LAUSR

INTRODUCTION The non-ischemic left ventricular scar (NILVS) is an emerging substrate of ventricular arrhythmias (VA) in the athlete. We tested the diagnostic value of VA reproducibility at repeated exercise testing (ET). METHODS We included consecutive athletes who underwent CMR for evaluation of VA and two consecutive ET off-therapy within 12 months. Those with positive family history for premature sudden death/cardiomyopathy, syncope/pre-syncope, ECG or echocardiography abnormalities or low-risk VA (exercise-suppressed infundibular or fascicular VA) were excluded. The NILVS was defined as subepicardial/midmyocardial stria of late gadolinium enhancement involving >5% of the LV mass. Reproducibility was defined as the occurrence of VA with the same pattern and behaviour during repeated ET. RESULTS Of 325 athletes who underwent CMR for evaluation of VA, 75 were included, and 30 showed NILVS involving 3 [2-4] LV segments. At first ET, athletes with NILVS showed a higher prevalence of exercise-induced VA (93% versus 53%, p<0.001), while other VA characteristics did not differ between groups. At repeated ET, reproducibility was observed in 97% of athletes versus 13% without NILVS (p<0.001). Reproducibility yielded a positive predictive value of 83% and negative predictive value of 98%. The remaining 87% of athletes with normal CMR either did not show any VA at repeated ET (59%) or showed arrhythmias with different patterns, mostly infundibular. CONCLUSIONS VA reproducibility at repeated ET predicted an underlying NILVS in athletes with VA and otherwise normal clinical workup. This finding may improve risk stratification and appropriate CMR referral of athletes with apparently idiopathic VA.