Fistula Between the Left Anterior Descending Artery and the Pulmonary Trunk.

Background: Coronary artery fistulas are usually asymptomatic anomalies diagnosed most often incidentally during conventional coronary angiography or computed tomography angiography (CTA) of the coronary arteries. Case report: We present the case of a 74-year-old woman with exertional dyspnoea, preserved left ventricular systolic function, no hemodynamically significant coronary artery stenosis, and a fistula between the anterior interventricular branch of the left anterior descending artery and the pulmonary trunk, identified by classic coronary angiography and CTA. Conclusion: The growing prevalence of CTA examination of the coronary arteries in recent years has increased the recognition of coronary fistulas. Early diagnosis and appropriate management are essential in symptomatic patients. LEARNING POINTS: Coronary artery fistulas, though rare, should be considered in the differential diagnosis of unexplained exertional dyspnoea, especially in elderly patients with comorbidities.Angio-computed tomography scan is the most effective imaging modality for identifying coronary artery fistulas and assessing their hemodynamic significance.Early diagnosis and appropriate intervention can prevent complications such as coronary steal syndrome, heart failure, and pulmonary hypertension, highlighting the importance of multidisciplinary management. Early recognition of coronary steal syndrome is crucial in symptomatic patients with exertional dyspnoea and no significant coronary artery stenosis.