右室收缩功能对多普勒超声心动图估测肺动脉压的影响

目的 探讨右室射血前期时间／射血加速时间（PEP／AT）和三尖瓣反流压差（ΔPTR）估测肺动脉压的价值和局限性。方法 用HP－8500超声仪测定44例高原性心脏病伴或不伴右室收缩功能减退患儿的PEP／AT、ΔPTR。结果 全部患儿PEP／AT值增高，提示肺动脉高压存在，其中右室收缩功能正常组（RVSNF）ΔPTR结果与PEP／AT一致，右室收缩功能减退组（RVSDF）ΔPTR不能提示肺动脉高压。结论 应用超声估测肺动脉压时应结合心功能对PET／AT、ΔPTR值进行综合分析。     

先天性心脏病并肺动脉高压的超声心动图诊断

先天性心脏病的发病率活产婴儿为 0 .6 %～ 0 .8% ,我国每年新出生约 10～ 15万先天性心脏病患儿 ,其中 5 0 %以上为左向右分流型先天性心脏病 (CHD)。肺动脉高压 (PH)是左向右分流型先天性心脏病常见严重并发症之一 ,重度PH可引起肺血管病变而失去手术机会 ,威胁患儿生命。因此 ,PH的诊断对CHD的病情评估、手术指征确定及预后判断方面十分重要。超声心动图具有无创、简便、易重复等优点 ,已被广泛用来评估PH程度 ,已部分取代创伤性心导管检查。　　一、肺动脉压的估测(一 )瓣膜返流或心内分流的速度应用频谱多普勒超声技术可准确测得…     

脉冲多普勒超声评估室间隔缺损患儿肺血管阻力方法的探讨

肺血管阻力(PVR)是评价室间隔缺损(VSD)血流动力学改变的重要参数。超声测量PVR目前尚无确定的方法。本文应用脉冲多普勒超声(PWDE)测量16例VSD患者的VSD分流压差和肺动脉瓣返流压差,分别计算肺动脉收缩压(PASP)和肺动脉舒张压(PADP),进而计算肺动脉平均压(PAMP)。二维超声结合PWDE测量VSD分流量和主动脉血流量(Qs)计算肺动脉血流量(Qp)。根据超声测量的     

先天性心脏病肺动脉高压肺组织超微结构的改变及临床意义

目的　探讨先心病肺动脉高压 (PH)患儿肺组织超微结构的改变及其临床意义。方法　 2 1例先心病患儿为 1997年 11月～ 1999年 2月间住院行心血管手术者 ,全组平均肺动脉压为 (5 8± 2 1)mmHg ,肺血管阻力 (760± 2 0 6)dyn·s·cm-5。除 4例动脉导管未闭 (PDA)行导管结扎外 ,其余患儿均在体外循环下行心内直视手术 ,于开胸后立即取肺组织在电镜下观察肺组织超微结构的变化。结果　 2 1例PH患儿肺组织均有不同程度的纤维化 ,且在毛细血管两侧不对称 ,主要集中于非气血交换侧 ,以胶原纤维增生最显著 ,弹力纤维增生次之。肺泡Ⅱ型细胞显著增多 ,其胞质内可见大量的线粒体、粗面内质网 ,板层小体增多并可见其内容物丢失。肺泡Ⅰ型细胞基膜显著增厚 ,肺小动脉平滑肌细胞增生 ,毛细血管基膜增厚。结论　重症先心病PH患儿肺组织超微结构发生明显改变 ,结合临床 ,提示对于先心病患儿宜尽早手术纠治 ,以从根本上消除形成PH的条件。     

全腔静脉肺动脉转流术在复杂先天性心脏病的应用

目的总结全腔静脉肺动脉转流术（TCPC）在复杂先天性心脏病的应用。方法回顾性分析复杂先天性心脏病患者16例实施TCPC的临床资料。男9例，女7例；年龄1．5～18岁。三尖瓣闭锁5例，单心室8例，右室双出12I2例，法洛四联症并完全型心内膜垫缺损1例。病例均有中、重度肺动瓣和（或）瓣下狭窄。在低温体外循环下行心房侧壁复合通道术式。结果死亡1例（死亡率696），并发术后左侧乳糜胸、低蛋白血症、肠蛋白丢失综合征各1例。随访2～12个月，纽约心脏协会（NYHA）心功能分级Ⅰ～Ⅱ级。结论体外循环下应用心房内复合侧通道的TLTC是治疗心脏复杂畸形的有效手术。掌握手术适应证和准确的术后处理是手术成功的关键。     

多普勒血流频谱法估测肺出血新生儿肺动脉压的研究

目的　研究肺出血新生儿心脏收缩功能和肺动脉压力变化及临床影响因素。方法　用M型二维超声多普勒和脉冲多普勒方法分别测定28例肺出血新生儿和28例非肺出血新生儿(含17例正常新生儿)心脏收缩功能及主肺动脉血流速度频谱,以肺动脉血流峰速时间/右室射血时间(TPV/RVET)比值反映肺动脉压力,分析肺出血新生儿心脏收缩功能和肺动脉压力变化及临床影响因素。结果　肺出血新生儿TPV/RVET比值(0.253±0.041)明显低于正常对照组(0.329±0.058)和非肺出血组(0.301±0.022)(P＜0.01);肺出血新生儿恢复期该比值(0.294±0.033)升高,肺出血死亡组TPV/RVET比值(0.219±0.022)和缩短分数［FS(31±5)%］明显低于存活新生儿(0.270±0.031,TPV/RVET39±7,FS)(P＜0.01);TPV(52±12)ms明显低于存活新生儿(44±8)(P＜0.05)。早产儿肺出血组TPV明显缩短(P＜0.01)。肺出血组TPV/RVET比值与动脉血pH值高度相关(r=0.84,P＜0.01)。结论　肺出血新生儿伴有肺动脉压力升高,严重者心脏收缩功能降低,导致心力衰竭,致新生儿死亡。     

多普勒超声心动图对先天性心脏病合并肺动脉高压儿童左室形态与功能的评价

目的：探讨多普勒超声心动图对先天性心脏病（CHD）儿童肺动脉高压（PAH）的诊断价值及PAH对左室重塑和舒张功能（LVDF）的影响。方法：对彩色多普勒超声心动图证实的45例继发肺动脉高压的先天性心脏病患儿的超声心动图和多普勒血流资料与22例无PAH的先天性心脏病患儿（对照组）对比分析。结果：PAH组及对照组的左室舒张末内径分别为18.24±1.71 mm vs 16.28±0.52 mm、右室内径 12.23±2.14 mm vs 8.14±0.73 mm、肺动脉内径 11.20±1.35 mm vs 7.92±0.21 mm。两组比较差异有显著性（P<0.05）；VTR 流速增快（2.56±0.46）m/s及PASP压力（40.23±4.56）mmHg升高 ，与对照组相比差异亦有显著性（P<0.05）；室间隔增厚与对照组相比差异不明显。对照组、PAH组的二尖瓣口血流多普勒频谱A峰流速分别为94.56±31.45 m/s vs 51.17±26.67 m/s、A峰流速速度时间积分为10.89±2.73 s vs 4.94±1.85 s及AV/EV为1.79±0.32 vs 0.59±0.19、AVTI/EVTI为1.61±0.49 vs 0.45±0.21 两组比较差异有显著性(P<0.01)。左室等容舒张时间分别为119. 86±54.62 s vs 52.31±28.06 s。PAH组明显延长(P<0.05)。E峰流速、E峰流速速度时间积分及E峰减速时间两组无明显改变(P>0.05)。而增高的肺动脉压与二尖瓣口血流频谱AV/EV比值呈正相关,相关系数 r=0.4 456， P<0.01。结论：多普勒超声心动图不仅是先天性心脏病儿童合并肺动脉高压最重要的诊断方法之一，还可提供肺动脉高压对左室重塑和舒张功能受损的指标，对临床判断病情轻重及预后有重要价值。［中国当代儿科杂志，2007，9（5）：422-424］     

全腔静脉肺动脉连接术后跨肺压的监测方法评估

目的:拟通过超声心动图估测的跨肺压与实测跨肺压进行对比来探讨估测跨肺压梯度(transpulmonary gradient,TPG)是否可靠。方法:回顾性分析上海儿童医学中心心胸外科数据库,纳入2015年1月至2018年12月进行全腔静脉肺动脉连接手术,具有血流动力学监测及超声检查结果的患者,根据公式分别计算出TPG,...     

先天性心脏病胎儿脑血管阻力变化研究

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 artery，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／UARI）。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。     

超声对不同海拔地区健康儿童肺动脉压相关参数的对比性研究

目的探讨高原地区健康儿童肺动脉压变化的特点。方法采用随机抽样调查的方法,应用美国HP-8500和CAL-163多普勒超声诊断仪测定海拔16 m、2260 m及3700 m地区1061例健康儿童的右室收缩时间间期(right ventricular systolic time interval,RSTI)和进行平均肺动脉压(mean of pulmonary arterial pressure,mPAP)的估测,并作对比性研究。结果 2260 m及3700 m组的右室射血加速时间(ascending time,AT)和右室射血加速时间/射血时间(AT/ejection time,AT/ET)比16 m组缩短(P值为0.03—0.000)。3700 m组右室射血前期(previous ejection period,PEP)、PEP/AT及mPAP明显高于16 m、2260 m组(P值为0.007～0.000)。3700 m组3岁及3岁之前各年龄段比3岁之后各年龄段的mPAP有明显升高(P值为0.006—0.000)。3700 m组移居汉族与世居藏族小儿血氧饱和度(SO2)、RSTI及mPAP差异无显著性(P>0.05)。结论 高原地区健康儿童肺动脉压不同于平原。海拔3700 m地区健康儿童的肺动脉压明显升高,新生儿及婴幼儿的肺动脉压升高更明显。儿童期在高原低氧环境下,种族对肺动脉压变化影响不明显。高原低氧环境是影响儿童肺动脉压变化的重要因素。     

Ultrasound assessment of ductal closure, pulmonary blood flow velocity, and systolic pulmonary arterial pressure in healthy neonates

Ultrasound Doppler was used to establish time of ductal closure, normal values for blood flow velocity in the pulmonary artery (PA), and time interval between pulmonary valve closure (Pc) and tricuspid valve opening (To) in 37 healthy neonates. Ductal closure had occurred in 23% of the children within 12 h after delivery and in 53% during the next 12 h. No open ductus was found after 30 h of age. Maximal blood flow velocity was 0.90 +/- 0.09 (SD) m/s during the first five days of life and 1.12 +/- 0.17 m/s at the age of 14-30 days. The Pc-To interval is known to reflect systolic PA pressure in adults. The Pc-To interval decreased significantly (p less than 0.01) from an average of 0.059 +/- 0.016 s at 3.5-12 h of age to 0.048 +/- 0.011 at 19-36 h of age and thereafter successively to 0.027 +/- 0.004 s at 20-30 days of age. This value is only slightly higher than that of 0.015-0.020 s for normal adults at comparable heart rates. These data suggest a rather sharp decline of systolic PA pressure during the first day of life and thereafter a slower decline; normal adult values are approached but not reached at 3-4 weeks of age. The Pc-To value seems to be of limited value in the early neonatal period, because even normal neonates have increased values with a large individual variation. After 3-4 weeks of age, an increased value should be taken as an indication of increased systolic PA pressure.     

超声心动图对儿童完全性肺静脉异位引流诊断价值的探讨

目的　旨在评价超声心动图对完全性肺静脉异位引流 (TAPVD)的诊断价值。方法　对 1987年 9月至2 0 0 2年 11月收治的TAPVD患儿 70例进行分析。均有完整的临床及超声心动图资料 ,其中 35例施行了手术治疗。结果　 70例TAPVD的解剖分型为 :心内型 5 2例、心上型 16例、心下型 2例 ,未发现混合型。 35例施行手术 ,32例与术前超声心动图的诊断一致 ;3例与超声心动图诊断不完全一致 ,其超声心动图诊断分别为 :三房心伴继发孔房缺、左房隔膜伴继发孔房缺、原发孔房缺伴卵圆孔未闭 ,而手术结果均显示为心内型TAPVD伴继发孔房缺。结论　超声心动图检查是诊断TAPVD重要且准确的方法 ,并能确定其分型 ,提供精确的解剖及血流动力学资料。在应用超声心动图诊断TAPVD时 ,应注意与三房心、左房隔膜等疾病进行鉴别。     

Prediction of peak pulmonary artery pressure by continuous-wave Doppler echocardiography in infants and children

Summary Continuous-wave Doppler echocardiography was used to estimate peak pulmonary artery (PA) pressure in 104 infants and children, aged 4 days to 16 years, with normal hearts (control group) and 43, aged 29 days to 13 years, with various kinds of heart disease (patient group). The Doppler transducer was directed toward the right ventricular outflow tract and angled until the maximal velocity signal was reached. Doppler velocity time intervals were measured as follows: acceleration time (AT), from the onset to the peak of the velocity curve; and ejection time (ET), from the onset to the termination of the velocity curve. In the control group, AT corrected through dividing by the RR interval of the electrocardiogram (ATc), and AT/ET by dividing by the square root of the RR interval (AT/ETc), were independent of body surface area. In the patient group, peak PA pressure had a significant inverse correlation with both ATc (r=-0.78) and AT/ETc (r=-0.87). Thus, AT/ETc derived from continuous-wave Doppler echocardiography is a good quantitative predictor of peak PA pressure in infants and children.     

Cerebral white matter blood flow and arterial blood pressure in preterm infants

It is generally assumed that one reason why white matter injury is common in preterm infants is the relatively poor vascular supply. Aim: To examine whether blood flow to the white matter is relatively more reduced at low blood pressure than is blood flow to the brain as a whole. Methods: Thirteen normoxic preterm infants had blood flow imaging on 16 occasions with single‐photon emission computed tomography (SPECT) using 99Tc labelled hexa‐methylpropylenamide oxime (HMPAO) as the tracer. Gestational age was 26–32 weeks. Transcutaneous carbon dioxide was between 4.7 and 8.5 kPa and mean arterial blood pressure between 22 and 55 mmHg. Results: There was no statistically significant direct relation between white matter blood flow percentage and any of the variables. Using non‐linear regression, however, assuming a plateau over a certain blood pressure threshold and a positive slope below this threshold, the relation to white matter flow percentage was statistically significant (p = 0.02). The threshold was 29 mmHg (95% confidence limits 26–33). Conclusion: Our analysis supports the concept of periventricular white matter as selectively vulnerable to ischaemia during episodes of low blood pressure.     

Doppler echocardiographic assessment of pulmonary blood flow in healthy newborns

The aim of this study was to determine interobserver variation in Doppler assessment of mean left pulmonary arterial flow velocity, and its normal values during the first 24 h of life. The interobserver variation was determined by a Bland and Altman analysis of the values of mean velocity measured in 21 newborns by 2 observers. Then, normal values of mean velocity were measured in 15 newborns at 5,10 and 15 min of life in the delivery room, and in 14 other newborns at 1, 2, 6, 12 and 24 h of life in the nursery unit. The interobserver variation was found to be acceptable. Mean velocity had a few variations within the first 24 h, but remained consistently above 20 cm s^-1. In conclusion, mean velocity values below 20 cm^-1 suggest low pulmonary blood flow.     

Seizures in the preterm infant: effects on cerebral blood flow velocity, intracranial pressure, and arterial blood pressure

The relationship of neonatal seizures to changes in the cerebral circulation was studied in 12 premature newborn infants. The objectives of the study were to determine whether important alterations in cerebral hemodynamics occur with neonatal seizures and whether such alterations relate to systemic hemodynamic events. Blood flow velocity in the anterior cerebral arteries was measured by a transcutaneous Doppler technique. A marked increase in cerebral blood flow velocity was documented with seizures in every patient. The prominent changes in the cerebral circulation occurred despite the fact that 10 of the 12 infants had only subtle seizures and all 12 were receiving mechanical ventilation at the time of the seizures. Accompanying the increase in cerebral flow velocity was a marked increase in intracranial pressure. The cerebral hemodynamic changes appeared to reflect directly changes in systemic hemodynamic events, that is, a marked increase in blood pressure at the time of seizures. The increase in cerebral blood flow velocity with seizures, an apparent adaptive physiologic response in older individuals, may be maladaptive in the newborn infant with certain vulnerable capillary beds, such as the germinal matrix in the premature infant or the margins of an infarct in the asphyxiated infant.