الفهرس 
Acknowledgment.Only 14 pages are availabe for public view
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Abstract
In nearly all patients, valvular mitral stenosis (MS) is caused by rheumatic involvement of mitral valve. Echocardiographic is the gold standard method for evaluating mitral stenosis (MS). Two – dimensional echocardiographic (2D) planimetry of the mitral valve orifice and pressure half – time (PHT) are the two most commonly used methods to estimate mitral valve orifice area. These methods have an excellent concordance and, in most cases, can be used interchangeable. Several studies have demonstrated that current echocardiographic techniques for estimating valve area in mitral stenosis have important limitations.
Therefore, a simple and accurate method for assessment of mitral stenosis (MS) severity is desirable. The mitral leaflet separation (MLS) index, measuring the distance between the tips of the mitral leaflets in parasternal long – axis and apical four chamber views was recently presented as a reliable measure of mitral stenosis severity and as a surrogate for mitral valve area (MVA).
The aim of this study was to evaluate the accuracy of mitral leaflets separation index (MLS) for assessment rheumatic mitral stenosis severity.
We studied 55 patients with rheumatic mitral stenosis, all patients were in sinus rhythm, and they were recrutied from the echocardiographic unit in the cardiology departments at Suez Canal University Hospital.
The patients were classified into three groups according to mitral valve area (MVA) by planimetry, group I: mild MS (MVA greater than 1.5cm2), group II: moderate MS (MVA 1 to 1.5 cm2) and group III: severe MS (MVA less than 1cm2).
The following patients were excluded, Patients with: Atrial fibrillation, Heavily calcified mitral valve, Associate moderate or severe mitral regurgitation, Associated moderate or severe aortic regurgitation, Prior mitral commisurotomy in the preceding 6 months.
All patients were subjected to full history taking, clinical examination and complete transthoracic echo Doppler study. Mitral stenosis severity was assessed using planimetry and pressure half time (PHT) methods, peak and mean gradient on the mitral valve were obtained as well as the mitral leaflets separation (MLS) index.
MLS index was compared with mitral valve area (MVA) assessed by planimetry and pressure half time (PHT) methods and peak and mean gradient on the mitral valve.
We found that there is a good significant correlation between (MLS) index (PLAX view) and (A4C view) and MVA (planimetry method) and MVA (PHT method) and inverse but significant correlation with the peak and mean gradient on the mitral valve.
The MLS index in both views was significantly different for different degrees of mitral stenosis and was significantly lower in patients with severe MS compared with mild MS.
ROC curve analysis demonstrated that MLS (PLAX view) 1.025cm had a 94.4% sensitivity and 94.6% specificity for predicting Mild MS, and showed that MLS (A4C view) 1.005cm had a 94.4% sensitivity and 94.6% specificity for predicting Mild MS.
A MLS index of 0.975 cm or more identified mild MS with 94.4% sensitivity, 78.4 % specificity, 68% PPV, 96.7% NPV and 83.6 total accuracy, MLS index of 1.025 cm or more identified mild MS with 94.4 % sensitivity, 94.6% specificity, 87.6% PPV, 88.9% NPV and 92.6% total accuracy.
On the other hand, MLS index of 0.71 cm or less identified severe MS with 84% sensitivity,100% specificity,100% PPV, 95% NPV and 96.2 % total accuracy, MLS index of 0.83 cm or less identified severe MS with 88% sensitivity, 100% specificity,100% PPV, 94% NPV and 92.7% total accuracy.
We attempted to find a new equation by which MVA could be calculated using MLS index.
Finally, the study showed that mitral leaflet separation (MLS) index is an easy, accurate and reliable measure to estimate severity of mitral stenosis, it provides a quick estimate of mitral stenosis severity from standard 2D echocardiographic views without having to resort to tedious measurements.
Thus, MLS index can be used as useful supplement to the existing method for assessment of MVA and probably help when there is a discrepancy between severities of MS estimated by existing methods.