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Introduction: Electrical isolation of pulmonary veins (PVI) is a cornerstone for atrial fibrillation (AF) ablation. The overall effect of AF ablation, and especially lesions beyond PVI, on left atrial (LA) function is currently poorly understood. Our aim was to determine if LA function is different in patients after extensive LA ablation compared to PVI only. We performed non‐inferiority analysis of LA function after PVI with additional nonpulmonary vein ablation lesions in LA (PVI+) and PVI alone. Methods: We studied 68 patients consecutive patients who underwent AF ablation and who had complete transthoracic echocardiogram (TTE) within 12 months before AF ablation and 1−12 months after the procedure. Patients were stratified into two groups: PVI only and PVI+. Primary outcome was change in LA reservoir strain (LASr). Noninferiority margin was defined at 6%. Results: The PVI only group had a higher proportion of patients with paroxysmal AF (70% vs. 30%). The PVI+ group was observed to have a slightly higher increase in LASr compared to PVI alone (5.0% vs. 4.3%, p <.01 for noninferiority). LASr noninferiority was confirmed when adjusted for age, sex, coronary artery disease, hyperlipidemia, and AF type, rhythm at preprocedure TTE in a multivariable linear regression model, 90% CI (−5.46 to 2.04), p <.01. Conclusion: LA functional improvement evaluated by LASr was noninferior after PVI with additional LA ablation lesions compared to PVI alone. These findings were confirmed when adjusted for confounding clinical variables, suggesting that more extensive ablation does not negatively affect LA function. [ABSTRACT FROM AUTHOR]

Introduction: Esophageal injury is rare but potentially a devastating complication of atrial fibrillation (AF) ablation. The goal here was to provide insight into the short‐term natural history of esophageal thermal injury (ETI) after radiofrequency catheter ablation (RFCA) for AFby esophagogastroduodenoscopy (EGD). Methods: We screened patients who underwent RFCA for AF and EGD based on esophageal late gadolinium enhancement (LGE) in postablation magnetic resonance imaging. Patients with ETI diagnosed with EGD were included. We defined severity of ETI according to Kansas City classification: type 1: erythema; type 2: ulcers (2a: superficial; 2b deep); type 3 perforation (3a: perforation; 3b: perforation with atrioesophageal fistula [AEF]). Repeated EGD was performed within 1−14 days after the last EGD if recommended and possible until any certain healing signs (visible reduction in size without deepening of ETI or complete resolution) were observed. Results: ETI was observed in 62 of 378 patients who underwent EGD after RFCA. Out of these 62 patients with ETI, 21% (13) were type 1, 50% (31) were type 2a and 29% (18) were type 2b at the initial EGD. All esophageal lesions, but one type 2b lesion that developed into an AEF, showed signs of healing in repeated EGD studies within 14 days after the procedure. The one type 2b lesion developing into an AEF showed an increase in size and ulcer deepening in repeat EGD 8 days after the procedure. Conclusion: We found that all ETI which did not progress to AEF presented healing signs within 14 days after the procedure and that worsening ETI might be an early signal for developing esophageal perforation. [ABSTRACT FROM AUTHOR]

Background: Class 1C antiarrhythmic drugs (AADs) are effective first‐line agents for atrial fibrillation (AF) treatment. However, these agents commonly are avoided in patients with known coronary artery disease (CAD), due to known increased risk in the postmyocardial infarction population. Whether 1C AADs are safe in patients with CAD but without clinical ischemia or infarct is unknown. Reduced coronary flow capacity (CFC) on positron emission tomography (PET) reliably identifies myocardial regions supplied by vessels with CAD causing flow limitation. Objective: To assess whether treatment with 1C AADs increases mortality in patients without known CAD but with CFC indicating significantly reduced coronary blood flow. Methods: In this pilot study, we compared patients with AF and left ventricular ejection fraction ≥50% who were treated with 1C AADs to age‐matched AF patients without 1C AAD treatment. No patient had clinically evident CAD (ie, reversible perfusion defect, known ≥70% epicardial lesion, percutaneous coronary intervention, coronary artery bypass grafting, or myocardial infarction). All patients had PET‐based quantification of stress myocardial blood flow and CFC. Death was assessed by clinical follow‐up and social security death index search. Results: A total of 78 patients with 1C AAD exposure were matched to 78 controls. Over a mean follow‐up of 2.0 years, the groups had similar survival (P =.54). Among patients with CFC indicating the presence of occult CAD (ie, reduced CFC involving ≥50% of myocardium), 1C‐treated patients had survival similar to (P =.44) those not treated with 1C agents. Conclusions: In a limited population of AF patients with preserved left ventricle function and PET‐CFC indicating occult CAD, treatment with 1C AADs appears not to increase mortality. A larger study would be required to confidently assess the safety of these drugs in this context. [ABSTRACT FROM AUTHOR]

CRT-P versus CRT-D Outcomes Background Cardiac resynchronization therapy (CRT) is commonly used to manage heart failure, yet published guidelines do not distinguish between recommendations for pacemakers (CRT-P) and defibrillators (CRT-D) despite significant differences in size, longevity, and cost between these devices. The purpose of this study is to compare the clinical characteristics and outcomes between elderly recipients of CRT-P and CRT-D. Methods and Results Data from 512 patients (405 CRT-D, 107 CRT-P) aged ≥75 years with LV ejection fraction ≤35% and QRS duration >120 milliseconds were retrospectively analyzed for baseline characteristics and followed to the primary outcome of all-cause mortality. Cox proportional hazards models were used to adjust for possible confounders. Results were further validated through propensity matching cohorts. Compared to CRT-D recipients, CRT-P patients were older (83 years vs. 81 years, P < 0.001) and had more comorbid conditions (Charlson index = 5 [3-6] vs. 4 [3-5], P = 0.007). During 40.8 months of follow-up, there were 280 deaths. Compared to CRT-D patients, CRT-P recipients had higher unadjusted mortality (HR 1.54, 95% CI 1.15-2.08, P = 0.004). However, this difference lost significance after adjusting for baseline differences between the groups (HR 1.18, 95% CI 0.78-1.77, P = 0.435). Conclusion Higher all-cause mortality in older CRT-P versus CRT-D patients is largely explained by baseline clinical and demographic differences between the two groups, which are likely the drivers of device selection in real-world clinical practice, where the published guidelines remain ambiguous. There is a need for randomized studies to determine optimal CRT device selection. [ABSTRACT FROM AUTHOR]

Ventricular Tachycardia and Atrioventricular Block Introduction In pediatric patients with pacemakers implanted for atrioventricular block (AVB), nonsustained ventricular tachycardia (NSVT) detected during routine surveillance is a finding of unknown significance. We sought to describe the incidence of NSVT and determine if there was an association between NSVT and adverse outcomes in these patients. Methods and Results This is a single-center retrospective study of 136 patients (1971-2013) with pacemakers implanted for advanced and complete AVB. Exclusion criteria: structural heart disease, diagnoses of myocarditis, cardiomyopathy or channelopathy preceding AVB diagnosis, and sustained or polymorphic ventricular tachycardia (VT) as the first occurring arrhythmia after pacemaker implant. During median follow-up of 11.6 years (IQR 4.3 years, 17 years), 14 (10%) patients had NSVT. There were 6 (4.4%) deaths. Overall, Kaplan-Meier 20-year survival from time of implant was 93%. By univariate analysis, earlier mortality was associated with NSVT (P = 0.010), sustained left ventricular (LV) dysfunction (P = 0.004), maternal autoantibodies (P = 0.017), and acquired AVB (P = 0.049). By multivariate analysis, earlier mortality was associated with NSVT (HR: 5.39 [95% CI: 1.02-28.41]; P = 0.047) and sustained LV dysfunction (HR: 10.24 [95% CI: 1.83-57.32]; P = 0.008). Conclusions In children with pacemakers implanted for AVB, NSVT is not uncommon and may be associated with increased mortality. Persistent LV dysfunction may also be a potential factor associated with death. Closer follow-up should be considered in patients with these findings. Large, multicenter studies should be considered to confirm these findings and identify risk stratification methods for this unique patient population. [ABSTRACT FROM AUTHOR]

Prediction Rule to Identify Patients at High Risk for Early Demise Following CRT Background In patients with advanced heart failure, the decision of whether to pursue cardiac resynchronization therapy (CRT) or to proceed directly to advanced heart failure therapies can be challenging. We sought to create a prediction rule to identify patients with advanced systolic heart failure at heightened risk of rapid deterioration despite receiving CRT. Methods Clinical data were collected on consecutive patients with advanced heart failure presenting for a new CRT device at the Cleveland Clinic between February 12, 2002 and July 8, 2008. Early demise was defined as death, left ventricular assist device, or heart transplant within 6 months following CRT implant. Using a multivariate model, variables associated with early demise were identified and a prediction rule created. Results A total of 879 patients were included of whom 47 met criteria for early demise. Using forward stepwise regression followed by a bootstrapping analysis, the final model included: left ventricular end-diastolic diameter ≥6.5 cm (OR 3.23 [1.72-6.06 g], P < 0.001), the presence of a non-left bundle branch block (non-LBBB) morphology (OR 2.18 [1.18-4.04, P = 0.013]), creatinine ≥1.5 mg/dL (OR 2.98 [1.52-5.49], P < 0.001), and lack of or intolerance to β-blocker use (OR 2.80 [1.46-5.39], P = 0.002). The specificity for ≥2 and ≥3 risk factors was 72.6% and 94.6%, respectively. Conclusions Left ventricular dilatation, the presence of a non-LBBB morphology, renal dysfunction, and lack of or intolerance to β-blockers are associated with early demise following CRT. In patients with at least 3 of these factors, bypassing CRT with early adoption of advanced heart failure therapies may be considered given the high specificity for rapid decline. [ABSTRACT FROM AUTHOR]

Late Gadolinium Enhancement and Arrhythmias. Introduction : The extent of left ventricular (LV) scar, characterized by late gadolinium enhancement cardiac MRI (LGE-CMR), has been shown to predict the occurrence of ventricular arrhythmias in implantable cardioverter defibrillator (ICD) recipients. However, the specificity of LGE-CMR for sudden cardiac death (SCD) versus non-SCD is unclear. The aim of this retrospective, observational study was to evaluate this relationship in a cohort of ICD recipients. Methods and Results : We included consecutive patients who had undergone LGE-CMR before ICD implantation over a 4-year period (2006-2009). Scar (defined as myocardium with a signal intensity ≥50% of the maximum in scar tissue) was characterized in terms of percent scar and number of transmural LV scar segments in a 17-segment model. The endpoints were appropriate ICD therapy and all-cause mortality. Sixty-four patients (average age 66 ± 11 years, 51 male, median LVEF 30%) were included. During 42 ± 13 months follow-up, appropriate ICD therapy occurred in 28 patients (44%), and 14 patients (22%) died. Number of transmural scar segments (P = 0.005) and percentage LV scar (P = 0.03) were both significantly associated with appropriate ICD therapy. However, neither number of transmural scar segments (P = 0.32) or percent LV scar (P = 0.59) was significantly associated with all-cause mortality. Conclusion : In this observational study, in medium-term follow-up, the extent of LV scar characterized by LGE-CMR was strongly associated with the occurrence of spontaneous ventricular arrhythmias but not all-cause mortality. We hypothesize that scar quantification by LGE-CMR may be more specific for SCD than non-SCD, and may prove a valuable tool for the selection of patients for ICD therapy. (J Cardiovasc Electrophysiol, Vol. 24, pp. 430-436, April 2013) [ABSTRACT FROM AUTHOR]