Neonatal dilated cardiomyopathy

Exposure to Pyriproxyfen Impacts Heart Development Causing Tissue and Cellular Impairments, Heart Arrhythmia and Reduced Embryonic Growth

In recent years, concerns have been raised regarding the safety of exposure to pyriproxyfen (PPF), a larvicide commonly used in drinking water reservoirs to control populations of disease-vector mosquitoes for human safety. These concerns are focused mainly on exposure by pregnant women, since studies have shown deleterious effects of PPF on embryonic development, mainly addressing the central nervous system. However, since previous studies showed reduced growth in embryos exposed to PPF, we hypothesize that PPF exposure impairs the cardiovascular system, responsible for ensuring appropriate blood supply, which leads to stunted growth. This study aimed to investigate the impact of PPF exposure on heart ventricular morphology, its influence on cell proliferation and apoptosis, as well as assess the impact on the functionality of the heart and on embryonic growth. Chicken embryos were used as a model and two sublethal concentrations were tested: 0.01 mg/L and 10 mg/L PPF. Thinning of cardiac tissue was evident in heart structures at 10 mg/L PPF. Furthermore, DNA double-strand breaks and reduced cell proliferation were observed, combined with decreased apoptosis suggesting cell cycle arrest, especially in the left ventricle for both concentrations. In addition, these PPF concentrations induced heart arrhythmia, although no changes in heart rate were observed. Embryos exposed to 0.01 mg/L showed reduced body and heart mass, crown-rump length, and thoracic perimeter, while head circumference was reduced in both exposed groups. Together, combining morphological, molecular, and physiological parameters, this study showed the cardiotoxic effects of PPF exposure and elucidated its impacts on embryonic growth.

Cardiomyopathy in Children and Adolescents in the Era of Precision Medicine

In childhood and adolescence, cardiomyopathies have their own characteristics and are an important cause of heart failure, arrhythmias, sudden death, and indication for heart transplantation. Diagnosis is a challenge in daily practice due to its varied clinical presentation, heterogeneous etiologies, and limited knowledge of tools related to clinical and molecular genetics. However, it is essential to recognize the different phenotypes and prioritize the search for the etiology. Recent advances in precision medicine have made molecular diagnosis accessible, which makes it possible to individualize therapeutic approaches, stratify the prognosis, and identify individuals in the family who are at risk of developing the disease. The objective of this review is to emphasize the particularities of cardiomyopathies in pediatrics and how the individualized approach impacts the therapy and prognosis of the patient. Through a systematized approach, the five-stage protocol used in our service is presented. These stages bring together clinical evaluation for determining the morphofunctional phenotype, identification of etiology, classification, establishment of prognosis, and the search for personalized therapies.

Homozygous TNNI3 frameshift variant in a consanguineous family with lethal infantile dilated cardiomyopathy

BACKGROUND

Dilated cardiomyopathy (DCM) is characterized by dilatation of the left ventricle, systolic dysfunction, and normal or reduced thickness of the left ventricular wall. It is a leading cause of heart failure and cardiac death at a young age. Cases with neonatal onset DCM were correlated with severe clinical presentation and poor prognosis. A monogenic molecular etiology accounts for nearly half of cases.

FAMILY DESCRIPTION

Here, we report a family with three deceased offspring at the age of 1 year old. The autopsy of the first deceased infant revealed a DCM. The second infant presented a DCM phenotype with a severely reduced Left Ventricular Ejection Fraction (LVEF) of 10%. Similarly, the third infant showed a severe DCM phenotype with LVEF of 30% as well, in addition to eccentric mitral insufficiency.

RESULTS

Exome sequencing was performed for the trio (the second deceased infant and her parents). Data analysis following the autosomal dominant and recessive patterns of inheritance was carried out along with a mitochondrial pathways-based analysis. We identified a homozygous frameshift variant in the TNNI3 gene (c.204delG; p.(Arg69AlafsTer8)). This variant has been recently reported in the ClinVar database in association with cardiac phenotypes as pathogenic or likely pathogenic and classified as pathogenic according to ACMG.

CONCLUSION

Genetic counseling was provided for the family and a prenatal diagnosis of choronic villus was proposed in the absence of pre-implantation genetic diagnosis possibilities. Our study expands the case series of early-onset DCM patients with a protein-truncating variant in the TNNI3 gene by reporting three affected infant siblings.

Accurate Classification of Non-ischemic Cardiomyopathy

PURPOSE OF REVIEW

This article aims to review the accurate classification of non-ischemic cardiomyopathy, including the methods, basis, subtype characteristics, and prognosis, especially the similarities and differences between different classifications.

RECENT FINDINGS

Non-ischemic cardiomyopathy refers to a myocardial disease that excludes coronary artery disease or ischemic injury and has a variety of etiologies and high incidence. Recent studies suggest that traditional classification methods based on primary/mixed/acquired or genetic/non-genetic cannot meet the precise needs of contemporary clinical management. This article systematically describes the history of classifications of cardiomyopathy and presents etiological and genetic differences between cardiomyopathies. The accurate classification is described from the perspective of morphology, function, and genomics in hypertrophic cardiomyopathy, dilated cardiomyopathy, restrictive cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, left ventricular noncompaction, and partially acquired cardiomyopathy. The different clinical characteristics and treatment needs of these cardiomyopathies are elaborated. Some single-gene mutant cardiomyopathies have unique phenotypes, and some cardiomyopathies have mixed phenotypes. These special classifications require personalized precision treatment, which is worthy of independent research. This article describes recent advances in the accurate classification of non-ischemic cardiomyopathy from clinical phenotypes and causative genes, discusses the advantages and usage scenarios of each classification, compares the differences in prognosis and patient management needs of different subtypes, and summarizes common methods and new exploration directions for accurate classification.

Whole-Exome Sequencing Identifies Homozygote Nonsense Variants in LMOD2 Gene Causing Infantile Dilated Cardiomyopathy

As an essential component of the sarcomere, actin thin filament stems from the Z-disk extend toward the middle of the sarcomere and overlaps with myosin thick filaments. Elongation of the cardiac thin filament is essential for normal sarcomere maturation and heart function. This process is regulated by the actin-binding proteins Leiomodins (LMODs), among which LMOD2 has recently been identified as a key regulator of thin filament elongation to reach a mature length. Few reports have implicated homozygous loss of function variants of LMOD2 in neonatal dilated cardiomyopathy (DCM) associated with thin filament shortening. We present the fifth case of DCM due to biallelic variants in the LMOD2 gene and the second case with the c.1193G>A (p.W398*) nonsense variant identified by whole-exome sequencing. The proband is a 4-month male infant of Hispanic descent with advanced heart failure. Consistent with previous reports, a myocardial biopsy exhibited remarkably short thin filaments. However, compared to other cases of identical or similar biallelic variants, the patient presented here has an unusually late onset of cardiomyopathy during infancy. Herein, we present the phenotypic and histological features of this variant, confirm the pathogenic impact on protein expression and sarcomere structure, and discuss the current knowledge of LMOD2-related cardiomyopathy.

Pediatric acute heart failure caused by endocardial fibroelastosis mimicking dilated cardiomyopathy: A case report

BACKGROUND

Endocardial fibroelastosis (EFE) is a diffuse endocardial collagen and elastin hyperplasia disease of unknown etiology, which may be accompanied by myocardial degenerative changes leading to acute or chronic heart failure. However, acute heart failure (AHF) without obvious associated triggers is rare. Prior to the report of endomyocardial biopsy, the diagnosis and treatment of EFE are highly susceptible to being confounded with other primary cardiomyopathies. Here, we report a case of pediatric AHF caused by EFE mimicking dilated cardiomyopathy (DCM), with the aim of providing a valuable reference for clinicians to early identify and diagnose EFE-induced AHF.

CASE SUMMARY

A 13-mo-old female child was admitted to hospital with retching. Chest X-ray demonstrated enhanced texture in both lungs and an enlarged heart shadow. Color doppler echocardiography showed an enlarged left heart with ventricular wall hypokinesis and decreased left heart function. Abdominal color ultrasonography revealed a markedly enlarged liver. Pending the result of the endomyocardial biopsy report, the child was treated with a variety of resuscitative measures including nasal cannula for oxygen, intramuscular sedation with chlorpromazine and promethazine, cedilanid for cardiac contractility enhancement, and diuretic treatment with furosemide. Subsequently, the child’s endomyocardial biopsy report result was confirmed as EFE. After the above early interventions, the child’s condition gradually stabilized and improved. One week later, the child was discharged. During a 9-mo follow-up period, the child took intermittent low-dose oral digoxin with no signs of recurrence or exacerbation of the heart failure.

CONCLUSION

Our report suggests that EFE-induced pediatric AHF may present in children over 1 year of age without any apparent precipitants, and that the associated clinical presentations are grossly similar to that of pediatric DCM. Nonetheless, it is still possible to be diagnosed effectively on the basis of the comprehensive analysis of auxiliary inspection findings before the result of the endomyocardial biopsy is reported.

An echocardiographic finding mimicking tricuspid atresia in a neonate with dilated cardiomyopathy

We report a neonate with dilated cardiomyopathy and have echocardiographic findings consistent with "functional" tricuspid atresia. There was an echo-bright, plate-like tissue at the tricuspid valve position with no forward flow across it. This report underscores the role of right ventricle intracavitary haemodynamic influence on the tricuspid valve leaflet excursion and demonstrates a phenomenon of "pseudo or functional tricuspid atresia" mimicking tricuspid atresia in a patient with acute presentation of cardiomyopathy.

Comparative efficacy of five Chinese medicine injections for treating dilated cardiomyopathy with heart failure: A Bayesian network meta-analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Chinese medicine injections (CMIs) are widely used by clinicians in China as an adjuvant treatment in dilated cardiomyopathy with heart failure (DCM-HF). However, comprehensive and systematic evidence supporting the beneficial effects of CMIs combined with Western medicine (WM) against DCM-HF was lacking.

OBJECTIVE

This network meta-analysis aimed to assess the effectiveness of five different CMIs in the treatment of DCM-HF.

METHODS

The Cochrane Library, Embase, PubMed, China National Knowledge Infrastructure (CNKI), Allied and Alternative Medieine Database (AMED), Chinese Biological Medicine Database (CBM), Wanfang Database, and Chinese Scientific Journal Database (VIP) were comprehensively searched from their inception to March 10, 2020, for randomized controlled trials (RCTs) focusing on the use of CMIs combined with WM to treat DCM-HF. The quality of the included RCTs was assessed using the Cochrane Handbook 5.1.0. Bayesian network meta-analysis were designed to access the effectiveness of different CMIs.

RESULTS

A total of 38 eligible RCTs involving 3247 patients were enrolled. The study showed that Huangqi injection, Shengmai injection, Shenfu injection, Shenmai injection, and Xinmailong injection combined with WM significantly improved performance compared with WM alone in treating DCM-HF. Xinmailong injection + WM had the highest likelihood of being the best treatment in terms of the improvement in the clinical effectiveness rate, left ventricular end-diastolic dimension, and 6-min walking distance. Huangqi injection + WM had the highest probability of being the best treatment on account of the enhancement of left ventricular ejection fraction. Shenmai injection + WM had the highest likelihood of being the best treatment considering the improvement in cardiac output and the reduction in brain natriuretic peptide.

CONCLUSIONS

The combination between CMIs and WM exerted a more positive effect in DCM-HF treatment. Xinmailong injection + WM had the best performance in treating DCM-HF, followed by Shenmai injection and Huangqi injection. However, due to the low qualities of the original studies, more high-quality studies are needed to support the findings.

Placental chorioangioma: an unusual cause of neonatal cardiomyopathy

A late preterm baby presented with clinical and echocardiographic features of cardiomyopathy and cardiac failure soon after birth. After extensive metabolic, infective and genetic investigations, the likely cause was established to be due to multiple small placental chorioangiomas. While large placental chorioangiomas are associated with maternal, fetal and neonatal complications, small chorioangiomas are usually asymptomatic and diagnosed incidentally on placental histology. Our case demonstrates that multiple small chorioangiomas might behave like a giant chorioangioma, causing significant neonatal morbidity. This report also highlights the importance of assessing the placental histology where no identifiable cause for neonatal cardiomyopathy can be found.

Immune Mechanism, Gene Module, and Molecular Subtype Identification of Astragalus Membranaceus in the Treatment of Dilated Cardiomyopathy: An Integrated Bioinformatics Study

Astragalus membranaceus has complex components as a natural drug and has multilevel, multitarget, and multichannel effects on dilated cardiomyopathy (DCM). However, the immune mechanism, gene module, and molecular subtype of astragalus membranaceus in the treatment of DCM are still not revealed. Microarray information of GSE84796 was downloaded from the GEO database, including RNA sequencing data of seven normal cardiac tissues and ten DCM cardiac tissues. A total of 4029 DCM differentially expressed genes were obtained, including 1855 upregulated genes and 2174 downregulated genes. GO/KEGG/GSEA analysis suggested that the activation of T cells and B cells was the primary cause of DCM. WGCNA was used to obtain blue module genes. The blue module genes are primarily ADCY7, BANK1, CD1E, CD19, CD38, CD300LF, CLEC4E, FLT3, GPR18, HCAR3, IRF4, LAMP3, MRC1, SYK, and TLR8, which successfully divided DCM into three molecular subtypes. Based on the CIBERSORT algorithm, the immune infiltration profile of DCM was analyzed. Many immune cell subtypes, including the abovementioned immune cells, showed different levels of increased infiltration in the myocardial tissue of DCM. However, this infiltration pattern was not obviously correlated with clinical characteristics, such as age, EF, and sex. Based on network pharmacology and ClueGO, 20 active components of Astragalus membranaceus and 40 components of DMCTGS were obtained from TCMSP. Through analysis of the immune regulatory network, we found that Astragalus membranaceus effectively regulates the activation of immune cells, such as B cells and T cells, cytokine secretion, and other processes and can intervene in DCM at multiple components, targets, and levels. The above mechanisms were verified by molecular docking results, which confirmed that AKT1, VEGFA, MMP9, and RELA are promising potential targets of DCM.

Recessive ciliopathy mutations in primary endocardial fibroelastosis: a rare neonatal cardiomyopathy in a case of Alstrom syndrome

Abstract

Among neonatal cardiomyopathies, primary endocardial fibroelastosis (pEFE) remains a mysterious disease of the endomyocardium that is poorly genetically characterized, affecting 1/5000 live births and accounting for 25% of the entire pediatric dilated cardiomyopathy (DCM) with a devastating course and grave prognosis. To investigate the potential genetic contribution to pEFE, we performed integrative genomic analysis, using whole exome sequencing (WES) and RNA-seq in a female infant with confirmed pathological diagnosis of pEFE. Within regions of homozygosity in the proband genome, WES analysis revealed novel parent-transmitted homozygous mutations affecting three genes with known roles in cilia assembly or function. Among them, a novel homozygous variant [c.1943delA] of uncertain significance in ALMS1 was prioritized for functional genomic and mechanistic analysis. Loss of function mutations of ALMS1 have been implicated in Alstrom syndrome (AS) [OMIM 203800], a rare recessive ciliopathy that has been associated with cardiomyopathy. The variant of interest results in a frameshift introducing a premature stop codon. RNA-seq of the proband’s dermal fibroblasts confirmed the impact of the novel ALMS1 variant on RNA-seq reads and revealed dysregulated cellular signaling and function, including the induction of epithelial mesenchymal transition (EMT) and activation of TGFβ signaling. ALMS1 loss enhanced cellular migration in patient fibroblasts as well as neonatal cardiac fibroblasts, while ALMS1-depleted cardiomyocytes exhibited enhanced proliferation activity. Herein, we present the unique pathological features of pEFE compared to DCM and utilize integrated genomic analysis to elucidate the molecular impact of a novel mutation in ALMS1 gene in an AS case. Our report provides insights into pEFE etiology and suggests, for the first time to our knowledge, ciliopathy as a potential underlying mechanism for this poorly understood and incurable form of neonatal cardiomyopathy.

Key message

Primary endocardial fibroelastosis (pEFE) is a rare form of neonatal cardiomyopathy that occurs in 1/5000 live births with significant consequences but unknown etiology.

Integrated genomics analysis (whole exome sequencing and RNA sequencing) elucidates novel genetic contribution to pEFE etiology.

In this case, the cardiac manifestation in Alstrom syndrome is pEFE. To our knowledge, this report provides the first evidence linking ciliopathy to pEFE etiology.

Infants with pEFE should be examined for syndromic features of Alstrom syndrome.

Our findings lead to a better understanding of the molecular mechanisms of pEFE, paving the way to potential diagnostic and therapeutic applications.

Supplementary information

The online version contains supplementary material available at 10.1007/s00109-021-02112-z.

The newborn Fmr1 knockout mouse: a novel model of excess ubiquinone and closed mitochondrial permeability transition pore in the developing heart

BACKGROUND

Mitochondrial permeability transition pore (mPTP) closure triggers cardiomyocyte differentiation during development while pathological opening causes cell death during myocardial ischemia-reperfusion and heart failure. Ubiquinone modulates the mPTP; however, little is known about its mechanistic role in health and disease. We previously found excessive proton leak in newborn Fmr1 KO mouse forebrain caused by ubiquinone deficiency and increased open mPTP probability. Because of the physiological differences between the heart and brain during maturation, we hypothesized that developing Fmr1 KO cardiomyocyte mitochondria would demonstrate dissimilar features.

METHODS

Newborn male Fmr1 KO mice and controls were assessed. Respiratory chain enzyme activity, ubiquinone content, proton leak, and oxygen consumption were measured in cardiomyocyte mitochondria. Cardiac function was evaluated via echocardiography.

RESULTS

In contrast to controls, Fmr1 KO cardiomyocyte mitochondria demonstrated increased ubiquinone content and decreased proton leak. Leak was cyclosporine (CsA)-sensitive in controls and CsA-insensitive in Fmr1 KOs. There was no difference in absolute mitochondrial respiration or cardiac function between strains.

CONCLUSION

These findings establish the newborn Fmr1 KO mouse as a novel model of excess ubiquinone and closed mPTP in the developing heart. Such a model may help provide insight into the biology of cardiac development and pathophysiology of neonatal heart failure.

IMPACT

Ubiquinone is in excess and the mPTP is closed in the developing FXS heart. Strengthens evidence of open mPTP probability in the normally developing postnatal murine heart and provides new evidence for premature closure of the mPTP in Fmr1 mutants. Establishes a novel model of excess CoQ and a closed pore in the developing heart. Such a model will be a valuable tool used to better understand the role of ubiquinone and the mPTP in the neonatal heart in health and disease.

Cardiomyopathy Associated With Coronary Arteriosclerosis in Free-Ranging Eurasian Lynx (Lynx lynx carpathicus)

The Eurasian lynx (subspecies Lynx lynx carpathicus) was reintroduced to Switzerland in the 1970's. Health monitoring of the reintroduced population started in the late 1980's. Since then, six lynx have been found affected by a myocardial disease. The earliest case was an animal that died after a field anesthesia. Two lynx were found dead, two were euthanized/culled because of disease signs, and one was hit by car. Two had a heart murmur at clinical examination. At necropsy, the first animal showed only lung edema but the other five had cardiomegaly associated with myocardial fibrosis. Three had multisystemic effusions. Histological examination of all six lynx showed mild to severe, multifocal, myocardial interstitial and perivascular fibrosis along with multifocal myocyte degeneration and loss, and replacement fibrosis. Moderate to severe multifocal arteriosclerosis with associated luminal stenosis of the small and medium-sized intramural coronary arteries and the presence of Anitschkow cells was also observed. The heart lesions may have led to sudden death in the first case and to a chronic right-sided heart failure in the remaining. None of the lynx showed lesions or signs suggestive of an acute or subacute infection. Given the common geographic origin of these animals and the severe loss of heterozygocity in this population, a genetic origin of the disease is hypothesized.

Sudden Unexpected Death of Infantile Dilated Cardiomyopathy with JPH2 and PKD1 Gene Variants

A Japanese girl with polycystic kidney disease (PKD) developed normally, but at 8 months of age, she was hospitalized for acute onset dyspnea. On the day after admission to hospital, her general condition suddenly became worse. An echocardiogram showed left ventricular dilatation with thin walls, severe mitral valve regurgitation, and a reduced ejection fraction. She died of acute cardiac failure 3 hours after the sudden change. Postmortem analysis with light microscopy showed disarray of cardiomyocytes without obvious infiltration of lymphocytes, and we diagnosed her heart failure as idiopathic dilated cardiomyopathy (DCM). Clinical exome sequencing showed compound heterozygous variants in JPH2 (p.T237A/p.I414L) and a heterozygous nonsense mutation in PKD1 (p.Q4193*). To date, several variants in the JPH2 gene have been reported to be pathogenic for adult-onset hypertrophic cardiomyopathy or DCM in an autosomal dominant manner and infantile-onset DCM in an autosomal recessive manner. Additionally, autosomal dominant polycystic kidney disease is a systemic disease associated with several extrarenal manifestations, such as cardiomyopathy. Here we report a sudden infant death case of DCM and discuss the genetic variants of DCM and PKD.

Therapeutic efficacy of shenmai injection as an adjuvant treatment in dilated cardiomyopathy: A protocol for systematic review

BACKGROUND

Shenmai injection (SMI) is a Traditional Chinese Medicine patent prescription consisting of extractions from ophiopogonis radix and ginseng radix rubra. Clinical studies showed that SMI combined with conventional medicine treatment (CMT) can enhance the therapeutic efficacy for dilated cardiomyopathy (DCM). However, there is still a lack of comprehensive and systematic evidence, which urgently requires us to verify its therapeutic efficacy. Hence, we provide a protocol for systematic review and meta-analysis.

METHODS

The systematic search on the MEDLINE/PubMed, China National Knowledge Infrastructure (CNKI), Wanfang database, VIP database, the Cochrane Library, Embase and Chinese Biomedical Database (CBM) in Chinese and English language with dates ranging from the earliest record to August 8, 2019. Next, the quality of each trial was assessed according to the criteria of the Cochrane Handbook for Systematic Reviews of Interventions. Then, the outcome data were recorded and pooled by RevMan 5.3 software.

RESULTS

The systematic review and meta-analysis aims to review and pool current clinical outcomes of SMI for the adjuvant treatment of DCM.

CONCLUSION

This study will provide a high-quality evidence of SMI for the adjuvant treatment on DCM patients.

PROSPERO REGISTRATION NUMBER

CRD42019146369.

TAZ encodes tafazzin, a transacylase essential for cardiolipin formation and central to the etiology of Barth syndrome

Tafazzin, which is encoded by the TAZ gene, catalyzes transacylation to form mature cardiolipin and shows preference for the transfer of a linoleic acid (LA) group from phosphatidylcholine (PC) to monolysocardiolipin (MLCL) with influence from mitochondrial membrane curvature. The protein contains domains and motifs involved in targeting, anchoring, and an active site for transacylase activity. Tafazzin activity affects many aspects of mitochondrial structure and function, including that of the electron transport chain, fission-fusion, as well as apoptotic signaling. TAZ mutations are implicated in Barth syndrome, an underdiagnosed and devastating disease that primarily affects male pediatric patients with a broad spectrum of disease pathologies that impact the cardiovascular, neuromuscular, metabolic, and hematologic systems.