Atrial Rhythms


    82 year old male with heart palpitations.

    31 year old male who is asymptomatic and has a history of cardiomyopathy.


    Question 1: Why do some beats aberrate with an incomplete RBBB pattern?

    Key Findings

    -Atrial fibrillation with intermittent aberration

    Coding for Boards

    -Atrial fibrillation

    -Aberrant conduction


    Question 1: Both P waves occur during the relative refractory period of the AV node. The second PAC is slightly later than the first and only has mild PR prolongation. The first PAC occurs earlier with more pronounced PR prolongation.