Pulmonary Annular Motion Velocity Assessed Using Doppler Tissue Imaging - Novel Echocardiographic Evaluation of Right Ventricular Outflow Tract Function

BACKGROUND

We assessed whether measuring pulmonary annular motion velocity could serve as a novel method of evaluating right ventricular outflow tract (RVOT) performance in pediatric patients with heart disease.

METHODS AND RESULTS

Tissue Doppler-derived pulmonary annular motion velocity was determined from the parasternal long-axis view of the RVOT. Pulmonary annular velocity was measured in children (age, 5-10 years) with an atrial septal defect (ASD), pulmonary arterial hypertension (PAH), surgically repaired tetralogy of Fallot (TOF) and healthy children (control). Pulmonary annular velocity waveforms comprised systolic bimodal (s1' and s2') and diastolic e' and a' waves in all groups. The peak velocity of s1' and s2' was significantly higher in the ASD group than in the controls (15.0±2.4 vs. 11.2±2.1 and 6.0±0.9 vs. 4.4±1.2 cm/s; P<0.01 and P<0.001, respectively). The s1' and s2' peak velocities were significantly lower in the PAH group (8.5±1.2 and 3.2±0.4 cm/s; P<0.05 for both), and in the group with TOF (5.3±2.2 and 3.4±1.4 cm/s; P<0.001 and P<0.05, respectively). The peak velocity of e' was significantly decreased in the PAH and TOF, compared with the control group (6.8±1.6 and 8.2±2.9 vs. 11.9±1.9 cm/s; P<0.001 for both).

CONCLUSIONS

Pulmonary annular motion velocity determined using tissue Doppler imaging is a promising method of assessing RVOT function.

Right ventricular thrombosis in two patients with pulmonary atresia with intact ventricular septum

Thrombosis was detected in the right ventricle 7 days after a bidirectional Glenn operation in a 1-year-old boy with pulmonary atresia with intact ventricular septum (PAIVS) and immediately before pulmonary valvuloplasty in a 21-day-old boy with PAIVS. The risk of thrombosis and the blood clotting cascade should be assessed by blood tests, and surveillance echocardiography should be frequently applied in order to diagnose thrombosis early in such patients.

Ratio of early diastolic tricuspid inflow to tricuspid lateral annulus velocity reflects pulmonary regurgitation severity but not right ventricular diastolic function in children with repaired Tetralogy of Fallot

The current study assessed relationships between the ratio of early diastolic tricuspid inflow to tricuspid lateral annular velocity (tricuspid E/e') and right ventricular (RV) function in children after tetralogy of Fallot (TOF) repair. The RV function of 25 asymptomatic children with surgically repaired TOF (age 3.3 ± 2.0 years) was assessed by echocardiography and cardiac catheterization. Right ventricular end-diastolic pressure and volume (RVEDP and RVEDV), systolic pressure, and ejection fraction, as well as mean pulmonary arterial pressure, mean right atrial pressure (RAP), and the severity of both pulmonary regurgitation (PR) and tricuspid regurgitation (TR) were assessed in terms of the contribution to tricuspid E/e'. Univariate analysis discovered a relationship between tricuspid E/e' and RVEDV (R(2) = 0172), pressure half-time of PR (PR-PHT) (R(2) = 0.173), and TR grade (R(2) = 0.145) (p < 0.01 for each). After multivariate adjustment, PR-PHT was significantly associated with tricuspid E/e' (β = 0.210; p < 0.001). Tricuspid E/e' was not significantly associated with RVEDP or RAP. In conclusion, tricuspid E/e' does not indicate RV diastolic function but reflects the severity of PR in asymptomatic children after TOF repair.

Subclavian and pulmonary artery steal phenomenon in a patient with isolated left subclavian artery and right aortic arch

We describe a patient with an isolated left subclavian artery associated with right aortic arch, patent ductus arteriosus, and ventricular septal defect. As the isolated left subclavian artery is supplied by the left vertebral artery in which blood flows in the retrograde direction, this anomaly is usually responsible for a congenital subclavian steal phenomenon. Atrophy of the left cerebral hemisphere and inverted left vertebral arterial flow were clearly depicted by echoencephalography in this patient, whose subclavian artery was connected to the main pulmonary artery by a patent ductus arteriosus.

Complete but not partial thymectomy in early infancy reduces T-cell-mediated immune response: three-year tracing study after pediatric cardiac surgery

OBJECTIVE

Thymectomy is often performed to secure an operative field in surgery for congenital heart defects in early infancy. However, how neonatal thymectomy affects the subsequent development of the immune system in humans remains unclear. We monitored patients for 3 years from the time of thymectomy that was performed during cardiac surgery in early infancy.

METHODS

For up to 3 years, we monitored the number of circulating lymphocytes and the clinical course of the children who underwent complete (n = 17), partial, and no (n = 15) thymectomy during congenital heart defect surgery performed at less than 3 months of age. The titers of immunoglobulin-G produced in response to vaccinated viruses and phytohemagglutinin responses were also measured.

RESULTS

Six months after surgery, the number of T cells, including CD4(+) and CD8(+) subpopulations, decreased in patients with complete but not partial thymectomy. The reduction in T-cell number persisted for 3 years, whereas the number of B cells did not change. In patients with complete thymectomy, the titers of immunoglobulin-G produced in response to vaccinated measles and rubella viruses were reduced, whereas the phytohemagglutinin-induced proliferation of T cells was not impaired. In addition, hospitalization frequency associated with infectious diseases increased in patients with complete but not partial thymectomy.

CONCLUSIONS

The results revealed that complete thymectomy in early infancy reduces the number of circulating T cells and T-cell-mediated immune responses for at least 3 years, suggesting that the thymus should be at least partially preserved during surgery in early infancy to maintain protective immunity.

Multidetector-row computed tomography evaluation of bilateral bronchial narrowing associated with increased pulmonary blood flow in children with congenital heart disease

BACKGROUND

Quantitative assessment of bilateral bronchial narrowing in children with congenital heart disease (CHD) with a left-to-right shunt has not yet been reported.

OBJECTIVE

In the present study, main bronchial size was evaluated bilaterally in normal subjects using multidetector-row computed tomography (MDCT), and the feasibility for diagnosis of bronchial narrowing in children with CHD associated with increased pulmonary blood flow was investigated.

MATERIAL AND METHODS

The short-axis diameter, long-axis diameter, and the cross-sectional area of the bilateral bronchi were measured immediately proximal to the origin of the superior lobar branch in 86 children aged 1-52 months. Subjects were divided into three groups as follows: group 1 (normal subjects; n = 52), group 2 (asymptomatic left-to-right shunt group; n = 25), and group 3 (symptomatic left-to-right shunt group with respiratory insufficiency; n = 9).

RESULTS

Age, height, weight, and body surface area were significantly correlated with short- and long-axis bronchial diameters, and bronchial cross-sectional area in group 1. In group 2, the left bronchial cross-sectional area was significantly lower than group 1 (P < .001), whereas the right bronchial area was not significantly different. In group 3, the right bronchial area was significantly lower than that in groups 1 and 2 (P < .05). Although the left bronchial area in group 3 was significantly lower than in group 1 (P < .001), it was not significantly different from that in group 2.

CONCLUSION

Our study suggests that MDCT can be used to quantify bilateral bronchial narrowing. Left main bronchial obstruction develops during the early stage of heart failure, followed by the development of right bronchial narrowing.

Stent placement in the ductus venosus of a neonate with total anomalous pulmonary venous return

A newborn with right isomerism, infracardiac total anomalous pulmonary venous return (TAPVR), and obstruction of the ductus venosus underwent stent implantation in the ductus venosus at 4 h after birth. This procedure averted early pulmonary venous obstruction. Since gradual neointimal proliferation subsequently occurred within the stent, the patient underwent stent balloon dilatation at 35 days of age and underwent surgical repair of the TAPVR with a Blalock-Taussig shunt operation at 53 days of age. Finally, the patient was discharged without any complications. Transthoracic echocardiography is very useful to confirm subsequent minimal change within the stent.

A novel bilayer approach to ventricular septal deformation analysis by speckle tracking imaging in children with right ventricular overload

BACKGROUND

The aim of this study was to evaluate functional differences between the left and right sides of the ventricular septum in children with right ventricular overload.

METHODS

Radial, longitudinal, and circumferential strain on both sides of the ventricular septum were compared using speckle-tracking echocardiography in patients with preoperative atrial septal defects (n = 22), postoperative tetralogy of Fallot (n = 23) and age-matched normal controls (n = 44). The duration between peak strain of the left and right ventricular septum (TLt-Rt) was also evaluated.

RESULTS

Radial and circumferential strain in the control group were significantly higher on the left than the right ventricular septum (41.3 ± 12.8% vs 22.6 ± 6.8% and -28.0 ± 5.4% vs -22.5 ± 4.8%, respectively; P < .0001 for both), whereas longitudinal strain did not significantly differ (-22.0 ± 4.9% and -20.7 ± 5.2%, respectively). TLt-Rt was 52.9 ± 35.6, 33.4 ± 29.0, and 38.7 ± 31.0 msec for radial, longitudinal, and circumferential strain, respectively. Longitudinal and circumferential strain on both sides were significantly increased in patients with atrial septal defects compared with controls (P < .05), although radial strain was similar on both sides. Radial strain on the right side was significantly increased in patients with tetralogy of Fallot compared with controls (P < .05), whereas that on the left side was significantly reduced (P < .001). Longitudinal strain on both sides was significantly decreased (P < .01 and P < .001 for the left and right sides, respectively). In addition, TLt-Rt in patients with tetralogy of Fallot was significantly increased with radial and circumferential deformation (P < .05 for both).

CONCLUSIONS

Deformation of both sides of the ventricular septum functionally differed. Bilayer analysis of the ventricular septum can help in the evaluation of right ventricular performance under volume and pressure overload.

Consideration of the Pathological Features of Pediatric Congenital Heart Diseases Which Are Ideally Suitable for Diagnosing With Multidetector-row CT

Background

A lots of articles published regarding the usefulness of multidetector-row computed tomography (MDCT) in children with congenital heart disease (CHD) mostly describe that it can be an alternative to the invasive catheterization and angiography. The unique diagnostic features of this imaging modality have been largely ignored or disregarded. We described the pathological conditions that cannot be diagnosed by conventional angiography with cardiac catheterization but can be accurately diagnosed by MDCT.

Methods

We retrospectively reviewed non-ECG-gated MDCT images acquired from 452 children and young adults with CHD between 2005 and 2010 in our institute. In this article, we focused on the diagnostic advantages of MDCT, and indicated five pathological conditions. (1) When Blalock-Taussig shunt total occlusion prevents catheter insertion into the artificial vessel and angiography is ruled out, the peripheral pulmonary artery during the peripheral pulmonary artery can be imaged and diagnosed using MDCT based on blood flow supplied from many small collateral vessels originating from the aorta. (2) The location and protrusion of the device in the vessel after coil embolization to treat patent ductus arteriosus can be accurately visualized by virtual endoscopy using MDCT. (3) Calcification of patches, synthetic blood vessels, and other prostheses that is indistinct on conventional angiograms is clear on MDCT. (4) Simultaneous MDCT observations of the anatomical relationships between arterial and venous systems on the same image can clarify the detail diagnosis for surgical treatment. (5) Compression of the airways by the great vessels and pulmonary segmental emphysematous change can be diagnosed by MDCT.

Results and Conclusions

Among patients with CHD, MDCT is useful not only as a non-invasive alternative to conventional angiography, but also as a tool for specific morphological diagnoses. In the future, it will be necessary to accumulate experience in the recognition of cardiovascular conditions under which MDCT is necessary and to perform as the appropriate examination.

Multidetector-row computed tomography visualized peripheral pulmonary artery patency in a patient with occluded modified Blalock-Taussig shunt

Multidetector-row computed tomography visualized peripheral pulmonary artery patency in a 19-year-old female with a single ventricle and an occluded Blalock-Taussig shunt whereas conventional invasive angiography did not.

Pulmonary emphysematous changes in patients with congenital heart disease associated with increased pulmonary blood flow: evaluation using multidetector-row computed tomography

BACKGROUND

The present study aimed to evaluate the prevalence and the location of segmental emphysematous change in congenital heart disease (CHD) patients with increased pulmonary blood flow using multidetector-row computed tomography (MDCT).

METHODS

A total of 129 consecutive patients (mean age, 5.8±5.4 years; range, 1 month to 24 years) underwent MDCT angiography of the thorax. The frequency of emphysematous change was evaluated in patients with ventricular septal defect (VSD, n=61), atrial septal defect (ASD, n=27), patent ductus arteriosus (PDA, n=36) and complete atriventriclar septal defect (CAVSD, n=5). In 59 patients who underwent cardiac catheterisation, the relationships between the emphysematous change and both pulmonary to systemic blood flow ratio (Qp/Qs) and mean pulmonary arterial pressure (mPAP) were evaluated.

RESULTS

The emphysematous change was detected in 57 patients (44.2%) out of 129 patients. The frequency of segmental emphysematous change in left side was higher than in right side (14.8% vs. 6.5%). Both Qp/Qs and mPAP affected the presence of emphysema.

CONCLUSION

MDCT can provide accurate detection of segmental emphysema in patients with CHD. Emphysematous change is not uncommon pathological lesion in children and adolescents with CHD.

Serum concentration of heart-type fatty acid-binding protein in children and adolescents with congenital heart disease

BACKGROUND

Serum heart-type fatty acid-binding protein (H-FABP) is widely applied as a marker of cardiac myocyte injury. Recently, it has been reported that levels of H-FABP are elevated in adult patients with chronic heart failure and thus provide useful prognostic information. The aim of the present study was to examine the relationships between serum H-FABP levels and pathophysiological characteristics in children and adolescents with congenital heart disease (CHD).

METHODS AND RESULTS

Serum H-FABP levels were preoperatively and postoperatively measured in 238 consecutive patients with CHD aged 1-31 years. The relationships between H-FABP levels and severity of heart failure, circulatory status and laboratory data were cross-sectionally analyzed. Multivariate regression analysis indicated that serum H-FABP levels are independently affected by age, New York Heart Association functional class, creatine kinase MB, creatinine and arterial oxygen saturation (standard regression coefficients, -0.378, 0.237, 0.422, 0.615, and -0.210, respectively). Neither left ventricular ejection fraction nor B-type natriuretic peptide correlated with H-FABP levels.

CONCLUSIONS

H-FABP could serve as a new monitoring tool to provide information that will guide the optimal therapy and management of CHD patients.

Assessment of modified Blalock-Taussig shunt in children with congenital heart disease using multidetector-row computed tomography

The purpose of this study was to assess the feasibility of multidetector-row computed tomography (MDCT) for the evaluation of modified Blalock-Taussig (B-T) shunt in children with congenital heart disease associated with reduced pulmonary blood flow. A total of 25 consecutive patients (mean age, 2.6 ± 3.6 years; range, 2 months-16 years) underwent MDCT angiography of the thorax with a 16-detector row scanner prior to cardiac catheterization. A total of 39 shunts (right, 22; left, 17) were included in the study. Conventional angiographic findings were used as the gold standard for the detection of B-T shunts. Shunt diameter was measured quantitatively and independently at four sites (the subclavian artery site, the pulmonary artery site, the widest site, and the stenotic site) on MDCT and on conventional invasive angiography. All B-T shunts were depicted on multiplanar reconstruction (MPR), maximum intensity projection (MIP), curved planar reconstruction (CPR), and three-dimensional volume-rendered (VR) images, enabling evaluation in all patients except for one with occluded shunt. There were excellent correlations between MDCT- and conventional angiography-based measurements of shunt diameter at the subclavian artery site, pulmonary artery site, and the widest site (R² = 0.46, 0.74 and 0.64, respectively; p < 0.0001 for each), although systematic overestimation was observed for MDCT (mean percentage of overestimation, 23.1 ± 32.4%). Stenotic site diameter and degree of stenosis showed a mild correlation (R² = 010 and 0.25, respectively; p < 0.01 for each). This study demonstrates that MDCT is a promising tool for the detection of lesions in B-T shunts.