Assessment Of Left Ventricular Systolic Function In Patients With Rheumatic Mitral Stenosis Using Automated Mitral Annular Tracking

Background and purposeRheumatic heart diease(RHD) is the sequelae caused by the rheumatic fever activity.Rheumatic carditis may cause heart valve stenosis or regurgitation, which lead to chronic rheumatic heart disease. In rheumatic valve disease, the most common is mitral stenosis. RHD is one of the the main types of heart disease which can cause heart failure, and is second only to coronary heart disease. The commonly clinical assessment left ventricular systolic function is to measure left ventricular ejection fraction(LVEF) by M-mode and two-dimensional echocardiography. The left ventricular preload reduce because the mitral stenosis cause obstruction of blood through left ventricular inflow tract, and myocardial interstitial fibrosis because of chronic rheumatic myocarditis and chronic micro-arterial diseases,and other reasons, so that rheumatic mitral stenosis (MS) patients with left ventricular damage systolic function, LVEF does not accurately reflect left ventricular systolic function in patients with MS, and it needs to find an accurate, objective indicator for assessment of MS patients with left ventricular systolic function. Many previous studies have confirmed that the systolic mitral annular displacement may reflect longitudinal systolic contraction of the left ventricular.This study used a new ultrasound technology-automated mitral annular tracking (automated mitral annular tracking, AMAT),which can measure systolic mitral annular displacement and the apex angle to evaluate left ventricular systolic function in patients with MS.Patients and methods50 patients with rheumatic mitral stenosis (MS) and 30 healthy controls were studied.Apex-max angle(Anglemax),Apex-min angle(Anglemin),angle difference between Apex-max and Apex-min(AAngle), the difference of systolic left ventricular length of long axis(ALength), the difference of systolic distance from Apex to septal and lateral sites of mitral annulus(AApex-s, AApex-1), systolic mitral annular displacement of septal and lateral sites of mitral annulus(Dm-s,Dm-1) were measured by AMAT. Analyse the difference between the patient group and the control group. Meanwhile, the atrioventricular plane displacement (DAv-s,DAv-1) were measured by M-mode echocardiography. The systolic mitral annular displacement and the atrioventricular plane displacement were determined with analysis of correlation statistics.Result1. There was no significant difference of LVEF between the patients with MS and the controls.2.ΔLength, AApex-s, AApex-1, Dm-s,Dm-1 were significantly lower in patients with MS than those of controls(P<0.01); And all variables were different in the patients with mild,moderate and severe MS(P<0.05),but there was no significant difference in these variables between mild MS and controls.3. There were no significant differences between Dm-s,Dm-1 measured by AMAT and DAV-s,DAV-1 measured by M-mode(P>0.05). 4. There was no significant difference of AAngle between the patients with MS and the controls.Anglemax,Anglemin were significantly lower in patients with MS than those of controls(P<0.01); And all variables were different in the patients with mild,moderate and severe MS(P<0.05), but there was no significant difference in these variables between mild MS and controls.Conclusion1. The left ventricular systolic function was early reduced in patients with MS, although LVEF was normal.2. The decrease of the long axis left ventricular systolic function was significantly different in patients with mild, moderate and severe MS.3. Systolic mitral annular displacement measured by AMAT correlated closely with the atrioventricular plane displacement measured by M-mode. So AMAT was a new technique for assessment left ventricular systolic function by measuring systolic mitral annular displacement of mitral annulus.4. There was no significant difference of extent of Apex movement between the patients with MS and the controls.Apex-max angle and Apex-min angle were decrease in patients with MS, and there were significant differences in patients with mild, moderate and severe MS,and the reason of this phenomenon need to further research in future.