**5.3 Calcific AS in the elderly**

Like AS in the pediatric patient, echocardiographic studies are very useful in characterizing the aortic valve morphology, in quantitating the degree of obstruction, and in assessing left ventricular response to increased afterload. The aortic valve leaflets have increased echo density and decreased valve leaflet motion. It is frequently difficult to discern whether it is a tricuspid or bicuspid aortic valve. The Peak Doppler flow velocity is increased which is used to calculate the systolic pressure gradient across the aortic valve by a modified Bernoulli equation, as reviewed above in the section on "Congenital AS in the Pediatric Patient." Other disease entities such as hypertrophic cardiomyopathy, mitral valve disease, and CHDs are excluded by echo studies. Left ventricular hypertrophy is usually detected by echo evaluation. Left ventricular ejection fraction can be quantitated; in most cases, it is preserved until late in the disease.
