Electrocardiographic predictors of left ventricular scar in athletes with right 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-ischaemic left ventricular scar (NLVS) in athletes. The aim of this cross-sectional study was to identify clinical and electrocardiogram (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 and results resonance (CMR) with late gadolinium enhancement in order to exclude the presence of a concealed structural heart disease. Thirty-six athletes (56%) showed NLVS at CMR and were assigned to the NLVS positive group, whereas 28 athletes (44%) to the NLVS negative group. Family history of cardiomyopathy and seven different ECG variables were statistically more prevalent in the NLVS positive group. At univariate analysis, seven 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, and 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). Conclusion In athletes with RBBB morphology non-sustained VAs, specific ECG abnormalities at 12-lead ECG can help in detecting subjects with NLVS at CMR. Lay summary In athletes with right bundle branch block (RBBB) morphology non-sustained ventricular arrhythmias (VAs), the presence of a non-ischaemic left ventricular scar (NLVS) may be highly suspected if one or more of the following electrocardiogram (ECG) characteristics are present at the 12-lead resting ECG: 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, and poor R-wave progression in right precordial leads. This score should be externally validated in a larger population of athletes with VAs.