缺氧性肺动脉高压新生儿右心室功能的组织速度多普勒超声研究

目的 探讨组织速度多普勒成像(TVI)技术评价缺氧性肺动脉高压(HPH)新生儿右心室功能的价值.方法 35例HPH患儿及28例正常新生儿于生后3 d应用超声心动图测量肺动脉收缩压(PASP),用传统超声技术测定右室射血分数(RVEF)值、右心室舒张早期峰值(E峰)、舒张晚期峰值(A峰)、E/A值,同时以TVI技术测量三尖瓣环指标(收缩期波Sa、舒张早期波Ea、舒张晚期波Aa、Ea/Aa值).结果 HPH组三尖瓣环Sa、Ea、Ea/Aa及RVEF值较对照组减低(t=2.67～4.69,P均<0.01).HPH组的右心室E/A值较对照组减低,但差异无统计学意义.HPH组的三尖瓣环Sa与RVEF值呈正相关(r=0.451,P<0.05).结论 HPH新生儿的右心室舒张、收缩功能减低,TVI技术与传统超声技术结合能更敏感地发现右心室功能变化.     

Tei指数和三尖瓣血流频谱评价左向右分流型先天性心脏病患儿右心功能的价值

目的探讨Tei指数和三尖瓣血流频谱评价左向右分流型先天性心脏病(CHD)患儿右心功能的价值。方法根据心室负荷将47例左向右分流型CHD患儿分为左心型组(30例)和右心型组(17例),应用三尖瓣血流频谱及Tei指数评价右心室功能,并与50例正常儿童进行对比研究。结果与正常组比较,CHD患儿42例三尖瓣血流频谱呈双峰型,均为舒张早期最大流速(EV)/舒张晚期最大流速(AV)>1;左心型组AV、A波流速积分(AVI)升高,右心型组EV、AV、E波流速积分(EVI)、AVI、E波减速时间(EDT)增大;左心型组右室等容舒张时间(IRT)和等容收缩时间(ICT) IRT延长;右心型组ICTI、RT和ICT IRT延长,右室射血时间(RVET)降低;两组CHD患儿右室Tei指数均增大;Tei指数与ICTI、RTI、CT IRT间呈显著性正相关(r=0.642,0.734,0.862 P均<0.01),与RVET间呈负相关(r=-0.481 P<0.01)。结论Tei指数能更简便、敏感、准确、综合评价右心室整体功能,与三尖瓣血流频谱结合可更全面了解CHD患儿右心功能。     

心脏超声诊断技术在儿科急救医学中的应用

1　心脏超声诊断技术在循环系统危重症中的应用1 1　先天性心脏病　婴幼儿先心病合并心力衰竭和呼吸衰竭是儿科常见的危重症。肺动脉高压 (ＰＨ)是其常见的合并症 ,也是病情进行性恶化的表现 ,故快速、准确测定肺动脉压力对病情评估及预后判断有重要意义。超声心动图研究显示 ,ＰＨ的患儿 ,收缩早期右室压力上升至肺动脉压力的时间延长 ,故射血前时间 (ＰＥＰ)延长 ;而收缩晚期右室压力下降至肺动脉压力的时间缩短 ,故射血时间 (ＥＴ)缩短 ,肺动脉Ｄｏｐｐｌｅｒ血流频谱形态表现为峰值前移 ,加速时间 (ＡｃＴ)与射血时间的比值缩小。Ｃａｃ…     

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。     

新生儿窒息后肺动脉高压对心功能影响的研究

目的 观察新生儿窒息后肺动脉高压的发生对其心功能的影响.方法 将2006年1～7月上海复旦大学附属儿科医院收治的42例新生儿窒息患者分为合并肺动脉高压组(21例)和无肺动脉高压组(21例),测定其心率、体循环收缩压,复苏后6～12h测定血清中肌酸激酶心肌同工酶(CK-MB)和心肌钙蛋白Ⅰ(cTnI)含量;运用超声心动图检测各项心功能指标,包括左室射血分数(LVEF)、右室射血分数(RVEF)、二尖瓣口舒张期血流E/A比值(ME/A)、三尖瓣口舒张期血流E/A比值(TE/A)、左室等客舒张时间LVIRT,肺动脉血流加速时间/射血时间比值(RVACT/ET).结果 肺动脉高压组LVEF、RVEF、ME/A、TE/A分别为(58.47±7.85)%,(52.85±8.34)%,0.93±0.20,0.77±0.18均明显低于对照组[(63.46±6.80)%,(62.92±6.70)%,1.09±0.23,0.34±0.18,均P<0.05],以RVEF、TE/A降低更为显著.肺动脉高压组IVRT明显延长,RVACT/ET缩短.两组血清CK-MB水平均高于正常,但两组间无统计学差异;两组间在临床表现、心率、体循环收缩压也无明显差别.结论 新生儿窒息后若合并肺动脉高压,可进一步加重心肌损害以及心功能特别是右心收缩、舒张功能的损害.早期干预可改善患儿的预后.     

新生儿窒息心脏功能及肺动脉压力变化的监测

运用脉冲多普勒超声及M型超声技术，于出生24小时内、72小时、7天及12～14天对新生儿窒息左、右心室的收缩和舒张功能、新生儿窒息后肺动脉压力变化规律、心肌酶谱和QT离散度进行研究。结果证实新生儿窒息心功能障碍是心肌损伤的结果，窒息性心功能障碍表现为舒张功能首先受累，收缩功能则右室重于左室。新生儿窒息后肺动脉压力与阻力增高．严重者可致持续胎儿循环，是病情严重的标志。     

婴幼儿肺炎左心功能估价:附57例分析

为探讨婴幼儿肺炎左心功能变化,本文应用心、肺阻抗微分图时相分析法,检测57例小儿的右心室收缩时间间期(RVSTI)、左心室收缩时间间期(LVSTI),同时检测左心泵血功能指标。结果表明,普通肺炎PEP/RVET、RPEP/T两个比值增大,而LVSTI、左心泵血功能无改变,提示合并不同程度肺动脉压增高,但尚未影响左心功能;肺炎心力衰竭前期右心功能处于代偿状态;肺炎心力衰竭期,Q-Zc间期增大,LVER、SV、CO降低,提示左室泵血功能衰竭,心肌收缩功能减弱;肺炎心力衰竭前期强心甙的使用可能是合适的。     

心先安对婴幼儿重症肺炎左室收缩、舒张功能的影响

目的　探讨心先安对婴幼儿重症肺炎左室收缩、舒张功能的影响。方法　 2 9例重症肺炎儿静滴心先安 30～ 6 0mg/d ,7～ 10d为一疗程 ,应用彩色多普勒超声测定左室射血分数 (EF)、短轴缩短率 (FS)、心脏指数(CI)、舒张早期和晚期血流峰值速度 (EV、AV)、EV/AV比值。结果　治疗前EF 0 .5 9± 0 .0 4 ,治疗后 0 .73±0 .0 6 ,FS治疗前 0 .30± 0 .0 2 ,治疗后 0 .39± 0 .0 6 ,CI治疗前 3.4 8± 1.10 [L/(min·m2 ) ],治疗后 5 .32± 1.5 8,AV治疗前 1.2 4± 0 .36cm/s,治疗后 0 .92± 0 .32cm/s。EV/AV治疗前 0 .79± 0 .36 ,治疗后 1.38± 0 .2 8,上述指标治疗后均好转 ,EV无变化。结论　婴幼儿重症肺炎存在左室收缩、舒张功能障碍 ,心先安可改善左室上述功能 ,早期应用可预防和治疗心力衰竭     

心血管系统疾病

9306“正常新生儿左右心功能超声心动图测量值成国英…//上海医科大学学报.一1992,19(5)一299 对32例正常新生儿于出生后6一24h和72一96h各测1次心输出量、左右室射血分数、右室射血分数、三尖瓣返流、二尖瓣返流、动脉异管分流以及左右心室收缩时问间期,包括射血前期、射血加速时问和射血期,取其比值分别对体循环和肺循环的压力和阻力进行半定量估测.两次测量比较发现:动脉导管分流率从6一24h的7 1 .9%下降为9.4%(P<0.001);RPEP尽VET从0.26士0.05下降为0.24士0·04(p<0·05)。表l参4(张家栋) 930667超声心动图对婴幼儿肺炎左右心室舒张…     

先天性心脏病肺动脉高压患儿左室舒张功能与血浆脑利钠水平的相关性研究

目的：探讨先天性心脏病 (CHD)合并肺动脉高压 (PAH) 患儿脑利钠肽（BNP）水平及与左室舒张功能的关系。方法：对95例CHD继发有PAH的患儿和42例无PHA的CHD患儿（对照组）的多普勒超声心动图资料与其血浆BNP水平进行对比分析。结果：与对照组相比, PAH组的左室舒张末内径（LVDd ）、右室舒张末内径（RVDd） 和肺动脉内径（PAd）明显增大(P<0.05),三尖瓣返流（VTR）速度增快及肺动脉收缩压（PASP）升高(P<0.05)。与对照组比较,PASP组患儿二尖瓣口多普勒血流频谱A峰流速（AV）、A峰流速积分（AVI）和E峰流速积分（EVI）及AV/EV和AVI/EVI比均逐渐明显增大(P<0.01);左室等容舒张时间明显延长(LIVRT)(P<0.05)。血浆BNP水平随着PASP增高而升高,与对照组相比差异有显著性（P<0.01）。PAH组先心病患儿其肺动脉压与二尖瓣口血流频谱AV/EV比值呈正相关（P<0.01）,二尖瓣口血流参数与血浆BNP水平亦呈正相关（P<0.01）。结论：CHD合并PAH患儿左室舒张功能与血浆BNP水平呈正相关;BNP在PAH引起左室舒张功能障碍的发生发展过程中发挥了重要作用。［中国当代儿科杂志,2010,12（1）：13-16］     

Left ventricular systolic time intervals in preterm infants with patent ductus arteriosus

Left ventricular systolic time intervals were recorded by a non-invasive technique, from the axillary artery, in 13 preterm infants with patent ductus arteriosus. At the onset of clinical symptoms, consistent with a large left-to right ductal shunt, the preejection intervals were shorter than in a control group of nine preterm infants without a patent ductus. The most pronounced difference was found in the shortening of the isovolumic contraction time, 10.7 msec in the ductus group compared with 22.4 msec in the control group. Ductal closure normalized the isovolumic contraction time to 22.1 msec. The very short preejection intervals, associated with a large ductal shunt, are suggested to reflect a combination of reduced aortic diastolic pressure and increased left ventricular filling pressure. In spite of increased volume load to the left ventricle there were no detectable changes in the systolic time intervals indicating impaired left ventricular function. The left ventricle seems to be competent to handle increased volume load in the presence of reduced afterload in preterm infants with symptomatic left-to right ductal shunts.     

LEFT VENTRICULAR SYSTOLIC TIME INTERVALS IN PRETERM INFANTS WITH PATENT DUCTUS ARTERIOSUS

ABSTRACT. Left ventricular systolic time intervals were recorded by a non-invasive technique, from the axillary artery, in 13 preterm infants with patent ductus arteriosus. At the onset of clinical symptoms, consistent with a large left-to right ductal shunt, the preejection intervals were shorter than in a control group of nine preterm infants without a patent ductus. The most pronounced difference was found in the shortening of the isovolumic contraction time, 10.7 msec in the ductus group compared with 22.4 msec in the control group. Ductal closure normalized the isovolumic contraction time to 22.1 msec. The very short preejection intervals, associated with a large ductal shunt, are suggested to reflect a combination of reduced aortic diastolic pressure and increased left ventricular filling pressure. In spite of increased volume load to the left ventricle there were no detectable changes in the systolic time intervals indicating impaired left ventricular function. The left ventricle seems to be competent to handle increased volume load in the presence of reduced afterload in preterm infants with symptomatic left-to right ductal shunts.     

Right Ventricular Performance in Hypotensive Preterm Neonates Treated with Dopamine

Systemic hypotension with left ventricular dysfunction is a common complication of neonatal respiratory distress syndrome and is often treated with inotropic agents. Although pulmonary hypertension with elevated pulmonary vascular resistance is also an important pathophysiological finding in respiratory distress syndrome, the effect of inotropes on the right ventricle has not been studied. The aim of this study was to assess changes in right ventricular dimensions and function with inotropic therapy in hypotensive preterm infants. Hypotensive neonates with respiratory distress syndrome were studied before and 1 hour after the initiation of a dopamine infusion. Right ventricular performance was assessed by two-dimensional echocardiography using the ellipsoid approximation method. Eight hypotensive neonates were recruited with a median (interquartile range) gestation of 27 weeks (26 to 27 weeks). Right ventricular end systolic volume decreased significantly from a median (interquartile range) of 1.06 ml/kg (0.81-1.50 ml/kg) to 0.73 ml/kg (0.51-0.99 ml/kg) (p < 0.01) 1 hour following dopamine therapy. Right ventricular end diastolic volume did not change significantly. Right ventricular ejection fraction increased significantly from 0.36 (0.29-0.46) to 0.51 (0.43-0.53) ( p < 0.01). There was a trend toward an increase in right ventricular output from 90 ml/kg/min (67-115 ml/kg/min) to 112 ml/kg/min-143 ml/kg/min) (p=0.07). Dopamine increases right ventricular ejection fraction through a reduction in right ventricular end systolic volume.     

Course of Right and Left Ventricular Function in Patients with Pulmonary Insufficiency After Repair of Tetralogy of Fallot

Surgical repair of tetralogy of Fallot (TOF) frequently results in pulmonary valve insufficiency. Nevertheless, no serial information is available on the long-term impact of the valvular insufficiency on right and left ventricular function. Right and left ventricular ejection fraction was measured serially by radionuclide angiocardiography in 21 patients with at least moderate pulmonary insufficiency after repair of TOF. A baseline study was obtained an average of 1.2 years after repair, and a follow-up study was performed an average of 10.2 years after surgery. Changes in ventricular function over time and deviations from the normal range were analyzed. At baseline evaluation the mean right ventricular ejection fraction (RVEF; 0.52 ± 0.10) and left ventricular ejection fraction (LVEF; 0.68 ± 0.10) were normal. At the time of follow-up the mean RVEF had significantly decreased to 0.45 ± 0.09 (p < 0.01). The mean LVEF had decreased to 0.60 ± 0.11 (p < 0.02). This change was independent of the RVEF (r=−0.13). Eleven patients (52%) had an abnormal RVEF or LVEF at follow-up. Nineteen patients (90%) showed a decrease of 0.05 or more in RVEF, LVEF, or both between studies. These data suggest a negative impact of long-standing pulmonary insufficiency on right and left ventricular systolic function after repair of TOF. Therefore, continued surveillance of biventricular function in this patient population appears warranted.     

Value of the new Doppler-derived myocardial performance index for the evaluation of right and left ventricular function following repair of tetralogy of fallot

The systolic and diastolic function in both ventricles may be altered even after successful corrective surgery of tetralogy of Fallot. The aim of this study was to assess the combined diastolic and systolic function of both ventricles using the Doppler-derived myocardial performance index (MPI) in patients with operated tetralogy of Fallot (TOF). We performed a prospective analysis of 51 patients following corrective surgery of TOF: 21 had a subannular patch, 20 had a homograft implantation at initial operation, and 10 were reoperated with secondary homograft implantation. Patients were examined with Doppler echocardiography, and the MPI, which incorporates ejection and isovolumetric relaxation and contraction times and is an index of global ventricular function, was calculated 10.2 +/- 8.0 (0.89-36) years after surgery. In 86.4% of the examined patients the right ventricular isovolumetric relaxation time was shortened compared to the normal published range or even did not exist (negative value) (p <0.01). The right ventricular MPI was paradoxically below the normal published range in 76.5% of the examined patients. The left ventricle global function was impaired in 23.5% of the examined patients, mainly due to altered systolic function with a prolonged left ventricular isovolumetric contraction time. The z score of the comparison between patients' left ventricular isovolumetric contraction time and the normal published values was 3.03. Patients with severe pulmonary regurgitation also had a prolongation of the isovolumetric relaxation time compared to patients with mild to moderate pulmonary regurgitation. The noncompliant right ventricle may shorten the right ventricular isovolumetric relaxation time, resulting in a paradoxically low right MPI. This may reduce the sensitivity of the index in recognizing patients with right ventricular dysfunction following corrective surgery of TOF. Additional diastolic impairment occurs in patients with right ventricular volume overload.     

Echocardiographic assessment of cardiac function during respiratory syncytial virus infection

Respiratory syncytial virus infection has been associated with increased morbidity and mortality in infants with underlying cardiac and pulmonary disease. To understand better the cardiopulmonary interaction in patients with acute respiratory syncytial virus bronchiolitis, we performed M-mode echocardiograms and pulsed Doppler assessment of pulmonary arterial flow in 19 patients with structurally normal hearts during acute illness. Studies were repeated in 11 of these patients following complete recovery. Based on severity of respiratory compromise, patients were grouped into those with severe illness (ten patients) or mild illness (nine patients). Left ventricular dimensions and shortening fraction were used to assess left ventricular function. Right ventricular systolic time intervals and specific Doppler flow velocity measurements were used to assess right ventricular function and elevation of pulmonary artery pressure. Comparisons were made between patients with severe and mild illness and between acute and follow-up studies. No statistically significant differences in left ventricular function, right ventricular systolic time intervals, or Doppler flow measurements were observed. We conclude that in patients with structurally normal hearts, respiratory syncytial virus bronchiolitis is not associated with significant depression of cardiac performance or elevation in pulmonary resistance.     

Aortic regurgitation during systole: Color flow mapping and Doppler interrogation following the Damus-Kaye-Stansel procedure

Summary Echocardiographic evidence of systolic aortic regurgitation following a Damus-Kaye-Stansel procedure for palliation of complex double-outlet right ventricle is presented. This procedure directs left ventricular output to the aorta through a proximal main pulmonary artery-aortic anastomosis and utilizes a valved conduit between the right ventricle and distal pulmonary artery. Postoperative Doppler and color flow echocardiographic findings revealed systolic and diastolic regurgitation from the native aorta to the right ventricle. Aortic valve closure at the time of the original Damus-Kaye-Stansel procedure would eliminate regurgitant flow and circumvent subsequent closure of this valve due to increased systolic aortic regurgitation.     

M-mode echocardiographic findings in children with idiopathic restrictive cardiomyopathy

Summary The M-mode echocardiographic findings in five pediatric patients, ages 4–15 years, with primary idiopathic restrictive cardiomyopathy, diagnosed by cardiac catheterization, and of 12 normal children (control group) are presented. The M-mode echocardiographic findings in patients with restrictive cardiomyopathy were (1) normal left and right ventricular end-diastolic dimension, (2) normal left ventricular posterior wall and interventricular septal thickness (three patients) or mild concentric hypertrophy (two patients), (3) normal opening and closing velocity of the mitral valve, (4) consistently enlarged left atrium (more than 40 mm) in all, and (5) right ventricular systolic time intervals compatible with pulmonary artery hypertension. The left ventricular ejection phase parameters (systolic time intervals, shortening fraction, and mean velocity of circumferential fiber shortening) were normal. Left ventricular relaxation phase parameters (diastolic function) were abnormal. The isovolumic relaxation time index was prolonged, 68±40 ms (±SD), in the study group as compared with 11±6 ms (±SD) in the control group (P<0.001). Percent relaxation of left ventricular posterior wall endocardium at 50% of diastole was decreased, 58±4% (±SD), in the study group as compared with 85±6% (±SD) in the control group (P<0.005). We conclude that M-mode echocardiography provides arelatively useful and specific noninvasive method for the diagnosis of primary restrictive cardiomyopathy in pediatric patients. This work was supported in part by NHLBI grant HL07436.     

Acute loads applied to the right ventricle: Effect on left ventricular filling dynamics in the presence of an open pericardium

To determine whether diastolic ventricular interdependence mechanisms would act in the presence of an open pericardial sac, as during cardiac surgery, moderate acute right ventricle afterload increases were applied to eight dogs with the chest and pericardium open while left ventricular filling dynamics were being assessed by Doppler echocardiography. Dogs were studied under basal conditions and after acute banding of the main pulmonary artery tightened to produce a 100% increase in right ventricular systolic pressure. With banding, the left ventricular filling velocity ratio (E/A), as assessed by Doppler echocardiography of mitral inflow, changed from a baseline value of 1.32 ± 0.05 to 1.16 ± 0.03 (p < 0.02), suggesting a restrictive pattern to early left ventricular filling, which is differed to that during the second half of diastole. Isovolumic relaxation time, measured as the time interval between aortic valve closure and mitral valve opening, assessed by M-mode echocardiography of both valves, was prolonged, though not significantly, from 63.3 ± 2.5 ms to 69.4 ± 2.9 ms, by banding of the pulmonary artery. E wave deceleration time, a filling variable influenced by chamber pressure/volume relations, was shortened by pulmonary artery banding, changing from 75.1 ± 1.7 ms to 68.0 ± 1.8 ms (p < 0.01). It was concluded that pressure loads applied to the right ventricle restricted early left ventricular filling. Prolonged relaxation and altered pressure–volume chamber relations were the diastolic interdependence mechanisms involved that proved to be acting even under open pericardium conditions.     

Exercise Testing in Children with Pulmonary Valvar Stenosis

Pulmonary valvar stenosis with intact ventricular septum is a common anomaly. This lesion poses a fixed obstruction to the right ventricular outflow. The right ventricle ejects the entire cardiac output across the stenotic valve. Right ventricular systolic pressure and oxygen demand are increased at rest and more so with exercise. Exercise tolerance in children and adults with mild valvar pulmonary stenosis is nearly normal, but is diminished in those with moderate and severe stenosis, indicating impaired ability to sustain adequate cardiac output. Following relief of stenosis, cardiac performance improves in children, but remains abnormal in adults. This appears to be related to postoperative resolution of right ventricular hypertrophy in children, whereas myocardial fibrosis may explain the lack of improvement in adults.