Case Report: Transcatheter closure of a giant asymptomatic right coronary artery-to-left ventricular fistula in a 16-year-old female.

A 16-year-old asymptomatic female was referred for evaluation of a single episode of self-limited sinus tachycardia (∼110 bpm) incidentally detected during a routine physical examination. Transthoracic echocardiography revealed a markedly dilated right coronary artery (15 mm) and a 7-mm fistulous tract communicating with the left ventricle. Cardiac computed tomography confirmed a right-dominant system, a tortuous, ectatic right coronary artery (maximum diameter 15 mm), and a 9-mm fistulous opening into the left ventricle. Indexed left ventricular end-diastolic diameter was significantly increased, indicating volume overload despite preserved systolic function. The patient underwent successful transcatheter closure using an 18 mm Amplatzer Vascular Plug II. At 6-month follow-up, indexed left ventricular end-diastolic diameter had normalized, and the patient remained asymptomatic. This case demonstrates that asymptomatic coronary artery fistula to the left ventricle can induce significant ventricular remodeling, which is reversible with timely intervention. Echocardiographic evidence of chamber enlargement alone should be considered an independent indication for closure.