Tricuspid annular plane systolic excursion in evaluation of right heart systolic function of fetuses in second and late trimester with conventional M-mode and free angle M-mode echocardiography

Abstract

Objective To evaluate the usefulness of free angle M-mode echocardiography (FAM) in obtaining tricuspid annular plane systolic excursion (TAPSE) for assessing the fetal right ventricular function, and to compare the results of measurements of TAPSE by conventional M-mode(CM) and FAM. Methods Two hundred and forty-three normal fetuses in second and late trimester were divided into 5 groups by gestational age(GA): 20-24 weeks, 24+ 1-28 weeks, 28+ 1-32 weeks, 32+ 1-36 weeks, 36+ 1-40 weeks. The TAPSE were measured by CM and FAM echocardiography, meanwhile multiple parameters for evaluating right ventricular function were obtained by using myocardial tissue Doppler imaging (TDI), and the correlation between TAPSE and other parameters were analyzed by linear correlation. ANOVA was used to compare CM-TAPSE, FAM-TAPSE, Em, Sm and right ventricular fractional shortening(RVFS) with different GA. Regression equation estimate was used to compare the relationship of FAM-TAPSE with GA. Independent sample t test was used to compare CM-TAPSE with FAM-TAPSE. Results There were significant differences in CM-TAPSE, FAM-TAPSE, Em, and Sm among 5 groups (P=0.000), the measured value of FAM-TAPSE was higher than that of CM-TAPSE (P=0.000). Both FAM-TPASE and CM-TAPSE showed significant positive correlations with GA, Em and Sm, but FAM-TAPSE demonstrated better correlation than CM-TAPSE. Conclusions By adjusting sample line of FAM, measuring the maximum displacement of tricuspid annular plane is feasible, and FAM may evaluate fetal right ventricular function more accurately and effectively. Key words: Ultrasonography, prenatal; Tricuspid annular plane systolic excursion; Ventricular function, right; Free angle M-mode echocardiography