Appearance mobility gradient

Aortic Stenosis

14/11/10

OH

Examinations Book

- obstruction can be supravalvular, valvular (most common) or subvalvular.

Severity Assessment
- appearance

- mobility

- gradient (continuous wave Doppler allows peak velocity to be measured -> peak gradient can be calculated using Bernoulli equation (peak gradient = 4 x peak velocity across the narrowing²) – normal peak gradient < 10mmHg, critical > 70mmHg, gradient measurements are very dependent on ventricular function so can be misleading.

- area – normal 2.5-5.5cm², critical < 0.92cm²

- dimensionless severity index = ratio of LVOT velocity/aortic valve velocity (V1/V2) – provides a dimensionless measurement of aortic stenosis which is independent of Q, < 0.25 implies a valve area of 0.75cm² (severe AS)

- complications: LV hypertrophy, dilation, systolic and diastolic dysfunction, post-stenotic dilation

Jeremy Fernando (2010)