Atypical Presentation of Non-dominant Right Coronary Artery Occlusion: Precordial ST-Segment Elevation

This case report details a rare presentation of ST-segment elevation myocardial infarction (STEMI) in a 46-year-old male, highlighting an unusual electrocardiographic (ECG) pattern where proximal total occlusion of the right coronary artery (RCA) manifested with ST-segment elevation (STE) in both inferior leads (II, III, aVF) and, strikingly, anterior precordial leads (V1-V6). Typically, precordial STE is a hallmark sign of anterior myocardial infarction (MI), commonly linked to occlusion of the left anterior descending (LAD) coronary artery. This patient's ECG initially suggested a widespread myocardial insult, but subsequent coronary angiography definitively pinpointed a complete blockage in the proximal RCA, while the LAD and circumflex arteries were normal. This case should influence diagnostic reasoning by compelling clinicians to consider a wider differential diagnosis for STEMI and to avoid absolute reliance on classic ECG patterns. The diagnostic workup of such unusual cases should include clinical presentations with updated ECG criteria and integrated imaging algorithms such as comprehensive transthoracic echocardiography to ensure accurate diagnosis and timely reperfusion therapy.