Chapter 8 - Diseases of the left ventricular outflow tract

Abstract

Diseases of the left ventricular outflow tract include subvalvar aortic stenosis, aortic valve disease, and supravalvar aortic stenosis. Subvalvar aortic stenosis is most often caused by the presence of a fibromuscular shelf or systolic anterior motion of the anterior mitral valve leaflet. Aortic valve disease causes either regurgitation or stenosis. Characteristic echocardiographic features of valvar aortic stenosis include an abnormal number of cusps, thickening of the cusps, restricted cusp motion, and commissural fusion, creating a “doming” appearance of the valve in systole. Supravalvar aortic stenosis is typically caused by a localized narrowing of the aorta at the level of the sinotubular junction and is usually seen in patients with Williams syndrome. An increase in afterload can result in the progressive development of left ventricular hypertrophy, dilatation, and possibly failure.