Acute coronary syndrome without elevation of the ST secondary to coronary fistula. Case presentation

Abstract

Introduction: Coronary artery fistulas are rare vascular anomalies that may alter myocardial perfusion and mimic acute coronary syndromes. Their clinical relevance lies in the fact that they can occur in the absence of obstructive coronary artery disease, representing a diagnostic challenge.

Objective: To describe a clinical case of non–ST-segment elevation acute coronary syndrome secondary to a coronary artery fistula.

Case presentation: A 53-year-old female patient with a history of arterial hypertension, grade I obesity, and chronic smoking presented with typical ischemic chest pain associated with dyspnea and autonomic symptoms. Electrocardiography showed dynamic ischemic changes with subsequent normalization. Cardiac biomarkers revealed elevated troponin T and CK-MB levels. Transthoracic echocardiography demonstrated regional wall motion abnormalities with preserved left ventricular ejection fraction. Coronary angiography revealed normal epicardial coronary arteries without atherosclerotic lesions and a fistula originating from the left anterior descending artery with drainage into the pulmonary circulation. Conservative medical treatment was indicated, with favorable clinical evolution.

Conclusions: Coronary artery fistulas may present as non–ST-segment elevation acute coronary syndrome in the absence of obstructive coronary disease. Coronary angiography is essential for definitive diagnosis and therapeutic decision-making. Conservative management may be effective in hemodynamically stable cases without significant shunt.