Right bundle branch block EKG examples

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

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EKG examples

EKG below is from an elderly woman who had previously undergone surgery for recurrent ventricular tachycardia. She was being treated with Tambacor and metoprolol. The cardiogram shows sinus rhythm with a wide QRS of 159ms consistent with a RBBB and a rightward axis suggesting right posterior hemi-block. The PR interval is slightly prolonged at 2121ms. The poor R wave progression seen best in lead V2 suggests previous anterior wall MI.

EKG below is a recording from an older man in the surgical intensive care unit. He was recovering from a motor vehicle accident where he sustained a chest injury from his seat belt. The rhythm is sinus rhythm with a prolonged p wave duration in lead III( >140ms) and a pronounced terminal negativity in V1 suggestive of left atrial abnormality. The QRS is wide with a duration of 137ms and a superior and right ward axis. There is an RSR in V1 and the S wave is greater than the R in V6. This is an unusual pattern for aberrance and is more in keeping with ventricular ectopy. In this case, this appears to be a right bundle branch block with a possible left posterior hemi-block.

Of note, in spite of this conduction disturbance the patient was able to sustain reentrant supraventricular tachycaridas requiring intravenous adenosine for termination.