Congenital left ventricle to coronary sinus fistulas are exceptionally rare, and only a few case reports of this condition exist. These fistulas may isolated or occur in conjunction with other CHDs. In this case report, we describe an 18-month-old boy who presented to our centre with a diagnosis of mitral valve insufficiency and a coronary sinus-type atrial septal defect. Upon echocardiographic evaluation, he was found to have a rare congenital left ventricle to coronary sinus fistula. Echocardiographic examination established the diagnosis. Contrary to initial suspicions, mitral regurgitation and atrial septal defect were not present. Instead, the echocardiogram revealed a left ventricular to coronary sinus fistula accompanied by dilation of the coronary sinus. These findings were corroborated by CT angiography. The fistula was then successfully occluded using a transcatheter method. Follow-up assessments at one-year post-procedure showed no complications and no evidence of significant shunting on echocardiography.
