Echocardiographic diagnostic criteria for severe aortic stenosis.
| Echocardiographic criterion | Method of measurement | Limitations |
|---|---|---|
| Peak jet velocity >4 m/sec | CW Doppler through aortic valve | Doppler measurement must be aligned with transvalve flow |
| Mean gradient >40 mmHg | AV CW using the Bernoulli formula | Doppler measurement must be aligned with transvalve flow |
| Aortic valve planimetry | Direct measurement of the valve orifice | Largely subjective, more difficult in the presence of calcification, poor reproducibility |
| AVA <1 cm2 | Need to measure: LVOT area, AV VTI (CW) and LVOT gradient (PW) | Must ensure anatomical measurements are correct to avoid large errors |
| AVA index <0.6 cm2/m2 | AVA/BSA | May overdiagnose severe AS in large individuals |
AV = aortic valve; AS = aortic stenosis; AVA = aortic valve area; BSA = body surface area; CW = continuous wave; LVOT = left ventricular outflow tract; PW = pulse wave; VTI = velocity time integral.