Myocarditis Presenting as Myocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA) in a Young Man: A Case Report

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a unique disorder that manifests as an acute myocardial infarction clinically without overt coronary arteries obstruction on angiography. Herein, we report a 17-year-old male presented with a chest pain occurring 3 hours before admission and fever lasting for 2 days. Electrocardiogram examination showed ST elevation in lead II, III, aVF and V3-V6. Laboratory tests results showed a normal leukocyte level of 9850/µL, an elevated troponin of 3.55 ng/mL and an elevated quantitative CRP of 46 mg/L. Coronary angiography performed, indicating 20-30% stenosis of the left anterior descending artery, left circumflex artery and right coronary artery, whereas in typical acute myocardial injury, angiography shows >50% coronary stenosis. Additional cardiac MRI examination showed a fulfillment of Lake Louis Criteria for myocarditis, with further findings of acute myocardial edema in the lateral wall of left ventricle, with left ventricle ejection fraction of 59.73%. As researchers are still working on the definition of MINOCA, present knowledge of the causes, pathophysiology, clinical features, or specific phenotypes of MINOCA is also limited. A stepwise diagnostic approach is needed to diagnose MINOCA, with subsequent differential diagnosis exclusion.