Mitral Leaflet Separation Index in Assessing the Severity of Mitral Stenosis

Abstract

Determining the severity of mitral stenosis (MS) is important for both prognostic and therapeutic reasons. The mitral valve area (MVA) can be measured by planimetry, pressure half-time, continuity equation, and proximal isovelocity surface area methods. In this study, we propose a novel yet simple, independent measure of MS severity–the mitral leaflet separation (MLS) index. This new index could be a useful surrogate measure of the MVA. This index would also help when there is a discrepancy between severities of MS estimated by existing methods, in the presence of atrial fibrillation and in the presence of mitral regurgitation.

3D Xplane Echocardiographic Technique for Validation of Mitral Leaflet Separation to Assess Severity of Mitral Stenosis

“…In past, MLS has been found to be reliable in correlating the severity with MVA by planimetry and cath studies using Gorlin's formula. 7,9,10 All previous studies used 2D echocardiography for assessment of MLS and planimetry. The major limitation of these studies was measurement of MLS and planimetry in different cardiac cycles at different times.…”

Assessment of Rheumatic Mitral Stenosis severity by Mitral Leaflet Separation Index

“…In cases of low stroke volume, planimetry might overestimate the severity of stenosis. Direct measurement of MVA by planimetry is accurate but is highly operator dependent and sometimes laborious 9 .…”

“…The transmitral gradient is also well correlated with MS severity. Transmitral gradient and continuity equation depend on transvalvular flow and may be affected by cardiac output and presence of mitral regurgitation 9 .…”

Mitral leaflet separation to evaluate the severity of mitral stenosis: Validation of the index by transesophageal three‐dimensional echocardiography

“…with 88 patients, the MLSI correlated well with MVA by planimetry and PHT using 2DTTE. In another similar study with 87 participants, Thomas et al . reported a strong correlation between MLSI and MVA by planimetry and PHT.…”

“…15 Being an easily obtainable index, MLS has shown a good correlation with MS severity and MVA measured by other techniques. [16][17][18][19][20] But its reliability has never been validated against the accurate method of 3DTEE planimetry with multiplane datasets. Therefore, we investigated the validity of MLS index by 2DTTE (MLSI 2D ) against the planimetered MVA by 3DTEE (MVA 3D ) for determining MS severity and assessed the accuracy of this index for MVA estimation.…”