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This study sought to determine the impact of adjunctive renal sympathetic denervation to catheter ablation in patients with atrial fibrillation (AF) and history of hypertension.There are limited data regarding the impact of upstream adjunctive renal sympathetic denervation (RSDN) to pulmonary vein isolation (PVI) in patients with symptomatic atrial fibrillation (AF) and hypertension.The data for this study were obtained from 2 prospective randomized pilot studies, the HFIB (Adjunctive Renal Denervation to Modify Hypertension and Sympathetic tone as Upstream Therapy in the Treatment of Atrial Fibrillation)-1 (n = 30) and HFIB (Adjunctive Renal Denervation to Modify Hypertension and Sympathetic tone as Upstream Therapy in the Treatment of Atrial Fibrillation)-2 (n = 50) studies, and we performed a meta-analysis including all published studies comparing RSDN+PVI versus PVI alone up to January 25, 2020, in patients with AF and hypertension.At 24 months, AF recurrence occurred in 53% and 38% in the PVI and PVI+RSDN groups (p = 0.43) in the HFIB-1 study, respectively, and 27% and 25% in the PVI and PVI+RSDN groups (p = 0.80) in the HFIB-2 study, respectively. When combined in a meta-analysis including 6 studies (n = 725), adjunctive RSDN significantly decreased the risk of AF recurrence (risk ratio [RR]: 0.68; 95% confidence interval [CI]: 0.55 to 0.83; p = 0.0002; IThe pilot HFIB-1 and HFIB-2 studies did not demonstrate a benefit with RSDN as an adjunctive upstream therapy during PVI. However, in the meta-analysis, adjunctive RSDN to PVI appears to be safe, and improves clinical outcomes in AF patients with a history of hypertension.

Defibrillation testing has been routinely performed as part of the implantable cardioverter-defibrillator (ICD) implantation procedure, and is currently supported by practice guidelines; however, more recently, this practice has been called into question. Such testing is safe, and serious complications are rare. With modern ICD systems, physicians will rarely encounter a patient in whom defibrillation will fail. This article reviews the literature regarding the utility, necessity, complications, and cost of routine operative and follow-up defibrillation testing, and, it is hoped, clarifies the issue of "Who doesn't get it?"

Defibrillation Thresholds in Hypertrophic Cardiomyopathy. Background: Defibrillation threshold (DFT) testing is performed in part to ensure an adequate safety margin for the termination of spontaneous ventricular arrhythmias. Left ventricular mass is a predictor of high DFTs, so patients with hypertrophic cardiomyopathy (HCM) are often considered to be at risk for increased defibrillation energy requirements. However, there are little prospective data addressing this issue. Objective: To assess DFTs in patients with HCM and evaluate the clinical predictors of elevated DFTs. Methods: Eighty-nine consecutive patients with HCM and 600 control patients with ischemic or nonischemic cardiomyopathy underwent a uniform modified step-down DFT testing protocol. DFT was compared between the control and HCM populations. Predictors of elevated DFT were evaluated in the HCM group. Results: There was no difference in DFT between HCM and control groups (10.4 ± 5.8 J vs 11.2 ± 5.6 J, respectively). Among patients with HCM, clinical parameters such as left ventricular ejection fraction, interventricular septal thickness, left ventricular mass, and QRS duration were not predictive of an elevated DFT. Only 3 patients (3.4%) with HCM had a DFT >20 J. Conclusion: Patients with HCM do not have elevated DFTs as compared to more typical populations undergoing implantable cardioverter-defibrillator implant; high-energy devices or complex lead systems are not needed routinely in this population. (J Cardiovasc Electrophysiol, Vol. 22, pp. 569-572 May 2011)

Cardiac resynchronization therapy (CRT) improves functional status, reduces heart failure hospitalizations, and decreases mortality. Several comorbidities including renal function affect outcomes with CRT. However, moderate to severe chronic kidney disease (CKD) was an exclusion criterion in the large randomized control trials.To evaluate the association of renal function on survival following CRT implantation.This was a retrospective analysis of 432 consecutive patients implanted with an implantable cardioverter defibrillator with CRT (CRT-D). The primary end point was defined as death by any cause, and it was determined using hospital records and the U.S. Social Security Death Index. A Kaplan-Meier analysis was performed separating renal dysfunction into renal stage based on glomerular filtration rate. Multivariate analysis was performed to assess the clinical predictors of mortality.Patients were followed for up to 12 years with a mean follow-up time of 4.3 ± 3.2 years. A total of 164 patients (39.3%) died over the course of the study. Patients with normal and mild renal diseases (Stages 1 and 2) had improved survival compared with those with moderate-, severe-, or end-stage (Stages 3-5) renal disease. This effect remained statistically significant after multivariate analysis. The estimated 5-year mortality was 36.3% for stage 1, 33.4% for stage 2, 40.6% for stage 3, and 62.1% for stage 4/5 kidney disease (P = 0.004 by log-rank test).CKD is a strong and an independent predictor of long-term mortality among patients undergoing CRT-D implantation.

In patients with structural heart disease, ventricular arrhythmias are associated with an increased risk of overall mortality and sudden cardiac death (SCD). Nonsustained ventricular tachycardia (NSVT) is common in patients with dilated cardiomyopathy of both ischemic and nonischemic origin. Recent studies suggest that NSVT may be a marker, but not a significant predictor, of mortality and SCD in that suppression of NSVT in these patients using antiarrhythmic drugs is of questionable benefit. Additionally, indications for implantable cardioverter defibrillator implantation do not include NSVT. This article focuses on the prognostic significance and treatment of patients with NSVT and ischemic or nonischemic dilated cardiomyopathy.

Introduction: Hypocalcemia occurs frequently after wide area circumferential ablation (WACA) of atrial fibrillation and is more common with the use of open-irrigated tip ablation catheters (ITAC) than 8-mm tip ablation catheters. The mechanism of this phenomenon is unknown, but may be related to binding of calcium to myocardial proteins, volume infusion, or other factors. The present study aims to identify variables associated with acute hypocalcemia after WACA with ITAC. Methods: We analyzed 106 patients undergoing WACA with ITAC. Pre- and post-procedural values of calcium, creatinine, glomerular filtration rate (GFR), hemoglobin, cardiac enzymes (CK, CK-MB and troponin-I), albumin, left atrial size, presence of post-procedure pericardial effusion, infused volume of normal saline, urine output, heparin, furosemide dosage, and procedure time were recorded. Univariate and multivariate analysis were performed to determine variables associated with post-ablation hypocalcemia. Results: The population had mean age of 59±9 years, mean weight of 95±22 kilograms, and 76% were male. Mean pre-procedure GFR was 101±39 mL/min, and mean volume of normal saline infused was 5.5±1.3 liters. The means for pre-procedure calcium, post-procedure calcium, and decrease in calcium were 9.2±0.4, 7.3±0.6, and 1.9±0.7 mg/dL respectively. Of the variables measured, multivariate analysis identified pre-procedure GFR (parameter estimate −0.005) and infused volume of normal saline (parameter estimate 0.11) as factors independently associated with post-ablation hypocalcemia (p value = 0.03). Factors associated with myocardial injury were not apparently related. Conclusions: Lower GFR and higher infused volume of normal saline correlated with acute hypocalcemia after WACA with ITAC. Rather than binding to injured myocardium, these results suggest impaired renal calcium absorption and/or dilutional effects as the principal mechanism(s).