Electrical alternans affecting the ST segment and T wave is common among patients at increased risk for ventricular arrhythmias. Subtle electrical alternans on the electrocardiogram may serve as a noninvasive marker of vulnerability to ventricular arrhythmias.

Objectives We assessed the association between depression and sudden cardiac death (SCD) and cardiac events among individuals without baseline coronary heart disease (CHD). Background Depression is a risk factor for cardiac events and mortality among those with CHD, possibly from arrhythmia. Methods We studied depressive symptoms, and a proxy variable for clinical depression consisting of severe symptoms and/or antidepressant medication use, and their relationship to cardiac events in the Nurses’ Health Study. Questionnaires in 1992, 1996, and 2000 assessed symptoms with the Mental Health Index (MHI-5), and antidepressant use was assessed in 1996 and 2000. Primary endpoints included SCD, fatal CHD, and non-fatal myocardial infarction (MI). Results Among 63,469 women without prior CHD/stroke in 1992, 7.9% had MHI-5 scores (<53) previously found to predict clinical depression. Depressive symptoms were associated with CHD events, and the relationship was strongest for fatal CHD, where the association remained significant even after controlling for CHD risk factors (HR=1.49; 95% CI 1.11–2.00 for MHI-5 score<53). In models from 1996 onward, our proxy variable for clinical depression was most associated with SCD in multivariable models (HR=2.33, 95% CI 1.47–3.70), and this risk was primarily due to a specific relationship between antidepressant use and SCD (HR=3.34, 95% CI 2.03–5.50). Conclusions In this cohort of women without baseline CHD, depressive symptoms were associated with fatal CHD, and a measure of clinical depression including antidepressant use was specifically associated with SCD. Although antidepressant use may be a marker of worse depression, its specific association with SCD merits further study. CONDENSED ABSTRACT We prospectively analyzed the association between depression and cardiac events in the Nurses’ Health Study. Symptoms of depression as measured by Mental Health Index (MHI-5) score were directly associated with risk of CHD events, and the relationship was strongest for fatal CHD. A proxy variable for clinical depression comprised of MHI-5 score<53 or antidepressant use was strongly associated with sudden cardiac death (SCD), primarily due to a specific relationship between antidepressant use and SCD. Although antidepressant use may be a marker of worse depression, its specific association with SCD merits further study.

After LVAD placement, there is a significant rise in the incidence of de novo MVT. By contrast, the incidence of PVT/VF was unaffected by LVAD placement.

Background - COVID-19 has led to over 1 million deaths worldwide and has been associated with cardiac complications including cardiac arrhythmias. The incidence and pathophysiology of these manifestations remain elusive. In this worldwide survey of patients hospitalized with COVID-19 who developed cardiac arrhythmias, we describe clinical characteristics associated with various arrhythmias, as well as global differences in modulations of routine electrophysiology practice during the pandemic. Methods - We conducted a retrospective analysis of patients hospitalized with COVID-19 infection worldwide with and without incident cardiac arrhythmias. Patients with documented atrial fibrillation (AF), atrial flutter (AFL), supraventricular tachycardia (SVT), non-sustained or sustained ventricular tachycardia (VT), ventricular fibrillation (VF), atrioventricular block (AVB), or marked sinus bradycardia (HR<40bpm) were classified as having arrhythmia. De-identified data was provided by each institution and analyzed. Results - Data was collected for 4,526 patients across 4 continents and 12 countries, 827 of whom had an arrhythmia. Cardiac comorbidities were common in patients with arrhythmia: 69% had hypertension, 42% diabetes mellitus, 30% had heart failure and 24% coronary artery disease. Most had no prior history of arrhythmia. Of those who did develop an arrhythmia, the majority (81.8%) developed atrial arrhythmias, 20.7% developed ventricular arrhythmias, and 22.6% had bradyarrhythmia. Regional differences suggested a lower incidence of AF in Asia compared to other continents (34% vs. 63%). Most patients in in North America and Europe received hydroxychloroquine, though the frequency of hydroxychloroquine therapy was constant across arrhythmia types. Forty-three percent of patients who developed arrhythmia were mechanically ventilated and 51% survived to hospital discharge. Many institutions reported drastic decreases in electrophysiology procedures performed. Conclusions - Cardiac arrhythmias are common and associated with high morbidity and mortality among patients hospitalized with COVID-19 infection. There were significant regional variations in the types of arrhythmias and treatment approaches.