Deep brain stimulators (DBS), used in the treatment of Parkinson disease (PD), may interfere with the function of implantable cardioverter-defibrillators (ICD) used for prevention of sudden cardiac death. DBS have been implanted in 150,000 patients worldwide. Few reports of implantation of an ICD in patients with preexisting DBS have reported safe outcomes when the 2 devices are placed away from each other (ie, in the contralateral shoulders or the abdomen and shoulder).1, 2 One report of a subcutaneous ICD (S-ICD) implantation in a patient with a right pectoral DBS demonstrated feasibility without evidence of oversensing or inappropriate shocks.

As the global burden of cardiovascular disease continues to increase worldwide, nurturing the development of early-career cardiologists interested in global health is essential to create a cadre of providers with the skill set to prevent and treat cardiovascular diseases in international settings. As such, interest in global health has increased among cardiology trainees and early-career cardiologists over the past decade. International clinical and research experiences abroad present an additional opportunity for growth and development beyond traditional cardiovascular training. We describe the American College of Cardiology International Cardiovascular Exchange Database, a new resource for cardiologists interested in pursuing short-term clinical exchange opportunities abroad, and report some of the benefits and challenges of global health cardiovascular training in both resource-limited and resource-abundant settings.

The subcutaneous implantable cardioverter defibrillators (SICD) is an alternative to the transvenous ICD for the prevention of sudden cardiac death (SCD). Multiple studies have shown that the SICD is safe and effective in treating ventricular arrhythmias. While earlier studies mainly enrolled younger patients with channelopathies, more recent reports included patients with “typical” indications for ICD therapy for the prevention of SCD. In this review we summarize the data available to date on the SICD while highlighting its pros and cons.

Background-—The incidence of cancer treatment–induced arrhythmia (CTIA) associated with novel, targeted chemotherapeutic agents (TCAs) has not been well described. Methods and Results-—We identified all patients treated at our institution from January 2010 to December 2015 with selected TCAs. We defined CTIA as any new arrhythmia diagnosis code within 6 months after treatment initiation. As a comparison, we also identified patients treated with anthracycline chemotherapy during the same period. We identified 5026 patients, of whom 2951 (58.7%) received TCAs and 2075 (41.3%) received anthracycline chemotherapy. In the overall cohort, 601 patients (12.0%) developed CTIA. Patients with CTIA were significantly older and more likely to have hypertension, diabetes mellitus, congestive heart failure, coronary disease, and sleep apnea. The incidence of CTIA at 6 months was significantly lower in the TCA group (9.3% versus 15.8%; P<0.001). In multivariate analysis, a history of hypertension (hazard ratio, 1.63; 95% confidence interval, 1.34–1.98), congestive heart failure (hazard ratio, 2.12; 95% confidence interval, 1.78–2.68), and male sex (hazard ratio, 1.25; 95% confidence interval, 1.06–1.47) were associated with a significantly increased risk of CTIA, whereas treatment with TCAs, compared with anthracycline chemotherapy, was associated with a significantly lower risk (hazard ratio, 0.60; 95% confidence interval, 0.51– 0.71). Conclusions-—Compared with anthracyclines, treatment with TCAs was associated with an ≈40% reduced risk of new-onset arrhythmia diagnoses during the first 6 months of treatment.

Background: T wave oversensing (TWOS) is a major drawback of the subcutaneous implantable cardioverter defibrillator (S-ICD). Data on predictors of TWOS in S-ICD recipients are limited. We sought to investigate predictors of TWOS in a cohort of patients receiving an S-ICD at our institution. Methods: S-ICD recipients at our center were identified retrospectively and stratified based on the presence or absence of TWOS. Clinical and electrocardiographic parameters were collected and compared between the 2 groups. Results: Ninety-two patients underwent an S-ICD implantation at our institution between April 2010 and January 2015. Six (6.5%) patients had TWOS. These patients were younger (38.1±13.7 vs. 52.3±16.1 years, p=0.04) and had higher left ventricle ejection fractions (48.5±14.9% vs. 28.4±12.2%, p<0.01) than patients without a history of TWOS. Baseline 12-lead electrocardiogram (ECG) parameters were not different between the 2 groups. Leads I, II, and avF (which mimic the sensing vectors of the S-ICD) were further inspected to identify ECG characteristics that could predict TWOS. The QRS amplitude in ECG lead I was significantly smaller in the TWOS group than in the non-TWOS group (3.7 vs. 7.4 mV, p=0.02). Conclusion: In this study, younger age, higher ejection fraction, and lower QRS amplitude were associated with TWOS. These findings could help identify patients referred for S-ICD at high-risk of TWOS.

The efficacy of implantable cardioverter-defibrillators (ICD) for primary prevention of sudden cardiac death (SCD) has not been studied in patients with end-stage renal disease (ESRD) and left ventricular dysfunction. We sought to identify predictors of long-term survival among ICD recipients with and without ESRD. Methods Patients implanted with an ICD at our institution from January 2006 to March 2014 were retrospectively identified. Clinical and demographic characteristics were collected. Patients were stratified by the presence of ESRD at the time of ICD implant. Mortality data were collected from the Social Security Death Index (SSDI). Results A total of 3453 patients received an ICD at our institution in the pre-specified time period, 184 (5.3%) of whom had ESRD. In general, ESRD patients were sicker and had more comorbidities. Kaplan Meier survival curve showed that ESRD patients had worse survival as compared with non-dialysis patients (p < 0.001). Following adjustment for differences in baseline characteristics, patients with ESRD remained at increased long-term mortality in the Cox model. The one-year mortality in the ESRD patients was 18.1%, as compared with 7.7% in the non-dialysis cohort (p < 0.001). The three-year mortality in ESRD patients was 43%, as compared with 21% in the non-dialysis cohort (p < 0.001). Conclusion ESRD patients are at significantly increased risk of mortality as compared with a non-dialysis cohort. While the majority of these patients survive more than one year post-diagnosis, the three-year mortality is high (43%). Randomized studies addressing the benefits of ICDs in ESRD patients are needed to better define their value for primary prevention of SCD.

Background: Clinical outcomes of cardiac resynchronization therapy (CRT) in patients over the age of 80 have not been well described. Methods: We retrospectively identified 96 consecutive patients ≥ 80 years old who underwent an initial implant or an upgrade to CRT, with or without defibrillator (CRT-D vs. CRT-P), at our institution between January 2003 and July 2008. The control cohort consisted of 177 randomly selected patients < 80 years old undergoing CRT implant during the same time period. The primary efficacy endpoint was all-cause mortality at 36 months, assessed by Kaplan-Meier time to first event curves. Results: In the octogenarian cohort, mean age at CRT implant was 83.1 ± 2.9 years vs. 60.1 ± 8.8 years among controls (P < 0.001). Across both groups, 70% were male, mean left ventricular ejection fraction (LVEF) was 24.8% ± 14.1% and QRS duration was 154 ± 24.8 ms, without significant differences between groups. Octogenarians were more likely to have ischemic cardiomyopathy (74% vs. 37%, P < 0.001) and more likely to undergo upgrade to CRT instead of an initial implant (42% vs. 19%, P < 0.001). The rate of appropriate defibrillator shocks was lower among octogenarians (14% vs. 27%, P = 0.02) whereas the rate of inappropriate shocks was similar (3% vs. 6%, P = 0.55). At 36 months, there was no significant difference in the rate of all-cause mortality between octogenarians (11%) and controls (8%, P = 0.381). Conclusion: Appropriately selected octogenarians who are candidates for CRT have similar intermediate-term mortality compared to younger patients receiving CRT.