Intracoronary Full Physiology and Imaging Unveiling a Rare Cause of MINOCA Presenting as Ventricular Fibrillation

BACKGROUND: Nonobstructive coronary artery disease is diagnostically challenging, especially in patients with recurrent chest pain and inconclusive imaging. Coronary functional abnormalities, such as vasospasm, microvascular dysfunction, and myocardial bridging, are key contributors to ischemia. CASE SUMMARY: A 57-year-old man with cardiovascular risk factors and a 10-year history of chest pain, empirically treated with vasodilators, presented with ST-segment elevation and ventricular fibrillation. Coronary angiography showed normal arteries. Invasive assessment with optical coherence tomography and coronary physiology revealed diffuse, nonobstructive lipid-rich atherosclerosis and a myocardial bridge in the mid left anterior descending artery. Ischemia was confirmed by resting full-cycle ratio. Coronary function testing showed microvascular dysfunction. Beta-blockers normalized indices, with symptom resolution at 6 months. DISCUSSION: This case illustrates the diagnostic value of invasive imaging and physiology in patients with myocardial infarction/myocardial ischemia with no obstructive coronary artery disease (INOCA/MINOCA). TAKE-HOME MESSAGES: Invasive physiology and imaging are crucial for diagnosing ischemia mechanisms in nonobstructive coronary artery disease. Empirical therapy without functional assessment may delay effective, personalized treatment.