Precordial Swirl Sign: A Subtle ECG Clue Unmasking Anterior Myocardial Ischemia.

Precordial swirl sign may provide a clue to anterior myocardial ischemia in patients whose electrocardiograms do not meet conventional ST-segment elevation myocardial infarction criteria. A 75-year-old man with previous coronary stenting presented with worsening chest pain and an initially negative troponin result. His admission electrocardiogram showed focal ST-segment elevation in V1, a hyperacute T wave in V2, and reciprocal ST-segment depression in V5-V6. Subsequent anterior Twave inversion and troponin elevation supported an ischemic interpretation. Coronary angiography revealed approximately 90% proximal left anterior descending coronary artery in-stent restenosis with TIMI 2 flow. Balloon angioplasty followed by drug-coated balloon treatment restored TIMI 3 flow. This case illustrates the importance of interpreting opposing precordial ST-T changes in relation to the ischemic vector rather than considering ST-segment elevation thresholds alone. Recognition of this pattern may prompt serial electrocardiography, repeat biomarker testing, and timely assessment for coronary intervention.