Q. What is Aortic stenosis?

Left Ventricular outflow tract obstruction can occur due to various aortic valvular, subvalvular and supra valvular lesions.

Valvular Aortic Stenosis

Etiology

Table: Etiology of Aortic Stenosis

Congenital Unicuspid
                                               Bicuspid
                                               Tricuspid valve with fused commissures
Acquired                                   Rheumatic
                                                Degenerated Tricuspid valve
                                                Degenerated bicuspid valve
Unusual acquired                        Hypercholesterolemia
                                                Obstructive vegetation
                                                Obstructive tumor
                                                Rheumatic arthritis
                                                Alkaptaneurea

Rheumatic aortic stenosis is often seen in young and middle aged individuals and is almost always associated with rheumatic involvement of mitral valve; Fibrocalcific degenerative changes of aortic valve is another important cause of aortic stenosis often seen in the elderly. Such changes occur more rapidly if the underlying valve is bicuspid or if atherosclerotic risk factors are present. Hypercholesterolemia typically hastens the degenerative changes of aortic valve and homozygous patients may present with aortic stenosis in younger age. Similarly hypertension, smoking and male sex also predispose to aortic valve degeneration leading to aortic stenosis.