Effects of lockdown on physical activity and arrhythmia burden in patients with an implantable cardioverter-defibrillator: the COVID-19 Lockdown ICD-Carelink (CLIC) study

Abstract

Abstract Background Both COVID-19 and the measures taken to control the pandemic may significantly affect cardiovascular health. The effects of a lockdown on physical activity and its potential consequences for arrhythmia burden remain largely unknown. Purpose In this study, we investigated the effect of the lockdown during the first COVID-19 wave on patients' physical activity and arrhythmia burden. Methods All patients with an ICD connected to a Carelink home-monitoring system from two Dutch hospitals were included. Anonymized data on physical activity, heart rate, and occurrence of ventricular tachycardia/fibrillation (VT/VF), and atrial fibrillation/tachycardia (AF/AT) were obtained and were compared between March-April 2020 (lockdown) and March-April 2019 (reference) within each patient. The study was approved by the local ethics committee. Results The ICDs of 531 patients registered significantly less activity during de lockdown period compared to the reference period (210±104 min vs 182±103 min, p<0.0001, Figure 1, panels A and B), while weather conditions improved (1A). Daytime and nighttime heart rates were significantly lower during lockdown compared to the reference period (71.3±9 bpm vs 72.6±9 bpm, p<0.0001 and 63.4±9 vs 63.8±9, p=0.02, respectively). AF/AT burden increased (Figure 2A) while number of VT/VF episodes decreased (2B). There was no significant difference in number of NSVT episodes. Conclusion During the lockdown in the first COVID-19 wave, the Carelink system revealed significantly less activity, increase in AF/AT burden and decrease in VT/VF episodes. Further investigation is needed to understand the relationship between physical activity and the occurrence of arrhythmias in ICD patients. Funding Acknowledgement Type of funding sources: None.