A 64-year-old diabetic man presents with chest discomfort at rest. ECG shows 1.5 mm ST segment elevation in lead aVR together with widespread ST segment depression in leads I, II, III, aVF, and V2 to V6. Blood pressure is 105/70 mmHg. Which coronary anatomy is most likely responsible for this pattern?
- A Critical left main coronary artery stenosis or severe multivessel disease ✓
- B Occlusion of the right coronary artery proximal to the crux
- C Isolated occlusion of a diagonal branch of the LAD
- D Spasm of the distal posterior descending artery
Correct answer: A. Critical left main coronary artery stenosis or severe multivessel disease
Explanation
Diffuse ST depression with ST elevation in aVR reflects global subendocardial ischemia with electrical forces directed rightward and superiorly, the classic signature of left main insufficiency or severe triple vessel disease. This is a STEMI-equivalent requiring emergent angiography rather than thrombolysis. Isolated branch occlusions produce regional patterns with reciprocal changes limited to mirror territories, not global ST depression with aVR elevation.
Reference: Braunwald's Heart Disease, 12th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.