Current recommendations for patients with implantable cardioverter-defibrillators (ICDs) advise against participating in sport that are more vigorous than bowling or golf. These recommendations are based on reasonably estimated hazards of ICD failure to defibrillate, loss of control and injury caused by arrhythmia-related syncope or shock, and damage to the ICD system; however, the data about occurrence of these adverse events was not available. Medical conditions for which ICD is administered vary as well as the age of receivers. Many subjects with ICD are young and otherwise healthy. Participation in sports for some is an important quality of life factor and they choose to participate despite possible risks. The frequency of adverse events and risk of serious injury in such subjects was addressed in a prospective study based on a multinational registry.
Patient-centered care is a basic principle in which the patient establishes what brings quality to his/her life and challenges the physician to provide evidence so the patient can make an informed decision. In this case, that evidence is not established; this provided the ethical justification of a study that reviewed subjects who were enrolled in activities against medical advice. The study protocol had to ensure that it does not appear as an encouragement for subjects with ICD to engage in sports.
The study enrolled 372 athletes with ICDs (age: 10–60 years) already participating in organized (n=328) or high-risk (n=44) sports and followed them prospectively for a median of 30 months. Data was obtained via phone interviews and medical records at baseline, if a shock occurred and every 6 months. Of the enrolled subjects, 33% were women. Sixty subjects were competitive athletes. Running, basketball, and soccer were the most common sports, but some also engaged in skiing (71) and surfing (13), which is considered high risk for syncope and ICD shock-related injuries.
This study found that shocks were not uncommon, but there were no injuries, deaths or need to externally defibrillate. Shocks occurred in 10% of study participants during competition/practice, in 8% during other physical activity and in 6% at rest. Lead malfunctions were not higher than in unselected populations.
In summary, many athletes with ICDs can engage in vigorous and competitive sports without physical injury or failure to terminate the arrhythmia, despite the occurrence of both inappropriate and appropriate shocks. This study also points out subgroups with likely higher risks; it also discusses specific tests and the process of patient evaluation necessary for informed physician advice and patient choices.
For my target audience, it is important to note that no scuba divers participated in this study. Scuba diving is considered a very high risk activity for subjects with ICD because the loss of control due to syncope or shock while underwater is likely to cause drowning. Some subjects with pacemaker, a device that does not provide shock, may be allowed to dive, but it appears that there are few out there since we had a lot difficulty recruiting participants for a survey-based study.