Background & aim: The De Winter ECG pattern is considered equivalent to acute ST-segment elevation myocardial infarction (STEMI) and requires immediate intervention. This   pattern may be misidentified because of the absence of classic ST-segment elevation.
Case Report: A 60-year-old man with a history of type 2 diabetes mellitus and   prior percutaneous coronary intervention (PCI) presented to the emergency department with chest pain. Initial ECG showed up sloping ST-segment depression with tall, symmetrical positive T waves in the anterior leads (V2-V6) and 1 mm ST elevation in lead AVR, consistent with De Winter's pattern. Immediate angiography confirmed acute thrombotic occlusion in the proximal left anterior descending (LAD) artery, and the patient underwent primary PCI successfully.
Conclusion: Rapid identification of the De Winter pattern is critical to avoid treatment delays and improve outcomes in patients with acute LAD occlusion. This pattern should be considered equivalent to STEMI and should be treated immediately with percutaneous coronary intervention (PCI).