Abstract
BACKGROUND: The evolution of a de Winter pattern to a Wellen pattern in acute coronary syndrome is a rare occurrence; both signify critical left anterior descending artery (LAD) lesion and warrant urgent early percutaneous coronary intervention (PCI). CASE SUMMARY: Electrocardiogram (ECG) of a 55-year-old man with retrosternal discomfort demonstrated a de Winter pattern that transiently normalized, leading to discharge. He re-presented after 12 hours, and repeat ECG demonstrated evolution to a Wellen pattern. Coronary angiography showed a critical mid-LAD lesion with preserved distal flow and a near-occlusive mid-right coronary artery (RCA) lesion with collateral-dependent distal RCA filling from the contralateral side. PCI to the RCA resulted in abrupt LAD artery closure, with angiographic evidence of collateral flow reversal and distal LAD filling from the RCA. DISCUSSION: This case illustrates dynamic ECG evolution in LAD ischemia and pressure-dependent bidirectional coronary collateral flow. TAKE-HOME MESSAGES: A de Winter ECG may evolve into Wellens pattern in critical LAD disease. Dynamic collaterals may influence PCI strategy in acute coronary syndrome.