right bundle branch block (RBBB)

Introduction

An ECG change characterized by an intraventricular conduction delay affecting the right ventricular wall. Acute occurrences most commonly result from myocardial ischemia.

Etiology

• myocardial ischemia (most common)
• hypertension
• rheumatic heart disease
• can be found in normal individuals

Diagnostic procedures

• electrocardiogram
• prolonged QRS
• triphasic complexes (bifid QRS)
• lead V1: rsR'
• lead V6: qRs

*RBBB tends to decrease voltage, thus can identify LVH.

*The initial septal activation is from the left to right & anteriorly. Right ventricular activation occurs following completion of the left ventricular activation. Delayed activation of the right ventricle is responsible for the rsR' pattern in V1 & the round deep S wave in V6.

More general terms

• bundle branch block