Left ventricular outflow tract obstruction

Abstract

The commissurae of the aortic valve may be fused, and the ring is occasionally small. The orifice of the aortic valve can be eccentric. The valve is commonly bicuspid in aortic stenosis and the leaflets are asymmetric in 40% of cases. There is occasionally more than one level of obstruction in the left ventricular outflow tract together with aortic valvular stenosis. About 10% of patients with aortic valvular stenosis have subvalvar aortic stenosis. Supravalvar aortic stenosis is rarely associated with aortic stenosis. In 50% of valvular aortic stenosis patients, a certain degree of aortic insufficiency is associated. Aortic valvular stenosis is not always the result of a bicuspid aortic valve, since bicuspid aortic valve is 10-20 times as common as aortic stenosis. Thus, a small number of bicuspid valves leads to aortic stenosis, but the majority will not develop into aortic stenosis. Right-to-left commissures have a worse prognosis in bicuspid aortic than anteroposterior commissures in developing aortic stenosis.