Correlation Between Mitral Valve And Left Heart Remodeling In Patients With Atrial Fibrillation

Objective: Atrial fibrillation(AF)is one of the common arrhythmias.As patients with AF progress,cardiac structure and function change,often leading to functional atrioventricular regurgitation.AF associated with Functional mitral regurgitation has attracted more and more attention,but the complex stereoscopic structure of the mitral valve is easily ignored by transthoracic two-dimensional echocardiography.Three-dimensional echocardiography can overcome the limitation of angle and obtain a more comprehensive understanding of complex structure.It is known that left atrium,left ventricle and mitral valve remodeling can affect functional mitral regurgitation in patients with preserved ejection fraction AF.However,the relationship between the severity of mitral regurgitation(MR)and mitral valve remodeling and left ventricular remodeling in AF patients with left ventricular ejection fraction preservation remains unclear.The purpose of this study was to explore the correlation between MR and left ventricular structure and function changes and mitral valve in AF patients.Methods: Seventy patients with AF were selected for transthoracic 2-D echocardiography and transesophageal echocardiography before transcatheter ablation.According to two-dimensional chest ultrasound examination,the patients were divided into mild regurgitation group(MR1,43 cases)and moderate to severe regurgitation group(MR2,27 cases)through different degrees of mitral valve regurgitation.Philips EPIQ7 C color Doppler ultrasonic diagnosis instrument was used,equipped with transthoracic ultrasound probe X5-1(frequency 1～5MHz)and transesophageal real-time three-dimensional matrix probe X7-2t(frequency 2～7MHz).QLab10-MVN was used for quantitative analysis of mitral valve images.Two-dimensional transthoracic echocardiography collected transsternal long axis section,apical four-chamber section,three-chamber section and two-chamber section,and color images of blood flow were also collected.LVEF,LVESV and LVEDV were measured by M-mode ultrasound,and the mitral valve structure and regurgitation degree were observed.RT-3D-TEE was used to collect mitral valve image via esophageal probe,and QLab10-MVN quantitative mitral valve analysis plug-in was used to measure mitral ring parameters: Anterolateral to posterolateral diameter(DAIPm),Anterior-to-posterior diameter(DAP),annulus height(AH),Mitral annulus circumference(C3D),Mitral annulus area(A2D),tenting volume(tenting Vol),Nonplanar circumference(θNPA),Anterior leaflet angle(θAnt),Posterior leaflet angle(θPost),Angle between aortic and mitral valves.Results:1.Comparison of basic clinical data and 2D transthoracic echocardiography parameters between the two groups: the differences of NT-pro BNP,LAD and LVESVi in AF patients between the two groups were statistically significant(P < 0.05);Gender,age,combined history of hypertension,coronary heart disease,hyperuricemia,hyperlipidemia,hyperhomocysteinemia,laboratory indexes,total cholesterol level,Aspartate aminotransferase,triglyceride level,homocysteine level,LVD,LVESV,LVEDV,LVEDVi,LVEF and RAD between the two groups were not statistically significant(P > 0.05).2.Comparison of mitral valve parameters measured by RT-3D-TEE between the two groups: There were statistically significant differences in DAIPm,DAP,AH,C3 D and A2 D among patients with different degrees of mitral regurgitation(P < 0.05).There were no significant differences in θNPA,θAnt,θPost and aortic valve-mitral Angle among patients with different degrees of mitral regurgitation(P > 0.05).3.Correlation analysis of LAD and mitral valve parameters: Pearson correlation analysis showed that LAD was positively correlated with DAIPm,DAP,A2 D,C3D,AH and tenting Vol(r=0.530,P < 0.001;r = 0.239,P = 0.046;r=0.398,P < 0.001;r =0.375,P= 0.001;r = 0.244,P = 0.042;r = 0.360,P = 0.002;r=0.370,P=0.002);There was no significant correlation with θNPA,θAnt,θPost,aortic valve and mitral valve Angle(P > 0.05).4.Comparison of correlation between GLS and mitral valve parameters: Pearson correlation analysis showed that GLS was significantly positively correlated with A2 D,DAP,θAnt,tenting Vol and C3D(r=0.278,P=0.020;r = 0.338,P = 0.004;r =0.289,P= 0.015;r= 0.248,P= 0.039;r=0.249,P=0.037),while it’s had no significant correlation with AH,θNAP,θPost,aortic and mitral valve Angle,DAIPm(P > 0.05).5.Risk factors associated with moderate to severe MR in patients with atrial fibrillation: DAIPm,GLS,LAD and their combined parameter models can all predict atrial fibrillation with moderate to severe MR,and the combined parameter has higher predictive efficacy than that used alone.6.Consistency test: The Bland-Altman drawing analysis method indicated that DAIPm,LAD,AH,DAP,GLS,C3 D and A2 D had good repeatability within and between observers.Conclusion:1.The combined model of DAIPm,LAD,GLS and three indexes showed high sensitivity and specificity in predicting atrial fibrillation with mitral valve moderate to severe regregence.2.Quantitative evaluation of mitral valve and left ventricular strain by RT-3D-TEE is helpful to understand mitral valve remodeling and the progress of AF,which has high clinical significance.