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Long-Term Outcome of AF Ablation in MMV Patients Introduction It is unclear whether extended pulmonary vein antrum isolation (PVAI) plus nonpulmonary vein (non-PV) trigger elimination prevents more arrhythmia recurrence than PVAI alone in patients with mechanical mitral valve (MMV) undergoing AF ablation. This study compared the efficacy and long-term outcome of 2 ablation strategies-PVAI alone versus extended PVAI plus non-PV trigger elimination-for the treatment of AF in patients with MMV. Methods and Results One hundred and nine consecutive AF patients with MMV were divided into 2 groups: standard PVAI was performed in group 1 (N = 45); in group 2 (N = 64) PVAI was extended to the LA posterior wall, LA septum, and CS; and all non-PV triggers were eliminated. Patients were followed up for 3 years. At the 12th month, 7 (15.6%) patients in group 1, and 39 (60.9%) patients in group 2 were arrhythmia free (log-rank P < 0.001). Four patients (8.9%; 3 cases of AT and 1 case of AF) from group 1, and 12 patients (18.8%; 9 cases of AT, and 3 cases of AFL) from group 2 experienced very late recurrence. At 36 ± 7 months follow-up, the cumulative recurrence after a single procedure was 42/45 (93.3%) in group 1, and 37/64 (57.8%) in group 2 (log-rank P < 0.001). Conclusion Compared with the standard PVAI alone, a strategy including extended PVAI and non-PV trigger elimination is associated with a higher 12-month and long-term arrhythmia-free survival in patients with MMV undergoing AF ablation. Very late recurrence may occur years after the initial procedure with focal AT as the most common type of recurrent arrhythmia. [ABSTRACT FROM AUTHOR]

Interventricular Electrical Delay Introduction The left ventricular (LV) pacing site and the magnitude of the electrical delay within the LV, as expressed by prolonged QRS duration, are major determinants of cardiac resynchronization therapy (CRT) efficacy. We investigated the incremental value of positioning the LV lead in areas of late activation in order to enhance the response to CRT in patients with different degrees of QRS complex lengthening. Methods and Results This analysis was performed on 301 heart failure patients who received a CRT defibrillator. On implantation, the right ventricular (RV)-to-LV interval was measured as the delay between local activations recorded through the RV and LV leads in the final position. After 1 year, 171 (57%) patients displayed reverse LV remodeling, as measured by a ≥15% reduction in the LV end-systolic volume. Both the RV-to-LV interval and its percentage value corrected for the QRS duration were significantly associated with a positive response to CRT. An RV-to-LV interval >80 milliseconds and an RV-to-LV interval/QRS >58% yielded the best prediction of reverse remodeling. Although the response to CRT decreased with shorter QRS duration in the overall population, patients with an RV-to-LV interval >80 milliseconds showed a response rate >65% in all QRS subgroups. Conclusion A longer RV-to-LV interval is associated with reverse LV remodeling after CRT. On implantation attempts could be made to maximize it when selecting the LV lead position, especially in patients with shorter QRS duration, and thus less likely to respond positively to CRT. [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]

Real-Time Contact Force Sensing for Pulmonary Vein Isolation Introduction The additional benefit of contact force (CF) technology during pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) to improve mid-term clinical outcome is unclear. Methods and Results Eligible patients with symptomatic paroxysmal AF were enrolled in this prospective trial, comparing circular antral catheter ablation (guided by Carto 3 System, Biosense Webster) using either a new open-irrigated CF catheter (SmartTouch Thermocool, Biosense Webster) (CF group) or a non-CF open-irrigated catheter (EZ Steer Thermocool, Biosense Webster) (control group). Overall, 30 patients were enrolled in each group, with a standardized 12-month follow-up, free of antiarrhythmic therapy. Demographic, cardiovascular and anatomic characteristics were similar in both groups. Though complete PVI was eventually achieved in all cases in both groups, success using an exclusive anatomic approach was 80.0% in CF group versus 36.7% in control group ( P < 0.0001). CF use was associated with significant reductions in fluoroscopy exposure ( P < 0.01) and radiofrequency time ( P = 0.01). The incidence rates of AF recurrence were 10.5% (95% CI, 1.38-22.4) in the CF group, and 35.9% (95% CI, 12.4-59.4) in the control group (log rank test, P = 0.04). After adjustment on potential confounders, the use of CF catheter was found to be associated with a lower AF recurrence (OR 0.18, 95% CI 0.04-0.94, P = 0.04). Conclusion Our findings suggest a potential benefit of real-time CF sensing technology, in reducing AF recurrence during the first year after PVI. [ABSTRACT FROM AUTHOR]

Left Atrial Sphericity Predicts AF Ablation Outcome Background Atrial fibrillation (AF) ablation outcome is mainly determined by atrial remodeling that, nowadays, is only estimated through clinical presentation (persistent vs. paroxysmal) and left atrial (LA) dimension. The aim of the study was to stage the atrial remodeling process using the Left Atrial Sphericity (LASP) and determine whether this technique may help to predict AF ablation outcome. Methods Consecutive patients who underwent contrast-enhanced cardiac magnetic resonance angiography before AF ablation were included in the study. Three-dimensional reconstruction of LA excluding pulmonary veins and the LA appendage was used to define the LA cavity. The LASP was automatically obtained with self-customized software. Results 106 patients were included and categorized in 3 groups (Gs): discoid-LA (G1), intermediate-LA (G2), and spherical-LA (G3). The G3 patients had larger LA anteroposterior diameter than G1 and G2 patients (47 ± 7 vs 43 ± 6 and 39 ± 5mm; P < 0.001), greater LA volume (90 ± 39 vs 86 ± 24 and 73 ± 20 mm; P = 0.012), and higher prevalence of persistent AF (75% vs 48% and 29%; P = 0.034) structural heart disease (75% vs 19% and 19%; P < 0.001), and AF recurrence at 12 months follow-up (58% vs 29% and 5%, P < 0.001). The LASP had linear correlation to predicted probability of recurrence. Multivariate analysis identified LASP (OR 1.320 [1.096-1.591], P = 0.004) and hypertension (OR 3.694 [1.282-10.645]; P = 0.016) as independent risk factors for arrhythmia recurrence. Conclusion Left Atrial Sphericity is a new independent predictor of recurrence after AF ablation and may be useful in selecting the best candidates for AF ablation. [ABSTRACT FROM AUTHOR]

Arrhythmia Inducibility Post-AF Ablation Introduction Prior reports demonstrate prognostic value in noninducibility of atrial arrhythmias after atrial fibrillation (AF) ablation and suggest their utility in guiding additional ablation lesion sets. The type and mechanism of induced atrial arrhythmias, their relationship to the underlying atrial substrate, and prognostic significance of induced organized atrial arrhythmias are unknown. Methods and Results One hundred forty-four patients (30 women; median age 60 years; 54% with paroxysmal AF) undergoing AF ablation (circumferential pulmonary vein isolation and focal ablation of nonvein triggers on isoproterenol) were evaluated prospectively. All underwent a standardized postablation induction protocol from the coronary sinus and right atrium: 15 beat burst pacing at 250 milliseconds and decrementing to 180 milliseconds. Sustained rhythms were defined as greater than 2 minutes Of 144 patients, 55 patients (38.2%) did not have sustained inducible arrhythmias. Fifty-two (36.1%) had inducible AF and 37 (25.7%) had inducible organized arrhythmias. A logistic regression analysis showed that age (OR 2.10 per decade; P = 0.003) and hypertension (OR 4.15; P = 0.009) were predictive of inducibility. However, inducibility of either AF or organized arrhythmias was not prognostic of clinical recurrence at 1 year postablation (P = 0.65). Furthermore, inducibility of organized arrhythmias did not predict clinical recurrence of an organized arrhythmia. Only LA size (OR 2.18; 95% CI 1.02-4.67; P = 0.04) and persistent AF (OR 2.43; 95% CI 1.09-5.40; P = 0.03) predicted atrial arrhythmia recurrence. Conclusions Multisite atrial burst pacing post-AF ablation induced organized rhythms in 25.7% and AF in 36.1% of patients after AF ablation. Hypertension and age predict inducibility of arrhythmias, but inducibility did not predict clinical recurrence in follow-up. Distinguishing organized atrial arrhythmias from AF did not yield any further prognostic information. The utility of aggressive stimulation protocols after AF ablation for prognosis and to guide therapy appears limited. [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]

Prognostic Impact of Inappropriate Shocks. Introduction: Recent studies suggest a worse impact of inappropriate shock therapies on the outcome of patients with an implantable cardioverter-defibrillator (ICD). However, it is not known whether the worse impact is attributed to the ICD shock itself or due to the underlying heart disease. The aim of the study was to evaluate the impact of inappropriate ICD shocks on clinical outcome by comparing ICD shocks triggered by atrial fibrillation (AF) with shocks caused by lead failure. Methods and Results: A total of 1,411 consecutive patients of the prospective single-center ICD-registry Ludwigshafen who underwent an ICD implantation between 1992 and 2008 for primary or secondary prevention of sudden cardiac death were analyzed. During the median follow-up of 3 years, 297 (21%) patients experienced inappropriate ICD shocks. Sixty percent of patients had inappropriate shocks due to AF and 24% due to lead defect or T-wave oversensing. Multiple ICD shocks (≥2) triggered by AF were associated with a worse prognosis, whereas a single shock due to AF or 1 or multiple shocks resulting from lead failure were not. ICD shocks caused by AF occurred more often in tandem with a serious adverse event than in patients with a lead failure (15% vs 6%, P < 0.05). Conclusion: Multiple ICD shocks triggered by AF are associated with a worse prognosis in ICD patients, whereas a single shock due to AF or shocks resulting from lead failure are not. These data support that the ICD shock itself has no worse impact on the outcome of ICD patients. (J Cardiovasc Electrophysiol, Vol. 23, pp. 735-740, July 2012) [ABSTRACT FROM AUTHOR]

Depression and Cardiac Resynchronization Therapy. Background: The relationship between depression and heart failure is neither coincidental nor trivial, since depression is a powerful predictor of re-hospitalization and mortality. We prospectively studied the prevalence and impact of depression on the clinical outcomes of patients attending for cardiac resynchronization therapy (CRT). We specifically examined whether patients with depression have a different rate of response to CRT and whether CRT has an effect on depressive symptoms. Methods: Sixty-eight recipients of CRT systems were included. The depressive status was evaluated before implant and after 6 months by a structured diagnostic interview measuring Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria of major depression and by a self-report questionnaire (Center for Epidemiological Studies Depression Scale, CES-D). The CRT response was assessed at 6 months by a clinical composite score. Results: At inclusion, DSM-IV criteria of major depression were identified in 41% of the population, while using the self-report questionnaire 65% were observed to have mild to major depressive symptoms (CES-D ≥ 16). Only 4 patients were taking antidepressants. At 6 months, 75% were considered responders to CRT. Response to CRT did not differ between those with and without depression at baseline. The rate of patients with depression at 6 months was significantly lower in responders to CRT compared with nonresponders. Conclusions: We found a high prevalence of depressive symptoms in patients receiving CRT systems. Patients with depression should not be excluded from CRT, because they demonstrate a similar rate of response than the persons without depression and the responders are less likely to be depressed at 6 months. (J Cardiovasc Electrophysiol, Vol. 23, pp. 631-636, June 2012) [ABSTRACT FROM AUTHOR]

Pacemakers and ICDs in Myotonic Dystrophy. Introduction: We assessed implant rates, indications, characteristics, and outcomes in patients with the neuromuscular disease, myotonic dystrophy type 1 (DM1) receiving a pacemaker or an implantable cardioverter-defibrillator (ICD). Methods and Results: Device use was evaluated in a prospective, multicenter registry of 406 genetically confirmed adult patients followed for 9.5 ± 3.2 years. Forty-six (11.3%) had or received a pacemaker and 21 (5.2%) received an ICD. Devices were primarily implanted for asymptomatic conduction abnormalities and left ventricular (LV) systolic dysfunction. However, 7 (15.2%) pacemakers were implanted for third-degree atrioventricular block and 6 (28.6%) ICDs were implanted for ventricular tachyarrhythmias (ventricular tachycardia [VT] or fibrillation [VF]). Patients receiving devices were older and more frequently had heart failure, LV systolic dysfunction, atrial tachyarrhythmias, and ECG conduction abnormalities compared to nondevice patients. Five (10.9%) pacemaker patients underwent upgrade to an ICD, 3 for LV systolic dysfunction, 1 for VT/VF, and 1 for progressive conduction disease. Seventeen (27.4%) of the 62 patients with devices were pacemaker-dependent at last follow-up. Three (14.3%) ICD patients had appropriate therapies. Twenty-four (52.2%) pacemaker patients died including 13 of respiratory failure and 7 of sudden death. Seven (33.3%) ICD patients died including 2 of respiratory failure and 3 of sudden death. The patients with ICDs and sudden death all had LV systolic dysfunction and 1 death was documented due to inappropriate therapies. Conclusions: DM1 patients commonly receive antiarrhythmia devices. The risk of VT/VF and sudden death suggests that ICDs rather than pacemakers should be considered for these patients. (J Cardiovasc Electrophysiol, Vol. 22, pp. 1369-1375, December 2011) [ABSTRACT FROM AUTHOR]