Clinical significance of exercise-induced ventricular tachyarrhythmias in trained athletes without cardiovascular abnormalities

BACKGROUND Exercise-induced ventricular tachyarrhythmias raise clinical concern as a marker of increased risk in the presence of underlying cardiovascular disease. OBJECTIVE The aim of this study was to clarify the clinical significance of exercise-induced ventricular tachyarrhythmias in competitive athletes without evident cardiac abnormalities. METHODS Exercise electrocardiographic testing was performed in 5011 consecutive athletes without heart disease and analyzed for the occurrence of ventricular arrhythmias. RESULTS Of the 5011 athletes, 367 (7.3%) showed >= 1 premature ventricular beat (PVB), including 331 (6.6%) with <= 10 PVBs and 36(0.7%) with > 10 PVBs and/or >= 1 ventricular couplets, and/or >= 1 bursts of nonsustained ventricular tachycardia. The 331 athletes with <= 10 PVBs had no restriction from competitive sports, and repeated exercise testing over 3-12 months showed spontaneous reduction of arrhythmia (from 5.2 +/- 4 to 4 +/- 6 PVBs; P = .002), including 83 of 331 (23%) with disappearance of PVBs. The remaining 36 athletes were disqualified from sports because of frequent and/or complex arrhythmias; 23 showed reduction of arrhythmia at 3-12 months (from 46 +/- 42 to 28 +/- 11 PVBs, from 8 +/- 10 to 3 +/- 3 couplets, and from 3.6 +/- 6 to 1 +/- 1 nonsustained ventricular tachycardia; P = .05) and were readmitted to competition. The other 13 athletes with persistent arrhythmias were considered for radiofrequency ablation, of whom 6 were successfully treated with abolition of arrhythmias and permitted to return to competitive sports. No events or cardiovascular disease occurred in the 367 athletes over a follow-up period of 7.4 +/- 5 years. CONCLUSION Exercise-induced ventricular tachyarrhythmias were present in a sizable minority of highly trained athletes without heart disease. These arrhythmias proved to be benign and not associated with adverse events or later development of cardiovascular disease.