Ductus venosus index: a method for evaluating right ventricular preload in the second-trimester fetus.

This study was designed to examine ventricular preload by measuring the ductus venosus index during the second trimester of pregnancy. A total of 137 women were entered into the study. Each fetus was examined with real-time, color and pulsed Doppler ultrasound. The color Doppler maximal velocity setting was adjusted so that the umbilical vein was homogeneous in color, did not demonstrate aliasing, and filled the venous lumen. The pulsed Doppler gate was placed within the ductus venosus in all subjects. Color Doppler identified a turbulent flow velocity within the ductus venosus which was not present in the umbilical vein, hepatic vein or inferior vena cava. The ductus venosus pulsed Doppler waveform demonstrated flow velocity from the umbilical vein to the heart during ventricular systole, the rapid filling phase of ventricular diastole, and atrial systole. However, flow velocity was decreased during atrial systole compared to ventricular systole and the rapid filling phase of diastole. The ductus venosus index was computed from the Doppler waveform of the ductus venosus at points consistent with ventricular and atrial systole ((ventricular systole - atrial systole)/ventricular systole). Regression analysis demonstrated a significant (p = 0.001) relationship between the ductus venosus index and gestational age (ductus venosus index = 75.5757 - 7.25484 x weeks gestation), standard error of the estimate = 7.21959; R = -0.451. One fetus with a hypoplastic left atrium and ventricle demonstrated a normal ductus venosus index. Two fetuses, one with pulmonary atresia and the second with severe cardiovascular dysfunction, demonstrated an abnormal ductus venosus index associated with absent flow velocity during atrial systole. This was associated with notching in the umbilical vein. The ductus venosus index is an angle-independent measurement from which right ventricular preload may be evaluated.     

Exceptional survival of a patient with large ventricular septal defect, bidirectional shunt, and severe pulmonary valve stenosis.

A 74-year-old man has survived in good health for an exceptionally long time despite the presence of a moderate-to-large-sized membranous ventricular septal defect (VSD). He has remained acyanotic with New York Heart Association class I function. Transthoracic and transesophageal echocardiography with color flow Doppler demonstrated a membranous VSD with left-to-right and right-to-left bidirectional shunts during ventricular systole and diastole, respectively, with an right ventricular systolic pressure of 93 mm Hg, dilation of the atria and the right ventricle, and right ventricular hypertrophy. The pulmonary valve was severely stenotic with transpulmonary valve peak velocity of 6.1 m/s and a peak pressure gradient of 147 mm Hg. The pulmonary artery and inferior vena cava were mildly dilated, and the left ventricular dimension and systolic function were normal. Transesophageal echocardiography with saline solution microbubble injection demonstrated positive contrast effect in the left ventricle in diastole confirming a right-to-left shunt at the ventricular level. This man is currently the oldest survivor with a moderate-to-large-sized membranous VSD reported in the literature.     

Pulmonary venous flow in large, uncomplicated atrial septal defect.

BACKGROUND: The pulmonary venous flow velocity pattern (PVFVP) in atrial septal defect (ASD) has not been previously studied in detail. Normally, PVFVP is primarily determined by the left heart performance. We hypothesized that the impact of left-sided heart dynamics on PVFVP is diminished in patients with ASD because of the presence of a left-to-right shunt into the low-resistance right side of the heart. METHODS AND RESULTS: Transesophageal echocardiography was performed in 19 adults and 3 children with a large, uncomplicated secundum ASD (maximum diameter 0.6 to 3.0 cm). All patients were in normal sinus rhythm with an average heart rate of 78 bpm in adults and 116 bpm in children. In 21 subjects the antegrade PVFVP lacked distinct systolic (S) and diastolic (D) waves. Instead, we observed a single continuous antegrade wave extending from the beginning of systole to the onset of atrial contraction. Furthermore, the amplitude of the atrial reversal (AR) wave was smaller than in historical controls. In 3 patients in whom ASD was surgically repaired, we observed an immediate return of distinct S and D waves postoperatively. This confirmed that PVFVP abnormality was indeed the result of the ASD. Also a large increase in the AR wave amplitude (46 + 15 cm/s) was noted postoperatively. CONCLUSIONS: This previously unrecognized PVFVP comprising a single continuous antegrade wave and a diminished AR wave sheds new light on the hemodynamics of ASDs. Its presence may also alert the echocardiographer to the possibility of an ASD when the septal defect cannot be visualized directly.     

Color and pulsed Doppler studies of atrial flow dynamics in normals and adult patients with uncomplicated atrial septal defects

Left and right atrial flow dynamics were compared by means of color and pulsed Doppler in order to study whether color Doppler could reliably provide differentiation between normals [15] and patients without atrial shunt at catheterization [12], vs patients with confirmed atrial septal defect [12]. The procedure consisted of sequential analysis of colored images throughout the cardiac cycle using an apical approach. In addition pulsed Doppler indices were calculated from both annular traces, relating diastolic early (E) and late (A) filling waves at each annulus (E/A); E and A waves were also summed (E + A), and the sum was related between both annuli (Tricuspid/Mitral ratio). Sequential analysis had a 100% sensitivity and specificity for the diagnosis of atrial septal defect, showing an asymmetrical pattern with predominant images in the right atrium, from the 2nd half of systole till End-diastole, vs the symmetrical ‘Horseshoe’ pattern found over both atria for control subjects. It avoided diagnostic errors due to overriding septal images in systole in 44% of controls. There also was a significant increase of the Tricuspid/Mitral ratios, (for duration and velocity time integral of waves) in patients with atrial septal defect. The correlation coefficient between ratios and values of the Pulmonary/Systemic flow ratio invasively calculated for 10 patients was respectively 0.6 and 0.7 (p<0.01). Sequential analysis of colored images appears highly reliable for the diagnosis of atrial septal defect; anomalies of ratios, although of moderate value for predicting shunt magnitude, substantiate the inequality of atrial fillings.     

Echocardiographic and hemodynamic characteristics of atrial septal defects created by percutaneous valvuloplasty

Twenty-nine patients were studied by pulsed, continuous wave, and color Doppler before and after percutaneous transseptal valvuloplasty. New atrial septal defects were detected in 14 patients, and the patients were monitored for up to 320 days after the procedure. The diameter of the defect, best evaluated by the transesophageal approach, was 3 to 15 mm. A narrow, high velocity (1.4 to 3.1 meters per second) left-to-right shunt jet was detected in 13 of 14 patients. The shunt jet was continuous in nine of 14 patients, late systolic-holodiastolic in four patients, and bidirectional in one patient. Cardiac catheterization in nine patients confirmed the Doppler findings and demonstrated a peak pressure gradient of 10 to 32 mm Hg between the left and right atria. Oximetry revealed a calculated pulmonary to systemic flow ratio ranging from 2.3:1 in the patient with the largest atrial septal defect by echocardiography to 1:1 (no oxygen saturation step-up) in the patient with the smallest atrial septal defect. In the three patients who underwent cardiac surgery, the operative findings confirmed those of echocardiography. We concluded that atrial septal defects are common after transseptal valvuloplasty. Usually, their relatively small size and the underlying valvular disease that produces high left atrial pressure are responsible for the high pressure gradient between the left and right atria. This results in the high velocity and continuous shunt jet detected by Doppler echocardiography.     

Transesophageal Doppler echocardiographic assessment of pulmonary venous flow pattern in subjects without cardiovascular disease

This study was designed to assess pulmonary venous flow dynamics using transesophageal Doppler echocardiography. Under general anesthesia, we studied 54 surgical patients with no history or physical evidence of cardiac disorders. In all patients pulmonary venous flow was easily identified by transesophageal color flow mapping. Pulmonary venous flow pattern, which was obtained clearly in 85% (4654) of patients by transesophageal pulsed Doppler echocardiography, was tri- or quadriphasic. The first wave, which was often biphasic in elderly patients, occurred during ventricular systole (S wave). The second wave occurred in diastole during the early ventricular filling phase of mitral flow (D wave). The third wave was reverse flow toward the pulmonary vein during atrial contraction (A wave). The following variables were measured: the peak flow velocities of each wave (PFVs, PFVd, PFVa), and the ratio of PFVs to PFVd (PFV(S/D)). The PFVd correlated with age (r=?0.56, P<0.001), indicating age-related decrease. The PFV(S/D) correlated with age (r=0.61, p<0.001), indicating age-related increase. These results would indicate that the contribution of pulmonary venous flow during diastole to total pulmonary venous flow decreases with age. Our data suggest that age-related diastolic dysfunction of the left ventricle would affect pulmonary venous flow dynamics and that left atrial storage volume during ventricular systole would increase with age.     

Doppler systemic venous flow patterns: Changes in children with mild/moderate pulmonic stenosis

To determine the usefulness of systemic venous flow patterns in patients with mild/moderate right ventricular hypertension, 17 patients with isolated mild/moderate pulmonic stenosis and 17 age-matched normal children were evaluated with pulsed Doppler echocardiography. Tricuspid valve, superior vena caval, and hepatic vein pulsed Doppler recordings were obtained with simultaneous respirometry and electrocardiography. Peak velocities and velocity-time integrals were measured for Doppler signals corresponding with ventricular systole, ventricular diastole, ventricular end systole, and atrial systole. The groups were similar in weight, heart rate, tricuspid inflow Doppler echocardiograms, and cardiac indexes. Compared with normal subjects, patients showed changes in respiratory variation for some superior vena caval and hepatic vein indexes. In addition, hepatic vein measurements made at ventricular end systole were significantly lower and measurements made at atrial systole were significantly higher in patients than in normal subjects. These changes in systemic venous flow patterns may provide a sensitive indicator of early right-sided heart dysfunction.     

Left ventricular end-diastolic pressure can be estimated by either changes in transmitral inflow pattern during valsalva maneuver or analysis of pulmonary venous flow.

We directly compared the transmitral inflow pattern during preload reduction and pulmonary venous flow velocities to determine left ventricular end-diastolic pressure (LVEDP) in 78 patients who underwent left heart catheterization. Transmitral inflow indexes (A-wave duration, ratio of peak flow velocity of early diastole [E] to peak flow velocity of late diastole during atrial contraction [A] [E/A ratio]) at rest and during the Valsalva maneuver (30 mm Hg for 15 seconds) and indexes of pulmonary venous flow (velocity and duration of the atrial reversal) were obtained. Fair correlations existed between LVEDP (mean 15+/-6 mm Hg) and the percentage decrease in the E/A ratio (r = 0.72), increase in duration of A wave during the Valsalva maneuver (r = 0.60), flow velocity of atrial reversal (r = 0.58), and difference of duration of atrial flow reversal and A wave (r = 0.62) (all P<.001). While sensitivity, specificity, and diagnostic accuracy to detect an elevated LVEDP were comparable, technically adequate Doppler recordings were obtained more often for the mitral inflow during the Valsalva maneuver than for the pulmonary venous flow (72 versus 66 patients, P< 0.05).     

正常成人上腔静脉多普勒血流频谱分析

目的利用多普勒超声对正常成人上腔静脉（SVC）频谱进行分析,探讨其血流频谱变化与呼吸、心动周期的关系。方法对随机选取的56名成年健康志愿者经右锁骨上窝切面,在彩色多普勒引导下获取SVC血流频谱,测定不同心动周期及呼吸周期的SVC血流动力学指标。结果经右锁骨上窝SVC长轴切面获取SVC多普勒图像,成功率为100%,声束与血流方向夹角<10°。在平静呼吸状态下,吸气相S波、D波速度较呼气相加快（P<0.001）,VR、AR则减慢（P<0.05）。呼气相时各波速度则相反。结论经右锁骨上窝SVC长轴切面能获得较满意的SVC彩色及脉冲多普勒图像;SVC血流频谱随心动周期、呼吸周期呈规律性变化。     

慢性心房颤动时上腔静脉血流动力学变化

目的　应用经胸超声心动图技术观察慢性心房颤动(房颤)时上腔静脉血流动力学的改变,探讨房颤对其血流频谱的影响及发生机制。方法　选择26例房颤患者和13 例窦性心律患者,采集上腔静脉多普勒血流频谱。测定上腔静脉收缩期S波、舒张早期D波和舒张晚期逆向 AR波的最大流速和流速积分;并与其他超声指标作相关性分析。结果　房颤时上腔静脉血流频谱各项指标与窦性心律组相比,收缩期 S波的峰值流速和流速积分显著降低(P<0.01);而舒张期 D波的峰值流速和流速积分无明显改变;舒张晚期逆向 AR波消失。上腔静脉收缩期S波峰值流速、流速积分与右房射血分数、右室射血分数、三尖瓣反流程度呈显著相关性(P<0.05~0.001)。舒张期D波峰值流速和流速积分与以上指标无显著相关性。结论　房颤时上腔静脉血流频谱形态明显改变,表现为舒张晚期逆向AR波消失;收缩期S波的峰值流速和流速积分较窦性心律时明显减小,舒张早期D波无明显变化,其血流频谱形态的改变很好地反映了右心压力的变化。     

组织多普勒成像评价左束支传导阻滞时不同步心室活动

目的超声评价左束支传导阻滞(LBBB)患者局部心肌的纵向运动。方法超声测量15例LBBB患者和15例正常人各瓣环，获得纵向上不同时相的峰值速度(VS、VE、VA)、持续时间(IVC、S、IVR、D)、最大时间-速度积分(TVImax)和最大下移距离(Dmax)，以及心电图QRS波起点到S波起点的时间(Q-Sb)、到S波顶点的时间(TTP)、E波的减速时间(Edc)等。结果LBBB患者左室室间隔、下后壁和前壁瓣环VS、VE、TVImax、Dmax明显减低，Q-Sb、TTP明显延长；左室室间隔、下后壁的IVC、IVR延长，D缩短，IVC／S增高。结论LBBB时左室激动顺序异常，引起左室整体和局部舒缩功能异常；左室各壁出现不同程度的收缩延迟，心室内不同步明显；右室收缩延迟不明显，左、右心室间明显不同步。     

房间隔缺损患者左心室几何形态的二维超声心动图特征

应用二维超声心动图观察了２８例房间隔缺损（ＡＳＤ）患者左心室几何形态及偏心指数（ＬＶＥＩ），并与４０例正常人对比研究。结果表明：ＡＳＤ患者舒张末室间隔变平、左移或凸向左室腔，左室腔形态由正常的圆形变为椭圆形或不规则形，ＬＶＥＩ较正常组明显增大（Ｐ＜０．０００５），收缩末左室腔几何形态及ＬＶＥＩ均恢复正常。结论认为：ＡＳＤ患者舒张末左室腔几何形态存在异常、ＬＶＥＩ增大，其机理可能与左、右心室充盈失衡及两室间舒张末跨隔压力阶差的逆转等因素有关     

Echocardiographic prediction of left-to-right shunt with atrial septal defects.

We investigated the ability of transthoracic echocardiography to predict a ratio of pulmonary to systemic flow (Qp/Qs) > or = 1.5 in patients with secundum atrial septal defects. The 44 study patients included 31 patients undergoing catheterization for device closure of atrial septal defects and 13 additional control patients with normal echocardiograms (median age 7.8 years, mean age 15.9 years, range 1.5 to 69 years). Right atrial end-systolic area, right ventricular end-diastolic volume, and the ratio of pulmonary annulus diameter to aortic annulus diameter were determined from standard transthoracic echocardiographic views. The 26 subjects in the shunt group had Qp/Qs between 1.5 and 3.0. The control subjects included the 5 catheterization patients with Qp/Qs between 0.9 and 1.2 and the 13 patients that did not undergo catheterization with assumed Qp/Qs = 1. The shunt patients had significantly increased median-indexed right atrial area (13.8 versus 8.5 cm(2)/M(2), P <. 0001), median-indexed right ventricular volume (85 versus 39 mL/M(2), P <.0001), and median ratio of pulmonary valve annulus to aortic valve annulus (1.26 versus 1.13, P =.008) compared with controls. Indexed right ventricular volume was the best predictor of significant shunt. A combination of right ventricular volume and right atrial area identified subjects with Qp/Qs >1.5 with 96% sensitivity, 94% specificity, and 96% positive and 94% negative predictive value. We conclude that quantitative transthoracic echocardiography can be used to screen for a significant shunt in patients with atrial septal defects.     

Late-diastolic forward flow in the aorta induced by left atrial contraction.

Late-diastolic forward flow is a well-described phenomenon detectable by Doppler echocardiography in the pulmonary trunk. It is supported by a restrictive right ventricular diastolic function and by a low end-diastolic pulmonary artery pressure. A similar phenomenon for the left ventricle and the aorta has not been described. We report a case of a preterm infant with aortic stenosis and endocardial fibroelastosis, who underwent balloon valvuloplasty. Restrictive left ventricular diastolic filling led to high left atrial pressure (27 mm Hg) and a very pathologic ratio of early-to-late peak velocities (2.6) for an infant of 29 weeks' gestation. In combination with a low diastolic aortic pressure (24 mm Hg) caused by moderate aortic regurgitation after intervention, a late-diastolic forward flow was detectable in the aorta during left atrial contraction with pulsed Doppler echocardiography.     

平静呼吸对室间隔缺损左向右分流影响的超声心动图研究

目的应用超声心动图检测室间隔缺损（VSD）患者平静呼吸过程中室水平左向右分流血流速度随呼吸的变化,探讨平静呼吸对VSD患者心功能影响的机制及其临床意义。方法超声记录28例VSD患者平静呼吸时室水平左向右分流的血流速度,同步记录心电图和呼吸曲线。结果平静呼吸时,VSD患者室水平左向右分流的血流速度均于吸气相低于呼气相。结论VSD患者平静呼吸时室水平左向右分流的血流速度随呼吸时相波动而规律性变化,证明了呼吸性胸压变化是导致室间隔缺损分流速度波动性变化的主要原因。     

新生儿超声心动图正常参考值及Z值回归方程式的研究

目的：研究新生儿超声心动图的正常参考值及其Z值回归方程,探讨新生儿心脏正常值的变化规律。方法对深圳市儿童医院288名出生0~28 d健康新生儿,进行超声心动图定量检测,包括M型、二维法、实时三平面几何法、多普勒血流、组织多普勒测量,并进行超声心动图结果与体重的相关回归分析,应用回归方程计算Z值。结果新生儿M型测量的右心室内径（RV）、左心室舒张末期内径（LVEDD）正常值,二维超声心动图测量的四腔图二尖瓣环内径（MV-D1）、两腔图二尖瓣环内径（MV-D2）、长轴图二尖瓣环内径（MV-D3）、主动脉瓣环内径（ARD）、主动脉窦内径（ASD）、主动脉升段内径（AAO）、主动脉弓内径（TA）、主动脉峡部内径（AI）、主动脉隔段内径（AO-Dia）、四腔图三尖瓣环内径（TV-D1）、右心室流入道图三尖瓣环内径（TV-D2）、右心室流出道内径（RVOT）、肺动脉瓣环内径（PVD）、主肺动脉内径（PA）的正常值,二尖瓣口舒张早期峰值流速（MV-E）、二尖瓣口左心房收缩峰值流速（MV-A）、三尖瓣口舒张早期峰值流速（TV-E）、三尖瓣口右心房收缩峰值流速（TV-A）、主动脉瓣峰值流速（AV-max）、主动脉瓣血流速度时间积分（AV-VTI）、肺动脉瓣峰值流速（PV-max）、肺动脉瓣血流速度时间积分（PV-VTI）的正常值,二尖瓣环侧壁收缩期速度（MV-s′）、二尖瓣环侧壁舒张早期速度（MV-e′）、二尖瓣环侧壁心房收缩期速度（MV-a′）、三尖瓣环侧壁收缩期速度（TV-s′）、三尖瓣环侧壁舒张早期速度（TV-e′）、三尖瓣环侧壁心房收缩期速度（TV-a′）、房室瓣环室间隔收缩速度（IVS-s′）、房室瓣环室间隔舒张早期速度（IVS-e′）、房室瓣环室间隔心房收缩速度（IVS-a′）的正常值,双平面法测量的左心房容积（LAV）、左心室舒张末期容积（LVEDV）、每搏量（SV）、心输出量（CO）的正常值,实时三平面几何法测量的LVEDV、SV、CO的正常值,左心室心肌质量（LV mass）、左心室心肌质量指数[LV mass/BSA、LV mass/H2.7;体表面积（BSA）、身长（H）]的正常值,与体重均呈非线性正相关（P均＜0.01）。MV-E/A、PV-E/A、MV-e′/a′、TV-e′/a′、IVS-e′/a′、MV-E/IVS-e′、左心室心肌质量容积比（LV mass/LVEDV）、双平面法及实时三平面几何法左心室射血分数（LVEF）与体重均无相关性（P均＞0.05）。除RV、MV-D1、MV-D2、MV-D3、TV-D1、TV-E、MV-s′、IVS-a′、TV-s′、TV-e′外,非线性回归法（lnY=a＋bX＋cX2＋dX3）获得的R2均大于线性回归法（Y=a＋bX）。Z值均无随体重变化趋势,均呈正态分布。结论新生儿超声心动图正常参考值的趋势图反映了随体重变化的规律,采用非线性回归方程可用于计算预测平均值,所获得的Z值呈标准正态分布,对新生儿心脏疾病的诊治具有重要意义。     

Assessment of right atrial pressure with 2-dimensional and Doppler echocardiography: a simultaneous catheterization and echocardiographic study

OBJECTIVE: To derive a clinically useful, noninvasive determination of right atrial pressure. Noninvasive assessment of right ventricular systolic pressure from Doppler-derived tricuspid regurgitant velocity requires an accurate assumption of right atrial pressure. PATIENTS AND METHODS: Seventy-one patients were studied in the cardiac catheterization laboratory, comparing right atrial pressure (measured at mid systole) with simultaneous 2-dimensional echocardiographic measurement of inferior vena cava diameter and Doppler recordings of hepatic vein systolic, diastolic, and atrial reversal velocities. The initial 28 patients were used to derive a clinical algorithm to predict right atrial pressure, which was tested in the subsequent 43 patients. RESULTS: Inferior vena cava dimension correlated directly with right atrial pressure (r2=0.74; P<.001). The systolic filling fraction of the hepatic vein velocity curves correlated poorly with right atrial pressure. However, the correlation between the hepatic vein Doppler sum of systolic forward flow velocity and atrial reversal velocity and right atrial pressure was inverse (r2=0.32; P=.002). With a combination of variables from both inferior vena cava diameter and hepatic vein velocity curves, patients can be divided into those with normal right atrial pressure, mildly increased right atrial pressure, and severely increased right atrial pressure. CONCLUSION: The combined information from inferior vena cava diameter and hepatic vein velocity curves can be used to assess right atrial pressure.     

Evaluation of Bi-ventricular Coronary Flow Patterns Using High-Frequency Ultrasound in Mice with Transverse Aortic Constriction

Using high-frequency color and pulsed Doppler ultrasound, we evaluated the flow patterns of the left (LCA), septal (SCA) and right (RCA) coronary arteries in mice with and without transverse aortic constriction (TAC). Fifty-two male C57BL/6J mice were subjected to TAC or a corresponding sham operation. At 2 and 8 wk post-surgery, Doppler flow spectra from the three coronary arteries, together with morphologic and functional parameters of the left and right ventricles, were measured. Histology was performed to evaluate myocyte size and neo-angiogenesis in both ventricles. In sham-operated mice, the LCA and SCA both exhibited low-flow waveforms during systole and dominantly higher-flow waveforms during diastole. The RCA exhibited generally lower flow velocity, with similar systolic and diastolic waveforms. TAC significantly increased the systolic flow velocities of all coronary arteries, but enhanced the flow mainly in the LCA and SCA. In the left ventricle, coronary flow reserve was partially preserved 2 wk post-TAC, but decreased at 8 wk, consistent with changes in neo-angiogenesis and systolic function. In contrast, no significant change was found in the coronary flow reserve, structure or function of the right ventricle. This study has established a protocol for evaluating the flow pattern in three principal coronary arteries in mice using Doppler ultrasound and illustrated the difference among three vessels at baseline. In mice with TAC, the difference in the associating pattern of coronary flow dynamics with the myocardial structure and function between the left and right ventricles provides further insights into ventricular remodeling under pressure overload.     

Right ventricular diastolic filling assessed by conventional doppler and tissue Doppler imaging in normal children

To examine age-related changes in right ventricular filling dynamics, we performed conventional pulsed Doppler (n=99) and tissue Doppler (n=30) echocardiographic studies in normal subjects aged 7 days to 273 months. The tricuspid flow velocity during early diastole (peak E) wave correlated significantly but weakly with the logarithm of age. The peak E wave in the early neonatal period was almost 80% of the older children's values and increased to 100% by 36 months of age. In the right ventricular tissue Doppler imaging, the peak myocardial velocity during early diastole also increased significantly with the logarithm of age. However, the tissue Doppler peak A did not change with age. There was a significant correlation between the tissue Doppler peak E wave and the tricuspid peak E wave and between the tissue Doppler peak E/A wave and the tricuspid peak E/A wave. The age-related changes in the tricuspid inflow velocity patterns were similar to the age-related alterations in the right ventricular myocardial velocity patterns. Age-related changes in the tricuspid inflow velocity and myocardial velocity patterns may be related to age-related maturation in the right ventricular diastolic performance.     

多普勒组织成像评价小儿心脏移植术后心功能

目的用超声心动图二维、M型、彩色多普勒及脉冲多普勒组织成像(PW-DTI)等方法对小儿心脏移植术后非排异期心脏的结构、形态、血流、功能等状态进行综合评价，重点探讨PW-DTI对小儿心脏移植术后非排异期心功能评价的意义。方法移植组和对照组各36例，应用超声心动图、PW-DTI测量左室舒张末期内径，室间隔厚度，左室后壁厚度，左室质量，左室短轴缩短率，二、三尖瓣前向血流舒张早、晚期峰值速率及心率；将PW-DTI取样容积置于二尖瓣瓣环水平左室侧壁、室间隔及三尖瓣环水平右室壁采样，获取收缩期和舒张早、晚期PW-DTI运动速度曲线。结果移植组的所有PW-DTI速度曲线参数均较对照组低。二尖瓣瓣环水平左室侧壁舒张早期峰值速率，室间隔及三尖瓣环收缩期峰值速率，舒张早、晚期峰值速率与对照组差异有显著性意义；而其他指标移植组与对照组基本相同。结论PW-DTI速度曲线参数的结果提示心脏移植术后非排异期患儿在常用的心功能指标测值正常时，已存在右室收缩、舒张功能及左室舒张功能的减低，以右心功能减低为明显。PW-DTI是一种敏感、简便的测量小儿心脏移植后左、右心功能的方法．