Left ventricular outflow tract

Abstract

Left ventricular outflow tract obstructions (LVOTO) encompass a series of stenotic lesions starting in the left ventricular outflow tract (LVOT), including the aortic valve and extending to the ascending aorta. Depending on definition, also intraventricular obstruction and hypoplastic left heart syndrome are included in the types of LVOTO. Left ventricular outflow tract obstructions can occur at several levels: Valvular LVOTO in the adult patient with congenital heart disease is usually due to bicuspid aortic valve. It usually occurs isolated but can be associated with other abnormalities, the most common being coarctation of the aorta, persistent ductus arteriosus, or aneurysm of the ascending aorta. Subvalvular LVOTO is usually either a discrete fibromuscular ridge which partially or completely encircles the LVOT or a long fibromuscular narrowing beneath the base of the aortic valve. Supravalvular LVOTO may occur rarely in isolation as an hourglass deformity. It is more often diffuse, however, involving the major arteries to varying degrees and begins at the superior margin of the sinuses of Valsalva.