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ESSENTIALS OF DIAGNOSIS
Congenital bicuspid aortic valve (usually asymptomatic until middle or old age).
“Degenerative” or calcific aortic stenosis; similar risk factors as atherosclerosis.
Visual observation of immobile aortic valve plus a valve area of less than 1.0 cm2 define severe disease; low-gradient but severe aortic stenosis can thus be recognized.
Delayed and diminished carotid pulses.
Soft, absent, or paradoxically split S2.
Harsh systolic murmur, sometimes with thrill along left sternal border, often radiating to the neck; may be louder at apex in older patients.
ECG usually shows LVH; calcified valve on radiography or fluoroscopy.
Echocardiography/Doppler is diagnostic.
Surgery typically indicated for symptoms. Percutaneous valve replacement is being used increasingly.
Surgical risk is typically low even in the very elderly. Percutaneous valve replacement may be an option for high surgical risk patients.
Surgery considered for asymptomatic patients with severe aortic stenosis (mean gradient greater than 55 mm Hg) or when undergoing heart surgery for other reasons (eg, coronary artery bypass grafting [CABG]).
BNP is a marker of early LV myocardial failure, and high levels suggest poor prognosis.
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GENERAL CONSIDERATIONS
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There are two common clinical scenarios in which aortic stenosis is prevalent (eFigure 10–37). The first is due to a congenitally abnormal unicuspid or bicuspid valve, rather than tricuspid. Symptoms can occur in young or adolescent individuals if the stenosis is severe, but more often emerge at age 50–65 years when calcification and degeneration of the valve become manifest. A dilated ascending aorta, due to an intrinsic defect in the aortic root media and the hemodynamic effects of the eccentric aortic jet, may accompany the bicuspid valve in about half of these patients. Coarctation of the aorta is also seen in a number of patients with congenital aortic stenosis. Offspring of patients with a bicuspid valve have a much higher incidence of the disease in either the valve, the aorta, or both (up to 30% in some series).
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A second pathologic process, degenerative or calcific aortic stenosis, is thought to be related to calcium deposition due to processes similar to those that occur in atherosclerotic vascular disease. Approximately 25% of patients over age 65 years and 35% of those over age 70 years have echocardiographic evidence of aortic valve thickening (sclerosis). About 10–20% of these will progress to hemodynamically significant aortic stenosis over a period of 10–15 years. Certain genetic markers are associated with aortic stenosis (most notably Notch ...