Objectives Cardiac resynchronisation therapy (CRT) improves the morbidity and mortality in patients with heart failure with QRS≥120 ms, yet most patients in clinical trials manifested baseline left branch bundle block (LBBB). Less than 10% of patients with heart failure (HF) and abnormal ventricular conduction have right branch bundle block (RBBB). Limited data are available in this particular population, and relevant research results are inconsistent.
Methods We studied eight consecutive patients with RBBB (QRS≥120 ms) advanced ischaemic HF, low ejection fraction (≤35%) and intraventricular asynchrony ≥50 ms scheduled for CRT. Response was defined by an improvement in New York Heart Association (NYHA) function class and some echocardiographic markers (ie, ≥15% reduction in LV end-systolic volume) of cardiac remodelling at 6 months after implant.
Results All patients with RBBB survived during 6 months' follow-up, and six out of 8 patients with RBBB demonstrated an improvement in NYHA function class, or improvement in ejection fraction (EF) with at least 5% and left ventricular (LV) reverse remodelling during 6 months' follow-up. No change was observed in the other two patients.
Conclusions Patients with HF and RBBB associated with major intraventricular asynchrony had good symptomatic and echocardiographic response after undergoing CRT.