Mitral Stenosis: Difference between revisions
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Revision as of 23:02, 9 December 2013
Quantification of mitral valve stenosis1
| Slight | Moderate | Severe | |
|---|---|---|---|
| PGmean | <5mmHg | 5-10mmHg | >10mmHg |
| PHT | <90m/s | 90-150m/s | >150m/s |
| MVA | >1.5cm2 | 1.5-1cm2 | <1cm2 |
Click here to calculate MVA by PHT
|
| Moderate / severe MS |
|---|
Various techniques can be used to estimate the severity of a mitral valve stenosis.
The peak pressure is unreliable for assessing the severity of mitral valve stenosis. Also, the pressure differential is strongly influenced by the heart rate. A high heart rate will greatly increase the pressure difference due to the strongly reduced duration of diastole. For heart rates between 60 - 90/min , the average gradient is estimated by "tracing" of the CW signal across the mitral.
Pressure half-time
| By using an empirical formula the mitral valve area can be calculated using: MVA = 220/PHT. |
|
Pitfalls:
In any situation where the LV diastolic pressure rises rapidly (AOI, non-compliant LV, myocardial ischemia) will give an underestimation of the severity of mitral valve stenosis. Immediately after balloon dilatation of the mitral valve, the method unreliable PHT Tachycardia at which the A-top merges with the E-top or boezemflutter which flutter waves the E-wave deformation may overestimate the incidence of mitral stenosis. Heart rates of between 60 and 90/min give best results
Click here for Wilkins score (also called Mitral Valvuloplasty score)
References
<biblio>
- 1 pmid=20435783
- 2 pmid=3190958
</biblio>