DOI: https://doi.org/10.36347/sjmcr.2026.v14i10.055

Pages: 2368-2372

Introduction and importance: Situs inversus totalis (SIT) is a rare congenital mirror-image arrangement of the viscera. Coronary artery spasm (CAS) is a transient, intense vasoconstriction of an epicardial coronary artery that can cause acute coronary syndrome (ACS). Their association is exceptional. Case presentation: A 51-year-old hypertensive woman presented with prolonged right-sided chest pain. Examination, electrocardiography (ECG), chest radiography and computed tomography revealed previously unknown SIT. The ECG recorded with mirror-image electrode placement showed diffuse ST-segment depression with ST elevation in aVR, and troponin was rising (NSTE-ACS). Coronary angiography, performed with mirror-image catheter manipulation, showed a 70–80% left main narrowing reproducing the chest pain, which resolved completely after intracoronary isosorbide dinitrate. Medical treatment led to a favourable outcome. Clinical discussion: In SIT, ECG recording and coronary angiography must be adapted to the mirror-image anatomy. Left main spasm must be distinguished from fixed atherosclerotic disease and catheter-induced spasm before any revascularization. Conclusion: Intracoronary nitrate testing is mandatory before treating any left main narrowing, particularly in unusual anatomy.