Revista de Métodos de Diagnóstico Médico
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Abstrato

Role of the Mitral Valve Resistance in Evaluation of Mitral Stenosis Severity

El-Dosouky II, Meshrif AM

Background: Mitral valve resistance (MVR) is an important hemodynamic consequence of mitral stenosis (MS). We aimed to determine whether the mitral valve resistance could be used as a clinically reliable method for estimation of MS severity.

Materials and Methods: Transthorathic echocardiographic study of 128 patients with rheumatic MS to estimate; mitral valve area (MVA); planimerty (2D) and pressure half time (PHT), mitral valve score (MVS), right ventricular systolic pressure (RVSP), mean transmitral pressure gradient (MPG), diastolic filling time (DFT), left ventricular out flow tract diameter (LVOTd) and velocity time integral (LVOT vti), MVR calculated as: MPG/aortic flow ratio [(LVOTd) (LVOTvti)/DFT] in dynes.sec.cm^-5.

Results: MVR at cut off values of: ≥105.26 dynes.sec.cm^-5, had a sensitivity of 86.7% and a specificity of 74.5% for severe MS, between 76.02 and 105.26 dynes.sec/cm⁵ it had a sensitivity of 85.2% and a specificity of 72% for moderate MS, at ≤76.02 dynes.sec/cm⁵ it had a sensitivity of 81% and a specificity of 91% for mild MS. MVR in moderate MS; can detect symptomatic patients at a cut off value ≥85.65 dynes.sec/cm5 with a sensitivity of 87% and a specificity of 100%. MVR had positive correlations with MVS and RVSP (r=0.618 and 0.401), -ve correlations with MVA-2D and PHT (r=-0.559 and -0.284), P<0.01. MVR was an independent predictor of the NYHA functional class (B ± SE0.003 ± 0.001, odds ratio 0.3, P<0.01). NYHA functional class showed the best correlation with MVR (r=0.630, P<0.01).

Conclusion: MVR can be used as a parameter for expression of stenosis severity, and could be used for evaluation of symptomatic moderate MS.