20. clinical decision making. In: Otto CM, ed. The practice of clinical
echocardiography. Philadelphia: WB Saunders, 1997:405-32.
11. Pellikka PA, Nishimura RA, Bailey KR, Tajik AJ. The natural
history of adults with asymptomatic, hemodynamically significant
aortic stenosis. J Am Coll Cardiol 1990;15:1012-1017.
12. Weyman AE, Griffin BP. Left ventricular outflow tract: the aortic
valve, aorta, and subvalvular outflow tract. In: Weyman AE, ed.
Principles and practice of echocardiography, 2nd ed. Philadelphia:
Lea & Febiger, 1994:498-574.