Negative association between right bundle branch block and inducibility of ventricular tachyarrhythmias in Chagas disease

I read with interest the article by Cedraz et al.(1) describing their findings on the electrophysiological study of 115 chagasic patients. The authors reported that the presence of right bundle branch block (RBBB) was associated with less induction of sustained ventricular tachycardia or ventricular fibrillation (VT/VF) in a univariate analysis. In 56 patients with RBBB, VT/VF was induced in 35 (37.5%), versus 21 of 59 cases (57.6%) without this disturbance (p=0.03). This difference resulted in an odds ratio of 0.44 (confidence interval 95%; 0.21-0.93). Unfortunately, the authors did not discuss this finding. Some studies have shown the inducibility of VT/VF as a predictor of mortality in Chagas disease.(2-4) The presence of RBBB was already demonstrated as an independent predictor of mortality in a multivariate analysis.(4,5) Therefore, the negative association between RBBB and inducibility of VT/VF in chagasic patients is a unique observation that should not be disregarded and needs further investigation.