ECG Basics & Fundamentals: electrical cardioversion of an unstable regular wide complex tachycardia

ECG Weekly Workout with Dr. Amal Mattu


A 50-year-old man is brought to the ED with a regular wide complex tachycardia (RWCT) shown below. He is pain free with a normal blood pressure and mental status. His exam is otherwise unremarkable and he is hemodynamically stable. The decision is made to electrically cardiovert the patient after treatment with amiodarone does not restore sinus rhythm. The rhythm strip during synchronized cardioversion is shown below:

Before watching this week’s video, ask yourself these questions:

  1. What ECG abnormalities do you notice?
  2. What caused the patient’s rhythm to deteriorate into ventricular fibrillation?
  3. What is your next best step in management?