Atrioventricular Blocks


    52 year old female on the cardiac telemetry floor.

    79 year old male with fatigue.


    Question 1: How do you know this is Mobitz I and not Mobitz II?

    Question 2: What are potential causes for the T wave abnormalities?

    Key Findings

    -Sinus rhythm

    -2nd degree AV block type I (Mobitz I)

    -Nonspecific diffuse T wave changes

    Coding for Boards

    -Sinus rhythm

    -Av block, second degree-Mobitz type II (Wenckebach)

    -Nonspecific ST and/or T wave abnormalities


    Question 1: After the pause the first and second conducted PR intervals are slightly increasing in length. Also, if you compare the last conducted PR interval before the pause with the first conducted PR interval after the pause, the change is more noticeable.

    Question 2: Possible causes include diffuse ischemia, severe LVH (not evident by the QRS height), or CNS injury (although these are not the classic appearing T waves for CNS injury).