EKG of the Week

This is a 67 y/o pt with a history of HTN, HFrEF (mild), and COPD (severe) who presented to the emergency room with a few days of worsening DOE.

+ EKG Interpretation

2nd degree AV block Mobitz 2

There are clear, regular P waves through the tracing. The atrial mechanism is sinus. Some of those P waves are conducted (the l5t, 3rd and 4th for example), others are not. That means he has 2nd degree AV block.

Is it Mobitz 1 or 2?

For much of the tracing every other beat is dropped, that is 2nd degree AV block in a 2:1 pattern and if that was all you could see, you could not say whether it was Ml or 2. But here you have that one spot where there are 2 in a row conducted (the 3rd and 4th P waves) and those 2 PR intervals are the same, so it is 2nd degree AV block Mobitz 2 with periods of 2:1 conduction. His overall ventricular rate is slow and during those periods of 2:1 block down in the 30's.

He also has a RBBB and a left axis consistent with a left anterior fascicular block (those findings were on old EKGs as well). The patient now has a pacemaker.

Further Reading:

Life in the Fast Lane: Mobitz

Follow up EKGs: