Right bundle branch block (RBBB)
Also calledRBBB · right bundle branch block · CRBBB · complete RBBB
Definition
Block of conduction in the right bundle branch. The left ventricle still activates normally through the intact left bundle, and the block shows up as a delay at the end of the QRS. Diagnosed by a QRS duration of 120 ms or more with an rsr', rsR' or rSR' pattern in V1 or V2 (in a minority, a wide and often notched R wave instead), slurred S waves in leads I and V6 that are longer than the R wave or longer than 40 ms, and T waves pointing opposite to the terminal QRS delay.
Sources
- Surawicz B, Childers R, Deal BJ, Gettes LS. AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part III: intraventricular conduction disturbances. Circulation. 2009;119(10):e235-e240. doi.org/10.1161/CIRCULATIONAHA.108.191095
- Kusumoto FM, Schoenfeld MH, Barrett C, et al. 2018 ACC/AHA/HRS guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay. Circulation. 2019;140(8):e382-e482. doi.org/10.1161/CIR.0000000000000628
- Samesima N, God EG, Kruse JCL, et al. Brazilian Society of Cardiology guidelines on the analysis and issuance of electrocardiographic reports - 2022. Arq Bras Cardiol. 2022;119(4):638-680. doi.org/10.36660/abc.20220623
- Whinnett Z, Naraen A, Vijayaraman P, Cleland JGF, Keene D. Physiological pacing: mechanisms, clinical indications, and perspectives. Eur Heart J. 2025;46(35):3407-3419. doi.org/10.1093/eurheartj/ehaf440
Last reviewed 2 October 2026. Every definition in the EKG Dictionary cites the guideline, consensus statement or original paper it comes from.