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Common physiological manifestations of cocaine are related to its adrenergic effects, due to inhibition of dopamine and norepinephrine uptake at the postsynaptic terminal. Few studies have documented bradycardia secondary to cocaine use, representing the antithesis of its adrenergic effects. We assessed the prevalence of sinus bradycardia (SB) in habitual cocaine users and postulated a mechanism for this effect. One hundred sixty-two patients with a history of cocaine use were analyzed and compared with age- and gender-matched controls. SB was defined as a rate of <60 beats/min and habitual cocaine use as 2 or more documented uses >30 days apart. Propensity score–matching analysis was applied to balance covariates between cocaine users and nonusers and reduce selection bias. Patients with a history of bradycardia, hypothyroidism, or concomitant beta-blocker use were excluded. Mean age of study patients was 44 ± 8 years. SB was observed in 43 of 162 (27%) cocaine users and in 9 of 149 (6%) nonusers (p = 0.0001). Propensity score–matching analysis matched 218 patients from both groups. Among matched patients SB was observed in 25 of 109 (23%) cocaine users and in 5 of 109 (5%) nonusers (p = 0.0001). Habitual cocaine use was an independent predictor of SB and associated with a sevenfold increase in the risk of SB (95% CI 2.52 to 19.74, p = 0.0002). In conclusion, habitual cocaine use is a strong predictor of SB and was unrelated to recency of use. A potential mechanism for SB may be related to cocaine-induced desensitization of the beta-adrenergic receptor secondary to continuous exposure. Symptomatic SB was not observed; thus, pacemaker therapy was not indicated.

Approximately 121,000 bariatric surgical procedures are performed annually, and salutary effects include a reduction in cardiovascular morbidity and mortality, risk factor modification, and improvement in sympathovagal tone. There are anecdotal accounts of unexplained sinus bradycardia (SB) after significant weight loss but no systematic studies have been conducted. The purpose of this study was to determine the frequency of incident SB, its timing, and association with weight loss, clinical characteristics, and predictors. We evaluated various clinical characteristics including resting heart rate, blood pressure, body mass index (BMI), heart rate reserve (HRR), basal metabolic rate, and exercise regimen in 151 consecutive patients who underwent bariatric surgery. Multiple logistic regression analysis was performed to determine predictors of SB. Twenty-five of 137 patients (18%) experienced postoperative SB. Patients with SB had significantly greater reduction in BMI than those without bradycardia (35 ± 9.6% and 25.7 ± 13%, respectively, p = 0.002). HRR was significantly greater in patients with SB (116 ± 14 beats/min) compared with those without bradycardia (105 ± 14 beats/min, p = 0.007). Multiple logistic regression analysis revealed that the odds of developing SB were 1.96 and 1.91 and associated with the percent decrease in BMI (95% confidence interval 1.3 to 3.0, p = 0.002) or increase in HRR (95% confidence interval 1.28 to 2.85, p = 0.002), respectively. In conclusion, SB occurred 14 ± 11 months postoperatively and its predictors were the percent reduction in BMI or increase in HRR.

Cardiac resynchronization therapy (CRT) improves clinical outcomes and reduces mortality in heart failure patients who remain symptomatic despite optimal medical therapy. CRT trials have reported significant hemodynamic benefits, improvement in functional status, and reduced mortality and heart failure hospitalizations. However, African-American patient representation in these studies is limited thus the results may not be applicable to them. We described baseline clinical characteristics of African-American patients undergoing CRT and determined their outcomes relative to those reported in clinical trials. We evaluated 131 African-American patients with New York Heart Association functional class II-IV heart failure undergoing CRT and determined predictors of all-cause mortality. Kaplan-Meier survival estimates and a Cox proportional hazards model determined mortality and risk of death. The mean age was 65 ± 12 years. Over a 6-year period, total mortality in African-Americans was 23% as compared with 29% in the MADIT-CRT trial. Increased mortality was associated with older age (hazard rate (HR) 1.04, 95% confidence interval (CI) 1.01–1.07, P=.01), ischemic cardiomyopathy (HR 2.86, 95% CI 1.36-6.04, P=.006), and absence of treatment with either an angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker (HR 2.75, 95% CI 1.30-5.80, P=.008), or beta-blocker (HR 2.56, 95% CI 0.98-6.69, P=.05). Hydralazine plus nitrate therapy was used in a small number of patients and did not influence mortality outcomes. African-Americans experience the same survival benefits from CRT as Caucasian patients reported in major clinical trials. Publication indices used to find publications listed in references: PubMed

While there are several completed clinical trials that address treatment strategies in patients with symptomatic and recurrent atrial fibrillation (AF), there are no randomized clinical trials that address first-line rhythm control of new-onset AF. Recent data suggest that early initiation of rhythm control within 1 year can improve outcomes. In this open-label pragmatic clinical trial nested within the Get with The Guidelines Atrial Fibrillation registry, approximately 3,000 patients with first-detected AF will be enrolled at approximately 200 sites. Participants will be randomized (1:1) to treatment with dronedarone in addition to usual care versus usual care alone. The primary endpoint will be time to first cardiovascular (CV) hospitalization or death from any cause through 12 months from randomization. Secondary endpoints will include a WIN ratio (all-cause death, ischemic stroke or systemic embolism, heart failure hospitalization, acute coronary hospitalization), CV hospitalization, and all-cause mortality. Patient reported outcomes will be analyzed based on change in Atrial Fibrillation Effect on Quality of Life (AFEQT) and change in Mayo AF-Specific Symptom Inventory (MAFSI) from baseline to 12 months. CHANGE AFIB will determine if treatment with dronedarone in addition to usual care is superior to usual care alone for the prevention of CV hospitalization or death from any cause in patients with first-detected AF. The trial will also determine whether initiation of rhythm control at the time of first-detected AF affects CV events or improves patient reported outcomes. - NCT05130268

Previous studies suggest that patients with sickle cell anemia (SCA) have an increased risk of sudden cardiac death; however, its etiology and mechanism are not well defined. Left ventricular hypertrophy (LVH), ventricular tachycardia (VT) and poor left ventricular systolic function are known risk factors for sudden cardiac death. An abnormal microvolt T-wave alter-nans (TWA) test is also a predictor of sudden cardiac death risk, but it has not been applied to this patient population. We performed a 12-lead electrocardiogram, 24hour Holter monitor, two-dimensional echocardiogram, nuclear stress test and microvolt TWA test to determine whether markers of sudden cardiac death could be identified. Twenty-six patients were evaluated with a mean age of 40±12years. The two-dimensional echocardiogram revealed a normal ejection fraction in 23 patients and LVH in 17 (65%), whereas hypertension was noted in only five (19%). Microvolt TWA testing was abnormal in six of 22 patients (27%). Holter monitor revealed VT in two patients. Among the clinical variables tested, only LVH was predictive of an abnormal TWA test. The sensitivity, specificity, positive and negative predictive value of LVH for and abnormal TWA test was 100, 56, 46 and 100%. LVH was common in patients with SCA and dis-proportional to the number of patients with hypertension. Microvolt TWA tests were abnormal in 27% of patients; however, LVH was the only clinical variable that predicted an abnormal TWA test. Risk stratification of SCA patients may require echocardiographic detection of LVH and an abnormal TWA test due to the high negative predictive value. The significance of an abnormal TWA test should be further evaluated in a large study, with a longer follow-up period.

Purpose The prepectoral approach is the procedure of choice for pacemaker or defibrillator (device) implantation. Epicardial or transiliac approaches are reserved for patients in whom the pectoral approach is not feasible. We studied the viability of the axillary subpectoral approach for implanting devices in patients in whom the standard prepectoral approach was not feasible. Methods Devices and leads were extracted from 16 patients with infected devices in the prepectoral position. The contralateral site was unsuitable for reimplantation because of infection or inadequate venous access. On the side ipsilateral to that with prior prepectoral device infection, we made an incision on the anterior axillary line along the border of the pectoralis major; dissection was continued below the muscle to create a pocket for generator implantation. Axillary venous puncture was performed from the axillary incision and beneath the pectoralis major muscle using a long 14-gauge needle. Long guidewires and peel-away sheaths were used for positioning the lead. The generator was placed in the subpectoral pocket; the wound was closed with absorbable sutures. Results One patient developed a pocket hematoma; one developed a pneumothorax; no other surgical complication, lead malfunction, or recurrence of infection was observed. Conclusion The axillary subpectoral approach is an acceptable, technically feasible method for reimplantation for patients with pectoral device infection and limited venous access options. It offers the advantage of a new sterile fascial plane ipsilateral to the site of prepectoral device infection.