We can now summarize our patient's history and physical examination. Most important is the history in infancy and childhood of both cyanosis that increases with exertion and progressive exercise intolerance. Physical examination confirms cyanosis with clubbing. Cardiac examination demonstrates a sustained right ventricular impulse, an aortic ejection sound and a high frequency, early peaking ejection murmur, loudest at the lower left sternal edge, consistent with right ventricular outflow tract obstruction. A single second heart sound, due to an audible P2 supports this interpretation of the murmur. There are no diastolic sounds or murmurs.