Organized thrombus in left main coronary artery in hypoplastic left heart syndrome.

A neonate is reported in whom, during Norwood stage I correction for hypoplastic left heart syndrome with mitral stenosis, an organized thrombus was found to protrude from the left coronary ostium into the aortic root. With ventricular assist device support the patient survived despite severe left ventricular ischemia. The presumed origin of the thrombus is from left ventriculocoronary arterial connections that serve to decompress the blind left ventricular cavity.