Aortic Stenosis

Aortic Stenosis

Aortic stenosis (AS) can be congenital or acquired. Congenital AS is often secondary to degenerative changes in a bicuspid aortic valve. Calcific AS of the elderly is related to dyslipidemia and atherosclerosis. Rheumatic fever is an important cause for AS in the developing countries. Rheumatic aortic valve disease is often a combination of stenosis and regurgitation. Severe AS causes left ventricular hypertrophy and angina pectoris as a result of coronary supply demand mismatch. When a person with severe AS exercises, syncope can occur due to the fixity of cardiac output. Peripheral vasodilatation with exercise leads to shunting of blood away from the brain and syncope.

ECG shows left ventricular hypertrophy with strain pattern in severe AS. Severity of AS can be assessed by Doppler echocardiography. Transvalvular gradient above 75 mm Hg is considered as severe aortic stenosis. Gradient can be falsely low with the onset of left ventricular dysfunction.

Severe AS can sometimes be treated by balloon valvotomy, often as a palliative treatment. The definitive treatment required is aortic valve replacement. Replacement can be done with mechanical and bioprosthesis. In young children pulmonary autograft (Ross procedure) is preferred. Mechanical prosthesis requires lifelong anticoagulation.