Aortic stenosis

Etiologies of aortic stenosis (AS) are almost evenly divided between rheumatic fever (RF) (40%), usually with concomitant mitral valve pathology, and congenital bicuspid anatomy (40%), with the remainder of cases due to senile, calcific degeneration. The classic triad of symptoms in AS includes angina, syncope, and congestive heart failure (CHF), each of these independently predicting a limited life expectancy: 5 years, 3 to 4 years, and 1½ to 2 years, respectively. Sudden death may occur in 15%–20% of cases, and the onset of symptoms, particularly near the age of 60, usually heralds precipitous decline leading to death. Therefore, operation is indicated at the onset of these symptoms, as well as in selected asymptomatic patients with estimated transvalvular gradients exceeding 50 mm Hg or valve orifice areas less than 0.8 cm. The orifice area is calculated using the Gorlin equation, which takes into account the cardiac output and square root of the transvalvular gradient.

Aortic regurgitation

Aortic regurgitation (AR) is caused in 50% of cases by RF, with remaining etiologies being endocarditis, myxomatous changes, rheumatoid arthritis, lupus, and a host of causes of aortic root dilatation (tertiary syphilis, Marfan's syndrome, Ehlers–Danlos, osteogenesis imperfecta, aortic dissection). Emergent operation may be indicated in acute aortic regurgitation as a result of aortic dissection, and is seen primarily in patients with uncontrolled hypertension, ascending aortic aneurysms, annuloaortic ectasia, and Marfan's syndrome. In this setting, operation may require replacement or resuspension of the aortic valve plus ascending aortic reconstruction with a tube graft.