RESUMO
Coronary artery-to-pulmonary artery fistulae are a not uncommon finding in patients with Tetralogy of Fallot (TOF) and collateral-dependent pulmonary blood flow. Management for these fistulae is often primary surgical ligation or unifocalization at the time of complete repair, dependent on the presence of dual blood flow to the involved areas. We present the case of a 32-week premature boy weighing 1.79 kg with TOF, confluent branch pulmonary arteries, major aortopulmonary collaterals, and right coronary artery to main pulmonary artery fistula. The patient demonstrated evidence of coronary steal into the pulmonary vasculature with an elevation in the troponin level without hemodynamic instability, and subsequently underwent successful transcatheter occlusion of the fistula via right common carotid access using a Medtronic 3Q microvascular plug. This case demonstrates the realistic potential for early coronary steal in this physiology and possibility of transcatheter therapy even in a small neonate.