Transthoracic Doppler echocardiography of normally originating coronary arteries in children

Myocardial perfusion and function dichotomy in growth restricted preterm infants

Compared to preterm appropriate for gestational age (AGA) fetuses, fetuses with fetal growth restriction (FGR) have earlier visualisation of coronary artery blood flow (CABF) but impaired cardiac function. This dichotomy remains uncharacterised during postnatal life. This study compared CABF and cardiac function in preterm FGR infants, against AGA infants during the postnatal period. FGR was defined as birthweight < 10^th centile for gestation and sex with absent/reversed antenatal umbilical artery Doppler. Diastolic CABF was measured in the left anterior descending coronary artery. Twenty-eight FGR infants were compared with 26 AGA infants (gestation and birthweight, 29.7 ± 1.3 vs 29.9 ± 1 weeks, P = 0.6 and 918 ± 174 vs 1398 ± 263g, P < 0.001, respectively). Echocardiography was performed in the second week of life. FGR infants had higher CABF (velocity time integral, 2.4 ± 0.9 vs 1.6 ± 0.8 cm, P = 0.002). Diastolic function was impaired (↑ trans-mitral E/A ratio in FGR infants; 0.84 ± 0.05 vs 0.79 ± 0.03, P = 0.0002) while the systolic function was also affected (mean velocity of circumferential fibre shortening [mVCFc], 1.9 ± 0.3 vs 2.7 ± 0.5 circ/s, P < 0.001). Indexing CABF to cardiac function noted significant differences between the groups (CABF: E/A [FGR vs AGA], 2.9 ± 1.1 vs 2.1 ± 1, P = 0.01 and CABF: mVCFc [FGR vs AGA], 1.3 ± 0.5 vs 0.6 ± 0.3, P < 0.001). Diastolic blood pressure (BP) was significantly higher, and CABF to diastolic BP ratio trended higher in FGR infants (30 ± 2 vs 25 ± 3 mmHg, P < 0.001 and 0.08 ± 0.03 vs 0.06 ± 0.03, P = 0.059, respectively). Greater CABF in FGR infants did not translate into better cardiac function. This dichotomy may be a persistent response to fetal hypoxaemia (fetal programming) and/or reflection of altered cardiac architecture.

A Case of a Left Atrial Appendage Disguised as a Coronary Artery Aneurysm

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LAA is a complex, variable anatomic structure that can be mistaken for other cardiac structures.

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Color and spectral Doppler may help to discern the LAA from surrounding structures.

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Cross-sectional imaging such as CTA can aid in defining the morphology of the LAA.

The Author's Contributions to Echocardiography Literature (Part II-1991-2020)

The author's contribution up to 1990 was reviewed in part I and the echo contributions from 1991 to 2020 will be reviewed in part II. These include defining the relationship between the quantity of shunt across the atrial septal defect (ASD) and the diameter of ASD by echo and angio on the one side and the stretched diameter of the ASD on the other; echocardiographic assessment of balloon-stretched diameter of secundum ASDs; development of echocardiographic predictors of accomplishment of percutaneous closure of ASDs with the buttoned device, highlighting limitations of echocardiography in comprehensive assessment of mixed type of total anomalous pulmonary venous connection; description of follow-up echocardiographic results of transcatheter closure of ASD with buttoned device; review of ultrasound studies; depiction of collaborative echocardiographic and Doppler studies; echocardiographic appraisal of the outcome of balloon pulmonary valvuloplasty; editorials; ventricular septal aneurysm causing pulmonary outflow tract obstruction in the morphologic left ventricle in corrected transposition of the great arteries; dependability of echocardiographic assessment of angiographic minimal diameter of the ductus; occurrence of supravalvular pulmonary artery stenosis after a Nuss procedure; echocardiographic assessment of neonates who were suspected of having heart disease; role of echocardiographic studies in the appraisal of patent ductus arteriosus in the premature babies; and the role of pressure recovery in explaining differences between simultaneously measured Doppler and cardiac catheterization pressure gradients across outflow tract stenotic lesions.

The Author's Contributions to Echocardiography Literature (Part I-1978-1990) †

The author has undertaken multiple echocardiographic studies during his academic career; most of these were published in peer-reviewed journals. These studies include an evaluation of the role of echocardiography in the estimation of left-to-right shunt in isolated ventricular septal defects, an examination of the utility of contrast echocardiography in the diagnosis of anomalous connection of the right superior vena cava to the left atrium, a description of pitfalls in M-mode echocardiographic assessment of the aortic root in left ventricular hypoplasia syndromes, reviews of echocardiographic evaluation of left ventricular function, study of the role of contrast echocardiography in the evaluation of hypoxemia following open heart surgery, a quantification of left ventricular muscle mass by m-mode echocardiography in children, an examination of race and sex related differences in echocardiographic measurements in children, study of cardiac size and function in patients with sickle cell disease, an examination of afterload reduction in the management of primary myocardial disease, study of the utility of echo-Doppler studies in the evaluation of the results of balloon pulmonary valvuloplasty, study of the usefulness of Doppler in the prediction of pressure gradients in valvar pulmonary stenosis, a review of Doppler echocardiography in noninvasive diagnoses of heart disease, echo-Doppler studies of the evaluation of the results of balloon angioplasty of aortic coarctation, study of the value of Doppler in the prediction of pressure gradients across coarctation of the aorta, and a characterization of foramen ovale and transatrial Doppler velocity patterns in the normal fetus.

Transthoracic Echocardiographic Assessment of Coronary Flow in the Diagnosis of Right Ventricular-Dependent Coronary Circulation in Pulmonary Atresia with Intact Ventricular Septum

Right ventricular-dependent coronary circulation (RVDCC) is associated with pulmonary atresia with intact ventricular septum and is defined by two or more epicardial coronary arteries with atresia or severe stenosis resulting in the dependency of coronary supply by retrograde flow. The hypothesis of this study is that coronary Doppler flow patterns on echocardiography can be used to distinguish patients with RVDCC. Between 2007 and 2016, we reviewed 16 patients with pulmonary atresia or critical pulmonary stenosis. Patients were divided into two groups, those with RVDCC (determined by angiography or pathology evaluation) and those without. Echocardiographic evaluation of the coronary arteries included 2-dimensional measurements and pulse wave Doppler flow pattern in 3 epicardial coronary arteries. Velocity-time integral (VTI) and maximal velocity (V_max) were measured and compared between the two groups. Three coronary flow patterns were demonstrated: (1) all antegrade flow, (2) antegrade to retrograde VTI flow ratio > 1, and (3) antegrade to retrograde VTI flow ratio ≤ 1. Of the 7 patients with RVDCC, 6 (86%) had evidence of flow pattern 3 in ≥ 2 of the 3 coronary arteries in contrast to 0 (0%) of the non-RVDCC patients (p = 0.001). Higher retrograde V_max was associated with RVDCC (p < 0.001) and coronary artery dilatation with Z-score ≥ + 3 was also associated with RVDCC (p = 0.02). Echocardiographic evaluation of the coronaries can be useful in identifying RVDCC. More retrograde flow in at least two coronary arteries is strongly suggestive of RVDCC. Dilatation of the coronary arteries is also supportive evidence.

Potential for Using 3D Technology to Image the Origins of the Coronary Arteries

When young patients present to the echocardiography laboratory with chest pain, one consideration is that there may be an anomalous coronary artery. For this reason, it is critical that the sonographer evaluate the origins of the coronary arteries and map them with color Doppler flow to ensure that the blood is going in the correct direction. Although this may sound simple, not all sonographers have been trained to image the coronary arteries in detail and map them as far as possible. This pilot study investigated the feasibility of using volume acquisition from the parasternal short-axis and apical views. The results demonstrated that coronary artery origins can be successfully identified in adults using reconstruction of 3D volume data sets without adding significant time to the examination.

Adenosine induces dilation of epicardial coronary arteries in mice: relationship between coronary flow velocity reserve and coronary flow reserve in vivo using transthoracic echocardiography

For an accurate estimate of volumetric coronary flow reserve (CFR) using Doppler-assessed flow velocity measurement, it is important to take into consideration potential diameter change during coronary hyperemia. Using ultrasound techniques, left coronary artery (LCA) flow velocity and LCA lumen diameter (LCA(D)) were measured simultaneously for the first time to measure coronary flow during baseline and adenosine-induced hyperemic condition in isoflurane-anesthetized C57BL/6 (n = 38) and in old apolipoprotein E-gene deficient (ApoE(-/-)) mice (n = 44) mice. LCA(D) increased significantly and to a similar extent during adenosine infusion in both groups (3.7 +/- 1.1 %, p < 0.003 for C57BL/6; 4.2 +/- 0.9 %, p < 0.00003 for ApoE(-/-)). Yet, a positive correlation was still found between velocity-based coronary flow velocity reserve (CFVR) and volumetric CFR in both strains (R(2) = 0.77, p < 0.001 for C57BL/6; R(2) = 0.80, p < 0.001 for ApoE(-/-)). Coronary reserve was higher in C57BL/6 mice than in ApoE(-/-) mice (CFR 1.93 +/- 0.17 vs. 1.47 +/- 0.07, p < 0.05; CFVR 1.73 +/- 0.13 vs. 1.28 +/- 0.07, p < 0.01). Thus, ultrasound techniques can be used to measure volumetric flow in the LCA and flow-based CFR measurements of intact, living mice. The positive correlation between CFR and CFVR, together with the lower method variability of the latter, makes CFVR a more robust protocol for assessing mouse in-vivo coronary artery function. Therefore, the CFVR protocol will probably work well in most settings.

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.

Echocardiographic diagnosis of clinically silent congenital coronary artery anomalies

BACKGROUND

The incidence of congenital coronary anomalies is mainly derived from autopsy series and pre-participation exams in athletes. Limited data exist regarding the spectrum of coronary anomalies that can be detected in asymptomatic patients. We sought to describe echocardiographically detected congenital coronary artery anomalies in asymptomatic children after implementing a screening protocol mandating identification of coronary artery origin and proximal course in all initial studies.

METHODS

Our database was searched from 1/1/1993 to 3/31/2006 and all echocardiograms coded for coronary anomalies were identified. Clinically "silent" congenital coronary anomalies were culled from that group.

RESULTS

Of the 168 "silent" coronary anomalies detected, 111 were anomalies of aortic origin, including 59 patients with "high coronary takeoff" and 30 patients with "wrong sinus" origin of either the left or right coronary artery. Small coronary fistulas were seen in 57. Associated congenital heart defects were found in 53% of individuals with coronary anomalies.

CONCLUSIONS

This study comprises the largest group of echocardiographically detected, "silent" but potentially clinically significant, congenital coronary anomalies in children. Prospective echocardiographic diagnosis of "high coronary takeoff", a risk factor for injury during cardio-pulmonary bypass, and asymptomatic intraseptal coronary stenosis are described for the first time.

Posterior descending coronary artery flow reserve assessment by Doppler echocardiography in children with and without congenital heart defect: comparison with invasive technique

To evaluate whether transthoracic Doppler echocardiography can reliably measure coronary flow velocity and coronary flow velocity reserve (CFVR) in the posterior descending coronary artery (PD) in children, we examined 32 patients who had congenital heart disease (ventricular septal defect in 10, tetralogy of Fallot in 6, tricuspid atresia in 3, double-outlet right ventricle in 2, patent ductus arteriosus in 2, and aortic valve stenosis in 2) and 7 patients who had a history of Kawasaki disease without stenosis or aneurysm formation of the coronary artery. Average peak flow velocity (APV) in the PD was measured by transthoracic Doppler echocardiography at the time of intracoronary Doppler study. CFVR was defined as the ratio of hyperemic to basal APV. Clear envelopes of basal and hyperemic APV in the PD were obtained in 23 of 32 patients by transthoracic Doppler echocardiography. APV obtained from transthoracic Doppler echocardiography correlated highly with that from the Doppler guidewire method (r=0.91). The mean difference between transthoracic Doppler echocardiography and the Doppler guidewire method was 0.1+/-2.9. There was an excellent correlation between transthoracic Doppler echocardiography and the Doppler guidewire method for the measurements of CFVR (r=0.84). The mean difference between transthoracic Doppler echocardiography and Doppler guidewire was -0.016+/-0.198. Noninvasive measurement of coronary flow velocity and CFVR in the PD using transthoracic Doppler echocardiography accurately reflects invasive measurement of coronary flow velocity and CFVR by the Doppler guidewire method in pediatric patients with various heart diseases.

Effects of coil closure of patent ductus arteriosus on left anterior descending coronary artery blood flow using transthoracic Doppler echocardiography

Transthoracic Doppler echocardiography provides noninvasive measurements of coronary blood flow in the left anterior descending coronary artery (LAD). This method has the potential to show the effects of acute changes in loading conditions on blood flow. Coil closure of patent ductus arteriosus (PDA) is a model of acute changes in blood pressure and left ventricular (LV) preload that influences coronary blood flow. We applied this technique to assess the coronary blood flow changes for patients with PDA before and immediately after PDA coil closure. We examined 9 patients (1.8 +/- 1.1 years) with simple PDA and 8 age-matched healthy children. LV dimensions and LV mass were measured. Maximum peak flow velocity and flow volume in the LAD were measured. Pulmonary to systemic flow ratios (Qp/Qs) were obtained by cardiac catheterization. After PDA coil closure, LV end-diastolic dimension decreased, and systolic and diastolic blood pressures increased significantly. The maximum peak flow velocity, LAD flow volume, and the ratio of LAD flow volume to LV mass increased significantly. The changes in maximum peak flow velocity and the ratio of LAD flow volume to LV mass (F/M) correlated positively with the changes in diastolic pressure and Qp/Qs. In 5 patients who had Qp/Qs > 1.5, the mean F/M was significantly lower compared with control subjects, but they increased to normal values after coil closure of PDA. PDA coil closure increases diastolic pressure and decreases Qp/Qs, resulting in improvement of myocardial perfusion. These findings provide new insights into the relationship between cardiac function and coronary circulation in pediatric patients with heart diseases associated with PDA.

Normal values for left anterior descending coronary artery flow velocity assessed by transthoracic doppler echocardiography in healthy children

Normal values for left anterior descending coronary artery (LAD) flow velocity were assessed from a large number of normal children. In 303 healthy children, LAD peak flow velocity was measured by Doppler echocardiography. LAD peak flow velocities were calculated considering the angle between the Doppler beam and the coronary flow direction. The flow signals of LAD were recorded in 95% (288/303). The mean angle between the Doppler beam and Doppler flow signals of LAD was 42 +/- 8 degrees. The ratio of AT to total diastolic spectral duration was 0.19 +/- 0.088 and constant with age. LAD peak flow velocity correlated significantly with age (r = -0.57, p < 0.0001) and heart rate (r = 0.63, p < 0.0001). Multiple linear regression analysis showed that LAD peak flow velocity was associated with age and heart rate (LAD peak flow velocity = 20-0.34 (age) + 0.16 (heart rate), r2 = 0.41, p < 0 .0001). Normal data obtained in the present study provide a basis of the understanding and investigation in children with congenital heart disease or acquired heart disease such as atherosclerosis, left ventricular hypertrophy, or Kawasaki's disease.

Effects of balloon valvuloplasty on left anterior descending coronary artery blood flow in a neonate with critical aortic stenosis with transthoracic doppler echocardiography

Doppler echocardiography has recently been used in the assessment of coronary flow dynamics. We described the application of transthoracic Doppler echocardiography for the measurement of the coronary flow before and after balloon valvuloplasty in a neonate with critical aortic stenosis. In this case, coronary flow volume/left ventricular mass ratio increased after the procedure, suggesting the improvement of myocardial blood perfusion. Thus, this technique may provide additional information about coronary flow dynamics in patients with critical aortic stenosis.

Coronary flow reserve assessment by Doppler echocardiography in children with and without congenital heart defect: comparison with invasive technique

To evaluate whether transthoracic Doppler echocardiography can reliably measure coronary flow velocity (CFV) and CFV reserve (CFVR) in the left anterior descending coronary artery (LAD) in children, we examined 12 patients who had a history of Kawasaki disease without stenosis or aneurysm formation of coronary artery and 9 patients who had congenital heart disease (ventricular septal defect in 6, patent ductus arteriosus in 2, tricuspid atresia in 1). The pulmonary-to-systemic flow ratio ranged from 1.7 to 2.8. CFV in the proximal LAD was measured by transthoracic Doppler echocardiography at the time of Doppler guidewire examination. CFV in the proximal LAD was measured at baseline and hyperemic conditions by both transthoracic Doppler echocardiography and Doppler guidewire techniques. CFVR was defined as "the ratio of peak hyperemic to basal CFV in the proximal LAD." Clear envelopes of basal and hyperemic CFV in the proximal LAD were obtained in 19 of 21 patients by transthoracic Doppler echocardiography. There was a significant correlation between transthoracic Doppler echocardiography and Doppler guidewire methods for the measurements of CFV (r = 0.84, P <.0001). The mean difference between the 2 methods was -0.5 +/- 5.9 cm/s. CFVR from transthoracic Doppler echocardiography correlated well with that from Doppler guidewire examinations (r = 0.83, P <.0001). The mean difference between the 2 methods was 0.06 +/- 0.24. Noninvasive measurement of CFV and CFVR in the proximal LAD using transthoracic Doppler echocardiography accurately reflects invasive measurement of CFV and CFVR by Doppler guidewire method in pediatric patients with various heart diseases.

Normal Coronary Flow Reserve After Arterial Switch Operation for Transposition of the Great Arteries

Background— Recent studies performed with positron emission tomography have suggested that coronary flow reserve (CFR) is moderately to severely reduced after the arterial switch operation (ASO). These findings are of great concern but have not been confirmed by other methods.

Methods and Results— Eleven symptom-free children were studied between 4 and 11 (median 6.0) years after the ASO. Flow velocity in the left anterior descending (LAD) and right coronary arteries (RCA) was measured with a 0.014-inch Doppler FloWire (Cardiometrics) before and after intracoronary injection of adenosine (0.5 μg/kg) and nitroglycerin (5 μg/kg). CFR was defined as the ratio of hyperemic to basal average peak velocity (APV). The median (range) CFR in the LAD was 3.7 (3.0 to 4.8) and 3.4 (2.9 to 4.8) in the RCA. The increase in APV after intracoronary injection of nitroglycerin was 300% (240% to 420%) in the LAD and 260% (190% to 460%) in the RCA. APV at rest was 15.0 (14.0 to 21.0) cm/s in the LAD and 16.0 (9.6 to 30.0) cm/s in the RCA. A linear relation was found between right ventricular systolic pressure and resting APV in the RCA ( r =0.77, P =0.0056), and between resting APV and CFR ( r =-0.61, P <0.05) in the RCA.

Conclusions— The CFR and coronary vasoreactivity to nitroglycerin in children treated for transposition of the great arteries with the ASO was within normal limits. Increased right ventricular pressure and myocardial hypertrophy can cause increased resting coronary flow velocity in the RCA and affect CFR negatively.

Pulmonary Atresia with Intact Ventricular Septum

The prognosis for patients with pulmonary atresia with intact ventricular septum is poor with and without conventional surgical treatment. Because of this reason, a comprehensive program of medical, transcatheter, and surgical treatment is necessary to improve the long-term outlook of these infants. Algorithms of management plans should be developed based on the presence of right ventricular-dependent coronary circulation as well as size and morphology of the right ventricle. In a tripartite or bipartite right ventricle, transcatheter radiofrequency perforation is preferable. Alternatively, surgical valvotomy may be performed. Augmentation of pulmonary blood flow by prolonged infusion of prostaglandin E(1), stenting the ductus, or a surgical modified Blalock-Taussig shunt may be necessary in some of these patients. In patients with a unipartite or very small right ventricle or a right ventricular-dependent coronary circulation (Tricuspid valve Z score < -2.5), augmentation of pulmonary flow along with atrial septostomy should be undertaken. Follow-up studies to determine the feasibility of biventricular repair should be undertaken and, if feasible, surgical or transcatheter methods may be used to achieve the goals. If not suitable for biventricular repair, one-ventricle (Fontan) or one and one-half ventricular repair should be considered. Comprehensive and well-planned treatment algorithms may help improve survival rate.

Blood flow in the left anterior descending coronary artery in children with ventricular septal defect

High-frequency echocardiography offers a noninvasive approach for imaging left anterior descending coronary artery (LAD) blood flow from a transthoracic window. The purpose of this study was to assess the effects of left ventricular (LV) volume overload on LAD flow in pediatric patients with ventricular septal defect (VSD). The study subjects consisted of 38 children with VSD and 15 healthy children. LV mass, LAD diameter, and LAD flow were measured by using transthoracic echocardiography, then LAD diameter and LV mass were indexed for body surface area. Pulmonary to systemic flow ratios (Qp/Qs) were obtained by cardiac catheterization. The Qp/Qs ratios ranged from 1.2 to 3.1 (mean 2.1 +/- 0.5). The mean LAD flow velocities, flow velocity integrals, and flow volumes were significantly higher in the patients than in the control subjects. LAD flow velocity and flow volume showed significant positive correlations with Qp/Qs, LV mass, and LV end-diastolic volume. Stepwise regression analysis revealed that Qp/Qs was the most important determinant of both LAD flow velocity (r(2) = 0.45, P < .0001) and LAD flow volume (r(2) = 0.44, P < .0001). The ratios of LAD flow volume to LV mass did not differ between the 2 groups. In 8 patients who underwent surgical treatment, LAD flow velocity, flow velocity integral, and flow volume decreased significantly after surgery. The current results suggest that patients with VSD have a higher resting coronary blood flow, and that LAD flow pattern is dependent on LV volume overload and changes after surgery.

Left anterior descending coronary artery flow and its relation to age in children

Recent advances in Doppler and color echocardiographic techniques enable coronary flow dynamics to be estimated even in children. To assess quantitatively left anterior descending coronary artery (LAD) volumetric flow and to determine its relation to age and left ventricular (LV) mass, healthy children participated in a study that used high-frequency transthoracic echocardiography. We also studied whether Doppler echocardiography can reliably measure LAD flow in a clinical setting. In 57 healthy children, 2-dimensional echocardiography was used to measure the diameter and cross-sectional area of the LAD and LV mass. LAD peak flow velocity, flow velocity integral, and flow volume were measured by Doppler echocardiography. We then calculated the ratio of LAD cross-sectional area to LV mass and the ratio of LAD flow volume to LV mass. In 12 patients with Kawasaki disease, LAD flow velocity and flow velocity integral were measured by Doppler echocardiography at the time of Doppler guide wire examination. There were significant correlations between echocardiographic and Doppler guide wire methods for flow velocity and flow velocity integral (r = 0.77 and 0.83, P <.01, respectively). The LAD flow velocity decreased significantly with age (r = -0.43, P <.01). The LAD flow volume per minute increased significantly with age (r = 0.55, P <.01). However, LAD flow volume/LV mass ratio in younger infants was high and decreased significantly with age (r = -0.66, P <.01). This study shows that LAD flow patterns can be reliably assessed by transthoracic Doppler echocardiography in the majority of pediatric subjects. In the current study, the LAD flow velocity and the ratio of LAD flow volume to LV mass in infants was high and decreased with age, suggesting high myocardial perfusion. High LAD peak velocity in infants may be related with high resting coronary flow. Age-related changes in the LAD flow characteristics must be taken into consideration in the study of the coronary circulation in children.

Effects of dobutamine on coronary flow velocity response and their relations to age

The purpose of this study was to assess the effects of low-dose dobutamine on left ventricular (LV) functional and coronary flow reserves using transthracic echocardiography. The study group consisted of 30 children aged from 5 months to 16 years (mean 4.8 +/- 4.4 years). Echocardiographic studies were repeated before and during dobutamine infusion (5 microg/kg per minute). The peak diastolic velocity in the left descending coronary artery (LAD) was recorded by pulsed-Doppler under the guidance of color Doppler flow mapping. The coronary flow velocity (CFV) response was calculated as the ratio of LAD peak flow velocity at dobutamine infusion to basal LAD peak flow velocity. Left ventricular contractility was calculated by two-dimensionally directed M-mode echocardiography. The rate-corrected mean velocity of circumferential fiber shortening (mVcfc) and LV end-systolic wall stress (ESS) were used as indices of contractility. Adequate spectral Doppler recordings of the LAD peak flow velocity for the assessment of CFV response were obtained in 26 of 30 patients (87%). The LAD peak flow velocity at dobutamine infusion increased significantly compared with the basal values. The CFV response in the younger children was low and increased significantly with age. The CFV response did not show significant correlations with the changes in heart rate, systolic blood pressure, rate-pressure product, nor ESS during dobutamine infusion. However, a significant relationship between the CFV response and the percent change of mVcfc was observed. In the present study using high frequency transthoracic echocardiography, we demonstrated the age-related changes in CFV response and LV functional reserve by dobutamine infusion. Responses of LV contractility and coronary flow to dobutamine are less sensitive in youngerchildren and increased with increasing age.

Coronary flow abnormalities in neonates with aortic stenosis

Left coronary artery flow velocities in neonates were determined noninvasively with transthoracic pulsed wave Doppler ultrasonography. In normal subjects (n = 30) there was diastolic flow predominance with median (range) peak flow velocity in diastole, 23.8 cm/s (12.7 to 51.3 cm/s), and median peak flow velocity in systole, 12.7 cm/s (7.8 to 35.0 cm/s). In 3 neonates with severe aortic stenosis, retrograde left coronary flow throughout systole was observed before surgery. In these patients there was forward systolic flow 4 to 8 days after successful surgical valvulotomy was performed.

Aberrant origin of the left coronary artery from the right aortic sinus: surgical intervention based on echocardiographic diagnosis

An athletic 15-year-old girl with aberrant left coronary artery from the right coronary sinus, presented with syncope during exercise. Trans-thoracic echocardiography was the only imaging technique that clearly demonstrated her anomaly. The results of magnetic resonance and selective coronary angiographic imaging were inconclusive. Surgical intervention was successfully performed on the basis of the echocardiographic diagnosis.

Main coronary artery and coronary ostial stenosis in children: detection by transthoracic color flow and pulsed Doppler echocardiography

Coronary artery stenosis (CAS) and coronary ostial stenosis (COS) are potentially life-threatening conditions. The echocardiographic diagnosis of CAS and COS in children has not been described. We report on the transthoracic echocardiography (TTE) findings of CAS and COS in children. Six patients, aged 1 week to 12 years, with clinically confirmed COS (n = 5) and CAS (n = l) were diagnosed by TTE. Their echocardiographic findings were compared with 26 healthy control subjects of a similar age range. Left COS was associated with an aberrant left coronary artery (CA) from the contralateral aortic sinus (n = 2), an intramural left CA with d-transposition of the great vessels (n = l), and supravalvular aortic stenosis (n = l). Right COS was present in a patient with aortic valvular stenosis. Acquired left main CAS was diagnosed in the sixth patient 3 years after orthotopic heart transplantation. Coronary ostial stenosis was recognized when a color flow acceleration signal was present proximal to and extending into the coronary ostium (CO). Coronary artery stenosis was detected when a coarctated color flow stream was present within the stenosed CA segment with turbulent distal flow. These findings were not detected in the control cohort who demonstrated laminar CA and CO flow signals. All patients had increased spectral velocity in the CA distal to the stenosed segment (patients = 50 +/- 5 cm/s, controls = 24 +/- 6 cm/sec; P <.01). Delayed peak diastolic velocity seemed to indicate severe stenosis. We conclude that (1) CO acceleration signals and turbulent coarctated CA flow signals are abnormal findings in TTE coronary Doppler assessment. They indicate COS and CAS, respectively. (2) Knowledge of the normal TTE CA flow velocity patterns is essential so that abnormal velocity signals such as seen with CAS and COS can be recognized and a timely diagnosis made.

A case for routine screening of coronary artery origins during echocardiography: fortuitous discovery of a life-threatening coronary anomaly

Anomalous origin of the left main coronary artery from the right sinus of Valsalva with retropulmonary course is a rare congenital abnormality. It is associated with a high incidence of sudden cardiac death, particularly among young, athletic individuals. Many of these individuals do not have symptoms before sudden death, and the diagnosis is usually made at postmortem examination. We present a case of a 15-year-old boy who was evaluated for a systolic click with routine 2-dimensional echocardiography. The anomalous coronary artery was serendipitously identified, allowing surgical intervention. Coronary artery origin and proximal course should be visualized on routine echocardiography in the pediatric population.