ECG Basics and Fundamentals: causes of pauses or clumped/grouped beats on the ECG

UMEM Potpourri ECG Cases with Dr. Amal Mattu


A 72-year-old man with PMHx of HTN presents to the emergency department with vomiting and lightheadedness. He is noted to be slightly bradycardic with an irregular rhythm on arrival. The following ECG is obtained:

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

  1. What is your differential diagnosis when interpreting ECGs with pauses or grouped beats?
  2. What is the most likely cause of the pauses seen on this ECG?