Study of mitral valve remodling in patients with atrial functional mitral valve regurgitation using three-dimensional echocardiography
Authors: Khedr Kawkab , Elsharkawy Eman , Shehata Hoda , Mowafy Bassant 
Published: September 2023

Abstract

Background
The global burden of atrial fibrillation (AF) is enormous for healthcare systems. AF is typically classified into five distinct patterns depending on the onset, progression, and resolution of AF episodes, first diagnosed AF, paroxysmal AF, persistent AF, long-standing persistent AF& permanent AF. Atrial structural remodeling or exacerbation of atrial cardiomyopathy are generally defining features of the transition from paroxysmal to non-paroxysmal AF. The duration of rhythm monitoring and the presence of a substrate are both important factors in determining the rate of AF development.
In the existence of a structurally normal valve, functional MR develops when there is a mismatch between the tethering forces exerted by the heart & the closing forces exerted by the heart. In the context of functional MR annular dilation alone, can constitute a separate etiology of MR (atrial functional MR). TEE provides supplementary imaging, particularly if TTE windows are technically challenging, making it a useful tool even if TTE is the primary technique for assessing and quantifying mitral valve disease. 3DE data sets can be acquired from either TTE or TEE approach, allowing real-time visualization of the cardiac structures, it is superior to 2DE in quantification of cardiac chamber volumes and function, assessment of the mechanisms and severity of heart valve diseases, evaluation of cardiac complex anatomy.

Aim of the work
To study mitral valve apparatus remodeling in patients with atrial functional mitral valve regurgitation using three-dimensional echocardiography.

Methods
This study included a total of 30 patients with diagnosis of atrial fibrillation divided in to two groups, 15 patients having no/ mild mitral regurgitation while 15 patients having moderate/severe mitral regurgitation, they were subjected to 2D and 3D TEE echocardiographic assessment of MR degree, LA volumes, mitral leaflets and mitral annulus parameters.

Results
There was statistically significant difference between the two groups as regard the posterior leaflet area as larger area was estimated in (Mod/severe MR) group compared to (No/ mild MR) group, with mean posterior leaflet area in group I was (8.96 ± 2.60) and (7.30 ± 2.17) in group II with (P value = 0.029) as well as there was statistically significant difference between the two groups as regard total leaflet area/Mitral annular area ratio as smaller ratio was estimated in (Mod/severe MR) group as compared to (No/mild MR) group, with the mean total leaflet area /mitral annular area ratio in group I was (1.22 ± 0.04) and (1.26 ± 0.04) in group II with (P value = 0.008).

Conclusion
Isolated annular dilatation can cause significant functional atrial mitral regurgitation while mitral leaflet area increases in AF as the annulus dilates, but this adaptation may plateau at larger annular areas, with the resulting leaflet deficiency causing functional atrial mitral regurgitation.

Additional Content
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