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Left ventricular noncompaction (LVNC) is a cardiomyopathy characterized by excessive trabecular formation and deep recesses in the ventricular wall, with a bilaminar structure consisting of an endocardial noncompaction layer and an epicardial compacted layer. Although genetic variants have been reported in patients with LVNC, understanding of LVNC and its pathogenesis has not yet been fully elucidated. We addressed the latest findings on genes reported to be associated with LVNC morphogenesis and possible pathologies to understand the diverse spectrum between genotype and phenotype in LVNC. Also, the latest findings and issues related to the diagnosis of LVNC were summarized.This article is written as a commentary narrative review and will provide an update on the current literature and available data on common forms of LVNC published in the past 30 years in English through to May 2022 using PubMed.Familial forms of LVNC are frequent, and autosomal dominant mode of inheritance has been predominantly observed. Several of the candidate causative genes are also mutated in other cardiomyopathies, suggesting a possible shared molecular and/or cellular etiology. The most common gene functions were sarcomere function whereas genes in mice LVNC models were involved in heart development. Echocardiography and cardiac magnetic resonance imaging (CMR) are useful for diagnosis although there are no unified criteria due to overdiagnosis of imaging, poor consistency between techniques, and lack of association between trabecular severity and adverse clinical outcomes.This review reflects the current lack of clarity regarding the pathogenesis and significance of LVNC and showed the complexity of imaging diagnostic criteria, interpretation of the role of LVNC as a cause, and uncertainty regarding the specific genetic basis of LVNC.

We encountered cases in which the anticoagulant effects of warfarin (CYP2C9 substrate) were reversibly attenuated by the concomitant administration of rifampicin or bosentan, which are potent pregnane X receptor (PXR) ligands. The purpose of the present study is to report the previous case with rifampicin, and to evaluate the changes in the warfarin anticoagulant effects when withdrawing or switching bosentan treatment. The former is a case study of a 4-year-old girl undergoing warfarin treatment. The latter is a longitudinal study of 20 pediatric patients receiving stable warfarin treatment. The prothrombin time and international normalized ratio (PT-INR) values were extracted from the medical records and normalized by the daily-dose per body size as an index for the warfarin anticoagulant effects. Rifampicin treatment resulted in a 52.0% decrease in the anticoagulant index. On the other hand, 10 of 20 patients started bosentan and their anticoagulant index was reduced by a median of 2.00. Bosentan was withdrawn in 4 of 20 patients and their anticoagulant index increased by a median of 3.67. Six of 20 patients switched from bosentan to macitentan, which is considered not to activate PXR in clinical settings. However, switching from bosentan to macitentan resulted in a median of 2.25 reduction of the anticoagulant index rather than recovery of the response to warfarin. This study suggests not only the possibility of heterogeneity in the response to PXR activation and deactivation, but also the importance of long-term monitoring of drug-drug interactions when switching from bosentan to macitentan.

Background Left ventricular noncompaction (LVNC) is morphologically characterized by numerous prominent trabeculations and a severely thickened, two-layered myocardium. The fetal onset of LVNC has rarely been described.Methods and Results:We conducted nationwide retrospective surveys on fetal cardiomyopathy (CM) in Japan from 2010 to 2016, from which 38 fetal patients with CM were enrolled, including 16 patients with LVNC. The rate of diagnostic concordance was 56.3% between fetal and postnatal visits in LVNC patients. The increase in the ratio of noncompacted to compacted (N/C) myocardium was time-dependent throughout the fetal period till birth (LV lateral: 1.6±0.1 to 2.8±0.2; LV apex: 2.0±0.1 to 3.2±0.2). Of all fetuses, 16 (42.1%) died or underwent heart transplantation (HT), with 3 intrauterine deaths. Lower fetal cardiovascular profile score (odds ratio, 26.9; P=0.0266) was a risk factor for death or HT. N/C ratio ≥1.6 at the apex at the first visit was a significant predictor of LVNC (odds ratio, 47.8; P=0.0113). Conclusions This is the first study to reveal the etiology of fetal CM based on results from a nationwide survey in Japan, highlighting the difficulty of diagnosing LVNC in fetal patients. To better understand and manage fetal CM, novel diagnostic criteria of LVNC in fetus should be established.

Idiopathic bradyarrhythmia is considered to be due to pathological degeneration of the cardiac conduction system (CCS) during aging. There appears to have been no comprehensive genetic investigations in patients with idiopathic bradyarrhythmia.Methods and Results: Ten autopsy cases with advanced bradyarrhythmia (6 men and 4 women; age: 70-94 years, 81.5±6.9 years; 5 cases each of sinus node dysfunction [SND] and complete atrioventricular block [CAVB]) were genetically investigated by using whole-exome sequencing. Morphometric analysis of the CCS was performed with sex-, age- and comorbidity-matched control cases. As a result, severe loss of nodal cells and distal atrioventricular conduction system were found in SND and CAVB, respectively. However, the conduction tissue loss was not significant in either the atrioventricular node or the proximal bundle of His in CAVB cases. A total of 13 heterozygous potential variants were found in 3 CAVB and 2 SND cases. Of these 13 variants, 4 were missense in the known progressive cardiac conduction disease-related genes: GATA4 and RYR2. In the remaining 9 variants, 5 were loss-of-function mutation with highly possible pathogenicity.In addition to degenerative changes of selectively vulnerable areas in the heart during advancing age, the vulnerability of the CCS, which may be associated with "rare variants of small effect," may also be a contributing factor to the degeneration of CCS, leading to "idiopathic" bradyarrhythmia.

This study was performed for a better understanding of the pharmacokinetics of sildenafil (SIL) and N-desmethyl sildenafil (DMS) in 13 children treated in the intensive care unit (ICU). Blood samples were taken periodically after the first oral administration of SIL (0.5 mg/kg). Plasma concentrations were analyzed by tandem LC/MS. Of the 13 patients, apparent peaks in the plasma concentration of SIL were observed in four patients, with the other nine patients showing reduced or delayed drug absorption of SIL. The maximum plasma concentrations of SIL after administration varied in range from 7.8 to 101.0 ng/mL. The parent drug-to-metabolite (SIL/DMS) ratios of the nine patients with reduced or delayed drug absorption of SIL were relatively lower than those in the four patients with rapid absorption of the drug. These observations suggested that the inter-individual variability of intestinal absorption and/or first-pass extraction of SIL was involved in the pharmacokinetic variability of the drug. Next, we evaluated the impact of changes in the gastrointestinal absorption rate on the pharmacokinetics of the drug. That is, SIL (2.5 mg/body) was administered at two different rates in the duodenum of rats. When SIL was administered for 10 min, the Cmax and bioavailability were 3.46 ± 1.65 µg/mL and 23.2 ± 11.1%, respectively. When SIL was administered for 60 min, the Cmax and bioavailability were 0.990 ± 0.352 µg/mL and 9.91 ± 3.79%, respectively. These findings suggest that the drug absorption rate was at least partly responsible for the pharmacokinetic variability of SIL in the ICU children.

BACKGROUND Both congenital heart disease (CHD) and very-low birthweight (VLBW) infants are at a very high risk of neurodevelopmental delay. We investigated neurological development at 3 years in pediatric patients with CHD after surgical intervention, those of VLBW, and healthy controls. METHODS We enrolled pediatric patients with CHD (n = 67), VLBW (n = 67), and healthy controls (n = 81). Infants with CHD were grouped into those with single ventricle and two ventricles, and infants with VLBW were grouped into those with birthweights of

Left ventricular noncompaction (LVNC) is a hereditary cardiomyopathy and is associated with high morbidity and mortality. However, the role and significance of school screening for LVNC have not been fully elucidated. In this multicenter, retrospective cohort study, a total of 105 children with LVNC were included from 2000 to 2017. At the initial presentation, 44 patients (41.9%) were diagnosed by school screening. One (1.0%) patient underwent heart transplantation and four (3.8%) patients died during the study. Electrocardiogram data showed a high prevalence of fragmented QRS (33.4%) and J wave (15.7%). Treatments were needed in eight (18.2%) patients who were detected by school screening. The multivariable proportional hazards model showed T-wave abnormality on electrocardiogram in first graders was independent risk factors for major adverse cardiac events (odds ratio 4.94, p value = 0.0007). Moreover, dilation of the left atrium on chest X-ray and low ejection fraction on echocardiogram at the initial treatment were independent risk factors for treatment (odds ratio 1.7 × 107 and 22.3, p = 0.0362 and 0.0028, respectively). This study is the first report focusing on school screening in a large pediatric cohort with LVNC. With the use of abnormalities in electrocardiogram, school screening may be a good detector of and predictor for LVNC.

To define the correlation between neuroanatomic and developmental outcomes of children with single ventricle (SV) or transposition of the great arteries (TGA), a prospective longitudinal study was performed in preschool and school-age children. Twenty-seven children with congenital heart disease (9, TGA; 18, SV) were included. Participants underwent 3-dimensional magnetic resonance imaging (MRI) and neurodevelopmental assessment at around 3 years (preschool age) and at 9 years (school age), and 48 healthy controls underwent MRI, and their data were used to derive best-fit models for normal brain volumes for comparisons with congenital heart disease patients. Total brain volume (TBV) and regional brain volumes remained significantly smaller in SV children than in TGA children at both time points, though the growth slope of TBV was not significantly different between the SV and TGA groups. Although the psychomotor developmental index at preschool was significantly lower in SV patients, the full-scale IQ at school age was not significantly lower in SV patients. There was a strong correlation between full-scale IQ and TBV (r = 0.49, P = 0.005). Despite the current best practices, persistently lower TBV was seen in SV patients until 9 years of age. For both the SV and TGA groups, TBV at 3 years was a strong predictor of TBV at 9 years. Since there was a correlation between TBV and IQ at 9 years, identification of factors that affect brain growth until 3 years will be imperative to improve patients' cognitive function at school age.

To examine whether neurodevelopment at preschool age predicts IQ levels and needs for special education services in school-age children with single ventricle (SV) physiology. Thirty-five patients with SV physiology were assessed using the Bayley Scale of Infant and Toddler Development (BSID) II or III at 3 years and the Wechsler Intelligence Scale for Children-Fourth Edition (WISC) at 8 years. Whether the children were receiving special education services was also determined. Factors associated with the mental developmental index (MDI) of the BSID, the full-scale IQ (FSIQ) of the WISC, and special education services were also analyzed. The MDI and FSIQ of children with SV physiology were significantly lower than the values in healthy children (P0.01). The MDI at 3 years was moderately correlated with FSIQ at 8 years (P0.01, R

Background: Coronary artery fistulas (CAFs) presenting in infancy are rare, and data regarding postclosure sequelae and follow-up are limited. Methods: A retrospective review of all the neonates and infants ( Results: Forty-eight patients were included from 20 centers. Of these, 30 were proximal and 18 had distal CAF; 39 were large, 7 medium, and 2 had small CAF. The median age and weight was 0.16 years (0.01–1) and 4.2 kg (1.7–10.6). Heart failure was noted in 28 of 48 (58%) patients. Transcatheter closure was performed in 24, surgical closure in 18, and 6 were observed medically. Procedural success was 92% and 94 % for transcatheter closure and surgical closure, respectively. Follow-up data were obtained in 34 of 48 (70%) at a median of 2.9 (0.1–18) years. Angiography to assess remodeling was available in 20 of 48 (41%). I. Optimal remodeling (n=10, 7 proximal and 3 distal CAF). II. Suboptimal remodeling (n=7) included (A) symptomatic coronary thrombosis (n=2, distal CAF), (B) asymptomatic coronary thrombosis (n=3, 1 proximal and 2 distal CAF), and (C) partial thrombosis with residual cul-de-sac (n=1, proximal CAF) and vessel irregularity with stenosis (n=1, distal CAF). Finally, (III) persistent coronary artery dilation (n=4). Antiplatelets and anticoagulation were used in 31 and 7 patients post-closure, respectively. Overall, 7 of 10 (70%) with proximal CAF had optimal remodeling, but 5 of 11 (45%) with distal CAF had suboptimal remodeling. Only 1 of 7 patients with suboptimal remodeling were on anticoagulation. Conclusions: Neonates/infants with hemodynamically significant CAF can be treated by transcatheter or surgical closure with excellent procedural success. Patients with distal CAF are at higher risk for suboptimal remodeling. Postclosure anticoagulation and follow-up coronary anatomic evaluation are warranted.

ObjectiveLeft ventricular non-compaction (LVNC) is morphologically characterised by excessive trabeculations and deep recesses in the ventricular wall. The risk of thromboembolic disease in the paediatric patients with LVNC has not been clearly established. We conducted this systematic review to evaluate the prevalence and incidence of thromboembolism (TE) in paediatric and adult patients with LVNC and searched for risk factors for TE to explore management strategies.MethodsThe primary outcome was the prevalence and incidence of TE in the patients with LVNC. The secondary outcome was the TE and mortality and heart transplantation rates between paediatric and adult patients with LVNC. We searched for studies published in MEDLINE, Embase and Cochrane Central Register of Controlled Trials between January 1950 and December 2020. A systematic search of keywords related to LVNC, anticoagulants/antiplatelets and TE was conducted. Studies that did not present original research, non-human studies, duplicated studies were excluded.ResultsFifty-seven studies met the inclusion criteria. A total of 726 paediatric and 3862 adult patients were included. The mean prevalence rates of TE in the paediatric and adult patients with LVNC were 2.6% and 6.2% (I2=0%; p2=73.7%; p2=99.4%; p2=99.5%; pConclusionsThe prevalence and incidence rates in paediatric patients were lower than those in adult patients. TE was associated with a reduced systolic function in paediatric patients with LVNC.

Background The usefulness of electrocardiographic (ECG) voltage criteria for diagnosing hypertrophic cardiomyopathy (HCM) in pediatric patients is poorly defined.Methods and Results:ECGs at the 1st grade (mean [±SD] age 6.6±0.3 years) were available for 11 patients diagnosed with HCM at around the 7th grade (13.2±0.3 years). ECGs were available for another 64 patients diagnosed with HCM in the 1st (n=15), 7th (n=32), and 10th (n=17) grades. Fifty-one voltage criteria were developed by grade and sex using 62,841 ECGs from the general population. Voltage criteria were set at the 99.95th percentile (1/2,000) point based on the estimated prevalence of childhood HCM (2.9 per 100,000 [1/34,483]) to decrease false negatives. Conventional criteria were from guidelines for school-aged children in Japan. Of 11 patients before diagnosis, 2 satisfied conventional criteria in 1st grade; 5 (56%) of the remaining 9 patients fulfilled 2 voltage criteria (R wave in limb-lead I [RI]+S wave in lead V3 [SV3] and R wave in lead V3 [RV3]+SV3). Robustness analysis for sensitivity showed RV3+SV3 was superior to RI+SV3. For all patients after diagnosis, RI+SV4 was the main candidate. However, conventional criteria were more useful than voltage criteria. Conclusions Early HCM prediction was possible using RV3+SV3 in >50% of patients in 1st grade. Voltage criteria may help diagnose prediagnostic or early HCM, and prevent tragic accidents, although further prospective studies are required.

Although relatively uncommon, pathologists may encounter minimal inflammatory foci in the absence of typical structural heart disease; however, the clinicopathological significance of minimal inflammatory foci, including correlation with sudden unexpected death, is unexplored. From 1072 serial autopsy subjects, cases with unexplained minimal inflammatory foci, the extent of which was under 1% of the whole examined ventricle, were extracted to exclude cases with borderline/focal myocarditis resulting from local, systemic infection, or autoimmune mechanisms. Immunohistochemistry and genetic analysis targeting viral genomes and heart disease-related genes using next generation sequencing were performed. We detected 10 cases with unexplained minimal inflammatory foci (five males, five females, aged 15-68 years). The cause and/or manner of death were sudden unexpected death (6 cases, 60%), sudden unexpected death with epilepsy (1 case, 10%), drowning in a hot bath (1 case, 10%), and suicide (2 cases, 20%). In none of these cases was pathogen-derived DNA or RNA detected. In 8 of the 10 cases (80%), 17 possible pathogenic genetic variants causative for arrhythmogenic right ventricular cardiomyopathy or dilated cardiomyopathy; DSP was the most frequently involved gene (three cases with two different variants), followed by LAMA4 and MYBPC3 (two cases, two variants for each gene), LDB3 (two cases, one variant), and the remaining 10 variants occurred in seven cases (DSC2, RYR2, SOS1, SCN5A, SGCD, LPL, PKP2, MYH11, GATA6, and DSG2). All mutations were missense mutations. DSP_Lys1581Glu and DSC2_p.Thr275Met were classified according to American College of Medical Genetics and Genomics consensus statement guidelines as pathogenic or likely pathogenic for arrhythmogenic cardiomyopathy in three patients (30%). The remaining 15 variants were classified as potentially pathogenic variants. Unexplained minimal inflammatory foci may be an early sign of inherited cardiomyopathy, and such cases might already have arrhythmogenic potential that can lead to sudden unexpected death. Detection of minimal inflammatory foci by careful pathological examination may indicate the value of conducting comprehensive genetic analysis, even if significant structural abnormalities are not evident.

Rationale: To detect pulmonary arterial hypertension (PAH) at any early stage is a promising approach to optimize the outcome.Objectives: To investigate the impact of school ECG-based screening on ...

OBJECTIVES Neurodevelopmental disability is the most common complication among congenital heart surgery survivors. The Bayley scales are standardized instruments to assess neurodevelopment. The most recent edition (Bayley Scales of Infant and Toddler Development 3rd Edition, Bayley-III) yields better-than-expected scores in typically developing and high-risk infants than the second edition (Bayley Scales of Infant Development 2nd Edition, BSID-II). We compared BSID-II and Bayley-III scores in infants undergoing cardiac surgery. METHODS We evaluated 2198 infants who underwent operations with cardiopulmonary bypass between 1996 and 2009 at 26 institutions. We used propensity score matching to limit confounding by indication in a subset of patients (n = 705). RESULTS Overall, unadjusted Bayley-III motor scores were higher than BSID-II Psychomotor Development Index scores (90.7 ± 17.2 vs 77.6 ± 18.8, P CONCLUSIONS The Bayley-III yielded higher scores than the BSID-II and classified fewer children as severely impaired. The systematic bias towards higher scores with the Bayley-III precludes valid comparisons between early and contemporary cardiac surgery cohorts.

We previously demonstrated that the rational pediatric dosage of warfarin can be well-described by a SIZE parameter that includes an allometry exponent of weight. On the other hand, allometry alone is considered to be insufficient to predict drug clearance in neonates and infants. The primary purpose of the present study was to evaluate the effects of incorporation of the maturation process into the analysis model for the dose-response relationship of warfarin in Japanese children. In addition, we evaluated the effect of chronic heart failure (CHF) on the response to warfarin as an independent risk factor for increased anticoagulant effects. Thirty-eight patients with stable anticoagulation by warfarin were enrolled. During a mean follow-up period of 4.74 ± 3.51 years, 1092 data points including prothrombin time-international normalized ratio (PT-INR) were obtained. The data were subjected to multiple regression analysis to identify covariates related to the anticoagulant effects. Two different models describing the maturation process did not improve the predictive performance for the dose-response relationship in pediatric patients. In addition to the SIZE-normalized daily dose, the vitamin K epoxide reductase complex 1 (VKORC1) genotype, and concomitant use of bosentan, CHF was identified as a covariate increasing the anticoagulant effects of warfarin to 118%. The SIZE parameter was useful even without incorporation of maturation models to describe the response to warfarin in pediatric patients, and our longitudinal follow-up study design with multiple observations was beneficial to detect changes within individual subjects.

The purpose of this study was to determine the serum protein binding of tadalafil in children with protein-losing enteropathy (PLE) and to evaluate the specific binding of the drug to human serum-derived proteins in vitro. Seventeen serum samples from two PLE patients used after biochemical tests were collected, and the unbound fraction of tadalafil was determined by an ultrafiltration method. The serum albumin concentrations observed in patients #1 and #2 were 2.4-4.2 and 2.9-3.5 g/dL, respectively. The ranges of unbound fraction of tadalafil in patients #1 and #2 were 3.9-13 and 5.0-7.0%, respectively. This suggested that serum albumin was at least a binding carrier for tadalafil because the unbound fraction of tadalafil and serum albumin were slightly correlated. The unbound fraction of tadalafil at the total concentration of 300 ng/mL was negatively dependent on the serum albumin concentration (range: 1.0-5.0 g/dL) in vitro. In the presence of albumin, the additive effect of γ-globulin on the unbound fraction of tadalafil was marginal, but the addition of α1-acid glycoprotein to test samples decreased the unbound fraction of the drug. The decrease in the unbound fraction of tadalafil was greater at low albumin levels (2 g/dL). The addition of lipoprotein to test samples also decreased the unbound fraction of tadalafil, suggesting that lipoprotein was also a binding carrier of the drug. These results suggested that the disposition and/or response to tadalafil in PLE patients was altered by the change in protein bindings of the drug.

Background Left ventricular noncompaction cardiomyopathy (LVNC) is characterized by prominent ventricular trabeculations on cardiovascular imaging. Acquired reversible LVNC has not been reported in pediatrics without a genetic background. Case presentation A 9-year-old girl with a ventriculoperitoneal (VP) shunt for neonatal posthemorrhagic hydrocephalus was referred due to exacerbation of hydrocephalus caused by VP shunt dysfunction. Transthoracic echocardiography (TTE) revealed depressed left ventricular (LV) systolic function and thick prominent trabeculae in the LV, predominantly in the apex, suggesting LVNC. Following treatment with extraventricular drainage for hydrocephalus, prominent trabeculation of the LV was diminished on TTE within 3 months. Genetic testing using next-generation sequencing was performed, and no significant variants were identified. Conclusions We revealed for the first time a pediatric case of reversible LVNC without genetic predisposition. This case report provides valuable information on the pathogenesis of acquired LVNC and suggests that detailed evaluation is required to elucidate the diagnosis of this wide spectrum of etiologic–pathogenetic disorders.

Kawasaki disease (KD) is a systemic vasculitis that is currently the most common cause of acquired heart disease in children. However, its etiology remains unknown. Long non-coding RNAs (lncRNAs) contribute to the pathophysiology of various diseases. Few studies have reported the role of lncRNAs in KD inflammation; thus, we investigated the role of lncRNA in KD inflammation.A total of 50 patients with KD (median age, 19 months; 29 males and 21 females) were enrolled. We conducted cap analysis gene expression sequencing to determine differentially expressed genes in monocytes of the peripheral blood of the subjects.About 21 candidate lncRNA transcripts were identified. The analyses of transcriptome and gene ontology revealed that the immune system was involved in KD. Among these genes, G0/G1 switch gene 2 (G0S2) and its antisense lncRNA, HSD11B1-AS1, were upregulated during the acute phase of KD (P 0.0001 and0.0001, respectively). Moreover, G0S2 increased when lipopolysaccharides induced inflammation in THP-1 monocytes, and silencing of G0S2 suppressed the expression of HSD11B1-AS1 and tumor necrosis factor-α.This study uncovered the crucial role of lncRNAs in innate immunity in acute KD. LncRNA may be a novel target for the diagnosis of KD.This study revealed the whole aspect of the gene expression profile of monocytes of patients with Kawasaki disease (KD) using cap analysis gene expression sequencing and identified KD-specific molecules: G0/G1 switch gene 2 (G0S2) and long non-coding RNA (lncRNA) HSD11B1-AS1. We demonstrated that G0S2 and its antisense HSD11B1-AS1 were associated with inflammation of innate immunity in KD. lncRNA may be a novel key target for the diagnosis of patients with KD.

Restrictive cardiomyopathy (RCM) is a rare myocardial disease with an impaired diastolic function and poor prognosis. Almost all RCM patients are reported to have abnormal P-waves due to atrial overloading. This study aimed to reveal the characteristics of the P-waves in RCM patients and to suggest the diagnostic index of RCM in children with a 12-lead electrocardiogram (ECG). We retrospectively investigated 17 ECGs of children with idiopathic RCM during the initial visit at 15 institutes in Japan between 1979 and 2013. The RCM group was divided into four groups based on the age (elementary school [ES] and junior high school [JHS] students) and inception of the diagnosis (abnormal ECG on school-heart-screening [e-RCM] and some cardiovascular symptoms [s-RCM]), the ES/e-RCM (n = 5), ES/s-RCM (n = 4), JHS/e-RCM (n = 4), and JHS/s-RCM (n = 4) groups. As an aged-match control group, school-heart-screening ECGs of 1st-grade ES students (16,770 students) and 1st-grade JHS students (18,126 students) from Kagoshima in 2016 were adopted. For a comparison between the groups, we used the effect size “Hedge’s g” by calculating the mean and standard deviation of the two groups. An effect size of 0.8 (or above) had an overlap of 53% (or less). The effect sizes of the sum of the absolute values of the forward and backward amplitudes in lead V1 (P1 + P2 V1) was the largest, and the ES/e-RCM, ES/s-RCM, JHS/e-RCM, and JHS/s-RCM were 15.8, 22.1, 9.4, and 10.3, respectively. A P1 + P2 V1 > 200 μV was able to rule in all RCM patients, thus, we proposed 200 µV as the cutoff value for screening purposes. In conclusion, the P1 + P2 V1 in the school-heart-screening may be useful for detecting asymptomatic or early-stage RCM in school-age children.

Additional file 1: Figure S1. Head CT images before (A) and after (B) exacerbation of hydrocephalus. Figure S2. Serial ECG changes after admission. Table S1. List of 182 analyzed genes of NGS. Table S2. Silico predictive algorithms used in the study.

Background: Mutations in the nuclear envelope genes encoding LMNA and EMD are responsible for Emery-Dreifuss muscular dystrophy. However, LMNA mutations often manifest dilated cardiomyopathy with conduction disturbance without obvious skeletal myopathic complications. On the contrary, the phenotypic spectrums of EMD mutations are less clear. Our aims were to determine the prevalence of nonsyndromic forms of emerinopathy, which may underlie genetically undefined isolated cardiac conduction disturbance, and the etiology of thromboembolic complications associated with EMD mutations. Methods: Targeted exon sequencing was performed in 87 probands with familial sick sinus syndrome (n=36) and a progressive cardiac conduction defect (n=51). Results: We identified 3 X-linked recessive EMD mutations (start-loss, splicing, missense) in families with cardiac conduction disease. All 3 probands shared a common clinical phenotype of progressive atrial arrhythmias that ultimately resulted in atrial standstill associated with left ventricular noncompaction (LVNC), but they lacked early contractures and progressive muscle wasting and weakness characteristic of Emery-Dreifuss muscular dystrophy. Because the association of LVNC with EMD has never been reported, we further genetically screened 102 LVNC patients and found a frameshift EMD mutation in a boy with progressive atrial standstill and LVNC without complications of muscular dystrophy. All 6 male EMD mutation carriers of 4 families underwent pacemaker or defibrillator implantation, whereas 2 female carriers were asymptomatic. Notably, a strong family history of stroke observed in these families was probably due to the increased risk of thromboembolism attributable to both atrial standstill and LVNC. Conclusions: Cardiac emerinopathy is a novel nonsyndromic X-linked progressive atrial standstill associated with LVNC and increased risk of thromboembolism.

Background: Left ventricular noncompaction (LVNC) is a hereditary type of cardiomyopathy. Although it is associated with high morbidity and mortality, the related ion channel gene variants in children have not been fully investigated. This study aimed to elucidate the ion channel genetic landscape of LVNC and identify genotype-phenotype correlations in a large Japanese cohort. Methods: We enrolled 206 children with LVNC from 2002 to 2017 in Japan. LVNC was classified as follows: LVNC with congenital heart defects, arrhythmia, dilated phenotype, or normal function. In the enrolled patients, 182 genes associated with cardiomyopathy were screened using next-generation sequencing. Results: We identified 99 pathogenic variants in 40 genes in 87 patients. Of the pathogenic variants, 8.8% were in genes associated with channelopathies, 27% were in sarcomere genes, and 11.5% were in mitochondrial genes. Ion channel gene variants were mostly associated with the arrhythmia classification, whereas sarcomere and mitochondrial gene variants were associated with the dilated phenotype. Echocardiography revealed that the group with ion channel gene variants had almost normal LV ejection fraction and LV diastolic diameter Z scores. Fragmented QRS, old age, and an arrhythmia phenotype were the most significant risk factors for ventricular tachycardia ( P =0.165, 0.0428, and 0.0074, respectively). Moreover, the group with ion channel variants exhibited a greater risk of a higher prevalence of arrhythmias such as ventricular tachycardia, rather than congestive heart failure. Conclusions: This is the first study that focused on genotype-phenotype correlations in a large pediatric LVNC patient cohort with ion channel gene variants that were determined using next-generation sequencing. Ion channel gene variants were strongly correlated with arrhythmia phenotypes. Genetic testing and phenotype specification allow for appropriate medical management of specific LVNC targets.

Background Left ventricular noncompaction (LVNC) is a hereditary cardiomyopathy, associated with high morbidity and mortality, but the role of genetics in cases of fetal-onset has not been fully evaluated. The goal of this study was to identify the genetic background in LVNC fetal-onset patients using next-generation sequencing (NGS). Methods Thirty-three fetal-onset Japanese probands with LVNC (20 males and 13 females) were enrolled. In the enrolled patients, 81 genes associated with cardiomyopathy were screened using next-generation sequencing (NGS) retrospectively. Results Twenty-three patients had congestive heart failure (CHF), and six patients had arrhythmias. Prominent trabeculations were mostly observed in lateral LV, posterior LV, and apex of LV in patients with LVNC. Twelve died; three patients experienced intrauterine death or termination of pregnancy. Overall, 15 variants were found among eight genes in 16 patients. Seven variants were detected in MYH7 and two in TPM1. Sarcomere gene variants accounted for 75.0%. A multivariable proportional hazards model revealed that CHF at diagnosis and a higher ratio of the noncompacted layer/compacted layer in the LV posterior wall were independent risk factors for death in LVNC fetal-onset patients (odds ratio = 4.26 × 106 and 1.36 × 108, p = 0.0075 and 0.0005, respectively). Conclusions The present study is the first report focusing on genetic background combined with clinical features in LVNC fetal-onset patients using NGS. Sarcomere variants were most commonly identified in fetal-onset patients, and greater attention should be paid to fetal-onset patients with LVNC having prominent trabeculations in the LV because they are more likely to develop CHF.

Background: Left ventricular noncompaction (LVNC) is a hereditary cardiomyopathy that is associated with high morbidity and mortality rates. Recently, LVNC was classified into several phenotypes including congenital heart disease (CHD). However, although LVNC and CHD are frequently observed, the role and clinical significance of genetics in these cardiomyopathies has not been fully evaluated. Therefore, we aimed to evaluate the impact on the perioperative outcomes of children with concomitant LVNC and CHD using next-generation sequencing (NGS). Methods: From May 2000 to August 2018, 53 Japanese probands with LVNC (25 males and 28 females) were enrolled and we screened 182 cardiomyopathy-associated genes in these patients using NGS. Results: The age at diagnosis of the enrolled patients ranged from 0 to 14 years (median: 0.3 months). A total of 23 patients (43.4%) were diagnosed with heart failure, 14 with heart murmur (26.4%), and 6 with cyanosis (11.3%). During the observation period, 31 patients (58.5%) experienced heart failure and 13 (24.5%) developed arrhythmias such as ventricular tachycardia, supraventricular tachycardia, and atrioventricular block. Moreover, 29 patients (54.7%) had ventricular septal defects (VSDs), 17 (32.1%) had atrial septal defects, 10 had patent ductus arteriosus (PDA), and 7 (13.2%) had Ebstein’s anomaly and double outlet right ventricle. Among the included patients, 30 underwent surgery, 19 underwent biventricular repair, and 2 underwent pulmonary artery banding, bilateral pulmonary artery banding, and PDA ligation. Overall, 30 genetic variants were identified in 28 patients with LVNC and CHD. Eight variants were detected in MYH7 and two in TPM1. Echocardiography showed lower ejection fractions and more thickened trabeculations in the left ventricle in patients with LVNC and CHD than in age-matched patients with VSDs. During follow-up, 4 patients died and the condition of 8 worsened postoperatively. The multivariable proportional hazards model showed that heart failure, LV ejection fraction of &lt, 24%, LV end-diastolic diameter z-score of &gt, 8.56, and noncompacted-to-compacted ratio of the left ventricular apex of &gt, 8.33 at the last visit were risk factors for survival. Conclusions: LVNC and CHD are frequently associated with genetic abnormalities. Knowledge of the association between CHD and LVNC is important for the awareness of clinical implications during the preoperative and postoperative periods to identify the populations who are at an increased risk of additional morbidity.

BackgroundTBX5 is a transcription factor that has an important role in development of heart. TBX5 variants in the region encoding the T-box domain have been shown to cause cardiac defects, such as atrial septal defect or ventricular septal defect, while TBX5 variants have also been identified in a few cardiomyopathy patients and considered causative. We identified a TBX5 variant (c.791G>A, p.Arg264Lys), that is over-represented in cardiomyopathy patients. This variant is located outside of the T-box domain, and its pathogenicity has not been confirmed by functional analyses.ObjectiveTo investigate whether the TBX5 R264K is deleterious and could contribute to the pathogenesis of cardiomyopathy.Methods and resultsWe developed mice expressing Tbx5 R264K. Mice homozygous for this variant displayed compensated dilated cardiomyopathy; mild decreased fractional shortening, dilatation of the left ventricle, left ventricular wall thinning and increased heart weight without major heart structural disorders. There was no difference in activation of the ANF promotor, a transcriptional target of Tbx5, compared to wild-type. However, analysis of RNA isolated from left ventricular samples showed significant increases in the expression of Acta1 in left ventricle with concomitant increases in the protein level of ACTA1.ConclusionsMice homozygous for Tbx5 R264K showed compensated dilated cardiomyopathy. Thus, TBX5 R264K may have a significant pathogenic role in some cardiomyopathy patients independently of T-box domain pathway.

The diagnosis of Barth syndrome is challenging owing to the wide phenotypic spectrum with allelic heterogeneity. Here we report 3 cases of Barth syndrome with phenotypic and allelic heterogeneity that were diagnosed by different approaches, including whole exome sequencing and final confirmation by reverse-transcription polymease chain reaction.

Objectives Our goal was to evaluate whether endothlin-1 (ET-1) plays an important role in the Fontan circulation. Methods Thirteen patients with single-ventricle physiology (Glenn circulation, n = 7; Fontan circulation, n = 6) were evaluated using lung histopathological and immunohistochemical studies and then compared with the normal autopsied controls without congenital heart disease (n = 13). We evaluated the medial thickness of the small pulmonary arteries. For 10 of these patients, quantitative real-time polymerase chain reaction analyses of ET-1, endothelin receptors Type A and Type B, endothelin-converting enzyme-1 and endothelial nitric oxide synthase were performed. Results The medial thickness of the small pulmonary arteries in patients with single-ventricle physiology was greater than that of those in the control group (P = 0.0341). Severe medial hypertrophy of the pulmonary arteries was observed in patients who had poor outcomes. Immunohistochemical studies revealed that the marked expression of ET-1 was observed in the endothelium and media of their pulmonary arteries. In these patients, the messenger RNA expression of ET-1 was also increased. Two patients showed high levels of expression of ETAR and ETBR, although these 2 cases maintain good Fontan circulation. Conclusions Medial hypertrophy and the overexpression of ET-1 in the pulmonary arteries were observed in some patients in whom the Fontan circulation failed. Our data suggest that ET-1 may play an important role in maintaining the Fontan circulation.

It is well known that Down's syndrome is a strong risk factor for mortality after Fontan operations. We performed two lung biopsies in a Down's syndrome patient who underwent staged Fontan operations. The pathological findings revealed severe pulmonary arterial hypertrophy and a quantitative real-time polymerase chain reaction revealed the overexpression of endothelin and a decline in the eNOS level at the Fontan operation. Although the preoperative hemodynamic studies revealed that all of the criteria for Fontan had been fulfilled, the patient died of acute cardiac insufficiency, 35 days after the Fontan operation.

BACKGROUND The natural history of left ventricular noncompaction (LVNC) is largely unsolved, so the aim of the present study was to clarify the clinical features and long-term prognosis of children with LVNC until adulthood.Methods and Results:We conducted a nationwide survey over 20 years and compared the clinical features, anatomical characteristics and long-term prognosis of 205 patients divided into 2 classifications: infantile type (diagnosed at

The 81stAnnual Scientific Meeting of the Japanese Circulation Society was held in Kanazawa, Japan, on March 17-19, 2017 under a miraculously clear sky. The frontlines of healthcare and medicine are dramatically changing. Thus, "Cardiovascular Medicine for Next Generation" was chosen as the main theme of this meeting. The program was constructed around major identified issues, including renewal of our understanding of basic cardiovascular medicine, translational research, and preventive molecular medicine, all of which are anticipated to transcend the medical field over the next generation. Despite the provincial location, 15,672 participants, including more than 400 from overseas countries, attended the 3-day meeting, and there were in-depth discussions in the various sessions. In particular, to our great pleasure, Her Imperial Highness Princess Takamado kindly attended the opening ceremony and extended congratulations to us. The meeting successfully completed and we sincerely appreciate the great cooperation and support from all affiliates.

Introduction Restrictive cardiomyopathy (RCM) is a rare myocardial disease with an impaired diastolic function and poor prognosis. The mean survival duration after a diagnosis of RCM is reported to be around 2 years in children and most need heart transplantations. Purpose This study aimed to determine the 12-lead electrocardiogram (ECG) diagnostic criteria of RCM based on the initial diagnostic electrocardiogram. Methods ECGs in pediatric cardiomyopathy patients were collected from 15 institutes in Japan between 1979 and 2013. We compared the ECG findings, especially of the P wave, in RCM patients between the cardiomyopathy group and healthy children group separately for each gender and the age. The ECGs in the healthy group were obtained from school heart screening in Japan of first-graders, and seventh-graders. Statistical significance was determined as p Results Among 376 registered cardiomyopathy patients, 63 had hypertrophic cardiomyopathy (HCM) (36%), 91 (24%) dilated cardiomyopathy (DCM), 106 (28%) a left ventricular myocardial noncompaction (LVNCs), 25 (7%) restrictive cardiomyopathy (RCM), 14 (4%) arrhythmogenic right ventricular cardiomyopathy (ARVC), and 5 (1%) other cardiomyopathies. Of the 25 RCM patients (9.9±3.4 years old, F:M=11:14), 36% were discovered during school heart screening. The first onset was an abnormal ECG in 9, symptoms of heart failure in 6, respiratory tract infections in 3, syncope in 1, and 6 with other. Of those patients, 2 (8%) had a family history of RCM, 24 (92%) no family history. A genetic diagnosis was performed in 5 of the 25 cases, and 3 had genetic abnormalities related to RCM. The mean follow-up period was 65±95 months (mean±standard deviation). During follow up, 19 patients (76%) survived, 6 (24%) died, 7 (28%) had heart transplantations, and 3 (12%) were waiting for heart transplantations with a left ventricular assist device. The P wave was bimodal in lead I or biphasic in lead V1 in 15 patients (93%), and 13 (81%) patients had both variations. We evaluated the duration and amplitude of the first and second component of the P wave as P1 and P2. The number of control and RCM patients (control/RCM), duration of P1+P2, and sum total absolute value of the amplitude of P1+P2 in lead V1 were 8350/5, 90±9/116±10ms, and 72±28/528±278μV in first grade boys, 8423/3, 91±10/120±22ms, and 66±28/326±229μV in first grade girls, 8943/1, 97±1/100ms, and 71±31/328μV in seventh grade boys, and 9183/5, 98±11/112±10ms, and 55±27/315±56μV in seventh grade girls. Although the number of patients in the RCM group was small, sum total absolute value of the amplitude of P1+P2 in lead V1 showed a significant difference in any group. Conclusion The ECG in children with RCM exhibits P wave abnormalities in almost all patients. In particular, not the P wave interval but P wave shape in I and V1 and the sum total absolute value of the amplitude of P1+P2 in lead V1 were observed differences.

Summary Left ventricular noncompaction (LVNC) is a cardiomyopathy characterized by two layered structures composed of prominent trabecular meshwork and deep intertrabecular recesses. LVNC was thought to be rare; however, heightened awareness has resulted in an increased detection of the morphological features of LVNC in routine clinical practice especially in the adult population. Although LVNC was classified as an independent primary cardiomyopathy of genetic origin by the American Heart Association in 2006, its definition, diagnostic criteria and clinical implications are still being debated. Clinical manifestations are highly variable, even in the same family, ranging from no symptoms to disabling congestive heart failure, life-threatening arrhythmias, systemic thromboemboli, and sudden cardiac death. Among phenotypic subtypes of LVNC, children with isolated LVNC with normal cardiac function had the best outcomes: children with LVNC and dilated cardiomyopathy had the worst outcomes. Myocardial dysfunction or ventricular arrhythmias are predictors of mortality in adults with LVNC. LVNC, like other forms of inherited cardiomyopathy, is genetically heterogeneous and can be inherited as an autosomal dominant or X-linked recessive disorder. It has been linked to mutations in many genes, including ZASP, TAZ/G4.5, and those encoding sarcomeric, Z-disc, cytoskeleton proteins, and mitochondria. Disturbance of the NOTCH signaling pathway has been reported to be part of genetic pathway for LVNC as well. Although there are an increasing number of reports, genotype-phenotype correlations have been challenging and investigations are ongoing. Patients with mutations are more likely to have major adverse cardiovascular events, further, LV systolic dysfunction in mutation carriers makes them at high risk for cardiac events. Treatments focus on improvement in cardiac function and reduction of mechanical stress in patients with systolic dysfunction and on treatment of arrhythmia and implantation of an automatic implantable cardioverter-defibrillator for prevention of sudden death. Given that 20–40% of cases may be familial, family screening is recommended.

Background: Acute coronary syndrome (ACS), which is emerging in adults long after confirmed (followed-up or lost-to-follow), or missed Kawasaki disease (KD), is poorly characterized.Methods and Results: A Japanese retrospective nationwide hospital-based questionnaire survey of ACS during 2000–09 was conducted to characterize such patients. Among a total of 67 patients (median age 35, male 76%) recruited, low conventional coronary risks (≤1/6) was noted in 75%, a diagnosis of ST-elevation and myocardial infarction or cardiac arrest in 66%, medication before ACS in 22% (warfarin in 4%), and no prior history of acute myocardial infarction in 94%. One-month mortality was 19%. KD diagnosis was made in 32 during acute illness (Group A), in which 17 were lost to follow, and retrospectively in the other 35 from coronary imaging at ACS (Group B). Group A developed ACS at lower coronary risks (≤2/5 in 87 vs. 65% in group B, p = 0.043) at a younger age (26.5 vs. 40 yo, p < 0.001). In group A, followed-up patients developed ACS under medication before ACS (87 vs. 0% in lost-to-follow patients, p < 0.001) for giant aneurysm in culprit lesions (69 vs. 29%, p = 0.030). One-month mortality was comparable between groups A and B, and between patients followed-up and lost-to-follow in group A. The culprit lesion in group A was characterized by the association of an aneurysm ≥6 mm in acute KD (100%), lack of significant stenosis (61%) or giant aneurysm (50%) in the long-term (median interval 16 y), and the presence of intravascular ultrasound-derived calcification at ACS (86%).Conclusions: The present retrospective nationwide questionnaire survey demonstrated nationwide emergence of initial ACS in young adults at low coronary risks, who are followed-up or lost-to-follow after confirmed KD and initial coronary aneurysms ≥6 mm.

Between April 2005 and February 2019, 11 adult patients underwent redo reconstruction of the right ventricular outflow tract. The primary malformation was Fallot's tetralogy in 8, transposition of the great arteries in 2, and pulmonary atresia with intact ventricular septum in 1. Mean age at redo operation was 27.4 years. Right ventricular outflow tract was reconstructed with expanded polytetrafluoroethylene conduits with bulging sinuses and a fan-shaped valve in 9, transannular patch in 1, and right ventricular outflow patch in 1. There were no early and late deaths. One patient had residual branch pulmonary stenosis, while other 10 patients had no significant pulmonary stenosis and no significant pulmonary regurgitation. Signs and symptoms were improved in these 10 patients. Re-operation should be done before the development of right ventricular dysfunction, while it can be performed with satisfactory results in adult patients.

Background Left ventricular non-compaction (LVNC) is a heritable cardiomyopathy characterized by hypertrabeculation, inter-trabecular recesses and thin compact myocardium, but the genetic basis and mechanisms remain unclear. This study identified novel LVNC-associated mutations inNOTCH-dependent genes and investigated their mutational effects.Methods and Results:High-resolution melting screening was performed in 230 individuals with LVNC, followed by whole exome and Sanger sequencing of available family members. Dimerization of bone morphogenetic protein 10 (BMP10) and its binding to BMP receptors (BMPRs) were evaluated. Cellular differentiation, proliferation and tolerance to mechanical stretch were assessed in H9C2 cardiomyoblasts, expressing wild-type (WT) or mutant BMP10 delivered by adenoviral vectors. Rare variants, p.W143*-NRG1and p.V407I-BMP10, were identified in 2 unrelated probands and their affected family members. Although dimerization of mutant V407I-BMP10 was preserved like WT-BMP10, V407I-BMP10 pulled BMPR1a and BMPR2 receptors more weakly compared with WT-BMP10. On comparative gene expression and siRNA analysis, expressed BMPR1a and BMPR2 receptors were responsive to BMP10 treatment in H9C2 cardiomyoblasts. Expression of V407I-BMP10 resulted in a significantly lower rate of proliferation in H9C2 cells compared with WT-BMP10. Cyclic stretch resulted in destruction and death of V407I-BMP10 cells. Conclusions The W143*-NRG1and V470I-BMP10variants are associated with LVNC. Impaired BMPR-binding ability, perturbed proliferation and differentiation processes and intolerance to stretch in V407I-BMP10 mutant cardiomyoblasts may underlie myocardial non-compaction.

Myocyte disarray of &gt, 10% in the heart is broadly accepted as a diagnostic pitfall for hypertrophic cardiomyopathy (HCM) at postmortem. The present study aims to propose an additional diagnostic criterion of HCM. Heart specimens from 1387 serial forensic autopsy cases were examined. Cases with myocyte disarray were extracted and applied to morphometric analysis to determine the amount of myocyte disarray. Comprehensive genetic analysis by using next-generation sequencing was subsequently applied for cases with myocyte disarray. Fifteen cases with myocyte disarray were extracted as candidate cases (1.1%, 11 men and 4 women, aged 48&ndash, 94 years). In terms of the cause of death, only 2 cases were cardiac or possible cardiac death, and the other was non-cardiac death. Six cases showed myocyte disarray of &gt, 10% and 3 cases showed myocyte disarray of 5% to 10%. The other 6 cases showed myocyte disarray of &lt, 5%. Nine rare variants in 5 HCM-related genes (MYBPC3, MYH7, MYH6, PRKAG2, and CAV3) were found in 8 of 9 cases with myocyte disarray of &gt, 5%. The remaining 1 and 6 cases with myocyte disarray of &lt, 5% did not have any such variant. Myocyte disarray of &gt, 5% with rare variants in related genes might be an appropriate postmortem diagnostic criterion for HCM, in addition to myocyte disarray of 10%.