Changing Views: Safety and Efficacy of Implantable Cardioverter-Defibrillator Therapy in Athletes

The implantable cardioverter-defibrillator (ICD) is highly effective in reducing sudden death from ventricular tachyarrhythmia among high-risk cardiac patients. Conventional advice given to patients with ICD is to avoid physical activity more strenuous than playing golf or bowling. This recommendation is given due to a theoretical risk of arrhythmia precipitation, and thus increased risk of death due to failure to defibrillate, injury resulting from loss of control caused by arrhythmia-related syncope or shock, and also due to sport related direct damage to the ICD system. Recent prospective data from an international registry involving 372 athletes with ICDs in situ and actively participating in sports has been published. This indicates that, although physical activity resulted in an increased number of shocks compared to rest, there was no significant difference between intensive physical activity and any other activity (10% vs. 8%, p=0.34) in frequency of shocks. Furthermore, over a median follow-up period of 31 months (21-46 months), in the period of sports activity and 2 hour rest directly after there were no occurrences of death, resuscitated arrest or arrhythmia, or shock-related injury. This data is likely to start a shift in every-day clinical decision-making leading to revision of the high level of precautions imposed on the rapidly enlarging ICD recipient population.