Clinical History.—A 12-year-old white boy was admitted to the Montreal Children's Hospital with a history of a sudden onset of severe, sharp, nonradiating precordial chest pain of five hours' duration.
Past History.—A heart murmur was first heard when the boy was 18 months of age, but he was able to lead an active life. At 3 years of age, there was roentgenographic evidence of left ventricular enlargement and dilatation of the ascending aorta (not illustrated). Heart catheterization was performed when the boy was 10 years of age, and aortic valvular stenosis (gradient: 70 mm Hg) with aneurysmal dilatation of the ascending aorta was diagnosed. Subsequent chest roentgenograms, taken at times until the patient was 10 years of age, showed progressive dilatation of the ascending aorta and of the left ventricle.
On admission, he was pale and looked severely ill. His blood pressure was 100/80 mm Hg bilaterally (brachial).