In mitral stenosis, the pressure difference between the left atrium and ventricle falls more slowly the narrower the valve. The empirical constant 220 was derived by Hatle and colleagues in 1979.
How to use the Mitral Valve Area Calculator
- Measurement
- Time
Results update as you type, and every field accepts the units shown in its menu.
How it works
Enter the pressure half-time from the mitral inflow Doppler, or the deceleration time if that is what you measured.
Inputs explained
| Field | What to enter |
|---|---|
| Measurement | Choose one: Pressure half-time, Deceleration time |
| Time | In ms |
Example values
How the main result changes when Time changes and everything else stays at the example values above:
| Time (ms) | Mitral valve area (cm²) |
|---|---|
| 110 | 2 |
| 165 | 1.33 |
| 220 | 1 |
| 275 | 0.8 |
| 330 | 0.67 |
| 440 | 0.5 |
Health note: this calculator is for education and screening only and is not a diagnosis or treatment advice. Discuss your results with a qualified clinician.
Formula
MVA = 220 ÷ pressure half-time (ms)
Pressure half-time ≈ 0.29 × deceleration time
Severe MS: MVA ≤ 1.5 cm² (very severe ≤ 1.0)
Worked example
Inputs — Measurement: Pressure half-time; Time: 220 ms.
Results — Pressure half-time = 220 ms; Mitral valve area = 1 cm².
Key terms
- PHT
- Pressure half-time.
- MS
- Mitral stenosis.
Frequently asked questions
What is a normal mitral valve area?
4–6 cm².
When is the PHT method unreliable?
Right after balloon valvotomy, with severe aortic regurgitation or abnormal LV relaxation.
What is severe mitral stenosis?
Valve area 1.5 cm² or less (ACC/AHA 2020).