Decline in physical activity in the weeks preceding sustained ventricular arrhythmia in women

• Main Authors: Ashley E. Burch, PhD, Julia W. Erath, MD, Valentina Kutyifa, MD, PhD, FHRS, Birgit Aßmus, MD, Diana Bonderman, MD, Andrea M. Russo, MD, FHRS
• Format: Article
• Language: English
• Published: Elsevier 2020-10-01
• Series: Heart Rhythm O2
• Subjects: Defibrillation; Physical activity; Ventricular arrhythmia; Wearable cardioverter-defibrillator; Women
• Online Access: http://www.sciencedirect.com/science/article/pii/S2666501820300775

Background: Heightened risk of cardiac arrest following physical exertion has been reported. Among patients with an implantable defibrillator, an appropriate shock for sustained ventricular arrhythmia was preceded by a retrospective self-report of engaging in mild-to-moderate physical activity. Previous studies evaluating the relationship between activity and sudden cardiac arrest lacked an objective measure of physical activity and women were often underrepresented. Objective: To determine the relationship between physical activity, recorded by accelerometer in a wearable cardioverter-defibrillator (WCD), and sustained ventricular arrhythmia among female patients. Methods: A dataset of female adult patients prescribed a WCD for a diagnosis of myocardial infarction or dilated cardiomyopathy was compiled from a commercial database. Curve estimation, to include linear and nonlinear interpolation, was applied to physical activity as a function of time (days before arrhythmia). Results: Among women who received an appropriate WCD shock for sustained ventricular arrhythmia (N = 120), a quadratic relationship between time and activity was present prior to shock. Physical activity increased starting at the beginning of the 30-day period up until day -16 (16 days before the ventricular arrhythmia) when activity begins to decline. Conclusion: For patients who received treatment for sustained ventricular arrhythmia, a decline in physical activity was found during the 2 weeks preceding the arrhythmic event. Device monitoring for a sustained decline in physical activity may be useful to identify patients at near-term risk of a cardiac arrest.