From the Guidelines
Right bundle branch block (RBBB) is generally benign when found incidentally in asymptomatic individuals with no underlying heart disease, but its clinical significance increases when it occurs with other cardiac conditions, and a baseline cardiac evaluation including echocardiography is reasonable to exclude structural heart disease. The presence of RBBB on ECG may complicate the diagnosis of other conditions like left ventricular hypertrophy or myocardial infarction, requiring careful interpretation 1. RBBB may indicate underlying structural heart disease such as congenital heart defects, cardiomyopathy, myocardial infarction, or pulmonary conditions like pulmonary embolism or pulmonary hypertension. In acute settings, new-onset RBBB during chest pain may suggest myocardial infarction affecting the right coronary circulation and requires immediate evaluation.
Some key points to consider in the management of RBBB include:
- The importance of excluding structural heart disease with echocardiography, as RBBB can be associated with increased risk of left ventricular systolic dysfunction compared to those with completely normal ECGs, although the yield is lower than in patients with left bundle branch block (LBBB) 1.
- The potential for RBBB to complicate the diagnosis of other cardiac conditions, such as left ventricular hypertrophy, which may require alternative diagnostic criteria in the presence of RBBB 1.
- The need for careful interpretation of ECG findings in patients with RBBB, as the presence of this conduction abnormality can affect the sensitivity and specificity of electrocardiographic criteria for various cardiac conditions.
In terms of specific management strategies, a baseline cardiac evaluation including echocardiography is a reasonable approach to exclude structural heart disease in patients with RBBB. If RBBB is associated with left anterior or posterior fascicular block (bifascicular block), closer monitoring may be warranted due to increased risk of progression to complete heart block, though prophylactic pacemaker implantation is not routinely recommended without symptoms. Overall, management of RBBB focuses on treating any underlying cardiac condition rather than the conduction abnormality itself, with careful consideration of the potential complications and comorbidities associated with this ECG finding 1.
From the Research
Clinical Significance of Right Bundle Branch Block
The clinical significance of right bundle branch block (RBBB) is a topic of interest in the medical field. Several studies have investigated the diagnostic value and prognostic implications of RBBB.
Diagnostic Value of RBBB
- A study published in the Journal of Hypertension in 2003 2 compared the diagnostic value of exercise electrocardiography and dipyridamole stress echocardiography in chest pain patients with RBBB. The results showed that dipyridamole stress echo was effective in diagnosing coronary artery disease in both normotensives and hypertensives, and exhibited superior diagnostic information than exercise electrocardiography in hypertensives.
- Another study published in the American Journal of Cardiology in 2004 3 used dobutamine stress echocardiography to prognostically stratify patients with RBBB. The results showed that the presence of an abnormal dobutamine stress echocardiography was the strongest predictor of cardiac events.
Prognostic Implications of RBBB
- A retrospective cohort study published in Heart in 2019 4 investigated the relationship between electrocardiographic bundle branch block subtypes and the risk of cardiovascular outcomes in a primary care population. The results showed that RBBB was associated with pacemaker implantation, heart failure, and weakly associated with cardiovascular death in men.
- A study published in Echocardiography in 2025 5 used speckle tracking echocardiography to evaluate right and left ventricular deformation analysis in patients with idiopathic RBBB. The results showed that idiopathic RBBB significantly affected the longitudinal strain and synchronization of both the left and right ventricles.
Current Considerations
- A review article published in Current Cardiology Reviews in 2021 6 outlined the current considerations for RBBB, including its anatomy, epidemiology, causes, symptoms, ECG findings, diagnosis, differential diagnosis, treatment, complications, and prognosis. The article demonstrated that RBBB is a common pattern seen on the 12-lead ECG, and its clinical significance is still being investigated.