EKG Challenge #1

What is the diagnosis?

3rd Degree AV Block (Complete Heart Block) - Look at the rhythm strip and notice there is no relation between the P waves (Green Arrows) and QRS complexes which diagnoses 3rd Degree. It helps to get a piece of paper (calipers if you have) and measure the P waves. They can often be buried in the T wave or QRS complex.
It is not 2nd Degree AV Block because both Mobitz I (progressively prolonged PR interval before dropped QRS) and Mobitz II (intermittent AV Block) will show some pattern of relation between the P wave and QRS complex.
The escape rhythm is narrow and thus a junctional escape rhythm indicating the block is above the bundle of his. A wide complex would indicate a block at or below the bundle of His and ventricular escape rhythm.

Name some possible etiologies

Etiologies: Ischemia (especially inferior MI), Medications (CCB, Beta blockers etc.)
Hyperkalemia, and ask about travel and send a Lyme titer if pertinent or you’re feeling fancy

**Look closely at the EKG you’ll see pacemaker spikes (Red Arrows) which are followed by ventricular capture. The patient had a PPM which had not been check in > 10 years and battery failure. Thus the pacemaker was not firing**