LAUSR

BACKGROUND Ventricular tachyarrhythmias (VA) represent the first cause of death in athletes. The difference between electroanatomic substrate in athletes and non-athletes with complex VA is unknown. OBJECTIVE To compare the electroanatomic substrate of complex VA in athletes versus non-athletes. METHODS We prospectively enrolled young athletes and non-athletes with VA. Patients underwent 2D echo, cardiac magnetic resonance (CMR), coronary angiography, 3D-electroanatomic mapping (3D-EAM) and 3D-EAM guided endomyocardial biopsy (EMB). Follow-up included 24h ECG Holter or ICD/loop recorder interrogation for VA recurrence. RESULTS We enrolled 33 consecutive patients, 18 (56%) competitive athletes and 15 (44%) non-athletes. Left and right ventricular (LV and RV) findings by echo and CMR did not show structural disease. Nine (50%) athletes were asymptomatic compared to 1 (7%) non-athlete (p<0.05). Unifocal origin of VA was reported in 14 (93%) athletes and in 17 (94%) non-athletes. Athletes showed a larger RV unipolar than bipolar scar (18 ± 17 cm2 versus 3 ± 3.8 cm2, p= 0.04). Diagnostic yield of EMB was 50% in athletes and 40% in non-athletes. Among athletes, the final diagnosis was myocarditis in 2 cases, arrhythmogenic ventricular right cardiomyopathy and focal replacement fibrosis in one case each. Among non-athletes, EMB revealed focal replacement fibrosis in 4 cases. At median follow-up of 18.7 months, Kaplan Meyer curves showed lower VA recurrence in detrained athletes than non-athletes (53% versus 6%, p= 0.02). CONCLUSIONS Our data showed the need for an extensive diagnostic work-up in apparently healthy young patients with complex VA in order to characterize concealed cardiomyopathies.