I can't confirm 3rd degree AV block, and I need to correct my first read, where I said there was no AV block. After zooming into the rhythm strip, I think this is 2nd degree AV block, Mobitz I (Wenckebach). The inferior MI is possible but not certain.
Why not complete (3rd degree) AV block
- In complete heart block, the atria and ventricles are fully dissociated. The ventricular rate is slow and regular (usually 30-45 bpm), and the PR interval varies randomly.
- This strip is different. The P waves march out regularly at about 65-70 bpm, and the ventricular rate is similar, about 65 bpm. Most P waves are followed by a narrow QRS.
- The PR interval changes in a pattern, not randomly. It lengthens over the first few beats of a group, one P wave is then not followed by a QRS, and the cycle repeats.
- The pause is shorter than two P-P intervals. That fits Wenckebach and argues against complete block.
I measured on a photo of a printout, so the exact PR values are approximate. To be sure, put calipers on the P-P interval and check that the dropped-beat pause is less than twice that interval. A longer strip would also help.
Inferior MI
- In leads III and aVF I see a small q wave with notching and low R-wave amplitude, and the T waves are flat.
- I don't see convincing ST elevation in II, III or aVF. So this would look like an evolving or old inferior infarct, not an acute STEMI.
- Inferior MI plus Wenckebach is a classic pairing. The RCA supplies the AV node, so the block is usually transient and nodal.
What I'd still keep from my first read
- There are very tall voltages (deep S in V2-V3, tall R in V5-V6).
- There is lateral ST depression with T-wave changes in V4-V6. This could be LVH strain, ischemia or both.
Suggested answer
Sinus rhythm with 2nd degree AV block Mobitz I, inferior Q-wave changes (consistent with inferior MI), and LVH with lateral repolarization changes.
The page header mentions angina and the setting is a coronary care unit. If your question has answer options, send them and I'll match the best fit. If the stem says "complete AV block", I'd want to see ventricular escape beats and clearly independent P waves on the strip, and I don't see either here.