Predictive value of exercise testing in athletes with ventricular ectopy evaluated by cardiac magnetic resonance

Background: Exercise-induced ventricular arrhythmias (EIVA) in young athletes raise the suspicion of an underlying heart disease at risk of sudden death.

Objective: We aimed to assess the prevalence and determinants of abnormal cardiac magnetic resonance (CMR) findings in athletes referred for EIVA vs non-EIVA with negative or inconclusive echocardiography.

Methods: We performed CMR in a consecutive series of athletes aged 15-50 years referred for frequent (>500 per day) or repetitive premature ventricular beats. Clinical and CMR findings were compared between athletes with EIVA and those with non-EIVA, and predictors of abnormal CMR were assessed.

Results: We included 36 athletes with EIVA (median age 25 years; 27 (75%) males) and 24 with non-EIVA (median age 17 years; 18 (75%) males). CMR revealed cardiac abnormalities in 20 athletes with EIVA (56%) and in 5 with non-EIVA (21%) (P = .004). In particular, left ventricular late gadolinium enhancement was identified in 17 athletes with EIVA (47%) and in 3 with non-EIVA (13%) (P = .006), mostly with a nonischemic pattern. Predictors of abnormal CMR were T-wave inversion on electrocardiography (ECG) (odds ratio [OR] 5.2; 95% confidence interval [CI] 1.0-27.1; P = .05), complex ventricular arrhythmias on 24-hour ambulatory ECG monitoring (OR 4.5; 95% CI 1.1-18.7; P = .04), and complex EIVA with a right bundle branch block or polymorphic morphology on exercise testing (OR 5.3; 95% CI 1.4-19.4; P = .01).

Conclusion: Pathological myocardial substrates on CMR were observed significantly more often in athletes with EIVA than in those with non-EIVA. Repolarization abnormalities on baseline ECG and complex EIVA with a right bundle branch block or polymorphic morphology identified the subgroup of athletes with the highest probability of CMR abnormalities.