Morphologic Characteristics and Function of Right Ventricle in Patients With Isolated Right Bundle Branch Block

Background: The prevalence of right bundle branch block (RBBB) is estimated in 0.2 to 1.3% of healthy people. RBBB had independent association with decreased right ventricle (RV) function, which is considered as predictor of adverse cardiovascular outcomes. The aim of this study is to evaluate RV structure and function in patients with isolated RBBB (without structural heart disease) using two-dimensional echocardiography. Methods: A cross-sectional study conducted at Chitwan Medical College, Bharatpur from 1st January 2022 to 30th June 2022. Consecutive adult patients aged ≥18 years with isolated RBBB classified into complete RBBB (CRBBB) and Incomplete RBBB (IRBBB) based on electrocardiographic findings. The echocardiographic evaluation was done to assess RV dimension and function. Results: A total of 52 patients with isolated RBBB were included with mean age of the study population was 45.3 ± 9.3 years, (28 ,53.8%) had CRBBB, whereas the remaining (24, 46.2%) had IRBBB. Among the parameters used to assess RV function; mean RV-Fractional area change (P<0.001), Tricuspid annular plane systolic excursion(P<0.02) and Pulsed Doppler peak velocity at the lateral annulus RV(P<0.001) were significantly lower, while Pulsed Doppler myocardial performance index(P<0.001) was significantly high in CRBBB group as compared to IRBBB group. Similarly, Right atrium and RV dimensional parameters were significant higher in CRBBB compared to IRBBB group. Conclusions: Isolated RBBB is not as benign as it was considered and has deteriorating effect on RV morphology and function. Therefore, patients with Isolated RBBB need follow-up with passing age and more attention toward RV structural and functional analysis.