Right bundle branch block is a cardiac conduction abnormality in which electrical impulses are delayed or blocked along the right bundle branch, leading to altered depolarization of the right ventricle.
EKG
- QRS duration ≥ 120 ms (≥ 3 small boxes)
- rsR′ pattern in V1-V2 (terminal R′ wave)
- Broad/slurred S waves in leads I, V5, V6
- Normal or prolonged PR interval depending on AV conduction
Causes
- Normal variant (especially in young, healthy individuals)
- Ischemic heart disease
- Pulmonary embolism
- Right ventricular hypertrophy (pulmonary hypertension, COPD)
- Cardiomyopathy
- Congenital heart disease (atrial septal defect)
- Post-cardiac surgery or device placement
Clinical Significance
- Isolated RBBB with no structural heart disease is often benign
- In the presence of other disease (e.g., heart failure or MI), RBBB may reflect worse prognosis
- Can complicate ECG interpretation, particularly in acute myocardial infarction (ST-elevation may be obscured)
Management
- No treatment required for isolated, asymptomatic RBBB
- Sgarbossa Criteria does not apply to RBBB, less distortion of ST segments
- Further workup if symptomatic or new-onset RBBB:
- Echocardiogram to evaluate for structural disease
- Stress testing or coronary imaging if ischemia suspected
- Pacemaker only if associated with symptomatic bradycardia or complete heart block
Table
| Feature | RBBB Findings |
|---|---|
| QRS Duration | ≥ 120 ms |
| V1-V2 | rsR′ (terminal R′ wave) |
| Leads I, V5-V6 | Wide slurred S wave |
| Management | Observation unless symptomatic |
| Associated Conditions | PE, CAD, RVH, ASD, cardiomyopathy |