Aortic Stenosis
Narrowing of the aortic valve, most commonly from age-related calcific degeneration. The most common valvular cause of cardiac surgery and TAVR.
Aortic stenosis is progressive obstruction of left-ventricular outflow through a narrowed aortic valve. The dominant etiology in adults is age-related calcific (degenerative) AS; bicuspid valves and rheumatic disease account for the remainder.
Severity is graded echocardiographically using peak aortic velocity (Vmax), mean transvalvular pressure gradient, and aortic valve area (AVA) by continuity equation. Severe AS is defined as Vmax ≥4 m/s, mean gradient ≥40 mmHg, or AVA ≤1.0 cm².
Modern management is increasingly catheter-based (TAVR / TAVI), with broad indications across surgical risk strata. Reproducible echocardiographic grading is central to TAVR candidacy decisions.