with patients with normal QRS-T angle, those with abnormal angle had a fourfold higher risk of inducing ventricular tachycardia / ventricular fibrillation on EPS [odds ratio (OR) 4; confidence interval (CI) 1.298-12.325; p = 0.028]. After adjustment for other variables such as age, ejection fraction (EF) and QRS size, there was a trend for the abnormal QRS-T angle to identify patients with increased risk of inducing VT / VF during EPS (OR 3.95; CI 0.99-15.82; p = 0.052). The EF also emerged as a predictor of induction of VT / VF: for each point increase in EF, there was a 4% reduction in the rate of sustained ventricular arrhythmia on EPS.</AbstractText>Changes in the QRS-T angle and decreases in EF were associated with an increased risk of induction of VT / VF on EPS.</AbstractText> |
11,094 | Toxic Epidermal Necrolysis During Dronedarone Treatment: First Report of a Severe Serious Adverse Event Of A New Antiarrhythmic Drug. | A 77-year-old female patient with symptomatic atrial fibrillation with fast ventricular rate despite conventional antiarrhythmic therapy was treated with dronedarone. Five days later, she developed a maculopapulous exanthema and small flaccid blisters, which spread over the common integument predominantly located on the dorsal trunk. Over few days, the patient showed a severe epidermal necrolysis of approximately 30 % of the body area and ultimately died in multiorgan failure. Here, we report a rare case of toxic epidermal necrolysis during treatment with dronedarone leading to patient death. |
11,095 | Atrial fibrillation: effects beyond the atrium? | Atrial fibrillation (AF) is the most common sustained clinical arrhythmia and is associated with significant morbidity, mostly secondary to heart failure and stroke, and an estimated two-fold increase in premature death. Efforts to increase our understanding of AF and its complications have focused on unravelling the mechanisms of electrical and structural remodelling of the atrial myocardium. Yet, it is increasingly recognized that AF is more than an atrial disease, being associated with systemic inflammation, endothelial dysfunction, and adverse effects on the structure and function of the left ventricular myocardium that may be prognostically important. Here, we review the molecular and in vivo evidence that underpins current knowledge regarding the effects of human or experimental AF on the ventricular myocardium. Potential mechanisms are explored including diffuse ventricular fibrosis, focal myocardial scarring, and impaired myocardial perfusion and perfusion reserve. The complex relationship between AF, systemic inflammation, as well as endothelial/microvascular dysfunction and the effects of AF on ventricular calcium handling and oxidative stress are also addressed. Finally, consideration is given to the clinical implications of these observations and concepts, with particular reference to rate vs. rhythm control. |
11,096 | Feasibility and safety of left ventricular endomyocardial biopsy via transradial access: Technique and initial experience. | Endomyocardial biopsy constitutes an essential part of the diagnostic algorithm in patients with heart failure of unknown origin, but usually requires transfemoral access.</AbstractText>Here, we describe a novel method that allows interventional cardiologists to obtain left ventricular biopsies via transradial access with a 7.5F sheathless multipurpose (MP1.0) guiding catheter. This approach was successfully conducted in 37 consecutive patients at our institution with only one intraprocedural minor complication (ventricular fibrillation during insertion of the guiding catheter).</AbstractText>Transradial access to obtain left ventricular endomyocardial biopsies is a feasible and safe option for experienced radial operators.</AbstractText>© 2015 Wiley Periodicals, Inc.</CopyrightInformation> |
11,097 | Frontal planar QRS/T angle can be a prognostic factor in the early postoperative period of patients undergoing coronary bypass surgery. | Wide QRS/T angle reflects the ventricular repolarization heterogeneity and has been found in association with cardiac morbidity and mortality in various study populations. However, literature data about the availability of QRS/T angle in patients undergoing cardiac surgery has not yet been available.</AbstractText>A total of 157 patients who underwent isolated coronary artery bypass surgery were included in this study. A preoperative 12-lead ECG was obtained one day before surgical procedure. The absolute difference between the frontal QRS wave axes and T-wave axes was defined as frontal planar QRS/T angle. Afterwards, patients were divided into two groups according to their frontal planar QRS/T angle (the cut-off value as 90°).</AbstractText>Group 1 consisted of 109 patients with frontal planar QRS/T angle of <90, and the remaining 48 patients with frontal planar QRS/T angle 90 were placed into group 2. Mean EuroSCORE was much higher in group 2. There were significant differences for positive inotropic agent usage (27.5% for group 1 versus 58.3% for group 2, P < .001) and the prevalence of postoperative atrial fibrillation (11.9% for group 1 versus 31.2% for group 2, P = .004) between the two groups. In multivariate logistic regression analysis, used to determine the independent predictors of positive inotropic usage in the early postoperative period, only frontal planar QRS/T angle (OR: 0.989, 95% CI: 0.981-0.997, P = .008) and EuroSCORE (OR: 0.792, 95% CI: 0.646-0.971, P = .025) were found to be statistically significant.</AbstractText>We found that frontal planar QRS/T angle might be an important preoperative parameter in predicting the need for inotropic drugs in the early postoperative period following coronary artery bypass surgery.</AbstractText> |
11,098 | Magnetic resonance estimates of the extent and heterogeneity of scar tissue in ICD patients with ischemic cardiomyopathy predict ventricular arrhythmia. | The majority of patients receiving implantable cardioverter-defibrillator (ICD) implantation under current guidelines never develop sustained ventricular arrhythmia; therefore, better markers of risk for sustained ventricular tachycardia and/or ventricular fibrillation are needed.</AbstractText>The purpose of this study was to identify cardiac magnetic resonance arrhythmic risk predictors of ischemic cardiomyopathy before ICD implantation.</AbstractText>Forty-three subjects (mean age, 64.5 ± 11.9 years) with previous myocardial infarction who were referred for ICD implantation were evaluated by cardiac magnetic resonance imaging (MRI). The MRI protocol included left ventricular functional parameter assessment using steady-state free precession and late gadolinium enhancement MRI using inversion recovery fast gradient echo. Left ventricular functional parameters were measured using cardiac magnetic resonance software. Subjects were followed up for 6-46 months, and the events of appropriate ICD treatments (shocks and antitachycardia pacing) were recorded.</AbstractText>Twenty-eight patients experienced 46 spontaneous episodes during a median follow-up duration of 30 months. The total myocardial infarct (MI) size (18.05 ± 11.44 g vs 38.83 ± 19.87 g; P = .0006), MI core (11.63 ± 7.14 g vs 24.12 ± 12.73 g; P = .0002), and infarct gray zone (6.43 ± 4.64 g vs 14.71 ± 7.65 g; P = .0004) were significantly larger in subjects who received appropriate ICD therapy than in those who did not experience an episode of ventricular tachycardia and/or ventricular fibrillation. Multivariate regression analyses for the infarct gray zone and MI core adjusted for New York Heart Association class, diabetes, and etiology (primary or secondary prevention) revealed that the gray zone and MI core were predictors of appropriate ICD therapies (P = .0018 and P = .007, respectively).</AbstractText>The extent of MI scar may predict which patients would benefit most from ICD implantation.</AbstractText>Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,099 | Automated external defibrillator rescues among children with diagnosed and treated long QT syndrome. | Long QT syndrome (LQTS) is a potentially lethal yet highly treatable cardiac channelopathy. A comprehensive LQTS-directed treatment program often includes an automated external defibrillator (AED).</AbstractText>The purpose of this study was to determine the incidence of AED rescues among children evaluated, risk-stratified, and treated in an LQTS specialty center.</AbstractText>We performed a retrospective review of the electronic medical records to identify 1665 patients evaluated in our Genetic Heart Rhythm Clinic (1999-2013). Subset analysis was performed on 291 children managed without an implantable cardioverter-defibrillator (ICD).</AbstractText>The average age at diagnosis was 8.3 ± 5.7 years with an average. QTc of 463 ± 40 ms (17% ≥500 ms). The represented LQTS genotypes included type 1 (LQT1) in 52%, type 2 (LQT2) in 35%, and type 3 (LQT3) in 7%. During follow-up, 3 of 291 children (1%) had a cardiac arrest with an appropriate AED rescue (2/51 symptomatic, 1/240 asymptomatic). The first AED rescue occurred during exercise in a symptomatic 3-year-old boy with compound LQT1 treated with beta-blocker and videoscopic left cardiac sympathetic denervation (LCSD). The second AED rescue occurred in a remotely symptomatic 14-year-old boy with high-risk LQT2 (QTc >550 ms) on a beta-blocker who previously declined a prophylactic ICD. The third AED rescue involved an asymptomatic 17-year-old girl with LQT3 on mexiletine who collapsed in school.</AbstractText>An AED should seldom be necessary in an appropriately treated child with LQTS. Nevertheless, despite only 3 AED rescues in more than 1700 patient-years, an AED can be a lifesaving and cost-effective part of an LQTS patient's comprehensive sudden death prevention program.</AbstractText>Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
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