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 Funding Acknowledgements Type of funding sources: None. 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 (21,895±12,394min vs 25,173±12,532min, p<0.0001, panel a). Daytime and nighttime heart rates were significantly lower during lockdown compared to the reference period (71.3±9bpm vs 72.6±9bpm, p<0.0001 and 63.4±9 vs 63.8±9, p=0.02, respectively). 94 patients with VT/VF during the reference period did not show any VT/VF during lockdown, while only 4 patients without VT/VF during the reference period showed VT/VF during lockdown (p<0.0001, panel B). There was no significant difference in the occurrence of NSVT or AF/AT. Conclusion: During the lockdown in the first COVID-19 wave, the Carelink system revealed significantly less activity and lower heart rates. Moreover, there was a significant reduction in the occurrence of VT/VF.