Bilateral Epicardial Coronary Microfistulas With Anomalous Deviation

BACKGROUND: Bilateral coronary microfistulas with redirection to the left ventricle are extremely rare clinical events. Although most cases are asymptomatic, the severity varies according to the redirection of blood flow, possibly leading to type 2 myocardial infarction. CASE SUMMARY: A 79-year-old woman with a medical history of hypertension, type 2 diabetes mellitus, hypothyroidism, and anxiety presented with atypical chest pain. Electrocardiogram revealed sinus rhythm with an electrically inactive area in the inferior wall, and serial troponin measurements indicated myocardial injury. Coronary angiography demonstrated bilateral coronary microfistulas draining into the left ventricle, in the absence of obstructive coronary artery disease. The patient was discharged with atenolol and acetylsalicylic acid and remained stable during follow-up. DISCUSSION: This case contributes to the growing recognition of coronary microfistulas as a rare but clinically meaningful cause of type 2 myocardial infarction, emphasizing the diagnostic value of coronary angiography and reinforcing the importance of individualized conservative management in such diffuse presentations of fistulas.