Special features of right bundle branch block in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia.

UNLABELLED: We searched for special features in patients with complete and incomplete right bundle branch block diagnosed as having arrhythmogenic right ventricular cardiomyopathy/dysplasia. Whether right bundle branch block is a frequent finding in arrhythmogenic right ventricular cardiomyopathy should be studied. The question is whether special features exist such as T-wave inversions, localized right precordial QRS prolongation and r'/s ratio<1.

RESULTS

ARVC could be diagnosed according to ISFC/ESC criteria in 374 patients. CRBBB was found in 22 cases (6%) and iCRBBB was present in 47 cases (12.5%). In CRBBB T wave inversions ≥ V4 was found in 10 cases (n.s.) and r'/s ratio<1 was present in 12 cases (p<0.001). In iCRBBB T wave inversions ≥ V4 was found in 10 cases (n.s.) and ST segment elevation in right precordial leads was present in 19 cases (p<0.005). In all patients with ARVC localized right precordial QRS prolongation was found. Patients with CRBBB have a bad prognosis: 17 of 22 patients developed biventricular heart failure requiring heart transplantation and diuretic therapy.

CONCLUSIONS

CRBBB and iCRBBB are infrequent findings in arrhythmogenic right ventricular cardiomyopathy. Complete right bundle branch block is characterized by r'/s ratio<1. There are no significant T wave inversions ≥ V4. Incomplete right bundle branch block is characterized by ST segment elevation in right precordial leads but not by T wave inversions ≥ V4.