Serial Hemodynamic Observations in Asymptomatic Children with Valvar Aortic Stenosis

The natural history of valvar aortic stenosis in children is uncertain. This report analyzes serial clinical and catheterization data of nine initially asymptomatic children. The first hemodynamic study was performed at an average age of 6.8 years, and the follow-up study at an average age of 13.1 years. Cardiac indices and left ventricular enddiastolic pressures were consistently normal in all patients. The peak transvalvar pressure difference increased between the initial and final studies in seven out of nine patients. The gradient ranged from 15 to 40 mm Hg (mean 28.2) at the first study, and from 20 to 100 mm Hg (mean 61.6) at the most recent evaluation. Severe stenosis (gradient> 50 mm Hg, normal cardiac output; or calculated orifice <0.7 cm 2 /m 2 ) developed in five of nine patients during a 6.8 year average follow-up. The obstruction advanced from mild to moderate in two patients; mild obstruction was unchanged in the remaining two. While the onset of symptoms and changes in the electrocardiogram suggested the possibility of severe obstruction in two patients, there was a poor correlation between the presence of symptoms, the results of the electrocardiogram, the results of the chest X-ray, and the transvalvar pressure gradient in any individual patient. The results of this study suggest that a progressive increase in the severity of obstruction may occur commonly, even in young children, and support the application of serial hemodynamic study to routine patient management.