Severity
- Mild: MVA >1.5 cm², mean gradient <5 mmHg
- Moderate: MVA 1.0 to 1.5 cm², mean gradient 5 to 10 mmHg
- Severe: MVA <1.0 cm², mean gradient >10 mmHg
2D assessment
- Define etiology: rheumatic vs calcific
- Assess leaflet mobility, thickening, calcification, subvalvular disease
- Assess LA size, RV size/function, estimate RVSP
Planimetry
- Parasternal short-axis at leaflet tips
- Trace smallest orifice in mid-diastole
- Best direct measure of MVA if image quality adequate
Mean gradient
- CW Doppler from apical 4-chamber
- Trace full diastolic envelope
- Document heart rate and rhythm
- Gradient increases with tachycardia and high cardiac output
Pressure half-time
- MVA = 220 / PHT
- Less reliable with significant AR, elevated LVEDP, diastolic dysfunction, or after valvotomy
Continuity equation
- MVA = (LVOT area × LVOT VTI) / MV VTI
- Use if planimetry not feasible
Report
- MVA and method
- Mean gradient with HR
- Rhythm
- RVSP
- MR severity