Bundle Branch Blocks: RBBB & LBBB — ECG Academy Lesson

Recognize right and left bundle branch block patterns, understand V1/V6 morphology differences, and know when a BBB finding needs escalation versus baseline documentation.

Learning Objectives

• Explain what a bundle branch block means for ventricular activation
• Identify RBBB by its RSR’ pattern in V1 and wide S wave in V6
• Identify LBBB by its QS/rS pattern in V1 and broad notched R wave in V6
• Apply the MaRRoW and WiLLiaM mnemonics for quick BBB classification
• Distinguish chronic BBB from new-onset BBB and know when to escalate