The Pulse of Aortic Stenosis during Childhood.

The assessment of the severity of aortic stenosis has been the subject of much clinical research. Because of the changes in severe aortic valve lesions in adults, much consideration has been given to the nature and form of the pulse (Wood, 1958) particularly that in the brachial artery, as observed either by palpation or by the recording of an intra-arterial pulse tracing. Cosby et al. (1962) were unable to find any correlation between the severity of aortic stenosis and the contour of the brachial artery pulse, but Robinson (1963b) thought that the carotid pulse was more reliable, though in children it was not an infallible guide (Robinson, 1963a). All these authors have pointed out how change in cardiac output and peripheral resistance could modify these features. That the pressure gradient across the aortic valve alone is an unreliable index of the severity of aortic stenosis has been remarked on by Wood (1958) and Cosby et al. (1962). Braunwald et al. (1963) report the instance of a patient who had effort syncope and whose aortic valve gradient was only 35 mm. Hg. Braunwald et al. (1963) further drew attention to the fact that congenital aortic stenosis may be the cause of severe left ventricular obstruction without the symptoms of diminished cardiac reserve that are found in other forms of congenital heart disease. The difficulties in measuring blood flow in children are well known. The absence of clinical symptoms and signs in what may be at least moderate stenosis increases the difficulty of accurate diagnosis. Patients with severe aortic stenosis often die in infancy or early childhood. Those with mild lesions survive into adult life, and in middle age may develop calcific aortic stenosis. It is in the intermediate group, especially in childhood, that assessment is difficult. Radiographs and electro-cardiograms may give little help in the assessment of the true severity of the disease, and effort syncope and sudden death are real hazards. Dow (1940), while studying the aortic pulse at various situations in the aorta in dogs, noticed that there was an increase in the peak pressure of the pulse wave as the periphery was approached. Andersson and Porje (1946) and Kroeker and Wood (1955) also illustrated this phenomenon, and it has subsequently been studied in dogs by McDonald and Taylor (1959), McDonald (1960), and Taylor (1962). Dow on the other hand stated that there was little peripheral alteration in the …