Type of bundle branch block and incident risk of heart failure

From a report in Circulation: Heart Failure:

Methods and Results—Cox’s regression was used to evaluate hazard ratios with 95% confidence intervals for HF among 65 975 participants of the Women’s Health Initiative (WHI) study during an average follow-up of 14 years…

Compared with women with no BBB, LBBB, and intraventricular conduction defect were strong predictors of incident HF in multivariable-adjusted risk models (hazard ratio, 3.79; confidence interval, 2.95–4.87 for LBBB and hazard ratio, 3.53; confidence interval, 2.14–5.81 for intraventricular conduction defect). RBBB was not a significant predictor of incident HF in multivariable-adjusted risk model, but the combination of RBBB and left anterior fascicular block was a strong predictor (hazard ratio, 2.96; confidence interval, 1.77–4.93). QRS duration was an independent predictor of incident HF only in LBBB, with more pronounced risk at QRS greater than or equal to 140 ms than at less than 140 ms. QRS nondipolar voltage (RNDPV) was an independent predictor in both RBBB and LBBB and, in addition, in LBBB, QRS/STT angle and ST J-point depression in aVL were independent predictors.