Free Angle M-mode Echocardiography In Evaluation Of Left Ventricular Systolic Function Of Fetuses In Second And Late Trimester By Mitral Annular Displacement

Objective:To measure mitral annular displacement(MAD) by conventional M-mode echocardiograph,and free angle M-mode echocardiographic measurements respectively in the normal second and third trimester fetuses,and to analyze the differences between the two methods and to explore the correlation of MAD with gestational age and routine parameters for evaluation of fetal left ventricular function.Methods:Totally 233 fetuses of gestational age(GA)at 18 to 39 weeks were enrolled.MAD was measured respectively by conventional M-mode (MADCM) and free angle M-mode echocardiography (MADFM).Tissue Doppler imaging(TDI)was used to measure mitral annulus early diastolic peak velocity(Em),late diastolic peak velocity(Am) and peak systolic velocity(Sm).The correlation between the two methods for measurement differences and the correlation between MAD and other routine echocardiographic parameters were investigated.Results:The MADCM was(5.69±0.91)mm, the MADFM was(6.78±1.31)mm(P<0.05), MADcm and MADFM were found correlated with GA and showed a significant positive Correlation(P<0.01),MADCM and MADFM also demonstrated positive correlation (P<0.05)with Em,Am and Sm,and MADFM performed better correlation than MADCM. MAD did not correlated with left ventricular fraction shortening(LVFS)(P>0.05).No significant difference was found between MADCM and MADFM in fetuses with favorable apical four chamber(P>0.05),however significant difference was found between MADCM and MADFM in fetuses with unfavorable apical four chamber (P<0.05).Conclusions:In comparison with the traditional M-mode echocardiography,MAD obtained with free angle M-mode echocardiography has higher accuracy and repeatability in evaluation of fetal left ventricular systolic function.