Background: Understanding the mechanism and the main components involved in rheumatic mitral regurgitation (MR) associated with dominant pliable mitral stenosis (MS) may improve our ability to repair some mixed rheumatic mitral valve pathologies.
Objectives: To assess mitral valve structural components in pure mitral stenosis versus mitral stenosis associated with mild regurgitation
Methods: Using two-dimensional echocardiography, we performed mitral valve structural analysis in two groups of patients prior to balloon mitral valvuloplasty (BMV). The first group, consisting of 13 females and 2 males (mean age 39 ± 5 years), suffered from pure pliable mitral stenosis (PPMS), while the second group, with 22 females and 2 males (mean age 44 ± 5 years), had mixed mitral valve disease (MMVD) characterized by mild MR in the presence of dominant pliable MS. All echocardiographic measurements relating to the mechanism of MR were undertaken during the systolic phase.
Results: The mean Wilkins scores of the PPMS and MMVD groups were 7 ± 1 and 8 ± 1 respectively (P = 0.004). No significant differences were found between the MMVD group and the PPMS group regarding annular circumference (15.5 ± 1.4 cm vs. 15.4 ± 1.6 cm, P = 0.84), annular diameter (36 ± 4 mm vs. 38 ± 5 mm, P = 0.18), and chordae tendinae length directed to the anterior mitral leaflet (AML) (10 ± 2 mm vs. 11 ± 2 mm, P = 0.137). However, anterior vs. posterior mitral leaflet length during systole was significantly lower in the MMVD than in the PPMS group (2.2 ± 0.5 vs. 2.8 ± 0.4, P = 0.02), whereas the AML thickness at the co-aptation point was greater in the MMVD than in the PPMS group (7 ± 1 vs. 5 ± 1 mm, P = 0.0004).
Conclusions: In rheumatic valves, thickening and shortening of the AML are the main factors determining the appearance of mild MR in the presence of dominant pliable MS.