Mobitz I or Mobitz II: How to tell the difference

ECG Weekly Workout with Dr. Amal Mattu

HPI

A 79-year-old man is sent to a community hospital for evaluation of bradycardia discovered at his nursing facility. He is ultimately transferred to a tertiary care facility for consideration of pacemaker placement after the following ECG is obtained:

Before watching this week’s workout, carefully review the ECG and consider the following:

    1. Can Mobitz I AV block present with a wide QRS?
    2. What are the key ECG features that differentiate Mobitz I from Mobitz II?
    3. What is your interpretation of the rhythm in this case?