Anomalies of the Left Ventricular Outflow Tract and Aortic Valve

This chapter presents information on morphology, classification, pathophysiology, and imaging of subaortic stenosis, aortic valve stenosis, supravalvar aortic stenosis, bicuspid aortic valve, aortic valve cusp prolapsed, sinus of valsalva aneurysm, and aortico-left ventricular tunnel. Obstruction of the left ventricular outflow tract may occur below the level of the aortic valve, at the level of the aortic valve, or above the aortic valve, typically at the level of the sinotubular junction. Subaortic stenosis may be familial, but in most cases is felt to be the result of the interaction of a number of factors. The development of subaortic stenosis is thought to be due to abnormal shear forces in the left ventricular outflow tract, leading to abnormal growth of fibrous tissue. Aortic valve stenosis in children is due to a congenitally abnormal aortic valve rather than degeneration of a normal valve as may occur in late adult life.