Impaired Myocardial Work in Children with Hypertrophic Cardiomyopathy and Left Ventricular Fibrosis on Cardiac Magnetic Resonance Imaging.

Echocardiography is pivotal for diagnosis and monitoring of hypertrophic cardiomyopathy (HCM) and can evaluate myocardial function using myocardial work (MW) calculations. Echocardiography is often supplemented by cardiovascular magnetic resonance (CMR) imaging, which can detect myocardial fibrosis using late gadolinium enhancement (LGE). We sought to study the relationship between baseline LGE and MW at baseline and during follow-up in pediatric HCM patients. During the study period (2008-2023), 75 patients were followed up for HCM. In 14 patients (age 14.2 ± 2.8 years, 50.0% male, 6.4 ± 2.9 years follow-up), both LGE-CMR and echocardiography were performed. Global work index (GWI), global constructive work (GCW), global wasted work, and global work efficiency (GWE) were measured, and myocardial fibrosis was estimated by qualitative assessment of LGE. Patients with LGE (n = 7) exhibited significantly impaired baseline MW, including GWI (mean difference, MD - 487.4 mmHg %, 95% CI [- 866.8 mmHg % to - 108.3 mmHg %], p = 0.027), GCW (MD - 536.8 mmHg %, 95% CI [- 929.8 mmHg % to - 144.4 mmHg %], p = 0.020), and GWE (MD - 4.4%, 95% CI [- 8.1% to - 0.7%], p = 0.039). Regional analysis revealed impaired MW indices in segments with LGE, notably basal and mid septal segments. GWI demonstrated high diagnostic performance for LGE presence (sensitivity 93%, specificity 88%, and area under receiver operating characteristic curve 0.85). Baseline LGE presence had no significant impact on MW deterioration during follow-up. MW is significantly impaired in HCM patients with myocardial fibrosis, highlighting potential utility of echocardiography-derived MW analysis as a valuable tool.

Genome-wide DNA methylation profiling confirms a case of low-level mosaic Kabuki syndrome 1.

Kabuki syndrome is a Mendelian disorder of the epigenetic machinery characterized by typical dysmorphic features, intellectual disability, and postnatal growth deficiency. Pathogenic variants in the genes encoding the chromatin modifiers KMT2D and KDM6A are responsible for Kabuki syndrome 1 (KS1) and Kabuki syndrome 2 (KS2), respectively. In addition, 11 cases of KS1 caused by mosaic variants in KMT2D have been reported in the literature. Some of these individuals display milder craniofacial and growth phenotypes, and most do not have congenital heart defects. We report the case of an infant with severe hypoplastic left heart syndrome with mitral atresia and aortic atresia (HLHS MA-AA), pulmonary vein stenosis, and atypical facies with a somatic mosaic de novo nonsense variant in KMT2D (c.8200C>T, p.R2734*) identified on trio exome sequencing of peripheral blood and present in 11.2% of sequencing reads. KS was confirmed with EpiSign, a diagnostic genome-wide DNA methylation platform used to identify epigenetic signatures. This case suggests that use of this newly available clinical test can guide the interpretation of low-level mosaic variants identified through sequencing and suggests a new lower limit of mosaicism in whole blood required for a diagnosis of KS.

Fetal Echocardiographic Predictors of Postnatal Surgical Strategies in Critical Pulmonary Stenosis or Atresia with Intact Ventricular Septum: A Meta-Analysis.

BACKGROUND: Critical pulmonary stenosis or atresia with intact ventricular septum (PSAIVS) may be managed either by biventricular repair or univentricular palliation. This systematic review and meta-analysis aimed to synthesize the evidence for the role of fetal echocardiography in predicting the postnatal treatment pathway. METHODS: PubMed/MEDLINE, CINHAL, Cochrane Library, Academic Search Complete, Web of Science, and Trip Pro were searched for observational studies published before July 2021. Random-effects meta-analysis was performed to identify factors associated with biventricular repair. RESULTS: Eleven individual studies published between 2006 and 2021, including a total of 285 participants (159 biventricular repair; 126 univentricular palliation), met our eligibility criteria. The pooled estimated prevalence of biventricular repair among patients with PSAIVS was 55.6% (95% confidence interval 48.5-62.5%). Those who underwent biventricular repair had greater right to left ventricle and tricuspid to mitral valve dimension ratios, greater TV z score, and longer TV inflow duration/cardiac cycle length by fetal echocardiography. They were also more likely to have significant tricuspid regurgitation and less likely to have ventriculo-coronary connections (VCCs). CONCLUSIONS: Commonly obtained fetal echocardiographic measurements have strong associations with treatment pathway choice for patients with PSAIVS. Greater RV growth appears to favor biventricular repair, whereas patients with VCC almost invariably undergo univentricular palliation. Future studies should aim to establish how these fetal echocardiographic parameters might predict outcomes for the two treatment pathways.

Distinct muscle apoptotic pathways are activated in muscles with different fiber types in a rat model of critical illness myopathy.

Critical illness myopathy (CIM) is associated with severe muscle atrophy and fatigue in affected patients. Apoptotic signaling is involved in atrophy and is elevated in muscles from patients with CIM. In this study we investigated underlying mechanisms of apoptosis-related pathways in muscles with different fiber type composition in a rat model of CIM using denervation and glucocorticoid administration (denervation and steroid-induced myopathy, DSIM). Soleus and tibialis anterior (TA) muscles showed severe muscle atrophy (40-60% of control muscle weight) and significant apoptosis in interstitial as well as myofiber nuclei that was similar between the two muscles with DSIM. Caspase-3 and -8 activities, but not caspase-9 and -12, were elevated in TA and not in soleus muscle, while the caspase-independent proteins endonuclease G (EndoG) and apoptosis inducing factor (AIF) were not changed in abundance nor differentially localized in either muscle. Anti-apoptotic proteins HSP70, -27, and apoptosis repressor with a caspase recruitment domain (ARC) were elevated in soleus compared to TA muscle and ARC was significantly decreased with induction of DSIM in soleus. Results indicate that apoptosis is a significant process associated with DSIM in both soleus and TA muscles, and that apoptosis-associated processes are differentially regulated in muscles of different function and fiber type undergoing atrophy due to DSIM. We conclude that interventions combating apoptosis with CIM may need to be directed towards inhibiting caspase-dependent as well as -independent mechanisms to be able to affect muscles of all fiber types.

Time course of hypertension and myocardial dysfunction following anthracycline chemotherapy in pediatric patients.

Background: Anthracyclines are associated with cardiac dysfunction. Little is known about the interplay of pre-existing hypertension and treatment response. We aimed to investigate the relationship between hypertension and the development of cancer therapy-related cardiac dysfunction (CTRCD) in pediatric patients treated with anthracycline chemotherapy. Methods: Pediatric patients with cancer who received anthracycline chemotherapy from 2013 to 2021 were retrospectively included. Serial cardiac assessments were conducted during and after chemotherapy. The primary outcome was the development of CTRCD, classified as mild, moderate, or severe according to contemporary definitions. Results: Among 190 patients undergoing anthracycline chemotherapy, 34 patients (17.9 %) had hypertension (24 patients Stage 1, and 10 patients Stage 2) at baseline evaluation. Patients underwent chemotherapy for a median of 234.4 days (interquartile range 127.8-690.3 days) and were subsequently followed up. Hypertension was frequent during follow-up 31.3 % (0-3 months), 15.8 % (3-6 months), 21.9 % (0.5-1 years), 24.7 % (1-2 years), 31.1 % (2-4 years) and 35.8 % (beyond 4 years) (P for trend < 0.001). Freedom from mild CTRCD at 5 years was 45.0 %, freedom from moderate CTRCD was 87.8 % at 5 years. Baseline hypertension did not increase the risk of mild (HR 0.77, 95 % CI: 0.41-1.42, P = 0.385) or moderate CTRCD (HR 0.62, 95 % CI: 0.14-2.72, P = 0.504). Patients with baseline hypertension showed different global longitudinal strain (P < 0.001) and LVEF (P < 0.001) patterns during follow-up. Conclusions: Pediatric patients often develop CTRCD post-anthracycline chemotherapy. Those with pre-existing hypertension show a unique treatment response, despite no increased CTRCD risk, warranting further investigation.

Evaluation of Regional Myocardial Work Indices in Pediatric Essential and Renal or Renovascular Hypertension.

BACKGROUND: Myocardial work (MW) is an index of LV function based on pressure-strain loops and brachial cuff pressure measurement. MW has been proposed as more sensitive than conventional functional parameters, as it accounts for afterload and myocardial deformation. However, many studies have been limited to assessment of global MW indices, neglecting regional differences in cardiac associated with hypertension and consequent cardiac remodeling. We aimed to quantify regional MW in pediatric hypertension and compare the findings in renal or renovascular hypertension (RHTN) with essential hypertension (EHTN). METHODS: We retrospectively assessed conventional markers of LV function, and both global and regional MW indices in 78 patients (49 males, 15.4 ± 2.94 years) with EHTN and RHTN. RESULTS: Peak systolic strain (PSS) in the basal septal segment was significantly impaired in patients with RHTN compared to EHTN (-13.00% [-15.50%; -13.00%] vs. -15.00% [-17.50%; -13.50%], P = 0.034). Similarly, basal septal MW indices were significantly elevated in patients with EHTN compared to RHTN, including MW efficiency (MWE) (95.0% [93.0%; 98.0%] vs. 94.0% [89.0%; 95.0%], P = 0.004) and constructive work (CW) (1700 mm Hg% (409 mm Hg%) vs. 1520 mm Hg% (336 mm Hg%), P = 0.037). Wasted work (WW) was significantly elevated in the RHTN group (79.0 mm Hg% [28.5 mm Hg%; 104 mm Hg%] vs. 105 mm Hg% [62.0 mm Hg%; 164 mm Hg%], P = 0.010). CONCLUSION: Significant differences in basal septal PSS and MW indices were observed between EHTN and RHTN. These findings highlight the usefulness of regional MW indices in assessing disease and may help differentiate between etiologies of pediatric hypertension.

Characterization of Aortic Flow Patterns by High-Frame-Rate Blood Speckle Tracking Echocardiography in Children.

Background Blood speckle tracking echocardiography allows for direct quantification of interventricular and aortic flow profiles, principally in children. Here, we sought to demonstrate the feasibility and reproducibility of blood speckle tracking echocardiography in the aortas of healthy children. Methods and Results One hundred healthy White children evaluated for the screening of congenital heart disease were prospectively enrolled. Echocardiographic examinations were performed using a Vivid E 95 ultrasound system, with blood speckle tracking from a focused and zoomed view of the aortic root and the ascending aorta. Vortex position, height (mm), width (mm), sphericity index, and area (cm2) were measured and indexed by body surface area. Median (interquartile range) age was 8.2 (5.6-11.0) years, median (interquartile range) weight was 28 (19-35) kg, and median (interquartile range) body surface area was 1.01 (0.79-1.16) m2. Vortices were visualized in only a single phase of the cardiac cycle in 25 subjects-14 (56.0%) were evident in early diastole and 11 (44.0%) in late systole. Vortices visualized in diastole had a mean area of 0.27±0.1 cm2/m2, while those in systole had a mean area of 0.34±0.12 cm2/m2. In a subset of 20 patients, inter- and intraobserver coefficient of variation and intraclass correlation coefficients were determined and showed good reproducibility. Conclusions We demonstrate feasibility and reproducibility of blood speckle tracking and identified vortical flow patterns in the aortic root and ascending aorta in healthy children. These data may serve as a baseline for evaluating aortic flow patterns in children with congenital and acquired heart disease.

Deterioration in myocardial work indices precedes changes in global longitudinal strain following anthracycline chemotherapy.

BACKGROUND: Left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) have conventionally been used for surveillance of cardiac function after cancer therapy, but indices of myocardial work (MW) are potentially superior for this purpose because they take into account both myocardial deformation and loading conditions. OBJECTIVES: We aimed to investigate the usefulness of MW in the follow-up of children and young adults following anthracycline chemotherapy. METHODS: Conventional markers of LV function (LV fractional shortening [LVFS], LVEF, GLS) and MW indices (global work index [GWI], global constructive work [GCW], global wasted work [GWW], and global work efficiency [GWE]) were obtained from 2342 echocardiographic examinations in 598 patients (354 male, 12.2 [4.7-17.3] years at initiation of chemotherapy). RESULTS: GWI, GCW, GLS, LVFS, and LVEF all deteriorated significantly during and after anthracycline chemotherapy, while GWW decreased and GWE was preserved. On multivariable analysis, MW indices were correlated with conventional markers of LV function and with clinical information relating to underlying malignancy and chemotherapy. Cox regression analysis revealed that similar levels of deterioration in GWW, GWI, and GCW preceded those in GLS, LFS, and LVEF. CONCLUSIONS: Non-invasive MW indices correlate well with conventional markers of LV function. Indices of MW appear to provide an earlier and more sensitive marker of progression towards chemotherapy-related cardiac dysfunction. Future studies are warranted to validate whether the incorporation of non-invasive MW into the routine clinical surveillance in patients after chemotherapy would improve outcomes.

Screening of Coronary Artery Origin by Echocardiography: Definition of Normal (and Abnormal) Take-Off by Standard Echocardiographic Views in a Healthy Pediatric Population.

Background: Echocardiographic screening of anomalous coronary artery origin is of increasing interest for children participating in sport activities. However, criteria to define normal coronary artery origins in children are poorly defined. Thus, the aim of the present investigation is to define the normal origin and angle of emergence of coronary arteries by echocardiography in healthy children. Materials and methods: The distances of the left main and right coronary artery (LMCA, RCA) origins from the aortic annulus were measured in the parasternal long-axis view (LAX). The angle of coronary artery emergence was measured in the parasternal short-axis view (SAX). Results: A total of 700 healthy subjects (mean age: 9.53 ± 5.95 years; range: 1 day−17.98 years) were prospectively enrolled. The distance of the RCA and LMCA from the aortic annulus correlated with body surface area, and nomograms (Z-scores) were generated. The RCA origin was below the sinotubular junction (STJ) in 605 patients (86.43%), at the STJ in 66 patients (9.43%), and above the STJ in 29 patients (4.14%). The LMCA origin was below the STJ in 671 patients (95.86%), at the STJ in 12 patients (1.71%), and above the STJ in 17 patients (2.43%). With respect to the RCA, an emergence angle < 18.5° in the SAX predicted a high take-off. with a sensitivity of 98.3% and a specificity of 93.1% (AUC 0.998). With respect to the LMCA, an emergence angle > 119.5° in the SAX predicted a high take-off, with a sensitivity of 70.6% and a specificity of 82.4% (AUC 0.799). Conclusion: This study establishes nomograms for LMCA and RCA origin in standard echocardiographic projections in healthy children.

Characterization of left ventricular cavity flow, wall stress and energy loss by color doppler vector flow mapping in children and adolescents with cardiomyopathy.

BACKGROUND: Vector flow mapping is an emerging echocardiographic method allowing for investigation of intracardiac blood flow mechanics, wall shear stress (WSS), and energy loss (EL). We hypothesized that alterations in EL and WSS will differ among subjects with hypertrophic (HCM), dilated (DCM) cardiomyopathy, and normal controls. METHODS: Echocardiograms were prospectively performed with the ProSound F75CV (Hitachi HealthCare., Tokyo, Japan) on all subjects. 2D color Doppler cine loop images were obtained from apical 5 and the apical long axis views and stored digitally. Measurements were averaged over three cardiac cycles using VFM software to derive flow patterns, WSS, and EL. Standard left ventricular (LV) systolic and diastolic functional parameters were also obtained. RESULTS: A total of 85 subjects, 22 with HCM (age 18 ± 9 yrs.), 18 DCM (age 18 ± 9 yrs.), and 45 age and gender matched controls were included in the study. Diastolic wall shear stress was found significantly different in HCM (0.004 ± 0.185 N/m2) compared with DCM (0.397 ± 0.301 N/m2, P < 0.001), and controls (0.175 ± 0.255 N/m2, P = 0.027). Furthermore, indexed systolic EL was found to be significantly elevated in HCM (13.91 ± 13.17 mW/m2/m3) compared with DCM (8.17 ± 9.77 mW/m2/m3, P < 0.001), but not controls (6.45 ± 7.47 mW/m2/m3). CONCLUSION: Differences in abnormal ventricular mechanics observed in HCM and DCM are reflected in both EL and WSS, and are suggestive that changes in energetic parameters may represent novel indices of ventricular dysfunction.

Dynamic Systolic Changes in Tricuspid Regurgitation Vena Contracta Size and Proximal Isovelocity Surface Area in Hypoplastic Left Heart Syndrome: A Three-Dimensional Color Doppler Echocardiographic Study.

BACKGROUND: The aims of this study were to investigate the dynamic changes in the vena contracta (VC) and proximal isovelocity surface area (PISA) through systole in patients with hypoplastic left heart syndrome and tricuspid regurgitation and to identify the stage of systole (early, mid, or late) in which VC and PISA radius are optimal. METHODS: Twenty-eight patients with hypoplastic left heart syndrome were prospectively studied using continuous two-dimensional (2D) and three-dimensional (3D) echocardiography. Two-dimensional VC width, 3D VC area, and PISA radii (2D and 3D) were measured frame by frame throughout systole. The maximal 2D VC width, 3D VC area, and PISA radii in the first, middle, and last thirds of systole were compared, and correlations were explored with 3D tricuspid annular areas, right atrial volumes, and right ventricular volumes. RESULTS: In all, 35 data sets that met inclusion criteria were analyzed. On frame-by-frame analysis, maximal 2D VC width and 3D VC area were found in the first third of systole in 17% and 20% of studies, in the second third in 34% and 31%, and in the final third in 49% and 49%. Similarly, the maximal 2D and 3D PISA radii were found in the first third of systole in 26% and 17% of studies, in the second third in 28% and 34%, and in the final third in 46% and 49%. CONCLUSIONS: In hypoplastic left heart syndrome, detailed temporal analysis of tricuspid regurgitation-associated VC and PISA by 2D and 3D echocardiography reveals no reliable pattern predicting when in systole these parameters peak. Frame-by-frame measurement is necessary for identification of maximal VC and PISA radius on 2D and 3D color Doppler echocardiography because the severity of tricuspid regurgitation could be underestimated because of temporal variability in VC and PISA.