先天性心脏病胎儿脑血管阻力变化研究

Cerebral vascular resistance in fetuses with congenital heart diseases

目的检测患有先天性心脏病的胎儿脑血管阻力变化。方法使用脉冲多普勒超声技术对患有先天性心脏病的胎儿进行大脑中动脉(middle cerebral artery,MCA)及脐动脉(umbilical ar-tery,UA)血流动力学指数测量。包括搏动指数(pulsatility index,PI)、阻力指数(resistance index,RI)。计算脑/脐血管阻力指数比(cerebral-to-placental resistance ratio,CPR;CPR=MCA-RI/UA-RI)。研究包括25例胎儿先天性心脏病病例,病例组分为组1:包括胎儿左心发育不良、主动脉狭窄、完全性大血管转位,共12例;组2:包括右心血流阻塞的病例、胎儿肺动脉狭窄、肺动脉闭锁、法洛四联症及Ebstein畸形,共13例。对照组包括100例正常胎儿与病例组按胎龄配对。结果病例组与对照组MCA-PI、UA-PI差异无统计学意义。病例组1MCA-PI低于病例组2(P=0.026)及对照组(P=0.035)。病例组2UA-PI较病例组1升高(P=0.047)。病例组2与对照组MCA-PI,UA-PI差异无统计学意义。CPR在各病例组间两两比较,差异均无显著性意义。结论运用脉冲多普勒超声技术可检测到部分患有先天性心脏病的胎儿存在脑血管阻力降低的变化,不同类型的心脏畸形可能引起胎儿脑血管不同程度的代偿反应。

Objective To evaluate the significance of changes in cerebral vascular resistance in fetuses with congenital heart disease （CHD）. Methods Fetuses were divided into group 1 （left-side malformations, n = 12） and group 2 （right-sided obstructive lesions, n = 13）. The control group comprised 100 healthy fetuses of uncomplicated pregnancies matched for gestational age. Doppler blood flow velocimetry was performed in the middle cerebral artery （MCA） and umbilical artery （UA） in these fetuses. The pulsatility index （PI） and resistance index （RI） were recorded. The cerebral-to- placental resistance ratio （CPR） was calculated using the formula： MCA-RI/UA-RI. Results There was no statistical difference in PI of the MCA and the UA between all CHD and control fetuses. However, MCA-PI and UA-PI in group 1 were lower than those in group 2 and normal fetuses. No significant difference was observed in MCA-PI and UA-PI between group 2 and controls. There was no sig- nificant difference in CPR between groups. Conclusions The cerebral vascular resistance in fetuses with specific CHD may be decreased. The alterations in cerebral blood flow dynamics in fetus with CHD may represent a compensatory response to the decreased cerebral oxygen delivery.