Differential Diagnoses: AV blocks, tachyarrhythmias, and what you need to look for on the ECG of every patient with syncope

UMEM Potpourri ECG Cases with Dr. Amal Mattu


A 36-year-old woman is brought into the emergency department after an episode of syncope. She reports palpitations prior to the episode but is otherwise asymptomatic on arrival. Vital signs are normal. The following ECG is obtained with no prior ECGs available for comparison:

Before watching the video, look closely at this ECG and ask yourself:

  1. What diagnoses do you look for on an ECG in patients with syncope?
  2. Is there any ECG evidence of a cardiac cause of symptoms?
  3. What is the most likely diagnosis?