Scenario: This bedside rhythm strip is from an 86-year-old woman who came to the emergency department of a small community hospital with complaints of right hip pain. She lives alone and has no significant medical history except that she has been experiencing fatigue and frequent falls. She takes no medications. She reported that she was in her usual state of health when she felt dizzy and lightheaded and fell to the floor onto her right side. Her blood pressure was 140/50 mm Hg, heart rate was 43 beats per minute, and results of her laboratory studies were within normal ranges. Findings on radiographs of her hip also were unremarkable.

Sinus rhythm with second degree atrioventricular (AV) block, with 2:1 conduction, or Mobitz type II.

This rhythm might be mistaken for (1) sinus bradycardia with frequent nonconducted premature atrial contractions (PACs), or (2) third-degree AV block. Non-conducted PACs are ruled...

You do not currently have access to this content.