How can the severity of aortic stenosis be graded?

Severity can be graded based upon echocardiographic features: Grade Mild Moderate Severe(Associated with significant haemodynamic compromise) Critical Peak gradient <30 mmHg 30–50 mmHg >50 mmHg >70 mmHg Valve Area >1.5 cm2 1.0–1.5 cm2 0.6 -1.0...