Sudden cardiac deaths that occur on the athletic field in healthy-appearing sports participants are of great concern in the medical and lay communities. These deaths are probably secondary to ventricular tachyarrhythmias. The issue of how to handle athletes who have tachyarrhythmias identified by Holter monitor is currently unresolved. In addition, there are limited data available to guide physicians toward an approach to managing these arrhythmias in athletes who appear to be healthy. Therefore, it is difficult for physicians to determine which athletes may participate in sporting events and which should be restricted in their activities. Biffi and colleagues studied the clinical relevance of ventricular tachyarrhythmias in a large prospective evaluation of an athletic population.

The case records from the Institute of Sports Science were reviewed, and 355 athletes were identified who met one of the following inclusion criteria: (1) three or more premature ventricular depolarizations (PVDs) on a resting 12-lead electrocardiogram (ECG) or (2) a history of palpitations. Each athlete was evaluated with a medical history and a physical examination, 12-lead ECG, 24-hour Holter monitor, two-dimensional echocardiography, symptom-limited exercise ECG, and chest radiography. The Holter monitor was placed during the athletes' training period and was recorded for at least one hour of their normal training session. Athletes with frequent or complex PVDs were given a more extensive cardiac evaluation.

The 355 participants were divided into three groups. Group A had at least 2,000 PVDs and at least one nonsustained ventricular tachycardia (NSVT) per 24 hours (71 athletes); group B had 100 to 2,000 PVDs without NSVT per 24 hours (153 athletes); and group C had fewer than 100 PVDs without NSVT per 24 hours (131 athletes). Cardiac abnormalities were discovered in only 7 percent (26 athletes) of the study population. Participants with cardiac abnormalities were more likely to be in group A, with no abnormalities discovered in group C. Only the participants in group A were excluded from participating in competition. During the follow-up period, which had a mean of eight years, there was one cardiac death in group A, occurring when an athlete participated in a competitive field hockey game against medical advice. There were no deaths in groups B and C.

The authors conclude that frequent and complex ventricular tachyarrhythmias are common in trained athletes and are usually not associated with underlying cardiac disease. These ventricular tachyarrhythmias, when unassociated with cardiovascular abnormalities, are not clinically significant and do not, by themselves, justify disqualifying the athlete from competition.