Electrocardiographic predictors of left ventricular scar in athletes with right-ventricular-bundle-branch-block premature ventricular beats

Aims: Right bundle branch block (RBBB) morphology non-sustained ventricular arrhythmias (VAs) have been associated with the presence of non-ischemic left ventricular scar (NLVS) in athletes. Aim of this cross-sectional study was to identify clinical and ECG predictors of the presence of NLVS in athletes with RBBB VAs. Methods: Sixty-four athletes (median age 39(24-53) years, 79% males) with non-sustained RBBB VAs underwent cardiac magnetic resonance(CMR) with late gadolinium enhancement in order to exclude the presence of a concealed structural heart disease. Results: Thirty-six athletes (56%) showed NLVS at CMR and were assigned to NLVS positive group, whereas 28 athletes (44%) to NLVS negative group. Family history of cardiomyopathy and 7 different ECG variables were statistically more prevalent in NLVS positive group. At univariate analysis, 7 ECG variables (low QRS voltages in limb leads, negative T-waves in inferior leads, negative T-waves in limb leads I-aVL, negative T waves in precordial leads V4-V6, presence of left posterior fascicular block, presence of pathologic Q waves, poor R-wave progression in right precordial leads) proved to be statistically associated with the finding of NLVS; these were grouped together in a score. A score>2 was proved to be the optimal cut-off point, identifying NLVS athletes in 92% of cases and showing the best accuracy (86% sensitivity and 100% specificity, respectively). However, a cut-off >1 correctly identified all patients with NLVS (absence of false negatives). Conclusions: In athletes with RBBB morphology non-sustained VAs, specific ECG abnormalities at 12-lead ECG can help in detecting subjects with NLVS at CMR.