多普勒超声Tei指数估测心功能的研究

多普勒超声Tei指数可以反映心脏收缩及舒张的整体心功能变化,并且不依赖心脏的几何形态。本文就Tei指数估测心功能的原理、测量方法、应用情况、影响因素及存在的不足综述如下。     

多普勒超声Tei指数估测心功能的研究

多普勒超声Tei指数可以反映心脏收缩及舒张的整体心功能变化，并且不依赖心脏的几何形态。本文就Tei指数估测心功能的原理、测量方法、应用情况、影响因素及存在的不足综述如下。     

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。     

胎儿心力衰竭的准确评估及治疗

胎儿超声心动图能准确评价胎儿心脏解剖结构及宫内心血管系统临床表现,使胎儿心血管疾病产前诊断、胎儿心功能状况评估得以实现.胎儿心血管整体评分(CVPS)、心室Tei指数、脐动脉阻力指数(UARI)、搏动指数(PI)、收缩期最高血流速度与舒张期最低血流速度的比值(S/D)等逐渐成为胎儿心力衰竭程度及预后判断的主流评价指标.经胎盘转运地高辛治疗部分心力衰竭胎儿的临床应用明显改善了患胎预后.该文重点介绍胎儿心力衰竭的有效评估方法及治疗进展.     

32例生长激素缺乏症患者的心功能探讨

目的评价原发性生长激素缺乏症患者的心功能状况，以探讨生长激素对心功能的作用。方法用平衡法核素心血池显像技术及运动试验，对３２例儿童期诊断为垂体发育不良所致的生长激素缺乏症患者及１０例正常健康儿童进行心功能评价。结果３２例患者左心室总体射血分数和左心室舒张末期高峰充盈率明显低于正常健康组小儿；２５例（７８％）患者局部心室收缩功能降低；１５例（４７％）患者左心室总体收缩或（和）舒张功能降低；２５例（７８％）运动试验后出现心率改变、轻度ＳＴ段降低及Ｔ波改变。结论大部分生长激素缺乏症者在没有生长激素治疗的情况下，存在不同程度的心室收缩和舒张功能损害及心肌缺血和劳损。生长激素缺乏症者应尽早检测心功能、尽早给予生长激素治疗以预防成年后心血管疾病的发生     

米力农对先天性心脏病并肺动脉高压及心力衰竭患儿的术前干预作用

目的 探讨米力农对小儿先天性心脏病(CHD)并肺动脉高压(PAH)及心力衰竭(CHF)术前治疗的效果.方法 收集2006年1月-2008年7月上海交通大学附属儿童医院ICU收治的CHD患儿40例.年龄1个月～3岁.均为左向右分流型CHD,并PAH及CHF.将患儿随机分为研究组与对照组,各20例,二组病种、年龄、心功能及PAH程度比较无显著性差异.二组患儿均应用强心、利尿及扩血管治疗,另外,研究组20例加米力农静脉维持[0.5 μg/(kg·min)],对照组20例加多巴胺和多巴酚丁胺各5μg/(kg·min)静脉维持.分别于用药前、静脉维持用药72 h及停药后2 h通过彩色多普勒超声心动图检测二组各项心脏收缩、舒张功能及肺动脉压力指标.结果 研究组用药72 h各项心脏收缩功能指标(心脏指数、左室射血分数及左事短轴缩短率)和舒张功能指标(左室收缩时间间期、右室收缩时间间期及二尖瓣E峰和A峰比值)均显著优于对照组(Pa<0.05),肺动脉压力下降程度显著高于对照组(P<0.05);研究组改善心功能有效率显著高于对照组(P<0.05).结论 米力农对CHD并PAH及CHF患儿具有正性肌力和扩血管作用,能明显改善心功能和降低肺动脉压力,为手术纠正心脏畸形提供良好时机.     

小儿无创性心功能测定的研究进展

近年来心功能测定的研究发展迅速,目前可用于心功能测定的方法有:(1)血液内分泌变化;(2)心室腔大小的变化;(3)心搏血量的变化;(4)心脏收缩间期和舒张间期的变化;(5)心瓣膜流速的变化;(6)心血管解剖的变化等。上述方法随着科技的发展将会更加广泛应用于临床。     

小儿无创性心功能测定的研究进展

近年来心功能测定的研究发展迅速，目前可用于心功能测定的方法有：（１）血液内分泌变化；（２）心室腔大小的变化；（３）心搏血量的变化；（４）心脏收缩间期和舒张间期的变化；（５）心瓣膜流速的变化；（６）心血管解剖的变化等。上述方法随着科技的发展将会更加广泛应用于临床。     

心律平对小儿左室功能的影响

心律平对小儿心功能影响的系统观察国内外尚少见报道。我们用心机械图测收缩、舒张时间间期(STI、DTI),对口服、静注心律平患儿的左室功能进行了系统观察,现报告如下。1 材料与方法研究对象和分组:选频发早搏患儿34例,男21例,女13例,年龄3～13岁。临床无心功能不全、传     

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。     

Comparison of the Tissue Doppler-Derived Left Ventricular Tei Index to that Obtained by Pulse Doppler in Patients with Congenital and Acquired Heart Disease

We compared the left ventricular Tei index measured by tissue Doppler imaging (TDI) to that obtained by pulsed Doppler (PW) in patients with congenital heart disease. In 40 consecutive patients with a variety of congenital and acquired heart diseases, the left ventricular (LV) PW Doppler-derived Tei index was assessed on-line as previously described. TDI-derived anatomic curved M-mode and the unprocessed velocity trace from the basal septum were used to time the opening and closure of the mitral and aortic valves in one cardiac cycle, respectively. The TDI Tei index was calculated off-line according to the equation (isovolumetric relaxation time + isovolumetric contraction time)/ ejection time. The Tei index calculated from TDI correlated significantly with that measured by pulsed Doppler (r = 0.92, p = 0.001). The mean difference (range) between pulsed Doppler-derived Tei index and TDI-derived Tei index was 0.005 (−0.07–0.06), which was within the limits of agreements. Interobserver variability for the TDI-derived Tei index was 5 ± 3%. The TDI Tei index can be used to assess the global LV function in patients with congenital heart disease. In contrast to the PW Doppler-derived Tei index, the TDI-derived Tei index obtained from the same cardiac cycle may help to differentiate systolic from diastolic dysfunction by providing specific information on the isovolumetric intervals.     

Serial evaluation for myocardial performance in fetuses and neonates using a new Doppler index

BACKGROUND: Fetal echocardiography has been used for non-invasive evaluation of human fetal cardiac anatomy, function and hemodynamics. The Tei index, a new Doppler index known to be independent of both ventricular geometry and heart rate, has recently been applied to the evaluation of myocardial performance. METHODS: In the present study, the Tei index was prospectively and longitudinally determined in 50 normal fetuses, 35 fetuses with intrauterine growth retardation (IUGR), 30 fetuses of diabetic mothers (DM) and 20 normal infants. The Tei index of both left and right ventricles was calculated from a Doppler ventricular inflow and outflow trace using the following formula: Tei index = (ICT + IRT)/ET, where ICT is isovolumetric contraction time; IRT, isovolumetric relaxation time; and ET, ejection time). RESULTS: The Tei index of the left ventricle decreased linearly with advancing gestational age during 18-33 weeks and decreased acceleratively with increasing gestational age after 34 weeks. The index of the right ventricle decreased slightly and linearly with advancing gestational age during 18-41 weeks. In neonates, the Tci index of the left and right ventricle increased immediately and transitorily after birth and decreased and stabilized after 24 h of life. From 18 to 26 weeks of gestation, the Tei indices in fetuses with IUGR and of DM were not significantly different from controls. However, from 27 to 40 weeks of gestation, the Tei indices in both fetuses with IUGR and of DM were significantly greater than controls. CONCLUSIONS: This gradual decrease in the Tei index during gestation may represent the maturational or developmental alternation of myocardial performance in utero. Fetuses with IUGR and of DM may have abnormal myocardial performance in later gestation.     

Quantitation of the Global Right Ventricular Function in Children with Normal Heart and Congenital Heart Disease: A Right Ventricular Myocardial Performance Index

Although the assessment of right ventricular (RV) function is important in the clinical management of children with congenital heart disease, available imaging techniques have been limited because of the complex geometry of the right ventricle. A new Doppler index combining systolic and diastolic time intervals (the Tei index) has been reported to be useful for the assessment of global RV function in adults. However, normal values in children, age-related changes, and the clinical utility of the Tei index with regard to congenital heart disease have not been demonstrated. The purpose of this study was to prospectively assess RV function in children with normal heart and congenital heart disease using the Tei index. The subjects included 150 healthy children and 43 patients with congenital heart disease (35 patients with atrial septal defects and 8 patients who had had a Senning operation). The index was defined as the sum of isovolumetric contraction time and isovolumetric relaxation time divided by ejection time and was measured from conventional RV outflow and inflow Doppler velocity profiles. The Tei index was not affected by age in healthy children (0.24 ± 0.04). There was a significant difference in index rating between patients who had had a Senning operation (0.58 ± 0.09) and healthy children (p < 0.01), but there was no significant difference between children with atrial septal defect (0.25 ± 0.13) and healthy children. The Tei index is a feasible approach to use when assessing global RV function in children with congential heart disease.     

经胎盘转运地高辛治疗胎儿心力衰竭的非随机对照研究

目的 观察经胎盘转运地高辛治疗胎儿心力衰竭的临床疗效及安全性;探讨心血管整体评分（CVPS）和心室作功指数（Tei指数）对胎儿心力衰竭评估及治疗的指导意义。方法 按照研究设计,纳入2008年5月至2011年12月四川大学华西第二医院（我院）产前诊断的胎儿心力衰竭连续病例,知情同意下根据患胎父母意愿分为地高辛组及病例对照组。地高辛组经多学科会诊确定个体化经胎盘转运地高辛治疗方案。对病例对照组进行临床观察。动态监测两组患胎CVPS及心室 Tei指数并观察妊娠结局。同时纳入同期在我院建卡的健康孕妇及胎儿作为正常组,分别于妊娠20、24、28、32、36周及产前观察CVPS及心室 Tei指数演变。结果 ① 地高辛组共纳入10例胎儿心力衰竭病例,其中4例胎儿心房扑动（AF）、3例胎儿室上性心动过速（SVT）、2例轻型胎儿杂合型地中海贫血（MA）、1例胎儿扩张性心肌病（DCM）。AF、SVT及MA患胎经地高辛治疗后心力衰竭得到控制,治疗后孕期顺利,足月顺产,随访10~55个月,生长发育良好,Bayley婴幼儿发育量表测试显示患儿智力及行为发育均正常;治疗过程中CVPS逐渐上升,达到或接近10分,心室 Tei指数逐渐下降,均接近正常组水平。②病例对照组共纳入9例胎儿心力衰竭病例,其中4例AF、3例SVT、2例MA。其中1例AF、1例SVT分别于观察5及7 d后自然转复为窦性心律,其后转入地高辛组,给予地高辛治疗,孕期顺利,足月顺产。其余病例进行临床观察后,其CVPS逐渐降低,心室 Tei指数逐渐升高,最后终止妊娠。③地高辛组1例观察到胃肠道不良反应,地高辛减量后症状消失。结论 地高辛作为治疗胎儿心力衰竭的一线药物具有重要的临床价值,安全性较好;随胎儿心力衰竭控制,胎儿CVPS逐渐上升,心室 Tei指数下降,两者呈负相关关系;CVPS和心室Tei指数能有效指导经胎盘转运药物产前治疗胎儿心力衰竭;及时有效的产前治疗能明显改善疾病预后。     

Usefulness of a new Doppler index for assessing both ventricular functions and pulmonary circulation in newborn piglet with hypoxic pulmonary hypertension

Persistent pulmonary hypertension of the newborn is a clinical syndrome associated with a variety of cardiopulmonary diseases. Serial evaluation of pulmonary circulation and cardiac function is important, but available imaging techniques have been limited. A new Doppler index combining systolic and diastolic time intervals (the Tei index, which is a simple and noninvasive measurement) has been reported to be useful for the assessment of global cardiac function in adults and children. The purpose of this study was to test the effectiveness of the Tei index in prospectively assessing ventricular function and pulmonary circulation in a newborn piglet model with hypoxic pulmonary hypertension. One-day-old piglets (1.1-1.6 kg) were intubated and prepared for the experiments under room air and hypoxia. A complete two-dimensional Doppler echocardiographic examination was performed. Common hemodynamic variables were measured continuously throughout the study. The right ventricle (RV) Tei index under hypoxia (fraction of inspired oxygen = 0.10) was significantly higher than the value under air ventilation (medians, 0.38 versus 0.56; p < 0.05). Moreover, there was a significant correlation between RV Tei index and mean pulmonary artery pressure and positive linear correlation between individual changes in RV Tei index and changes in mPAP (r2 = 0.799, p < 0.05). We conclude that the Tei index is useful for assessing the function of the RV and the left ventricle and pulmonary circulation in a newborn piglet model with hypoxic pulmonary hypertension. These results suggest that the Tei index will become an objective method of assessing patients with persistent pulmonary hypertension of the newborn.     

Milrinone and Low Cardiac Output Following Cardiac Surgery in Infants: Is There a Direct Myocardial Effect?

We assessed the effect of milrinone on myocardial function in pediatric patients with postoperative low cardiac output syndrome by index of myocardial performance in a prospective, open-label, nonrandomized, consecutive study. Fifteen patients with low cardiac output syndrome following cardiac surgical treatment were studied in the tertiary cardiothoracic pediatric intensive care unit between April 2001 and November 2003 (age range, 0.2–16 months; median, 7; weight, 2.7–11.8 kg; median, 5). Echocardiographic, Doppler-derived, time interval-based index of myocardial performance (Tei index) was used to study cardiac function prior to and while on intravenous milrinone treatment for 18–24 hours. Treatment with milrinone led to improvement in biventricular myocardial function [mean right ventricular index from 0.521 (SD-0.213) to 0.385 (SD-0.215), p = 0.003; mean left ventricular index from 0.636 (SD-0.209) to 0.5 (SD-0.171), p = 0.012). No difference was found in the values of heart rate corrected right or left ventricular ejection time prior to and while on treatment with milrinone (right ventricle: mean, 1.23 (SD-0.42) and 1.14 (SD-0.48), p = 0.29; left ventricles: mean, 1.17 (SD-0.51) and 1.13 (SD-0.48), p = 0.66) Our data support the direct myocardial effect of milrinone as part of the mechanism behind its already proven benefit in children with low cardiac output syndrome following cardiac surgery.     

Effect of dobutamine on a Doppler echocardiographic index of combined systolic and diastolic performance

Dobutamine stress echocardiography has become accepted in the evaluation of cardiac functional reserve. Although the Doppler-derived index of combined systolic/diastolic myocardial performance (Tei index) has been reported to be easily obtainable and useful for predicting left ventricular performance, the effect of dobutamine on the Tei index has not been determined in children. To assess the effect of dobutamine on the Tei index, 8 patients who had undergone surgery for ventricular septal defect and 7 patients who had a history of Kawasaki disease were examined. Echocardiographic recordings were obtained before and after dobutamine infusion (5 microg/kg per minute). Variables measured were transmitral flow velocities (E, A, E/A), rate-corrected mean velocity of circumferential fiber shortening (rate-corrected Vcf), and IMP. We measured isovolumic contraction time (ICT), isovolumic relaxation time (IRT), and ejection time (ET) and then calculated the Tei index using the following formula: Tei index = (ICT + IRT)/ET. Dobutamine infusion increased rate-corrected Vcf (29%, p < 0.01), peak E (7%, p < 0.05), and peak A (13%, p < 0.05). E/A ratio did not change during dobutamine infusion. ET, ICT, and IRT were found to decrease during dobutamine infusion. The magnitude of the change in the ICT (-21%, p < 0.01) was greater than those in IRT (-12%, p < 0.01) and ET (-8%, p < 0.05). The decrease in Tei index (-16%, p < 0.01) resulted in a decrease in ICT/ET (-21%, p < 0.01) and a slight decrease in IRT/ET (-12%, p < 0.05). The Tei index has potential as a sensitive indicator of the effects of inotropic stimilation on global left ventricular function.     

Tissue Doppler Septal Tei Index Indicates Severity of Illness in Pediatric Patients With Congestive Heart Failure

The Doppler Tei index is an independent predictor of outcomes in adult heart failure. Tissue Doppler imaging (TDI) may be a superior method to measure the Tei index in children because it is less affected by heart rate variability. We hypothesized that the TDI Tei index reflects severity of illness in pediatric heart failure. Twenty-five pediatric heart failure patients were prospectively enrolled. Listing for heart transplantation or death were the outcomes used to define severity of illness. Baseline demographics, brain natriuretic peptide (BNP), and standard echocardiographic and TDI-derived parameters were analyzed to determine outcome indicators. Ten of the 25 patients (40 %) were listed for transplantation. There were no deaths. Multivariate analysis combining age, heart rate, standard echocardiographic parameters, and BNP resulted in shortening fraction (p = 0.002) as the best indicator of listing for transplantation (R ² = 0.32). A second multivariate analysis combining age, heart rate, TDI parameters, and BNP resulted in age (p = 0.03) and septal Tei index (p = 0.03) as the best predictive model (R ² = 0.36). The area under the receiver operating characteristic (ROC) curve for septal Tei index was 0.84 (95 % confidence interval = 0.64–0.96,), and it was comparable with the ROC curve for shortening fraction, p = 0.76. Optimal values of sensitivity (100 %) and specificity (60 %) were obtained with septal Tei index values >0.51. The TDI septal Tei index is an indicator of disease severity in pediatric heart failure patients and offers potential advantages compared with standard echocardiographic measures of left-ventricular ejection.     

Ventricular Arrhythmias: When to Worry

Although isolated premature ventricular contractions may be seen in as many as 15% of normal newborns, one third of normal adolescents, and two thirds of adolescents and adults with repaired heart disease, sustained ventricular arrhythmias are relatively rare in young normal hearts. Sudden cardiac health is rare in young normal hearts, although there is an increased incidence in dilated cardiomyopathies and following repair of particular congenital heart lesions. Noninvasive and invasive techniques imperfectly stratify these patients. Patients with cardiomyopathy often have ventricular arrhythmias, although the risk of mortality is more closely linked to ventricular function. There are many infants and pediatric patients with apparently normal hearts who have combinations of asymptomatic nonsustained ventricular tachycardia and potentially serious symptoms. The clinical concern is to identify diagnoses such as long QT syndrome associated with recurrent cardiac syncope and premature mortality so that appropriate choices can be made regarding drug and device therapy. Although this broad range of disease places a premium on careful evaluation, selective therapy, and continued research, serious symptoms, even in the absence of ectopy, are concerning in any patient.