A Quantitative Ultrasound Study Of Fetal Right Ventricular Function In Second-and Third-trimester Of Pregnancy In Normal Cases

Objective:Using Tissue Velocity Imaging(TVI)to get tricuspid motion spectrum,measuring Ea,Aa,Sa and analyzed them with conventional right ventricular systolic and diastolic function with the above indicators.We used free Angle M-mode echocardiography(FAM)to measure tricuspid annular plane systolic excursion(TAPSE)of normal fetuses among different gestational ages,and to analyze its correlation with commonly used measuring indexes of right ventricular function and its changing with the gestational ages.Simultaneously,establish the f-TAPSE measurement reference ranges of second-and third-trimester of pregnancy.Methods:We recruited 135 gravidae presenting to our centers from 20 to 40 weeks for targeted organ scans,fetal echocardiography or fetal surveillance,with structurally normal singleton fetuses and verified gestational age(GA).According to the different gestational ages,the cases were divided into four groups: 20 to 24+6d weeks,25 to 29+6d weeks,30-34 +6d weeks,35-40 weeks.Application of Pulsed Doppler Imaging and M-mode echocardiology,measurement of E,A,PSV,RV-SV,RVEF was obtained.Using TVI to measure Ea,Aa,Sa of fetuses from different gestational age groups,took correlation analysis of Ea,Aa,Sa with the above indexes;We also used free angle M-mode echocardiology to measure f-TAPSE.M-mode was applied to the tricuspid annulus,parallel to the ventricular septum,and the amplitude of the resulting wave was measured.ANOVA to compare f-TAPSE,E,A,Ea,Aa,Sa,PSV,RV-SV and RVEF with GA,and Pearson correlation analysis to compare various factors.Results:The conventional measurement of right ventricular function(E,A,PSV,RV-SV)increased along with the growing of GA.E/A ratio increased and get close to 1 with the growth but RVEF did not change apparently.Ea,Aa,Ea/Aa,Sa showed statistically significant discrepancy with different GA(P=0.000).They all increased with the elevated GA.Ea/Aa ratio changed from 0.41±0.08(20GA)to 0.73±0.03(40GA),and it always less than 1.And Ea/Aa showed similarity with E/A.With comparison,it showed us a significant correlation between Ea/Aa and E/A,in addition,Doppler values Ea,Aa and right ventricular diastolic function parameters E,A,PSV,RV-SV had a good correlation,Sa and right ventricular systolic function parameters PSV,RV-SV had a good correlation either.The differences of f-TAPSE with different gestational age were statistically significant.And f-TAPSE showed positive correlations with E,Ea,Sa,PSV,RV-SV(P<0.05),but showed uncorrelated relationship with RVEF(P>0.05).Conclusions:The applications of Tissue Dpppler Imaging provide a new approach to measuring fetal cardiac function.The measurement method is simple and quick.A spectrum can be integrated to reflect ventricular systolic and diastolic function.Since the way is to measure a mechanical movement of the tricuspid valve,it can reduce the influences that cused by the changes of valve orifice blood inflow(such as heart rate changes,preload changes).It can be widely applied.f-TAPSE can quantitatively reflect the right ventricular diastolic and systolic function either.The measurement of f-TAPSE is simple,fast and low requirements on equipment and technology.And the reference value ranges of f-TAPSE in second-and third-trimester of pregnancy are obtained in this study.F-TAPSE reference value ranges: 3.21 ~ 6.21 in second-trimester of pregnancy,4.74 ~ 9.68 in third-trimester of pregnancy.