Atypical de Winter Pattern: Clinical Judgement vs Rigid Criteria

Background The de Winter ECG pattern is a distinctive manifestation of acute coronary artery occlusion—classically involving the proximal left anterior descending artery (LAD)—that frequently does not fulfil conventional ST-segment elevation criteria and is therefore regarded as a STEMI equivalent. Case presentation: We report the case of an 85-year-old woman with sudden-onset chest pain radiating to both shoulders. The prehospital 12-lead ECG showed a de Winter–like pattern, prompting direct transport to a PCI-capable centre and administration of antiplatelet and anticoagulant therapy. On arrival, symptoms partially improved; however, repeat ECG evolved into typical anterior ST-segment elevation. Urgent coronary angiography demonstrated an 80% ostial LAD stenosis with thrombus, successfully treated with direct PCI and drug-eluting stent implantation. Conclusion This case illustrates the dynamic nature of the de Winter pattern and underscores that early recognition of STEMI equivalents is crucial to minimise reperfusion delays.