Assessment of aortic valve disease - a clinician oriented review

Table 1 Echocardiographic criteria for the definition of severe aortic stenosis: Advantages and disadvantages[18]

Criteria	Severe AS	Advantages	Disadvantages
Aortic surface area	≤ 1.0 cm2	Measures effective AVA. However, this may also constitute a disadvantage because it does not measure anatomical AVA	Very sensitive to measurement errors
		Less flow-dependent compared with other measurements
Indexed AVA to body surface area	≤ 0.6 cm2/m2	Useful for extreme heights/weights	Very sensitive to measurement errors
Mean transaortic pressure gradient	≥ 40 mmHg		Flow-dependent
			Requires correct alignment of Doppler signal with the flow direction
Peak transaortic flow velocity	≥ 4.0 m/s	Measures instantaneous velocity	Flow-dependent
		Best predictor of adverse events	Requires correct alignment of Doppler signal with the flow direction
Ratio between peak transaortic flow velocity and peak LVOT velocity	≤ 1/4	Good reproducibility (compared with AVA calculation)	Limited data on prognostic utility

AS: Aortic stenosis; AVA: Aortic valve area; LVOT: Left ventricular outflow tract.