Corrigendum: Use of the index of pulmonary vascular disease for predicting longterm outcome of pulmonary arterial hypertension associated with congenital heart disease

[This corrects the article DOI: 10.3389/fcvm.2023.1212882.].

Use of the index of pulmonary vascular disease for predicting long-term outcome of pulmonary arterial hypertension associated with congenital heart disease

Aims

Limited data exist on risk factors for the long-term outcome of pulmonary arterial hypertension (PAH) associated with congenital heart disease (CHD-PAH). We focused on the index of pulmonary vascular disease (IPVD), an assessment system for pulmonary artery pathology specimens. The IPVD classifies pulmonary vascular lesions into four categories based on severity: (1) no intimal thickening, (2) cellular thickening of the intima, (3) fibrous thickening of the intima, and (4) destruction of the tunica media, with the overall grade expressed as an additive mean of these scores. This study aimed to investigate the relationship between IPVD and the long-term outcome of CHD-PAH.

Methods

This retrospective study examined lung pathology images of 764 patients with CHD-PAH aged <20 years whose lung specimens were submitted to the Japanese Research Institute of Pulmonary Vasculature for pulmonary pathological review between 2001 and 2020. Clinical information was collected retrospectively by each attending physician. The primary endpoint was cardiovascular death.

Results

The 5-year, 10-year, 15-year, and 20-year cardiovascular death-free survival rates for all patients were 92.0%, 90.4%, 87.3%, and 86.1%, respectively. The group with an IPVD of ≥2.0 had significantly poorer survival than the group with an IPVD <2.0 (P = .037). The Cox proportional hazards model adjusted for the presence of congenital anomaly syndromes associated with pulmonary hypertension, and age at lung biopsy showed similar results (hazard ratio 4.46; 95% confidence interval: 1.45-13.73; P = .009).

Conclusions

The IPVD scoring system is useful for predicting the long-term outcome of CHD-PAH. For patients with an IPVD of ≥2.0, treatment strategies, including choosing palliative procedures such as pulmonary artery banding to restrict pulmonary blood flow and postponement of intracardiac repair, should be more carefully considered.

Analysis of Coronary Arterial Aneurysm Regression in Patients With Kawasaki Disease by Aneurysm Severity: Factors Associated With Regression

Background Coronary arterial aneurysms (CAAs) associated with Kawasaki disease (KD) significantly affect prognosis. However, the clinical course of CAAs and factors associated with CAA regression have not been well analyzed. Methods and Results The cohort of the Z-Score 2nd Project Stage study, a multicenter, retrospective, cohort study involving 44 institutions in Japan including 1006 patients with KD, was examined. CAAs were classified by the z score of their internal diameter in the acute phase: small (z<5), medium (5≤z<10), and large (z≥10). The lower limit of small CAA was based on the Japanese Ministry of Health, Labour and Welfare criteria. In the right coronary artery, the CAA regression rates 10 years after diagnosis were 95.5% for small, 83.2% for medium, and 36.3% for large. In the proximal left anterior descending artery, the regression rates 10 years after diagnosis were 95.3% for small, 80.1% for medium, and 28.8% for large. Cox regression analysis showed that diagnosis under the age of 1 year and onset of KD in 2010 to 2012 for the right coronary artery and the left anterior descending artery, and female for the right coronary artery were significantly associated with a high regression rate, whereas large CAAs for the right coronary artery and the left anterior descending artery were significantly associated with a low regression rate. Conclusions The current study, the largest Japanese study of its kind, found that small aneurysm, recent onset, and diagnosis under the age of 1 year predict regression, and that even giant aneurysms could regress. These data may contribute to long-term management of coronary aneurysms. Registration URL: https://www.umin.ac.jp/ctr/; Unique identifier: UMIN000010606.

Novel large deletion involving EVC and EVC2 in Ellis-van Creveld syndrome

Ellis-van Creveld syndrome is an autosomal recessive skeletal dysplasia that is characterized by thoracic hypoplasia, polydactyly, oral abnormalities, and congenital heart disease. It is caused by pathogenic variants in the EVC or EVC2 genes. We report a case of a newborn with a compound heterozygous variant comprising NM_147127.5: c.1991dup:[p.Lys665Glufs*10] in the EVC2 gene and a novel large deletion involving exon 1 in EVC and exons 1-7 in EVC2.

Duplications in the G3 domain or switch II region in HRAS identified in patients with Costello syndrome

Costello syndrome (CS) is an autosomal-dominant disorder characterized by distinctive facial features, hypertrophic cardiomyopathy, skeletal abnormalities, intellectual disability, and predisposition to cancers. Germline variants in HRAS have been identified in patients with CS. Intragenic HRAS duplications have been reported in three patients with a milder phenotype of CS. In this study, we identified two known HRAS variants, p.(Glu63_Asp69dup), p.(Glu62_Arg68dup), and one novel HRAS variant, p.(Ile55_Asp57dup), in patients with CS, including a patient with craniosynostosis. These intragenic duplications are located in the G3 domain and the switch II region. Cells expressing cDNA with these three intragenic duplications showed an increase in ELK-1 transactivation. Injection of wild-type or mutant HRAS mRNAs with intragenic duplications in zebrafish embryos showed significant elongation of the yolk at 11 h postfertilization, which was improved by MEK inhibitor treatment, and a variety of developmental abnormalities at 3 days post fertilization was observed. These results indicate that small in-frame duplications affecting the G3 domain and switch II region of HRAS increase the activation of the ERK pathway, resulting in developmental abnormalities in zebrafish or patients with CS.

Three-dimensional imaging of pulmonary arterial vasa vasorum using optical coherence tomography in patients after bidirectional Glenn and Fontan procedures

AIMS

We evaluated pulmonary arterial (PA) vasa vasorum (VV) in Fontan candidate patients with a novel three-dimensional (3D) imaging technique using optical coherence tomography (OCT).

METHODS AND RESULTS

This prospective study assessed the development of adventitial VV in the distal PA of 10 patients with bidirectional Glenn circulation (BDG group, 1.6 ± 0.3 years) and Fontan circulation (Fontan group, 3.3 ± 0.3 years), and in 20 children with normal PA haemodynamics and morphology (Control group, 1.5 ± 0.3 years). We assessed the PA VV with two-dimensional (2D) cross-sectional, multi-planar reconstruction (MPR), and volume rendering (VR) imaging. VV development was evaluated by the VV area/volume ratio, defined as the VV area/volume divided by the adventitial area/volume. Compared to the control group, the observed VV number and diameter on 3D images of MPR and VR were significantly higher, and curved and torturous-shaped VV were more frequently observed in the BDG and Fontan groups (P < 0.001, all). The median VV volume ratio was significantly greater in the BDG than in the control group (3.38% vs. 0.61%; P < 0.001). Although the VV volume ratio decreased significantly after the Fontan procedure (2.64%, P = 0.005 vs. BDG), the ratio remained higher than in the control group (P < 0.001 vs. control).

CONCLUSION

3D OCT imaging is a novel method that can be used to evaluate adventitial PA VV and may provide pathophysiological insight into the role of the PA VV in these patients.

Pregnancy and Delivery in Patients With Repaired Congenital Heart Disease - A Retrospective Japanese Multicenter Study

BACKGROUND

Although advances in cardiac surgery have led to an increased number of survivors with congenital heart disease (CHD), epidemiological data regarding the pregnancies and deliveries of patients with repaired CHD are scarce.Methods and Results:In this study, we retrospectively reviewed the clinical outcomes of pregnancies and deliveries of women with repaired CHD. Overall, 131 women with repaired CHD were enrolled and there were 269 gestations. All patients were classified as New York Heart Association (NYHA) Class I or II. The prevalence of cesarean sections was higher in patients with (CyCHD) than without (AcyCHD) a past history of cyanosis (51% vs. 19%, respectively; P<0.01). There were 228 offspring from 269 gestations and the most prevalent neonatal complication was premature birth (10%), which was more frequent in the CyCHD than AcyCHD group (15.7% vs. 5.6%, respectively; P<0.01). Five maternal cardiac complications during delivery were observed only in the CyCHD group (8%); these were classified as NYHA Class II and none was fatal.

CONCLUSIONS

Delivery was successful in most women with repaired CHD who were classified as NYHA Class I or II, although some with CyCHD and NYHA Class II required more attention. Cesarean sections were more common in the CyCHD than AcyCHD group, and CyCHD may be a potential risk for preterm deliveries.

Next-generation sequencing for the diagnosis of patients with congenital multiple anomalies and / or intellectual disabilities

Background : In clinical practice, a large proportion of patients with multiple congenital anomalies and/or intellectual disabilities (MCA / ID) lacks a specific diagnosis. Recently, next-generation sequencing (NGS) has become an efficient strategy for genetic diagnosis of patients with MCA/ID.

OBJECTIVE

To review the utility of NGS for the diagnosis of patients with MCA / ID.

METHOD

Patients with MCA/ID were recruited between 2013 and 2017. Molecular diagnosis was performed using NGS-based targeted panel sequencing for 4,813 genes. Promising causative variants underwent confirmation by Sanger sequencing or chromosomal microarray.

RESULTS

Eighteen patients with MCA/ID were enrolled in this study. Of them, 8 cases (44%) were diagnosed by targeted panel sequencing. Most of diagnosed patients were able to receive better counseling and more appropriate medical management.

CONCLUSION

NGS-based targeted panel sequencing seems to be an effective testing strategy for diagnosis of patients with MCA/ID. J. Med. Invest. 67 : 246-249, August, 2020.

Molecular diagnosis of an infant with TSC2/PKD1 contiguous gene syndrome

A 1-month-old Japanese infant with cardiac rhabdomyoma was diagnosed with TSC2/PKD1 contiguous gene syndrome by targeted panel sequencing with subsequent quantitative polymerase chain reaction that revealed gross monoallelic deletion, including parts of two genes: exons 19–42 of TSC2 and exons 2–46 of PKD1. Early molecular diagnosis can help to detect bilateral renal cyst formation and multidisciplinary follow-up of this multisystem disease.

Assessment of right ventricular function by isovolumic acceleration of pulmonary and tricuspid annulus in surgically repaired tetralogy of Fallot

Assessment of right ventricular (RV) function is quite important in patients with surgically corrected tetralogy of Fallot (TOF). However, quantitative assessment of RV function remains challenging, mainly because of the complex RV geometry. This prospective study investigated isovolumic acceleration (IVA), a parameter of myocardial systolic function not influenced by either preload or afterload, using tissue Doppler imaging. We evaluated IVA measured on pulmonary annulus (PA-IVA) and tricuspid annulus (TA-IVA), because we considered that PA-IVA and TA-IVA correspond with systolic function of the RV outflow tract (RVOT) and RV basal function, respectively. Thirty-nine patients with surgically repaired TOF (TOF group) and 40 age-matched healthy children (control group) were enrolled in this study. No significant difference was seen between TA-IVA (2.5 ± 0.8 m/s2) and PA-IVA (2.4 ± 0.8 m/s2) in the control group. In the TOF group, PA-IVA (1.0 ± 0.5 m/s2) was significantly lower than TA-IVA (1.3 ± 0.6 m/s2, p < 0.05). Both TA-IVA and PA-IVA were significantly lower in the TOF group than in the control group (p < 0.05 each). We concluded that PA-IVA offers a useful index to assess RVOT function in TOF patients. J. Med. Invest. 67 : 145-150, February, 2020.

Right Ventricular Myocardial Stiffness and Relaxation Components by Kinematic Model-Based Transtricuspid Flow Analysis in Children and Adolescents with Pulmonary Arterial Hypertension

We hypothesized that the kinematic model-based parameters obtained from the transtricuspid E-wave would be useful for evaluating the right ventricular diastolic property in pediatric pulmonary arterial hypertension (PAH) patients. The model was parametrized by stiffness/elastic recoil k, relaxation/damping c and load x. These parameters were determined as the solution of m⋅d²x/dt² + c⋅dx/dt + kx = 0, which is based on the theory that the E-wave contour is determined by the interplay of stiffness/restoring force, damping/relaxation force and load. The PAH group had a significantly higher k and c compared with the control group (182.5 ± 72.4 g/s vs. 135.7 ± 49.5 g/s², p = 0.0232, and 21.9 ± 6.5 g/s vs. 10.6 ± 5.2 g/s, p <0.0001, respectively). These results indicate that in the PAH group, the right ventricle had higher stiffness/elastic recoil and inferior cross-bridge relaxation. The present findings indicate the feasibility and utility of using kinematic model parameters to assess right ventricular diastolic function.

Optical coherence tomography for observing development of pulmonary arterial vasa vasorum after bidirectional cavopulmonary connection in children

BACKGROUND

Hypoxia and low pulmonary arterial (PA) blood flow stimulate the development of systemic-to-pulmonary collateral blood vessels, which can be an adverse factor when performing the Fontan operation. The aim of this study was to use optical coherence tomography (OCT) to elucidate the morphological changes in PA vasculature after creation of a bidirectional cavopulmonary connection (BCPC) in children.

METHODS

This prospective study evaluated PA wall thickness and development of PA vasa vasorum (VV) in the distal PA of eight patients (BCPC group, 1.3 ± 0.3 years) and 20 age-matched children with normal pulmonary artery hemodynamics and morphology (Control group, 1.4 ± 0.3 years). VV development was defined by the VV area ratio, defined as the VV area divided by the adventitial area in cross-sectional images.

RESULTS

There was no significant difference in PA wall thickness between the BCPC and control groups (0.12 ± 0.03 mm vs. 0.12 ± 0.02 mm, respectively). The VV area ratio was significantly greater in the BCPC group than in the Control group (14.5 ± 3.5% vs. 5.3 ± 1.6%, respectively; p<0.0001).

CONCLUSION

OCT is a promising new tool for evaluating PA pathology, including the development of VV in patients after BCPC.

Development of acquired intrapulmonary venous anastomosis contributing to establishment of Fontan circulation

Pulmonary venous (PV) obstruction is associated with a poor prognosis, as well as a high risk of recurrence, following surgical treatment. It can also interfere with the successful completion of Fontan circulation in patients with complex congenital heart disease. A case of a patient who had right isomerism (also known as asplenia syndrome), total anomalous pulmonary venous connection (TAPVC), and a single right ventricle is presented. Although bilateral total occlusion of the inferior PVs was identified postoperatively, the formation of the anastomosis and collateral vessels into the superior and middle PVs enabled successful completion of Fontan circulation. Anastomoses and collateral flow of the PVs were found largely in the interlobar pleura and not in the lung parenchyma.

Association of Severity of Coronary Artery Aneurysms in Patients With Kawasaki Disease and Risk of Later Coronary Events

IMPORTANCE

Few studies with sufficient statistical power have shown the association of the z score of the coronary arterial internal diameter with coronary events (CE) in patients with Kawasaki disease (KD) with coronary artery aneurysms (CAA).

OBJECTIVE

To clarify the association of the z score with time-dependent CE occurrence in patients with KD with CAA.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter, collaborative retrospective cohort study of 44 participating institutions included 1006 patients with KD younger than 19 years who received a coronary angiography between 1992 and 2011.

MAIN OUTCOMES AND MEASURES

The time-dependent occurrence of CE, including thrombosis, stenosis, obstruction, acute ischemic events, and coronary interventions, was analyzed for small (z score, <5), medium (z score, ≥5 to <10; actual internal diameter, <8 mm), and large (z score, ≥10 or ≥8 mm) CAA by the Kaplan-Meier method. The Cox proportional hazard regression model was used to identify risk factors for CE after adjusting for age, sex, size, morphology, number of CAA, resistance to initial intravenous immunoglobulin (IVIG) therapy, and antithrombotic medications.

RESULTS

Of 1006 patients, 714 (71%) were male, 341 (34%) received a diagnosis before age 1 year, 501 (50%) received a diagnosis between age 1 and 5 years, and 157 (16%) received a diagnosis at age 5 years or older. The 10-year event-free survival rate for CE was 100%, 94%, and 52% in men (P < .001) and 100%, 100%, and 75% in women (P < .001) for small, medium, and large CAA, respectively. The CE-free rate was 100%, 96%, and 79% in patients who were not resistant to IVIG therapy (P < .001) and 100%, 96%, and 51% in patients who were resistant to IVIG therapy (P < .001), respectively. Cox regression analysis revealed that large CAA (hazard ratio, 8.9; 95% CI, 5.1-15.4), male sex (hazard ratio, 2.8; 95% CI, 1.7-4.8), and resistance to IVIG therapy (hazard ratio, 2.2; 95% CI, 1.4-3.6) were significantly associated with CE.

CONCLUSIONS AND RELEVANCE

Classification using the internal diameter z score is useful for assessing the severity of CAA in relation to the time-dependent occurrence of CE and associated factors in patients with KD. Careful management of CE is necessary for all patients with KD with CAA, especially men and IVIG-resistant patients with a large CAA.

Analysis of Right Ventricular Myocardial Stiffness and Relaxation Components in Children and Adolescents With Pulmonary Arterial Hypertension

Background

The rate of left ventricular pressure decrease during isovolumic relaxation is traditionally assessed algebraically via 2 empirical indices: the monoexponential and logistic time constants (τ_E and τ_L). Since the pattern of right ventricular (RV) pressure decrease is quite different from that of the left ventricular, we hypothesized that novel kinematic model parameters are more appropriate and useful to evaluate RV diastolic dysfunction.

Methods and Results

Eight patients with pulmonary arterial hypertension (age 12.5±4.8 years) and 20 normal subjects (control group; age 12.3±4.4 years) were enrolled. The kinematic model was parametrized by stiffness/restoring Ek and damping/relaxation μ. The model predicts isovolumic relaxation pressure as a function of time as the solution of d²P/dt²+(1/μ)dP/dt+EkP=0, based on the theory that the pressure decay is determined by the interplay of inertial, stiffness/restoring, and damping/relaxation forces. In the assessment of RV diastolic function, τ_E and τ_L did not show significant differences between the pulmonary arterial hypertension and control groups (46.8±15.5 ms versus 32.5±14.6 ms, and 19.6±5.9 ms versus 14.5±7.2 ms, respectively). The pulmonary arterial hypertension group had a significantly higher Ek than the control group (915.9±84.2 s⁻² versus 487.0±99.6 s⁻², P<0.0001) and a significantly lower μ than the control group (16.5±4.3 ms versus 41.1±10.4 ms, P<0.0001). These results show that the RV has higher stiffness/elastic recoil and lower cross‐bridge relaxation in pulmonary arterial hypertension.

Conclusions

The present findings indicate the feasibility and utility of kinematic model parameters for assessing RV diastolic function.

Pulmonary annular motion velocity reflects right ventricular outflow tract function in children with surgically repaired congenital heart disease

Right ventricular (RV) dysfunction is generally evaluated using analyses of tricuspid annular motion. However, it represents only one aspect of RV performance. Whether measuring pulmonary annular motion velocity could serve as a novel way to evaluate global RV and/or RV outflow tract (RVOT) performance in pediatric congenital heart disease (CHD) patients with surgically repaired RVOT was evaluated. In this prospective study, tissue Doppler-derived pulmonary annular motion velocity was measured in children (aged 2-5 years) with RVOT reconstruction (RVOTR group, n = 48) and age-matched healthy children (Control, n = 60). The types of RVOTR procedures were as follows: pulmonary valve-sparing procedure (PVS, n = 7); transannular patch with monocusp valve reconstruction (TAP, n = 29); and RV-to-PA conduit reconstruction using a pericardial valve with expanded polytetrafluoroethylene conduit (Rastelli, n = 12). Pulmonary annular motion velocity waveforms comprised systolic bimodal (s1' and s2') and diastolic e' and a' waves in all participants. The peak velocities of s1', s2', e', and a' were significantly lower in the RVOTR group than in the control group (all p < 0.0001). Furthermore, these parameters depended significantly on the type of surgical procedure. The peak velocities of s1', s2', and e' had significant correlations with RVOT ejection fraction (RVOT-EF) (r = 0.56, 0.49, and 0.34, respectively), and RVOT fractional shortening (RVOT-FS) (r = 0.72, 0.55, and 0.41, respectively), although there were no significant correlations between pulmonary annular motion and global RV function, including RV ejection fraction (RVEF) and RV fractional area change (RVFAC) in the assessment of all RVOTR group patients. The pulmonary annular motion parameters in the PVS group had significant correlations with both global RV and RVOT performance. The TAP group showed significant correlations between RVOT function and pulmonary annular motion. The Rastelli group showed almost no significant correlations between RV/RVOT function and tissue Doppler parameters. Pulmonary annular motion velocity is a simple, rapid, reproducible, and useful method of assessing RVOT function in children with surgically repaired CHD.

Assessment of pulmonary arterial compliance evaluated using harmonic oscillator kinematics

We hypothesized that K_PA, a harmonic oscillator kinematics-derived spring constant parameter of the pulmonary artery pressure (PAP) profile, reflects PA compliance in pediatric patients. In this prospective study of 33 children (age range = 0.5–20 years) with various cardiac diseases, we assessed the novel parameter designated as K_PA calculated using the pressure phase plane and the equation K_PA = (dP/dt_max)²/([Pmax – Pmin])/2)², where dP/dt_max is the peak derivative of PAP, and Pmax – Pmin is the difference between the minimum and maximum PAP. PA compliance was also calculated using two conventional methods: systolic PA compliance (sPAC) was expressed as the stroke volume/Pmax – Pmin; and diastolic PA compliance (dPAC) was determined according to a two-element Windkessel model of PA diastolic pressure decay. In addition, data were recorded during abdominal compression to determine the influence of preload on K_PA. A significant correlation was observed between K_PA and sPAC (r = 0.52, P = 0.0018), but not dPAC. Significant correlations were also seen with the time constant (τ) of diastolic PAP (r = −0.51, P = 0.0026) and the pulmonary vascular resistance index (r = −0.39, P = 0.0242). No significant difference in K_PA was seen between before and after abdominal compression. K_PA had a higher intraclass correlation coefficient than other compliance and resistance parameters for both intra-observer and inter-observer variability (0.998 and 0.997, respectively). These results suggest that K_PA can provide insight into the underlying mechanisms and facilitate the quantification of PA compliance.

Prenatal assessment of coronary artery anatomy using color Doppler in cases of D-transposition of the great arteries: Case reports

Abnormal coronary artery (CA) anatomy is common in cases of D-transposition of the great arteries (TGA) and can be a significant risk factor during the arterial switch operation. Here, we report three cases of TGA in which CA anatomy was assessed prenatally using color Doppler imaging. All CA, except the left circumflex CA in one case, were identified. CA anatomy was completely correctly diagnosed in one of our three cases. In the two remaining cases, the left circumflex CA could not be visualized in one patient, and the origin of the left anterior descending CA was not correctly diagnosed in the other. We found that prenatal assessment of CA anatomy using color Doppler in TGA was feasible, but the diagnostic accuracy was limited. We anticipate that more experience with the advancing technology will improve accuracy.

Long-term Results After Open Mitral Commissurotomy for a One-Month-Old Infant With Mitral Stenosis

The strategy for an infant with congenital mitral stenosis should be determined by three important factors: left ventricular volume, the degree of the systemic outflow tract obstruction, and the type of mitral valve dysfunction. A successful staged biventricular repair in early infancy for a patient who had congenital mitral stenosis with short chordae, hypoplastic left ventricle and coarctation of the aorta, and the long-term results are described. There were the following important hemodynamic factors that led to the successful biventricular repair in the patient. Total systemic output was barely supplied through the hypoplastic left ventricle after closure of the ductus arteriosus on admission. The neonate underwent repair of coarctation of the aorta alone as the initial stage at 9 days after birth. Also, spontaneous closure of the foramen ovale following repair of coarctation of the aorta accelerated the progressive left ventricular growth. Open mitral commissurotomy with an interatrial fenestration using the modified Brawley's approach was performed for a 40-day-old infant. Good left ventricular growth and good mitral valve function have been observed for 18 years after open mitral commissurotomy. Appropriate early augmentation of left ventricular inflow through the mitral valve might be effective for growth of a hypoplastic left ventricle. J. Med. Invest. 64: 187-191, February, 2017.

The Action of Smooth Muscle Cell Potassium Channels in the Pathology of Pulmonary Arterial Hypertension

Many different types of potassium channels with various functions exist in pulmonary artery smooth muscle cells, contributing to many physiological actions and pathological conditions. The deep involvement of these channels in the onset and exacerbation of pulmonary arterial hypertension (PAH) also continues to be revealed. In 2013, KCNK3 (TASK1), which encodes a type of two-pore domain potassium channel, was shown to be a predisposing gene for PAH by genetic mutation, and it was added to the PAH classification at the Fifth World Symposium on Pulmonary Hypertension (Nice International Conference). Decreased expression and inhibited activity of voltage-gated potassium channels, particularly KCNA5 (Kv1.5), are also seen in PAH, regardless of the cause, and facilitation of pulmonary arterial contraction and vascular remodeling has been shown. The calcium-activated potassium channels seen in smooth muscle cells also change from BKca (Kca1.1) to IKca (Kca3.1) predominance in PAH due to transformation and have effects including the facilitation of smooth muscle cell migration, enhancement of proliferation, and inhibition of apoptosis. Elucidation of these roles for potassium channels in pulmonary vasoconstriction and remodeling may help bring new therapeutic strategies into view.

Noninvasive assessment of pulmonary arterial capacitance by pulmonary annular motion velocity in children with ventricular septal defect

Background

We hypothesized that longitudinal pulmonary arterial deformation during the cardiac cycle reflects pulmonary arterial capacitance. To examine this hypothesis, we assessed whether tissue Doppler-derived pulmonary annular motion could serve as a novel way to evaluate pulmonary arterial capacitance in pediatric patients with ventricular septal defect (VSD).

Methods

In this prospective study, pulmonary annular velocity was measured in children (age, 6 months–5 years) with a preoperative VSD (VSD group, n = 35) and age-matched healthy children (Control group, n = 23). Pulmonary artery capacitance was calculated by two methods. Systolic pulmonary arterial capacitance (sPAC) was expressed as the stroke volume/pulmonary arterial pulse pressure. Diastolic pulmonary arterial capacitance (dPAC) was determined according to a two-element windkessel model of the pulmonary arterial diastolic pressure profile.

Results

Pulmonary annular velocity waveforms comprised systolic bimodal (s1′ and s2′) and diastolic e’ and a’ waves in all participants. The peak velocities of s1′, s2′, and e’ were significantly lower in the VSD group than in the Control group. On multiple regression analysis, sPAC was an independent variable affecting the peak velocities of the s1′, s2′, and e’ waves (β = 0.41, 0.62, and 0.35, respectively). The dPAC affected the s1′ wave peak velocity (β = 0.34). The time durations of the s1′ and e’ waves were independently determined by the sPAC (β = 0.49 and 0.27).

Conclusion

Pulmonary annular motion velocity evaluated using tissue Doppler is a promising method of assessing pulmonary arterial capacitance in children with VSD.

Electronic supplementary material

The online version of this article (doi:10.1186/s12947-016-0081-4) contains supplementary material, which is available to authorized users.

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.