Management of congenital aortic stenosis in children and young adults

Abstract

ORTIC STENOSIS ranks among the 10 most common congenital cardiac malformations. 1 It occurs in 3 to 6 per cent of cases in 4 large series TM of patients with congenital heart disease. The growing significance of congenital aortic stenosis with increasing age has been demonstrated by the results of a mass detection study recently conducted on 50,000 high school children/This investigation showed that approximately one-fifth of congenital heart disease found in this population consisted of aortic stenosis in its various forms. In a validity study carried out to check the detection method used in that survey the high incidence of aortic stenosis was confirmed/ Because oi the reported rate of sudden death of approximately 7.5 per cent ~ prior to the surgical era, it is important to review current medical and surgical attitudes toward the management of individuals with congenital aortic stenosis. The lower incidence of sudden death recently reported in the natural history study of aortic stenosis S has probably been influenced by the fact that this study began during the surgical age. Of the 4 types of congenital aortic stenosis, the valvular form is by far the most common. The aortic leaflets are usually thickened and deformed and the commissures are fused. In infants particularly, the deformity may be so severe that the components of the valve are not recognizable. The aortic ring may be narrow in infants and the ascending aorta hypoplastic, while in adults there is usually poststenotic dilatation of the aorta. The subvalvular fibrous type may consist of a fibrous ridge below the aortic valve or of a more diffuse mass of fibrous tissue involving the outflow tract of the left ventricle. In the muscular form of subvalvular aortic stenosis, there is usually no localized obstruction but the musculature of the septum and of the free wall of the left ventricle is extremely thickened producing a dynamic obstruction. The supravalvular variety of aortic stenosis may be localized or diffuse, occasionally involving the entire arch of the aorta. The clinical course in congenital aortic stenosis varies with the age of the patient at the time the first symptoms appear. In infants, obstruction severe enough to produce clinical manifestations, usually indicates an extremely poor prognosis, ~ whereas children surviving this early period have a better outlook. There is a low correlation between symptoms and the degree of obstruction, and sudden death has been reported occasionally in totally asymptomatic individuals. 7 Also, complications such as bacterial endocarditis, although decreasing in frequency, are a potential hazard in these patients.