Evaluation Of Left Ventricular Long-Axis Function Before And After Mitral Valve Replacement By Ultrasonic Tissue Doppler Imaging

Objective:To evaluate the left ventricular(LV) long-axis function in healthy volunteers and patients with mitral stenosis(MS) before and after mitral valve replacement(MVR) using ultrasonic tissue doppler imaging(TDI),understanding the dysfunction pre-operation and the recovery post-operation; To explore the relationship between the LV function and the mitral effective orifice area(EOA) in MS patients;To compare the myocardial movement of different mitral annular sites and explore the best section of the apical window and the best mitral annular site,thus facilitate clinical evaluating the LV function rapidly and accurately and then evaluate the effect of surgery,guide treatment and assess prognosis.Methods:22normal group(8men,14women;average age41.55±7.79years) and34patients with MS(10men,24women;average age44.15±7.24years) who underwent MVR successfully experienced TDI and conventional echocardiography examinations before operation and in1st week(lw),3rd month(3m),6th month(6m) after MVR using Philips IE33echocardiography with a2-5MHz cardiac transducer. End-systolic left atrial diameter(LA),LV end-diastolic diameter(LVDd),LV end-systolic diameter(LVDs),LV ejection fraction(LVEF),LV fractional shortening (LVFS), mitral inflow velocity(E) and maximum transvalvular pressure gradient(MPG) were measured.Estimate the mitral EOA using pressure half time(PHT) method in MS patients pre-and post-operation.Start the TDI,adjust the frame rate>80/s.the pulsed doppler(PW) sample volume was placed in six sites of the mitral annulus (posteroseptal,lateral,inferior,anterior,posterior,anteroseptal) when showing the apical4-chamber,2-chamber and long-axis view clearly in subjects with end-expiratory, adjust the angle to make the sampling line consistent with the LV long-axis movement direction as far as possible(Doppler angle<20degrees),adjust the gain and store the map until the waveform display clearly. Measure the Peak systolic velocity(Sa),early diastolic peak velocity(Ea) for six sites of the mitral annulus and calculate E/Ea,(E/Ea)/Sa and their means M-Sa,M-Ea,M-E/Ea, M-(E/Ea)/Sa. All parameters were taken the average of five cardiac cycles.Results:1、compared with controls,the pre-operation MS Group had significantly increased LA,E,MPG and gradually decreased in lw,3m,6m after MVR,but still higher than the controls(P<0.05).LVDd was significantly higher in6m than pre-operation (P<0.05),while there were no differences among pre-operation,inlw and3m(P>0.05), LVDs had no significant difference pre-and post-operation (P>0.05), LVEF and LVFS were all within normal limits.2、①compared with controls, the pre-operation MS Group had significantly decreased Sa,Ea and their means(P<0.05);in lw,Sa lateral and Ea posteroseptal, inferior,anterior,anteroseptal and M-Ea were significantly increased than pre-operation(P<0.05);in3m,Sa posteroseptal,M-Sa and Ea posteroseptal,inferior, anterior,anteroseptal,M-Ea were significantly increased than pre-operation;in6m,all sites Sa,Ea and M-Sa,M-Ea were significantly increased than pre-operation,1w and3m, but still lower than the controls.②compared with the controls, the pre-operation MS Group had significantly increased E/Ea,(E/Ea)/Sa and their means(P<0.05) and gradually decreased in lw,3m and6m, but still higher than the controls.3、For MS group,LV long-axis function indicators M-Sa and M-Ea were positively correlated(r=0.77,p<0.05);M-E/Ea and M-Ea were negatively correlated (r=-0.84,p<0.05);M-(E/Ea)/Sa and M-Sa,M-Ea showed a negative correlation respectively(r=-0.78and r=-0.85,p<0.05).4、For MS Group,M-Sa,M-Ea and EOA were positively correlated(r=0.60and r=0.70,P<0.05);M-E/Ea,M-(E/Ea)/Sa and EOA were negatively correlated respectively(r=-0.57andr=-0.58,p<0.05).5、①LV mitral annulus of different sites are not uniform,lateral and posterior higher while posteroseptal and interoseptal lower.②Sa,Ea of LV mitral annular lateral,anterior,posterior have higher coefficient than the posteroseptal,inferior,anteroseptal. Conclusion:1、Compared with controls,MS patients had significantly impaired LV long-axis function pre-operation and improved gradually after MVR,but failed to return to the normal level in the short term.2、The LV long-axis systolic dysfunction occured earlier than the short-axis systolic dysfunction for MS patients,Analysis of the long-axis systolic function was more useful for early detection of cardiac dysfunction.3、The LV long-axis function was negatively correlated with mitral EOA for MS patients,that was,the smaller the EOA was,the more severe the LV long-axis function was impaired.4、Different sites of LV mitral annulus were not uniform for the controls and the MS group,lateral and posterior higher while the posteroseptal and interoseptal lower; lateral,anterior,posterior were the better sites for the evaluation of LV long-axis function; the apical4-chamber and the lateral was the best section and site.5、TDI could accurately evaluate the LV long-axis function in patients with MVR;E/Ea and (E/Ea)/Sa as new quantitative indicators could evaluate LV diastolic and overall function.