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Renal Function and Outcomes After Defibrillator Implantation Background Implantable cardioverter defibrillators (ICDs) and cardiac resynchronization therapy (CRT) reduce mortality in patients with heart failure (HF) and left ventricular dysfunction. However, their efficacy in patients with chronic kidney disease (CKD) is controversial. Objective We examined the association between renal dysfunction and clinical outcomes in patients undergoing ICD and CRT defibrillator (CRTD) implantation. Methods Data were collected from the Israeli ICD registry. Estimated glomerular filtration rate (eGFR) at implantation was assessed using the modification of diet in renal disease formula. Primary outcome was all-cause mortality. Secondary outcomes included the composite endpoints of death or HF and death or ventricular arrhythmias (ventricular tachycardia/ventricular fibrillation [VT/VF]); any hospitalizations; first appropriate and inappropriate ICD therapy. Results During the study period (July 2010-November 2012), 2,811 patients were implanted with ICD or CRTD. One-year follow-up data were available for 730 ICD patients and 453 CRTD patients. Patients with eGFR < 30 mL/minute/1.73 m2 (n = 54, 4.6%) were older, had a higher prevalence of diabetes, hypertension, or ischemic heart disease. eGFR <30 mL/minute/1.73 m2 was associated with increased mortality risk in ICD (HR 5.4; 95% CI 1.5-19.2), but not in CRTD patients (HR 0.9; 95% CI 0.1-7.5). Renal dysfunction was associated with the composite endpoints of death or HF and death or VT/VF in ICD, but not in CRTD patients. Mean eGFR during follow-up decreased by 8.0 ± 4.3 mL/minute/1.73 m2 in ICD patients (P = 0.06) and by 1.8 ± 1.3 mL/minute/1.73 m2 in patients with CRTD (P = 0.2). Conclusion Based on this retrospective analysis, CKD is associated with adverse prognosis after ICD implantation, but not after CRTD implantation. GFR decreased in patients with ICD, but not in CRTD patients. [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]

Role of Ischemia and Scar in CRT Patients with CAD Introduction Cardiac resynchronization therapy (CRT) recipients with ischemic cardiomyopathy (ICM) have scar segments that may limit ventricular resynchronization and clinical response. The impact of myocardial viability at the left ventricular (LV) pacing site on CRT response is poorly elucidated. Methods and Results A retrospective cohort of 160 ICM patients with single photon emission computed tomography-myocardial perfusion imaging before device implantation were included. Coronary venous angiography and chest radiographs helped classify segmental location of LV lead (LVL). The primary outcome was a composite of heart failure (HF) hospitalization and mortality at 3 years, and secondary outcome was change in systolic function at 6 months. The patients were divided into groups based on the myocardial substrate at the site of LVL: LVL on or adjacent to (1) normal myocardium (LVL-N, n = 64), (2) segmental scar (LVL-S, n = 62), and (3) scar and ischemia (LVL-SI, n = 34). Upon follow-up, 75 (47%) patients reached primary endpoint with a higher incidence noted in LVL-S (60%), and LVL-SI (53%), compared to 31% in LVL-N (P = 0.004). Kaplan Meier method demonstrated poor event free survival for primary outcome in LVL-S (P = 0.002), and LVL-SI (P = 0.03). In Cox proportional hazard model, LVL-S (HR: 2.26, P = 0.004), and LVL-SI (1.9, P = 0.047) were independent predictors of primary outcome. Conclusion In CRT recipients with ICM, scar and reversible ischemia in or adjacent to LV pacing site were independent predictors of HF hospitalization and death. [ABSTRACT FROM AUTHOR]

Arrhythmia Termination and Long-Term Outcome Background The influence of procedural arrhythmia termination on long-term single-procedure clinical outcome in patients with non-paroxysmal atrial fibrillation (AF) remains controversial. Methods An individualized stepwise ablation strategy was used in 200 consecutive patients with non-paroxysmal AF who underwent first-time radiofrequency catheter ablation, with pulmonary vein isolation and sinus rhythm (SR) restoration as the primary endpoints. Results SR was restored by ablation in 94 patients, including 32 with AF directly and 62 with intermediate atrial tachycardia (AT). Cardioversion was performed to restore SR in 106 patients, including 31 with intermediate AT, and 75 with sustained AF. During a mean follow-up of 50.0 ± 9.3 months, single-procedure success was achieved in 99 (49.5%) patients. There was a significant difference in long-term success between patients with SR restoration by ablation and by cardioversion (63.8% vs 36.8%; P < 0.001), but not between patients with AF termination by ablation and by cardioversion (53.6% vs 42.7%; P = 0.146). SR restoration by ablation (odds ratio = 3.032; 95% confidence interval = 1.703-5.398; P < 0.001) was the only predictor of single-procedure success by logistic regression analyses. In patients with intermediate AT (n = 93), AT termination by ablation was associated with a higher success rate than AT termination by cardioversion (62.9% vs 22.6%; P < 0.001). Conclusions SR restoration and AT termination by ablation were both associated with an improved long-term single-procedure clinical outcome in patients with non-paroxysmal AF. [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]

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]

Long-Term Efficacy of Single Procedure Remote Magnetic Catheter Navigation. Background: Remote magnetic navigation (RMN) aims to reduce some inherent limitations of manual radiofrequency (RF) ablation. However, data comparing the effectiveness of both methods are scarce. This study evaluated the acute and long-term success of RMN guided versus manual RF ablation in patients with ischemic sustained ventricular tachycardia (sVT). Methods: One hundred two consecutive patients (age 68 ± 10 years, LVEF 32 ± 12%, 88 men) with ischemic sVT were ablated with RMN (Stereotaxis; 49%) or manually (51%) using substrate and/or activation mapping (Carto) and open-irrigated-tip catheters. All received implantable defibrillators or loop recorders. Acute success was defined as noninducibility of any sVT at the end of the ablation procedure and long-term success as freedom from VT upon follow-up. Results: There was no difference in the baseline characteristics between the groups. Three patients died in hospital. Acute success rate was similar for RMN and manual ablation (82% vs 71%, P = 0.246). RMN was associated with significantly shorter fluoroscopy time (13 ± 12 minutes vs 32 ± 17 minutes, P = 0.0001) and RF time (2337.59 ± 1248.22 seconds vs 1589.95 ± 1047.42 seconds, P = 0.049), although total procedure time was similar (157 ± 40 minutes vs 148 ± 50 minutes, P = 0.42). There was a nonsignificant trend toward better long-term success in RMN group: after a median of 13 (range 1-34) months, 63% in the RMN and 53% in the manual ablation group were free from VT recurrence (P = 0.206). Conclusion: RMN guided RF ablation of ischemic sustained VT is equally efficient compared with manual ablation in terms of acute and long-term success rate. These results are achieved with a significantly reduced fluoroscopy time and shorter RF time. (J Cardiovasc Electrophysiol Vol. 23, pp. 499-505, May 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]

Very Early Recurrence of AF. Introduction: Early restoration of sinus rhythm following ablation of atrial fibrillation (AF) facilitates reverse atrial remodeling and improves the long-term outcome. The purpose of this study was to determine the predictors and outcome in patients with very early AF recurrences (< 2 days). Methods and Results: Ablation was performed in 339 consecutive AF patients (paroxysmal AF = 262). Biatrial voltage was mapped during sinus rhythm. If recurrent AF occurred within 2 days following the ablation, electrical cardioversion was performed to restore sinus rhythm. Very early recurrences of AF occurred in 39 (15%) patients with paroxysmal AF and 26 (34%) with nonparoxysmal AF. Patients with very early recurrence had a higher incidence of nonparoxysmal AF (40% vs 18.6%, P< 0.001), requirement of electrical cardioversion during procedure, larger left atrial (LA) diameter (43 ± 7 vs 39 ± 6 mm, P< 0.001), lower left ventricular ejection fraction (54 ± 10% vs 59 ± 7, P< 0.001), longer procedural time, and lower LA voltage (1.5 ± 0.7 vs 1.9 ± 0.8 mV, P< 0.001). A multivariate analysis revealed that the independent predictors of a very early recurrence were a longer procedural time and lower LA voltage. During a follow-up of 13 ± 5 months, a very early recurrence did not predict the long-term outcome of a single procedure recurrence in the patients with paroxysmal AF, but was associated with a late recurrence in the nonparoxysmal AF patients. Conclusion: Very early recurrence occurred in patients with paroxysmal AF is not associated with long-term recurrence. Nonparoxysmal AF is an independent predictor of late recurrence of AF in patients with very early recurrence. (J Cardiovasc Electrophysiol, Vol. pp. 1-6) [ABSTRACT FROM AUTHOR]

AF Ablation Technologies and Silent Cerebral Ischemic Lesions. Introduction: Silent cerebral ischemic lesions have recently emerged as the most frequent complications after pulmonary vein isolation (PVI). To reduce thromboembolic complications, new types of catheters and energy source have been introduced in clinical practice. The study purpose is to compare the incidence of new silent cerebral ischemic events in patients with paroxysmal atrial fibrillation (PAF) undergoing PVI with different ablation technologies. Methods and Results: One hundred and eight patients (67% men; age 56 ± 9 years) with PAF were enrolled in a consecutive manner to undergo PVI performed with irrigated radiofrequency (RF) catheter (Group 1, 36 patients), multielectrode catheter (PVAC) associated with duty-cycled RF generator (Group 2, 36 patients) and cryoballoon (Group 3, 36 patients). The protocol included a cerebral magnetic resonance imaging before and after the procedure. After PVI, the following patients showed new silent cerebral ischemic lesions at postprocedural cerebral MRI: 3 patients in Group 1 (8.3%), 14 patients in Group 2 (38.9%), 2 patients in Group 3 (5.6%). PVAC related to higher incidence of silent cerebral ischemic events compared to irrigated RF (P = 0.002) and cryoballoon (P = 0.001), whereas no statistical differences were found between irrigated RF catheter and cryoballoon groups (8.3% vs 5.6%, P = 0.5). At the multivariate analysis, the only independent predictor of new ischemic asymptomatic cerebral lesions after PVI was ablation performed with PVAC (OR 1.48 95% CI 1.19-1.62, P < 0.001). Conclusion: The incidence of silent cerebral lesions after PVI is different depending on technologies used: PVAC increases the risk of 1.48 times compared to irrigated RF and cryoballoon ablation. (J Cardiovasc Electrophysiol, Vol. 22, pp. 961-968, September 2011) [ABSTRACT FROM AUTHOR]