Effects of nonvalvular atrial fibrillation on the structure and function of mitral valves (a STROBE-compliant article)

Abstract

The aim of this study was to explore the effects of nonvalvular atrial fibrillation (NVAF) on the structure and function of mitral valve and analyze independent risk factors of moderate to severe mitral regurgitation (MR) by quantitative measurement of mitral parameters using real-time 3-dimensional transesophageal echocardiography.This study included 30 subjects with sinus rhythm group, and 65 patients with NVAF. The 65 patients with NVAF were divided into 35 with paroxysmal atrial fibrillation group and 30 with persistent atrial fibrillation. According to MR degree, the patients with NVAF were again divided into no or mild MR group (n = 44) and moderate to severe MR group (n = 21).There were significant differences in anterolateral-to-posteromedial diameter (DAlPm), anterior-to-posterior diameter, 3-dimensional circumference (C3D), 2-dimensional area (A2D), mitral leaflet surface area in late systolic phase, the index of mitral valve coaptation and left atrial internal diameter (LAID) between different cardiac rhythm groups (all P < .05). The DAlPm, C3D, A2D, nonplanar angle (θNPA), and LAID were greater but the mitral valve coaptation index was smaller in the moderate to severe MR group than in the no or mild MR group (all P < .05). Logistic regression analysis indicated that DAlPm and LAID were independent risk factors of moderate to severe MR in the patients with NVAF (OR > 1, P < .05).DAlPm and LAID are independent risk factors of moderate to severe MR in the patients with NVAF. NVAF can change the structure and function of mitral valve, which leads to MR.

Figure 1

Image acquisition. A, Mitral valve in the midesophageal 5-chamber view. B, Mitral valve in 3D en-face view. Ao = aorta, LA = left atrial, LV = left ventricle, RA = right atrial, RV = right ventricle.

Figure 2

Image analyses, placing annular points and tracing leaflets. A, Mitral valve in end-systole phase. B, Mitral valve in early-diastolic phase. A = anterior, AL = anterolateral, Ao = aorta, P = posterior, PM = posteromedial.

Figure 3

The 3D reconstruction of the mitral valve in late systolic phase, from which several parameters are automatically calculated.

Figure 4

The 3D reconstruction of the mitral valve in early diastolic phase, from which several parameters are automatically calculated.

Figure 5

Bland-Altman plots showing interobserver and intraobserver differences and limits of agreement of DAlPm, DAP, H, and C3D measured by RT-3D-TEE. The solid line represents the mean difference between the measurements analyzed by 1 observer or by 2 observers, and the dashed lines represent the 95% confidence interval for agreement. ± SD: mean ± standard deviation.

Figure 6

Bland-Altman plots showing interobserver and intraobserver differences and limits of agreement of A2D, θNPA, mitral valve coaptation area, and mitral valve coaptation index measured by RT-3D-TEE. The solid line represents the mean difference between the measurements analyzed by 1 observer or by 2 observers, and the dashed lines represent the 95% confidence interval for agreement. ± SD: mean ± standard deviation.