【作者】 潘美；

【导师】 赵博文；

【作者基本信息】 浙江大学 ， 影像医学与核医学， 2004， 硕士

【摘要】 胎儿超声心动图(Fetal Echocardiography)是近几年发展起来的一门新的超声心动图技术，随着彩色多普勒技术和围产医学的发展，以及胎儿期先天性心血管畸形介入治疗技术的进步，这一影像技术在胎儿心脏形态结构异常和心律失常的产前诊断中发挥着愈来愈加重要的作用。本研究采用一种新的综合评价心室收缩和舒张功能的多普勒指数-Tei指数，通过检测131例正常胎儿的多普勒时间参数，旨在建立正常胎儿Tei指数范围，并进一步探讨不同孕龄及心率对Tei指数的影响。 资料与方法 一、研究对象 自2002年12月至2003年2月间共有143名孕妇在本院超声科进行了胎儿超声心动图检查。其中131名孕妇作为研究对象，年龄21～43岁，平均27.3±3.6岁，孕龄15～40周，平均32.64±5.6周。所有研究对象均符合以下条件：常规产科超声检查未见异常，胎儿超声心动图检查未见明显的心血管畸形，产后随访：均为单胎，适于胎龄儿，无心血管及其他系统畸形。其余12名胎儿存在下列情况之一从研究中剔除:胎儿超声心动图检查发现心血管畸形，持续性心律不齐，频谱图像质量欠佳。二、方法 应用GE LOGIQ 700型及philips HDI 5000 SONO CT彩色多普勒超声诊断仪，频率为2.5一7.OMF[z，应用FET HRT软件，Fetal Echo软件及常规妇产科软件。多普勒频谱扫描速度为50或100 mm/s。 1.一般产科检查:确定胎位，测量双顶径、股骨长径，估算胎儿孕龄。 2.Tei指数:以胎儿脊柱、肝脏、胃泡、降主动脉、卵圆孔血流方向等作为辨别左心室和右心室的标志，在四腔心切面、左、右心室长轴切面和大血管短轴切面，分别将脉冲多普勒取样容积置于左、右心室流入道和流出道，取得血流频谱，测量时尽量使超声束与血流方向平行或夹角<300。 2.1计算左心室Tei指数多普勒参数包括:二尖瓣口舒张期血流频谱止点到下一频谱起点时间间距(a)，主动脉瓣口收缩期血流频谱持续时间(b)。Tei指数=( ICT+IRT)尼T，IeT为等容收缩时间，xRT为等容舒张时间，ET为射血时间，ICT+IRT等于a一b，ET等于b，故左心室Tei指数=由一b夕/b。右心室Tei指数测量方法同左心室。 2.2以上测量均由同一检查者操作，连续记录3个心动周期，取平均值。对单纯性阵发性房性或室性期前收缩的胎儿，测量a、b值时，取期前收缩前或后至少3个窦性心动周期以外的频谱测量。 结果一、共对131例孕妇进行了胎儿超声心动图检查135次，其中4例孕妇接受了2次检查。胎儿心脏形态结构及心律均正常116例，胎儿单纯性阵发性房性或室性心律不规则巧例，心率均在正常范围 (120一180次/m in)。二、左心室Tei指数为0.37士0.12，右心室Tei指数为0.36士0.12。三、左、右心室Tei指数相关分析显示两者呈正相关(二0.41，P<0 .01)。四、不同心率胎儿之间Tei指数比较差异无显著性意义。五、不同孕龄胎儿之间Tei指数比较差异无显著性意义。 结论 Tei指数是一种简单可靠的定量综合评价心脏收缩和舒张功能的多普勒指数，不受心室几何形态、心率及孕龄的影响，与传统评价方法比较，具有更好的可靠性和重复性。Tei指数对于先天性心脏病和心律失常时胎儿心功能的评价具有潜在应用价值，有待于进一步研究。更多还原

【Abstract】 Fetal echocardiography is a well-established tool for the prenatal diagnosis of congenital structural heart diseases and arrhythmias. High-resolution imaging and Doppler interrogation, which has evolved over the past two decades, has permitted an accurate evaluation of fetal cardiac morphology and function and has resulted in a better understanding of the prenatal natural history and predictors of outcome for most fetal cardiovascular abnormalities. Fetal cardiac dysfunction is the leading factor for high perinatal mortality. Recently, a conceptually new Doppler-derived index ?Tei index for quantitative assessment of fetal overall ventricular function was proposed, and this study was therefore designed to define the value of this index in normal fetuses, and evaluate the influence of the gestational age and fetal heart rate on the index.Study population and Methods 一、 Study populationFrom December 2002 to February 2003, fetal echocardiographicexaminations were performed in 143 consecutive pregnant women, among them 131 were included as our study group (age 27.3±3.6 years, range 21-43 years, gestational age 32.6±5.6 weeks, range 15-40 weeks). They fulfilled the following inclusion criteria: (1) no evidence of structural cardiovascular disease founded by fetal echocardiography, (2) no evidence of other organ system diseases detected prenatally by 2-dimensional or Doppler ultrasonography, (3) without clinical signs of cardiovascular diseases by follow-up after birth, (4) all fetuses included were singletons and appropriate for gestational age infants. Fetuses with either persistent arrhythmias or poor Doppler imaging quality were excluded. @二、 Echocardiographic ExaminationComplete M-mode, two-dimensional and color Doppler echocardiograms were performed by using GE LOGIQ 700 and Philips ATL HDI 5000 color Doppler blood flowing scanners with 2.5-7.0 MHz transducers. Fetal echo or Fetal Heart setup was used.1. Fetal heart rate was measured and fetal gestational age was assessed by biparietal diameter and femur length.2. The ventricular inflow velocity pattern was recorded from the 4-chamber or long-axis views with the pulsed wave Doppler sample volume of 2 to 4 mm positioned at the tips of the atrioventricular valve leaflets during diastole. Subsequently, the ventricular outflow velocity pattern was recorded from the long-axis view with pulsed wave Doppler sample volume positioned just below the aortic or pulmonary annulus. Care was taken to direct the transducer beam as close as possible to the Doppler beam at <30 in selected planes. The Doppler examination was recorded at a paper speed of 50 or 100mm/s, and simultaneously printed for later analysis. All echocardiographic examinations were performed by oneexperienced echocardiographer.2.1 Tei index: is defined as the sum of isovolumic contraction and relaxation times divided by ventricular ejection time. The ejection time was measured from the onset to the end of corresponding ventricular outflow velocity pattern. The mitral or tricuspid closing-to-opening time was measured as the interval from the end to the onset of the corresponding atrioventricular inflow velocity pattern. Interval "a" is the time from the cessation to the onset of the next mitral inflow, which is equal to the sum of the isovolumic contraction time, ejection time and isovolumic relaxation time. The ejection time "b" is measured as duration of LV outflow. The sum of the isovolumic contraction time and isovolumic relaxation time was easily obtained by subtracting "6" from "a". The LV Tei index was calculated as {a-b)/b. The measurement of Doppler time intervals of RV is as same as that of LV.2.2 To account for slight variations in fetal heart rate, each interval was measured in 3 consecutive beats and the values averaged to obtain each interval duration. In fetuses with either premature atrial or ventricular beats, care was taken to exclude these ectopic beats when determining Tei index. Meanwhile, fetal heart rate was measured and更多还原