Right bundle branch block
(Redirected from Right Bundle Branch Block)
Evaluation
- QRS > 0.12 in limb leads
- Triphasic QRS (rSR') or biphasic (qR), often with ST depression & TWI in V1-V3
- V1 must have a positive complex
- Second R wave in V1 is always taller than the first (rSR')
- Slurred S in 1 and V6
- ST depression and TWI in other leads should arouse suspicion
- Any ST elevation is abnormal in RBBB and must prompt evaluation for STEMI
Differential Diagnosis
Wide-complex tachycardia
Assume any wide-complex tachycardia is ventricular tachycardia until proven otherwise (it is safer to incorrectly assume a ventricular dysrhythmia than supraventricular tachycardia with abberancy)
- Regular
- Monomorphic ventricular tachycardia
- PSVT with aberrant conduction:
- PSVT with bundle branch block^
- PSVT with accessory pathway
- Atrial flutter with bundle branch block^
- Sinus tachycardia with bundle branch block^
- Accelerated idioventricular rhythm (consider if less than or ~120 bpm)
- Metabolic
- Irregular
- Atrial fibrillation/atrial flutter with variable AV conduction AND bundle branch block^
- Atrial fibrillation/atrial flutter with variable AV conduction AND accessory pathway (e.g. WPW)
- Atrial fibrillation + hyperkalemia
- Polymorphic ventricular tachycardia
^Fixed or rate-related
See Also
References
- Journal of Electrocardiology. Vol 43 (2010). 40-42.