Corrigendum: Comparison of cardiac function between single left ventricle and tricuspid atresia: assessment using echocardiography combined with computational fluid dynamics.

[This corrects the article DOI: 10.3389/fped.2023.1159342.].

Comparison of cardiac function between single left ventricle and tricuspid atresia: assessment using echocardiography combined with computational fluid dynamics.

Patients with single left ventricle (SLV) and tricuspid atresia (TA) have impaired systolic and diastolic function. However, there are few comparative studies among patients with SLV, TA and children without heart disease. The current study includes 15 children in each group. The parameters measured by two-dimensional echocardiography, three-dimensional speckle tracking echocardiography (3DSTE), and vortexes calculated by computational fluid dynamics were compared among these three groups. Twist is best correlated with ejection fraction measured by 3DSTE. Twist, torsion, apical rotation, average radial strain, peak velocity of systolic wave in left lateral wall by tissue Doppler imaging (sL), and myocardial performance index are better in the TA group than those in the SLV group. sL by tissue Doppler imaging in the TA group are even higher than those in the Control group. In patients with SLV, blood flow spreads out in a fan-shaped manner and forms two small vortices. In the TA group, the main vortex is similar to the one in a normal LV chamber, but smaller. The vortex rings during diastolic phase are incomplete in the SLV and TA groups. In summary, patients with SLV or TA have impaired systolic and diastolic function. Patients with SLV had poorer cardiac function than those with TA due to less compensation and more disordered streamline. Twist may be good indicator for LV function.

Ventricular function and dyssynchrony in children with a functional single right ventricle using real time three-dimensional echocardiography after fontan operation.

BACKGROUND: This study aimed to evaluate the feasibility and clinical value of real time three-dimensional echocardiography (RT-3DE) for assessing ventricular systolic dysfunction and dyssynchrony in children with an functional single right ventricle (FSRV) having undergone the Fontan procedure. METHODS: Twenty-five children with an FSRV and 25 healthy children were enrolled in our study. RV volume analysis was performed compared with magnetic resonance imaging (MRI) as the reference standard in FSRV patients. The patients were divided into wide and narrow QRS interval groups. Global and regional functions of the RV in three compartments (inflow, body, and outflow) were compared between FSRV and control subjects, including RV systolic dyssynchrony indices of maximal difference of time to minimal volume (Tmsv-Dif), standard deviation of time to minimal volume (Tmsv-SD), maximal difference of time to minimal volume corrected by R-R interval (Tmsv-Dif%), and standard deviation of time to minimal volume corrected by R-R interval (Tmsv-SD%). RESULTS: RT-3DE measurements were significantly lower than MRI measurements for RV-EDV, RV-ESV, RV-SV, and RVEF (p < 0.01).Compared with controls, patients with an FRSV had significantly higher dyssynchrony indices and significantly lower global EF in both narrow QRS interval and wide QRS interval groups. Tmsv-SD% was shown to be most strongly correlated with MRI-RVEF (r = -.570, p = 0.003). CONCLUSIONS: RT-3DE tended to underestimate RV ventricular volume in children with FSRV. Children with an FSRV and either a wide or narrow QRS interval had reduced ventricular function and higher dyssynchrony than normal subjects. Worsening RV dyssynchrony is associated with overall decline in function after the Fontan operation.

Diagnosis of Double-chambered Left Ventricle of Superior-inferior Type by Echocardiography: A Retrospective Study of 9 Subjects across Two Heart Centers.

BACKGROUND: Double-chambered left ventricle (DCLV) is extremely rare. Challenges remain in accurate diagnosis of DCLV by echocardiography, because it is easily confused with left ventricular diverticulum, left ventricular aneurysm, ventricular septal defect, etc. Herein, we reviewed echocardiographic characteristics of DCLV and evaluated the accuracy of echocardiographic diagnosis. METHODS: Clinical and echocardiographical databases of two heart centers were reviewed. Nine children with DCLV of superior-inferior arrangement were studied retrospectively. RESULTS: Normal elliptical geometry of LV cavity is preserved in DCLV. Fibromuscluar bundles separate LV into the main chamber and the accessory chamber. The associated malformations included ventricular septal defects, mitral regurgitation, mitral valve stenosis, pulmonary stenosis, and left ventricular noncompaction in our study. Eight of nine subjects with DCLV of superior-inferior arrangement were diagnosed correctly by initial echocardiographic examination, and one case was mistaken as left ventricular diverticulum. CONCLUSIONS: Double-chambered left ventricle could be diagnosed and followed up by echocardiography. The morphological classification is a simplified way to improve diagnostic accuracy.

Regression equations for calculation of z scores for echocardiographic measurements of left heart structures in healthy Han Chinese children.

OBJECTIVE: Clinical decision making in children with heart disease relies on detailed measurements of cardiac structures using two-dimensional and M-mode echocardiography. However, no echocardiographic reference values are available for the Chinese children. We aimed to establish z-score regression equations for left heart structures in a population-based cohort of healthy Chinese Han children. METHOD: Echocardiography was performed in 545 children with a normal heart. The dimensions of the aortic valve annulus (AVA), aortic sinuses of Valsalva (ASV), sinotubular junction (STJ), ascending aorta (AAO), left atrium (LA), mitral valve annulus (MVA), interventricular septal end-diastolic thickness (IVSd), interventricular septal end-systolic thickness (IVSs), left ventricular end-diastolic diameter (LVIDd), left ventricular end-systolic diameter (LVIDs), left ventricular posterior wall end-diastolic thickness (LVPWd), left ventricular posterior wall end-systolic thickness (LVPWs) were measured. Regression analyses were conducted to relate the measurements of left heart structures to body surface area (BSA). Left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) were calculated. Several models were used, and the adjusted R2 values were compared for each model. RESULTS: AVA, ASV, STJ, AAO, LA, MVA, IVSd, IVSs, LVIDd, LVIDs, LVPWd, and LVPWs had a cubic relationship with BSA. LVEF and LVFS fell within a narrow range. CONCLUSIONS: Our results provide reference values for z scores and regression equations for left heart structures in Han Chinese children. These data may help make a quick and accurate judgment of the routine clinical measurement of left heart structures in children with heart disease.

Regression equations for calculation of z scores for echocardiographic measurements of right heart structures in healthy Han Chinese children.

OBJECTIVE: Clinical decision making in children with congenital and acquired heart disease relies on measurements of cardiac structures using two-dimensional echocardiography. We aimed to establish z-score regression equations for right heart structures in healthy Chinese Han children. METHODS: Two-dimensional and M-mode echocardiography was performed in 515 patients. We measured the dimensions of the pulmonary valve annulus (PVA), main pulmonary artery (MPA), left pulmonary artery (LPA), right pulmonary artery (RPA), right ventricular outflow tract at end-diastole (RVOTd) and at end-systole (RVOTs), tricuspid valve annulus (TVA), right ventricular inflow tract at end-diastole (RVIDd) and at end-systole (RVIDs), and right atrium (RA). Regression analyses were conducted to relate the measurements of right heart structures to 4body surface area (BSA). Right ventricular outflow-tract fractional shortening (RVOTFS) was also calculated. Several models were used, and the best model was chosen to establish a z-score calculator. RESULTS: PVA, MPA, LPA, RPA, RVOTd, RVOTs, TVA, RVIDd, RVIDs, and RA (R2 = 0.786, 0.705, 0.728, 0.701, 0.706, 0.824, 0.804, 0.663, 0.626, and 0.793, respectively) had a cubic polynomial relationship with BSA; specifically, measurement (M) = ß0 + ß1 × BSA + ß2 × BSA2 + ß3 × BSA.3 RVOTFS (0.28 ± 0.02) fell within a narrow range (0.12-0.51). CONCLUSIONS: Our results provide reference values for z scores and regression equations for right heart structures in Han Chinese children. These data may help interpreting the routine clinical measurement of right heart structures in children with congenital or acquired heart disease. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:293-303, 2017.

Electrochemical shell-isolated nanoparticle-enhanced Raman spectroscopy: correlating structural information and adsorption processes of pyridine at the Au(hkl) single crystal/solution interface.

Electrochemical methods are combined with shell-isolated nanoparticle-enhanced Raman spectroscopy (EC-SHINERS) for a comprehensive study of pyridine adsorption on Au(111), Au(100) and Au(110) single crystal electrode surfaces. The effects of crystallographic orientation, pyridine concentration, and applied potential are elucidated, and the formation of a second pyridine adlayer on Au(111) is observed spectroscopically for the first time. Electrochemical and SHINERS results correlate extremely well throughout this study, and we demonstrate the potential of EC-SHINERS for thorough characterization of processes occurring on single crystal surfaces. Our method is expected to open up many new possibilities in surface science, electrochemistry and catalysis. Analytical figures of merit are discussed.

Coronary artery indexed diameter and z score regression equations in healthy Chinese Han children.

OBJECTIVE: In children with coronary disease, clinical decision should be based on detailed measurements of the coronary arteries by two-dimensional echocardiography. We aimed to establish coronary artery reference indexed diameter and z scores regression equations in a large cohort of Chinese Han children. METHODS: We measured the diameter of the proximal right (RCA), left main (LMCA), left anterior descending, and left circumflex coronary artery, and of the aortic annulus, and calculated the coronary-aorta index (coronary artery-to-aortic annulus ratio) in 506 Chinese Han children with normal hearts whose ages ranged from 1 day to 18 years. Regression analyses were performed, relating the coronary artery dimensions to body surface area (BSA). Several models were used, and the best model (yielding the maximum adjusted R(2) ) was chosen to establish a z score calculator. RESULTS: Based on cubic regression, (M) = ß0 + ß1 × BSA + ß2 × BSA(2) + ß3 × BSA(3) , the adjusted R(2) values were 0.515, 0.553, 0.505, and 0.518 for the RCA, LMCA, left anterior descending, and left circumflex coronary artery models, respectively. RCA/aortic annulus was 0.14 ± 0.02 (range, 0.07-0.24) and LMCA/AOA was 0.15 ± 0.03 (range, 0.10-0.28). CONCLUSIONS: Our results provide reference values of coronary artery z scores, regression equation, and coronary-aorta index as a quick guide to determine coronary dilation in Chinese Han children.

Left ventricular torsional mechanics and diastolic function in congenital heart block with right ventricular pacing.

BACKGROUND: The effects of right ventricular (RV) pacing on left ventricular (LV) diastolic function are unknown. This study aimed to test the hypothesis that right ventricular (RV) pacing is associated with LV diastolic dysfunction and impairment of LV torsion in children and young adults with congenital heart block. METHODS: Eighteen patients aged 20 ± 7 years and 12 healthy controls aged 19 ± 7 years were studied. Transmitral and mitral annular diastolic velocities and global longitudinal diastolic strain rate were determined and compared between the 2 groups. Parameters of LV torsion including peak systolic basal and apical rotations, and systolic twisting and diastolic untwisting velocities were further determined by speckle tracking echocardiography. In 12 patients, these parameters were compared before and after interruption of RV pacing. RESULTS: Compared with controls, patients had significantly lower mitral early diastolic annular velocity (p=0.007), LV global diastolic strain rate (p<0.001), basal (p<0.001) and apical (p=0.002) rotations, peak systolic torsion (p<0.001), and peak systolic twisting velocities (p=0.009). In patients, the peak diastolic untwisting velocity correlated with peak systolic torsion (r=0.64, p=0.004) and peak systolic twisting velocity (r=0.74, p<0.001). No significant improvement in LV diastolic function or torsion was observed during pacing interruption (all p>0.05). CONCLUSION: Right ventricular pacing in childhood is associated with LV diastolic dysfunction and impaired LV torsion, which do not improve with pacing interruption.

Modulating effects of matrix metalloproteinase-3 and -9 polymorphisms on aortic stiffness and aortic root dilation in patients after tetralogy of Fallot repair.

Matrix metalloproteinases (MMPs) are capable of degrading extracellular matrix proteins, which are important determinants of arterial stiffness. This study aimed to test the hypothesis that MMP-3 and MMP-9 polymorphisms may modulate aortic stiffness and magnitude of aortic root dilation in patients after surgical repair of tetralogy of Fallot (TOF). We analyzed the MMP-3 promoter and MMP-9 -1562 C>T polymorphism in 79 TOF patients aged 19.9 ± 9.5 years and determined their associations with aortic stiffness and sinotubular dimension. Genotypic and allelic frequencies of MMP-3 for the 6A6A genotype and MMP-9 for the T allele did not differ between patients and published control data (all p>0.05). For the MMP-3 locus, patients with a 6A6A genotype and those with a 6A6A/5A6A genotype had similar aortic stiffness (p=0.60), heart-femoral pulse wave velocity (p=0.63), and z score of sinotubular junction (p=0.81). For the MMP-9 locus, the -1562T allele carriers had significantly lower aortic stiffness (p=0.005), slower heart-femoral pulse wave velocity (p=0.03), and smaller z score of sinotubular junction (p=0.047). Multivariate linear regression identified MMP-9 polymorphism (ß=-0.31, p=0.005) as a significant correlate of aortic stiffness after adjustments for age at study, age at operation, sex, body mass index, systolic and diastolic blood pressures, and MMP-3 polymorphism. In conclusion, MMP-9 but not MMP-3 polymorphism exerts a modulating influence on aortic stiffness and aortic root dilation in patients after TOF repair.

[3D visualization for simulating percutaneous transcatheter closure of atrial septal defect:a pilot clinical study].

OBJECTIVE: To evaluate the clinical value of 3D visualization method for simulating percutaneous transcatheter closure of atrial septal defect (ASD). METHODS: 3D volume render method was used for visualizing ASD and surrounding structures and 3D modeling method was applied for simulate the shape of occlusion device. The size and the distance between the lower edge of device and atria-ventricular valve of simulation occluder and actual selected atrial septal occluder (ASO) were compared in 30 patients underwent successful transcatheter closure of ASD. RESULTS: The location, geometry, size, extent of ASDs in children were displayed in 3D visualization. No significant difference was found between simulation occluder and ASO size measured from left atrium [(26.07 +/- 5.32) cm vs. (25.91 +/- 5.32) cm] and right atrium [(22.13 +/- 5.31) cm vs. (22.08 +/- 5.26) cm, all P > 0.05]. The distances from simulation occluder to mitral valves [(5.76 +/- 2.39) cm] and to tricuspid valves [(8.25 +/- 2.40) cm] were similar as ASO to atria-ventricular valves [(5.61 +/- 2.26) cm and (8.02 +/- 2.48) cm, respectively, all P > 0.05]. CONCLUSIONS: The simulating percutaneous transcatheter closure of ASD by 3D visualization technique could be a helpful noninvasive approach for ASO selection before the procedure of transcatheter occlusion of ASD.

Left ventricular myocardial deformation and mechanical dyssynchrony in children with normal ventricular shortening fraction after anthracycline therapy.

OBJECTIVE: The M-mode-derived left ventricular shortening fraction is incorporated into most of the paediatric oncology protocols for monitoring of cardiotoxicity. This study tested the hypothesis that alteration of left ventricular myocardial deformation and mechanical dyssynchrony may occur in asymptomatic children after anthracycline therapy despite having left ventricular shortening fractions within the limits of normal. DESIGN: Cross-sectional study. SETTING: Tertiary paediatric cardiac centre. METHODS: Left ventricular longitudinal, circumferential and radial myocardial deformation was determined using speckle tracking echocardiography in 45 patients aged 15.3+/-5.8 years. Real-time three-dimensional echocardiographic data were acquired for the measurement of left ventricular volumes and systolic dyssynchrony index (SDI), the latter derived from the dispersion of time-to-minimum regional volume using a 16-segment model. The results were compared with those of 44 controls. RESULTS: Compared with controls, patients had reduced left ventricular global systolic longitudinal strain (p=0.012), circumferential strain (p<0.001), radial strain (p=0.006) and circumferential strain rate (SR; p=0.002). The cumulative anthracycline dose correlated negatively with global longitudinal (r=-0.33, p=0.027) and circumferential (r=-0.32, p=0.035) SR. The left ventricular SDI was significantly greater in patients than controls (4.46+/-1.52% vs 3.80+/-0.58%, p=0.03). The prevalence of left ventricular mechanical dyssynchrony (SDI >4.96%) in patients was 16% (95% CI 6% to 29%). In patients, SDI correlated negatively with left ventricular ejection fraction (r=-0.52, p<0.001), radial strain (r=-0.35, p=0.021), circumferential strain (r=-0.37, p=0.015) and circumferential SR (r=-0.43, p=0.004), but not with the cumulative anthracycline dose (p=0.82). CONCLUSIONS: Impaired left ventricular myocardial deformation and mechanical dyssynchrony may exist in children after anthracycline therapy despite having normal left ventricular shortening fractions.

Impact of temporary interruption of right ventricular pacing for heart block on left ventricular function and dyssynchrony.

BACKGROUND: The increasing data suggest an association between chronic right ventricular (RV) and left ventricular (LV) dysfunction. We sought to determine the effect of temporary interruption of long-term RV pacing on LV function and mechanical dyssynchrony in children and young adults with complete heart block. METHODS: Twelve patients aged 20.0 + or - 7.4 years with congenital heart block (group I) and six patients aged 22.7 + or - 11.0 years with surgically acquired heart block (group II) with RV pacing were studied. The pacing rate was reduced to less than patient's intrinsic heart rate and maintained for 5 minutes. The LV ejection fraction (EF), three-dimensional systolic dyssynchrony index (SDI), two-dimensional global longitudinal strain and strain rate, and Doppler-derived isovolumic acceleration before and after interruption of RV pacing were compared. RESULTS: The LVEF and GLS increased while QRS duration decreased after the pacing interruption in both the groups (all P < 0.05). While SDI decreased in both groups I (6.8 + or - 2.3%- 3.8 + or - 0.8%, P = 0.001) and II (9.2 + or - 4.1%-5.0 + or - 1.6%, P = 0.032), it remained higher in group II than in group I (P = 0.046) after the pacing interruption. The prevalence of LV dyssynchrony (SDI > 4.7%) decreased in group I (83%-25%, P = 0.006) but not in group II (67%-50%, P = 0.50). The %increase in LVEF correlated positively with %reduction of LV SDI (r = 0.80, P = 0.001). CONCLUSIONS: Temporary interruption of chronic RV pacing acutely improves LV dyssynchrony and systolic function in children and young adults, the magnitude of which is greater in patients with congenital than those with surgically acquired heart block.

Impact of right ventricular pacing on three-dimensional global left ventricular dyssynchrony in children and young adults with congenital and acquired heart block associated with congenital heart disease.

The aim of this study was to determine the effect of long-term right ventricular pacing on left ventricular (LV) mechanical dyssynchrony in children and young adults with congenital and acquired heart block. Eighteen patients aged 19 +/- 7 years with congenital heart block (group I), 9 aged 21 +/- 11 years with acquired heart block after congenital heart surgery (group II), and 15 healthy control subjects (group III) were studied. The LV volumes, ejection fractions, and systolic dyssynchrony index (SDI) values, as determined using 3-dimensional echocardiography, were compared among groups. Groups I (6.68 +/- 2.44%) and II (9.43 +/- 4.44%) had significantly greater SDI values than group III (3.88 +/- 0.63%) (p = 0.011 and p <0.001, respectively). The prevalence of LV mechanical dyssynchrony (SDI >5.14%, mean + 2 SDs of controls) in groups I and II was 72% and 67%, respectively. In 27 patients with right ventricular pacing, LV SDI values were correlated negatively with the LV ejection fractions (r = -0.74, p <0.001). The times to minimum regional volume were significantly longer in lateral, posterior, and inferior segments in group I and septal and inferior segments in group II compared to those in group III (p <0.05). Compared to patients without LV dyssynchrony, patients with LV dyssynchrony had lower LV ejection fractions (p <0.001), had shorter RR intervals (p <0.001), and tended to have dual-chamber pacing (p = 0.088) but had similar durations of pacing, QRS durations, and positions of pacing wires (epicardial vs endocardial). In conclusion, permanent right ventricular pacing in childhood has a negative effect on LV systolic function through the induction of mechanical dyssynchrony, the magnitude and pattern of which differ between congenital and acquired heart block.