Mitral Stenosis Stages A to D (ACC/AHA)
Applies the ACC/AHA rheumatic mitral stenosis stages.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Mitral valve area
- 1.2 square cm
- Diastolic pressure half-time
- 180 ms
- Mean mitral gradient, recorded but not used to stage
- 9 mmHg
- Reduced exercise tolerance or exertional breathlessness
- Yes
Result: stage D
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Stage A
- At risk: mild doming of the valve in diastole, with a normal transmitral velocity and no commissural fusion.
- Stage B
- Progressive: commissural fusion with diastolic doming, a valve area above 1.5 square cm and a pressure half-time below 150 ms.
- Stage C
- Asymptomatic severe: a valve area of 1.5 square cm or less, OR a diastolic pressure half-time of 150 ms or more.
- Stage D
- Symptomatic severe: the same hemodynamics with reduced exercise tolerance or breathlessness on exertion.
- Very severe
- Inside the severe range: a valve area of 1.0 square cm or less, or a pressure half-time of 220 ms or more.
- The gradient does not grade it
- Typically above 5 to 10 mmHg when severe, but it rises with heart rate and cardiac output. Severity is defined by the valve area and the half-time, not by it.
- Why the gradient moves
- Tachycardia shortens diastole and inflates it; a slow, low-output patient deflates it. The same valve reads differently on two days.
- Limits of the half-time
- The empirical area of 220 divided by the half-time breaks down with significant aortic regurgitation, immediately after balloon valvuloplasty, and where compliance is abnormal.
What you enter
- Mitral valve area
- Diastolic pressure half-time
- Rheumatic changes: doming only, or commissural fusion
- Mean mitral gradient, recorded but not used to stage
- Heart rate, for reading the gradient
- Reduced exercise tolerance or exertional breathlessness
How this is calculated
Otto CM, Nishimura RA, Bonow RO, et al. 2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease. Circulation. 2021;143(5):e72-e227. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.