Clinical Study Of Cerebrovascular Blood Flow Dynamics In Fetus With Congenital Heart Disease

Background: Congenital heart disease (CHD) is a common fetal defect which has a strong impact on postnatal morbidity and mortality. A lot of studies have shown that fetuses with CHD had different levels of nervous system abnormalities due to developmental damage caused by cerebrovascular blood flow change in utero. However, few studies investigating hemodynamic, especially cerebrovascular hemodynamic in fetuses with CHD have been reported. Thus, it is important to study changes of cerebrovascular hemodynamic in fetus with CHD.Objectives: To measure hemodynamic index in normal fetuses and fetuses with CHD using Doppler ultrasound, and to determine whether CHD modify cerebrovascular flow dynamics in CHD fetus, and the influences in different types of CHD.Methods: 200 normal fetuses and 196 fetuses which were diagnosed CHD by prenatal echocardiogram were studied. CHD fetuses were divided into 6 groups according to hemodynamics: hypoplastic left heart syndrome (HLHS, n=23); left-sided obstructive lesions (LSOL, n=19); hypoplastic right heart syndrome (HRHS, n=15); right-sided obstructive lesions (RSOL, n=33); septal defect (SD, n=36); conotruncal defects (CTD, n=33). In addition, the fetuses with CHD were further divided into 2 groups base on whether heart failure (HF) occurred: CHD fetuses with HF and CHD fetuses without HF. Using Acuson Sequioa 512 and GE Voluson 730 color Doppler flow system to measure blood flow velocities in the middle cerebral artery (MCA) and umbilical artery (UA) in normal and CHD groups, including the pulsatility index (PI), and the cerebroplacental Doppler ratio (CPR) which was calculated by formula: CPR=MCA-PI/UA-PI.Results:â‘ MCA-PI in HLHS,HRHS,RSOL,CTD and SD groups all decreased compared with normal fetuses, (P <0.05) ,with HLHS decreased the most notably, whereas MCA-PI in LSOL did not significantly changed compared with control group, (P >0.05) .â‘¡UA-PI in HLHS,HRHS,RSOL,CTD and SD groups all increased compared with normal fetuses, (P <0.05 ),with RSOL increased the most notably, whereas UA-PI in LSOL did not significantly changed compared with control group, (P >0.05) .â‘¢CPR in HLHS,HRHS,RSOL,CTD and SD groups all decreased compared with normal fetuses, (P <0.05) ,whereas CPR in LSOL did not significantly changed compared with control group, (P >0.05) .â‘£MCA-PI and CPR decreased, and UA-PI increased in both CHD fetuses with and without HF, (P <0.05) . All indexes in CHD fetuses with HF changed more significant compared with CHD fetuses without HF, (P<0.05) .Conclusions: Fetuses with CHD had decreased cerebrovascular impedance. Furthermore, CHD fetuses with HF were more likely to have lower cerebrovascular impedance. Different types of CHD had different levels of cerebrovascular impedance, which indicated that different types of CHD induced different levels of cerebrovascular circulation compensation.