Simultaneous Myocardial Infarctions in Dual Coronary Territories Due to a Single Culprit Lesion: A Diagnostic and Management Challenge.

Electrocardiographic (ECG) changes in myocardial infarction (MI) typically evolve predictably over time, allowing early identification of the ischemic territory and culprit vessel. Rarely, simultaneous ischemic changes in territories supplied by two different coronary arteries are observed, complicating diagnosis and urgent management. We present a rare case of acute chest pain with concurrent hyperacute T-waves in anterior leads, suggestive of left anterior descending (LAD) artery occlusion, and ST-segment elevations in inferior leads, suggestive of right coronary artery (RCA) occlusion. Coronary angiography revealed a chronic total occlusion of the RCA with retrograde filling from the LAD and an acute thrombotic lesion in the mid-LAD. Emergency percutaneous intervention in the LAD restored perfusion to both coronary beds, with rapid clinical and ECG recovery. This case highlights the importance of understanding ECG evolution in MI and emphasizes early revascularization strategies when facing diagnostic dilemmas.