Congenital Aortic Stenosis

Of 3,022 patients with congenital heart disease studied in the heart clinic of the Royal Liverpool Children's Hospital during the last five years, 120 presented with signs of uncomplicated aortic stenosis giving an incidence of 4% of all cases of congenital heart disease. Swan, Wilkinson, and Blount (1958) noted an incidence of 5% of all patients in their congenital heart disease clinic. It has been reported twice as commonly in males as in females and the ratio was just 2: 1 in our series. Most patients present with an isolated stenosis of the aortic valve or the outflow tract of the left ventricle, but in some other cardiovascular abnormalities are associated. In our experience, in addition to the 120 with uncomplicated aortic stenosis, there was an associated patent ductus arteriosus (in 9 subjects), ventricular septal defect (5), coarctation of the aorta (3), pulmonary stenosis (2), mitral stenosis (2), atrial septal defect (2), dextrocardia (2), vascular ring (1), transposition of the great vessels (1), and tricuspid atresia (1). The cause of the development of the condition in foetal life is obscure, but a comparison can naturally be drawn with isolated congenital pulmonary stenosis. The form of cusp fusion and annular hypoplasia, where present, is similar in both conditions as also is the relative incidence of valvar to subvalvar stenosis. Combined aortic and pulmonary stenosis must be rare, and apart from the two cases not included in the series, we have only seen a single example at operation, one of our two cases with supravalvar stenosis. Of the 120 known cases in the heart clinic, 44 have been submitted to detailed investigation. Thirty-two of these patients have been operated upon, of whom four died, and altogether 10 cases were available for post-mortem examination. The following account of the condition and its treatment is based upon this material.