A 10 day old asymptomatic baby girl was evaluated for a to-and-fro systolic and diastolic murmur grade III/VI, audible along the left sternal border. The echocardiogram showed a valvar pulmonary stenosis with a maximum systolic gradient of 55 mm Hg across a thick, poorly mobile pulmonary valve, and an aortico-right ventricular tunnel between the left aortic sinus and the right ventricle. The aortic orifice …