Subcutaneous ICD sports safety registry (SISS registry)

Background: Exercise has a positive impact on physical function and quality of life. However, individuals with an implantable cardioverter-defibrillator (ICD) may experience adverse events during sports activities. To date, scientific data on the safety of sports participation in patients with subcutaneous ICDs (S-ICDs) are lacking. This study aims to analyze the occurrence of appropriate and inappropriate arrhythmic events related to sports activity in a population of S-ICD patients. Methods: Consecutive patients who underwent S-ICD implantation were enrolled. Baseline clinical data, as well as information on sports activity and arrhythmic events, were collected. Results: Among 280 patients (median age 46 [32-55] years; 72 % male) included in the registry, 205 (73 %) engaged in sports activities. During a follow-up period of 38 ± 13 months, 27 patients (13 %) experienced appropriate shocks. Of these, 20 (74.1 %) occurred at rest and 7 (25.9 %) during peak performance in sports. All patients who received appropriate shocks were implanted for secondary prevention. Additionally, 27 patients (13.1 %) experienced inappropriate shocks, with 15 (55.6 %) occurring at rest and 12 (44.4 %) during peak physical activity, primarily due to T-wave oversensing. No significant differences were observed in type or intensity of sports activity between patients who experienced shocks and those who did not. Conclusion: In S-ICD patients, both appropriate and inappropriate shocks occur more frequently during peak physical performance but are not associated with the type or intensity of sports activity. Appropriate shocks were most common in patients with arrhythmogenic or ischemic cardiomyopathy, while inappropriate shocks were mainly due to T-wave oversensing.