Noninvasive assessment of surgical systemic to pulmonary artery shunts by range-gated pulsed Doppler echocardiography.

Suprasternal range-gated pulsed Doppler echocardiography was used to evaluate surgical shunt patency in children with cyanotic congenital heart disease and right ventricular outflow obstruction following systemic artery to pulmonary artery anastomoses. Normal patients had laminar Doppler auditory signals and time interval histogram flow patterns because right pulmonary artery turbulence was not present during systole or diastole. Patients with pulmonary valvar stenosis had turbulence during systole only. In all nine postoperative patients with surgical shunts, turbulent systolic and diastolic time interval histograms and abnormal auditory signals were present. A typical shunt murmur was not audible to auscultation in six of the postsurgical patients at the time of the study. Suprasternal range-gated pulsed Doppler echocardiography affords an accurate, safe and simple noninvasive bedside means for confirming shunt patency in patients who have undergone surgical systemic artery to pulmonary artery anastomoses.     

Single Doppler Detection of Left to Right Shunt through the Ductus Arteriosus

ABSTRACT. Forty-two infants and children were examined with unguided continuous and pulsed Doppler echocardiography before and/or after surgical closure of ductus arteriosus or in connection with cardiac catheterization. Presence or absence of diastolic reverse flow in the main pulmonary artery was evaluated for sensitivity and specificity to detect left to right ductus shunt. Diastolic reverse flow was detected in 15 of 16 patients with such a shunt and in 3 of 38 patients without a left to right ductus shunt. This corresponds to 94% sensitivity and 92% specifcity. It is concluded that the accuracy of a single Doppler system in diagnosing patent ductus arteriosus is comparable to the results obtained with a Doppler interfaced to M-mode or cross-sectional echocardiography.     

Spontaneous Near Closure of Coronary Artery Fistula: Doppler Echocardiographic Findings

A 1-year-old girl was diagnosed as having a fistula between the left coronary artery and the right ventricle by selective coronary angiography. The left to right shunt ratio was 38%. At a second angiography, the fistula was markedly diminished in size. Turbulent flow was detected throughout the cardiac cycle in the left coronary artery and during systole in the right ventricle by Doppler echocardiography on the first visit. At 3 years of age the systolic component of the left to right shunt flow in the left coronary artery and the right ventricle was reduced in size. Doppler echocardiography proved useful in observing the natural history of this coronary artery fistula.     

Pulmonary artery pressure evaluated by pulsed Doppler echocardiography in children with a left-to right intracardiac shunt

Summary In a study of 25 children with left-to-right intracardiac shunt we found a good correlation (r>0.92;p<0.001) between right ventricular pre-ejection period/acceleration time, derived from pulsed Doppler echocardiography, and pulmonary artery systolic, diastolic, and mean pressures, measured at cardiac catheterization. This may enhance the noninvasive estimation of pulmonary artery pressure.     

Magnetic resonance imaging compared with echocardiography in the evaluation of pulmonary artery abnormalities in children with tetralogy of Fallot following palliative and corrective surgery

Background. Abnormalities of the pulmonary arteries following palliative or corrective surgery for tetralogy of Fallot (TOF) are common. Our purpose was to compare the usefulness of magnetic resonance imaging (MRI) and echocardiography in the post- operative evaluation of the pulmonary arteries in children with TOF. Objective. Our hypothesis was that MRI is more sensitive than echocardiography in the detection of branch pulmonary artery abnormalities in children with TOF. Materials and methods. Pulmonary artery MRI and echocardiography were performed in 20 children following palliative and/or corrective surgery for TOF. MRI and echocardiography were compared in their ability to detect abnormalities of the pulmonary arteries. Angiographic or surgical correlation was available in 15 children. A perfusion scan for confirmation of pulmonary artery patency was available in one additional child. Results. Abnormalities of the branch pulmonary arteries identified by MRI included: absence or occlusion (2), focal stenosis (15), hypoplasia (2), aneurysm (1), and non-confluence (1). Echocardiography could not adequately visualize the right and left branch pulmonary arteries in eight and ten children, respectively. Echocardiography missed stenosis in 13 branch pulmonary arteries, patency of hypoplastic pulmonary arteries in two children, non-confluence of the pulmonary arteries in one child, and a left pulmonary artery aneurysm in one child. Abnormalities identified by MRI were confirmed in 16 children by angiography, surgery or perfusion scan. Conclusion. MRI is more sensitive than echocardiography for the evaluation of branch pulmonary artery abnormalities in children following surgery for TOF. Received: 13 January 1997 Accepted: 31 July 1997     

Ventricular diastolic filling indices in pulmonary stenosis

Children with valvar pulmonary stenosis have right ventricular diastolic filling abnormalities that may be due to either right ventricular hypertrophy or right ventricular outflow obstruction. In order to investigate the reason for this abnormality, 23 consecutive cases with pulmonary stenosis (mean age 7.94 +/- 3.33 years) undergoing transluminal pulmonary balloon valvuloplasty without significant tricuspid or pulmonary valvar regurgitation were studied prospectively. Right ventricular diastolic filling indices and pulmonary valvar systolic gradients were measured in these children one day before and after pulmonary balloon valvuloplasty and were re-examined six months later. Right ventricular diastolic indices based on rapid early diastolic filling peak velocity (peak E), peak velocity during atrial contraction (peak A), and ratio of E/A were determined by pulsed Doppler echocardiography. In conclusion, right ventricular diastolic filling indices in patients with pulmonary stenosis did not improve after pulmonary balloon valvuloplasty in the first day but when re-examined by the sixth month there was a significant improvement. These data suggest that diastolic filling abnormalities are more likely a result of right ventricular hypertrophy than of right ventricular outflow obstruction.     

先天性左冠状动脉主干闭锁3例超声心动图特征及文献复习

目的 通过研究先天性左冠状动脉主干闭锁（LMCAA）的超声心动图表现,提高对LMCAA诊断的准确性。方法 回顾性分析经冠状动脉造影证实的3例LMCAA患儿的超声心动图检查结果,并复习相关文献,总结LMCAA超声心动图特征。结果 LMCAA特异性超声心动图特征：①主动脉左冠状动脉窦内无左冠状动脉主干开口,左冠状动脉主干近心端闭锁呈盲端,远心端内径细窄,发育不良;②右冠状动脉内径增宽;③多切面未显示左冠状动脉与肺动脉确切连接的证据。LMCAA非特异性超声心动图特征：①左心室明显扩大,左室收缩功能可正常或减低;②二尖瓣腱索、乳头肌回声显著增强,可伴有二尖瓣脱垂。彩色多普勒超声特征： ①收缩期二尖瓣口可见中至大量反流信号;② 左、右冠状动脉之间形成细小侧支循环; ③左冠状动脉前降支和回旋支血流为逆向灌注（向心性）;④发育不良的左冠状动脉虽然在肺动脉周围分布,但彩色多普勒超声不能显示其与肺动脉连接的确切逆灌血流信号。结论 LMCAA有特异性的超声心动图特征,提高对LMCAA的全面认识是诊断本病的关键。     

Coronary Blood Flow in Healthy Neonates: Effects of Left Ventricular Function and Mass

This study used transthoracic echocardiography, including pulsed-wave Doppler, to register coronary flow parameters in 55 healthy neonates. Intraobserver variability was tested in 20 neonates. A Doppler tracing of sufficient quality for analysis was obtained in the left anterior descending coronary artery (LAD) in 53 of 55 studies (96.4% feasibility) and in the right coronary artery (RCA) in 11 of 55 studies (20.0% feasibility). Estimation of intraobserver variability showed coefficients of variation of 7.5–8.0% for diastolic LAD Doppler flow parameters and volume flow but 17.5% for systolic peak flow velocity. Doppler flow parameters were significantly higher in the LAD than in the RCA. Correlation was found between LAD Doppler flow parameters and age, left ventricular (LV) mass, mitral peak early wave velocity as a measure of diastolic LV function, and the aortic velocity time integral/minute as a measure of systolic LV function. This study shows that diastolic LAD Doppler flow parameters and flow volume can be obtained in neonates by transthoracic echocardiography with acceptable reproducibility. In healthy neonates, left coronary flow parameters are linearly related to age, LV mass, and LV systolic and diastolic function. RCA flow parameters in neonates are lower than in the LAD.     

Innominate Artery Steal Syndrome After Stage I Palliation for Hypoplastic Left Heart Syndrome

Four neonates with hypoplastic left heart syndrome (HLHS) were found to have innominate artery steal syndrome (IASS) following stage I palliation with a modified Blalock–Taussig (B–T) shunt. All patients presented in the early postoperative period with a persistent supplemental oxygen requirement. Two-dimensional echocardiography with Doppler flow analysis and cardiac catheterization with angiography demonstrated obstruction at the origin of the innominate artery. This obstruction was associated with intermittent retrograde flow through the right vertebral and common carotid arteries into the distal innominate artery and modified B–T shunt. An ascending neoaorta to right pulmonary artery shunt, with takedown of the B–T shunt, was performed in two of the patients. The other two patients were treated with percutaneous balloon dilatation of the obstructed area. Both procedures improved arterial blood oxygen saturations and eliminated the need for supplemental oxygen. In three of four patients, the left common carotid artery was found to be larger than the right. All four patients developed microcephaly, and one patient had encephalomalacia in the distribution of the right anterior and middle cerebral arteries. The development of IASS following stage I palliation for HLHS and the association of neurologic sequelae from this complication are discussed.     

Comparison of Tissue Doppler Imaging with MRI T2* and 24-Hour Rhythm Holter Heart Rate Variability for Diagnosing Early Cardiac Impairment in Thalassemia Major Patients

Objectives: Cardiology follow up is important in thalassemia major patients. The object of this study is to define parameters which can be used in the early detection of cardiac impairment. Material and Methods: Forty seven beta thalassemia major patients (mean age 16.3 ± 4.47 years; 22 boys, 25 girls) whose left ventricular systolic functions were normal and a healthy control group of fifty age and gender matched children were included in the study. M-mode echocardiographic measurements, systolic and diastolic functions with PW and tissue Doppler and heart rate variabilities (HRVs) were compared between the two groups. The patients were also grouped according to MRT2*, ferritin and left ventricular diastolic diameters (LVDds) to compare the echocardiographic and Holter parameters among them. Results: None of the children in the study group had symptomatic congestive heart failure. PW Doppler late diastolic forward flow in pulmonary artery was higher in the thalassemia group when compared with the control group (P = 0.01) indicating decreased compliance of the right ventricle. While the systolic and diastolic functions were normal, all the HRV parameters in the thalassemia group were significantly lower than the control group (P = 0.005). Conclusions: Significant decrease in HRV and increase in PW late diastolic forward flow in pulmonary artery in the absence of systolic or diastolic dysfunction, points out that these parameters can be useful in detection of early cardiac impairment.     

Coronary flow and flow reserve in children

Aortic blood pressure affects coronary blood flow, but within the normal physiological blood pressure range coronary blood flow is constant. The coronary flow is pulsatile, being maximal in the early diastole. There is a smaller systolic flow component. The low systolic pressure in the right ventricle favours systolic flow. The proportion of systolic flow is greater in the right than in the left coronary artery. Heart diseases in children cause several haemodynamic and functional changes that are likely to affect myocardial perfusion. Newborns with severe valvular aortic stenosis may have a retrograde systolic flow in the left coronary artery. Children with dilated cardiomyopathy have a reduced coronary flow related to myocardial mass. Coronary flow reserve (CFR) is defined as the ratio of maximal coronary blood flow, as induced by reactive hyperaemia or administration of vasodilators, divided by resting flow. Coronary flow can normally increase 2.5–4-fold. CFR is reduced if basal flow is increased due to myocardial hypertrophy, strain or hypoxaemia. Very low CFR values measured with positron emission tomography are reported in neonates with surgically treated congenital heart disease. Measurement of coronary flow velocity with the intracoronary Doppler guide wire may be regarded as a reference or "gold standard" in the evaluation of coronary flow velocity and CFR.
Conclusions : Coronary flow and CFR in children is a largely unexploited field, and has vast potential for future research.     

Coronary flow and flow reserve in children

Aortic blood pressure affects coronary blood flow, but within the normal physiological blood pressure range coronary blood flow is constant. The coronary flow is pulsatile, being maximal in the early diastole. There is a smaller systolic flow component. The low systolic pressure in the right ventricle favours systolic flow. The proportion of systolic flow is greater in the right than in the left coronary artery. Heart diseases in children cause several haemodynamic and functional changes that are likely to affect myocardial perfusion. Newborns with severe valvular aortic stenosis may have a retrograde systolic flow in the left coronary artery. Children with dilated cardiomyopathy have a reduced coronary flow related to myocardial mass. Coronary flow reserve (CFR) is defined as the ratio of maximal coronary blood flow, as induced by reactive hyperaemia or administration of vasodilators, divided by resting flow. Coronary flow can normally increase 2.5-4-fold. CFR is reduced if basal flow is increased due to myocardial hypertrophy, strain or hypoxaemia. Very low CFR values measured with positron emission tomography are reported in neonates with surgically treated congenital heart disease. Measurement of coronary flow velocity with the intracoronary Doppler guide wire may be regarded as a reference or "gold standard" in the evaluation of coronary flow velocity and CFR. Coronary flow and CFR in children is a largely unexploited field, and has vast potential for future research.     

Two-dimensional and Doppler echocardiographic findings of congenital coronary artery fistula.

Three patients with coronary artery fistula confirmed by coronary angiography and surgery were studied using two-dimensional and Doppler echocardiography. Two of these patients had left coronary artery-right ventricle fistula. The proximal dilatation of the coronary arteries was visualized in all three patients by two-dimensional echocardiography. The course of the dilated right coronary artery and left circumflex artery was demonstrated by two-dimensional echocardiography in two patients. We were able to detect the disturbed flow at the drainage site in one patient by using the conventional Doppler echocardiography. In conclusion, it should be emphasized that two-dimensional and Doppler echocardiography can be useful methods in diagnosing coronary artery fistula.     

Changes in Pulmonary Venous Flow Patterns in Patients with Ventricular Septal Defect

We studied pulmonary venous (PV) flow patterns using Doppler echocardiography in 26 patients with ventricular septal defect less than 3 years of age. Fifteen patients had moderate or severe symptoms, and the remaining 11 had no significant symptoms. Peak velocity of PV diastolic flow and flow velocity integral of PV diastolic flow in the symptomatic patients were significantly larger than those in either asymptomatic patients or the normal controls. The ratio of PV diastolic flow velocity to PV systolic flow velocity and the ratio of flow velocity integral of PV diastolic flow to that of PV systolic flow in the symptomatic patients were significantly larger than those in either asymptomatic patients or the normal controls. The ratio of PV diastolic flow velocity to PV systolic flow velocity as well as the ratio of flow velocity integral of PV diastolic flow to that of PV systolic flow correlated with V wave in left atrial or pulmonary capillary wedge pressure and indexes of left ventricular mass and left atrial volume. We conclude that the abnormal pulmonary venous flow patterns in ventricular septal defect might be associated with large left-to-right shunting and left atrial pressure V wave.     

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.     

How is pulmonary arterial blood flow affected by pulmonary venous obstruction in children? A phase-contrast magnetic resonance study

Background: Hemodynamic changes within a stenosed pulmonary vein might not reflect the severity of the obstruction if redistribution of pulmonary artery flow occurs. Objective: The purpose was to investigate flow changes in branch pulmonary arteries in the presence of pulmonary vein stenosis. Materials and methods: Twelve children (age range 3–180 months) who had undergone MRI for pulmonary vein stenosis were identified. The severity of vein stenosis was assessed from percentage diameter reduction. Pulmonary artery flow distribution was correlated with the severity of pulmonary vein stenosis. Nine of the patients had unilateral stenosis; three had bilateral involvement. Results: Unilateral vein stenosis was associated with diastolic reversal in the ipsilateral branch pulmonary artery (mean flow reversal 12.3%, range 2.4–42%) and continuous diastolic forward flow in the contralateral pulmonary artery in seven of nine patients. Severe stenosis was associated with decreased systolic flow to the ipsilateral lung. The ratio of net forward flow through pulmonary arteries correlated well with the cross-sectional area ratio of pulmonary arteries (r=0.75, P=0.006). Conclusions: Severe pulmonary vein obstruction results in redistribution of pulmonary arterial flow. When investigating pulmonary vein stenosis by MR, an evaluation of the pulmonary arterial system should be included to assess the functional importance of an obstruction.     

Echocardiographic assessment of patent ductus arteriosus shunt flow pattern in premature infants

AIMS—To identify the patent ductus arteriosus (PDA) shunt flow pattern using Doppler echocardiography; and to assess whether it could be used to predict the development of clinically significant PDA.
METHODS—Premature infants weighing under 1500 g, who required mechanical ventilation, and in whom daily echocardiography could be performed from day 1 until the ductus closed, and on day 7 to confirm closure, were studied. The PDA shunt flow was identified from four Doppler patterns, and the closed pattern of a closed duct was also presented. Clinically significant PDA was diagnosed when there was colour Doppler echocardiographic evidence of left to right ductal shunt associated with at least two of the following clinical signs: heart murmur (systolic or continuous); persistent tachycardia (heart rate>160/min); hyperactive precordial pulsation; bounding pulses; and radiographic evidence of cardiomegaly or pulmonary congestion.
RESULTS—Of 68 infants enrolled into this study, clincally significant PDA developed in 31. The most recordable sequence of transition change of shunt flow pattern for clinically significant PDA was: pulmonary hypertension pattern, to growing pattern, to pulsatile pattern, to closing pattern, to closed pattern. And that for non-clinically significant PDA was: pulmonary hypertension pattern, to closing pattern, to closed pattern. The growing and the pulsatile patterns were mostly documented in infants with clinically significant PDA. The first documented growing pattern to predict clinically significant PDA gave a sensitivity of 64.5% and a specificity of 81.1%; the first documented pulsatile pattern gave a sensitivity of 93.5% and a specificity of 100%.
CONCLUSION—Doppler echocardiographic assessment of PDA shunt flow pattern during the first 4 days of life is useful for predicting the development of clinically significant PDA in premature infants. At that stage, the closing or closed Doppler pattern indicates that infants are not at risk of developing clinically significant PDA; the growing or pulsatile Doppler pattern indicates a continuing risk of developing clinically significant PDA.

     

Echocardiographic proof of pulmonary hypertension with irreversible increased resistance in the pulmonary circulation as a complication after placement of a ventriculo-atrial shunt for internal hydrocephalus.

Increased resistance in the pulmonary vessels in children with ventriculo-atrial shunts is a rare and often unrecognized permanent complication. We report 2 children in whom this diagnosis was detected by two-dimensional echocardiography. The first patient received a ventriculo-atrial shunt at age 9 days for congenital internal hydrocephalus. At 17 months it had to be replaced because of infection of the efferent catheter limb. At 22 months at a routine follow-up the echocardiographic diagnosis of pulmonary hypertension was made. Invasive studies confirmed the presence of irreversible increased resistance in the pulmonary circulation. The second patient received a ventriculo-atrial shunt at age 13 months because of a cerebral cyst. After repeated catheter infections, at 28 months a ventriculo-peritoneal shunt was placed. At age 4 years the diagnosis of pulmonary hypertension was made by routine echocardiography. This finding was confirmed by invasive studies. The left pulmonary artery was completely occluded. Both patients had developed microemboli, caused or aggravated by catheter sepsis, in the second case probably through contiguous clot growth up to complete occlusion of the left pulmonary artery. Therapeutic measures seemed not to be indicated. Two-dimensional echocardiography proved to be a reliable method for diagnosing increased resistance and pulmonary hypertension. We recommend routine echocardiography for follow-up in all children with ventriculo-atrial shunts.     

冠状动脉造影和三磷酸腺苷负荷超声心动图对川崎病冠状动脉损害远期追踪的价值

目的 探讨选择性冠状动脉造影及三磷酸腺苷负荷超声心动图对川崎病（KD）冠状动脉损害远期追踪的价值。方法 选取1999至2007年广州市儿童医院KD急性期超声心动图检查发现合并冠状动脉损害的患儿，同时采用三磷酸腺苷负荷超声心动图及选择性冠状动脉造影于恢复期进行远期随访。结果依据纳入标准和排除标准逐层筛选，确定9例KD患儿为本研究的样本。男8例，女1例，急性期发病年龄为1～10岁，平均（4.44±3.09）岁。检查时年龄4～12岁，平均（7.89±2.62）岁。追踪时间1.5~7年，平均（3.44±1.67）年。急性期超声心动图示9例患儿中冠状动脉巨瘤5例，冠状动脉瘤3例，冠状动脉扩张1例。三磷酸腺苷负荷超声心动图示：节段性室壁运动异常6/9例；冠状动脉血流储备下降5/9例。冠状动脉造影示：双侧主干冠状动脉瘤4例，同时伴远端动脉瘤3处，冠状动脉左前降支狭窄1处，并冠状动脉扭曲，狭窄或充盈缺损3处，附近侧支血管形成1处；左前降支动脉瘤、右冠状动脉闭塞伴侧支循环形成1例，冠状动脉扩张4例。与同期超声心动图检查比较 ，冠状动脉造影新发现冠状动脉远端瘤3处，右冠状动脉远端狭窄2处，左前降支狭窄1处，右冠状动脉闭塞伴侧支血管形成1例。5例三磷酸腺苷负荷超声心动图检查结果阳性者与冠状动脉造影比较：均发现相应冠状动脉支狭窄或充盈缺损表现；1例三磷酸腺苷负荷超声心动图检查结果阳性，冠状动脉造影仅见轻度冠状动脉扩张。结论 KD合并冠状动脉损害特别是动脉瘤造成的心脏损害可长期存在。对于远期追踪观察KD患儿冠状动脉病变，三磷酸腺苷负荷超声心动图具无创、安全可靠的优点，是判断心肌缺血的重要方法；选择性冠状动脉造影可明确显示冠状动脉病变的位置、形态、数目及严重程度，特别对冠状动脉狭窄、闭塞及远端病变能做出准确的评估。两种方法结合检查对KD冠状动脉损害的远期追踪有重要帮助。     

Coronary artery stenosis in asymptomatic child after arterial switch operation: detection by transthoracic colour-flow doppler echocardiography

Arterial switch operation (ASO) has become the definitive anatomical correction for transposition of great arteries (TGA). Left coronary artery (LCA) ostial stenosis was detected by transthoracic Doppler echocardiography (TTDE) as a flame like colour flow diastolic signal and coronary flow reserve (CFR) was low, 1.3. It was treated successfully by a drug-eluted stent. These findings could be diagnostic for coronary ostial stenosis. CONCLUSION: Coronary artery stenosis can be detected with colour Doppler echocardiography. Assessment of CFR provides information of the physiological significance of the coronary stenosis.