Dressler - de Winter sign with acute inferoposterior STEMI: An ECG dilemma in artery localization

The Dressler-de Winter sign is an electrocardiogram (ECG) pattern characterized by upsloping ST-segment depression in leads V1-V6 followed by tall, hyperacute T waves, typically indicating an occlusion of the left anterior descending artery (LAD). We present a case involving an inferoposterior ST-segment elevation myocardial infarction (STEMI) with a variant of the de Winter sign, a concept of ST-segment continuum in the precordial leads. Despite initial ECG findings suggesting right coronary artery (RCA) or left circumflex artery (LCX) involvement, coronary angiography confirmed occlusion of the wrap-around LAD distal to the first septal (S1) and diagonal branch (D1) and revealed a left dominant system accompanied by a small non-dominant RCA. This case highlights the diagnostic complexity in accurately localizing the culprit artery in STEMI cases exhibiting the de Winter sign. Understanding such ECG variants is crucial for analyzing the mechanisms of acute ischemia and ensuring accurate assessment of the culprit vessel for effective revascularization.