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Cureus May 2024The public health concerns from Chagas disease warrant improved cardiovascular imaging efforts, and in this report, we review a military service member presenting with...
The public health concerns from Chagas disease warrant improved cardiovascular imaging efforts, and in this report, we review a military service member presenting with electrocardiographic and cardiac magnetic resonance imaging (CMR) findings that recognized a Chagas dilated cardiomyopathy. We present an updated Chagas staging classification incorporating CMR to increase diagnosing cardiomyopathies.
PubMed: 38854227
DOI: 10.7759/cureus.59900 -
BioRxiv : the Preprint Server For... Jun 2024Cardiomyopathy, disease of the heart muscle, is a significant contributor to heart failure. The pathogenesis of cardiomyopathy is multifactorial and involves genetic,...
Cardiomyopathy, disease of the heart muscle, is a significant contributor to heart failure. The pathogenesis of cardiomyopathy is multifactorial and involves genetic, environmental, and lifestyle factors. Identifying and characterizing novel genes that contribute to cardiac pathophysiology are crucial for understanding cardiomyopathy and effective therapies. In this study, we investigated the role of a novel gene, ( ), in cardiac pathophysiology using a cardiac-specific knockout mouse model as well as a Drosophila model. Our previous work demonstrated that OLA1 modulates the hypertrophic response of cardiomyocytes through the GSK-beta/beta-catenin signaling pathway. Furthermore, recent studies have suggested that OLA1 plays a critical role in organismal growth and development. For example, null mice exhibit increased heart size and growth retardation. It is not known, however, if loss of function for leads to dilated cardiomyopathy. We generated cardiac-specific knockout mice (OLA1-cKO) to evaluate the role of OLA1 in cardiac pathophysiology. We found that -cKO in mice leads to dilated cardiomyopathy (DCM) and left ventricular (LV) dysfunction. These mice developed severe LV dilatation, thinning of the LV wall, reduced LV function, and, in some cases, ventricular wall rupture and death. In Drosophila, RNAi-mediated knock-down specifically in developing heart cells led to the change in the structure of pericardial cells from round to elongated, and abnormal heart function. This also caused significant growth reduction and pupal lethality. Thus, our findings suggest that OLA1 is critical for cardiac homeostasis and that its deficiency leads to dilated cardiomyopathy and dysfunction. Furthermore, our study highlights the potential of the gene as a therapeutic target for dilated cardiomyopathy and heart failure.
PubMed: 38854005
DOI: 10.1101/2024.05.28.596265 -
Communications Biology Jun 2024The Drosophila model is pivotal in deciphering the pathophysiological underpinnings of various human ailments, notably aging and cardiovascular diseases. Cutting-edge...
The Drosophila model is pivotal in deciphering the pathophysiological underpinnings of various human ailments, notably aging and cardiovascular diseases. Cutting-edge imaging techniques and physiology yield vast high-resolution videos, demanding advanced analysis methods. Our platform leverages deep learning to segment optical microscopy images of Drosophila hearts, enabling the quantification of cardiac parameters in aging and dilated cardiomyopathy (DCM). Validation using experimental datasets confirms the efficacy of our aging model. We employ two innovative approaches deep-learning video classification and machine-learning based on cardiac parameters to predict fly aging, achieving accuracies of 83.3% (AUC 0.90) and 79.1%, (AUC 0.87) respectively. Moreover, we extend our deep-learning methodology to assess cardiac dysfunction associated with the knock-down of oxoglutarate dehydrogenase (OGDH), revealing its potential in studying DCM. This versatile approach promises accelerated cardiac assays for modeling various human diseases in Drosophila and holds promise for application in animal and human cardiac physiology under diverse conditions.
Topics: Animals; Cardiomyopathy, Dilated; Aging; Disease Models, Animal; Machine Learning; Drosophila melanogaster; Deep Learning; Heart; Humans; Drosophila
PubMed: 38849449
DOI: 10.1038/s42003-024-06371-7 -
Circulation. Heart Failure Jun 2024The immune systems and chronic inflammation are implicated in the pathogenesis of dilated cardiomyopathy (DCM) and heart failure. However, the significance of neutrophil...
BACKGROUND
The immune systems and chronic inflammation are implicated in the pathogenesis of dilated cardiomyopathy (DCM) and heart failure. However, the significance of neutrophil extracellular traps (NETs) in heart failure remains to be elucidated.
METHODS
We enrolled consecutive 62 patients with heart failure with idiopathic DCM who underwent endomyocardial biopsy. Biopsy specimens were subjected to fluorescent immunostaining to detect NETs, and clinical and outcome data were collected. Ex vivo and in vivo experiments were conducted.
RESULTS
The numbers of NETs per myocardial tissue area and the proportion of NETs per neutrophil were significantly higher in patients with DCM compared with non-DCM control subjects without heart failure, and the numbers of NETs were negatively correlated with left ventricular ejection fraction. Patients with DCM with NETs (n=32) showed lower left ventricular ejection fraction and higher BNP (B-type natriuretic peptide) than those without NETs (n=30). In a multivariable Cox proportional hazard model, the presence of NETs was independently associated with an increased risk of adverse cardiac events in patients with DCM. To understand specific underlying mechanisms, extracellular flux analysis in ex vivo revealed that NETs-containing conditioned medium from wild-type neutrophils or purified NET components led to impaired mitochondrial oxygen consumption of cardiomyocytes, while these effects were abolished when PAD4 (peptidyl arginine deiminase 4) in neutrophils was genetically ablated. In a murine model of pressure overload, NETs in myocardial tissue were predominantly detected in the acute phase and persisted throughout the ongoing stress. Four weeks after transverse aortic constriction, left ventricular ejection fraction was reduced in wild-type mice, whereas PAD4-deficient mice displayed preserved left ventricular ejection fraction without inducing NET formation.
CONCLUSIONS
NETs in myocardial tissue contribute to cardiac dysfunction and adverse outcomes in patients with heart failure with DCM, potentially through mitochondrial dysfunction of cardiomyocytes.
Topics: Cardiomyopathy, Dilated; Humans; Extracellular Traps; Heart Failure; Male; Female; Middle Aged; Animals; Myocardium; Neutrophils; Stroke Volume; Myocytes, Cardiac; Ventricular Function, Left; Mice; Aged; Mitochondria, Heart; Mice, Inbred C57BL; Biopsy
PubMed: 38847093
DOI: 10.1161/CIRCHEARTFAILURE.123.011057 -
European Journal of Case Reports in... 2024Studies have shown major cardiovascular effects associated with ketamine use disorder including dose-dependent negative inotropic effects. Preoperative ketamine use has...
BACKGROUND
Studies have shown major cardiovascular effects associated with ketamine use disorder including dose-dependent negative inotropic effects. Preoperative ketamine use has been linked to ketamine-induced stress cardiomyopathy.
CASE PRESENTATION
A 28-year-old female with a history of recurrent cystitis and ketamine use disorder (twice weekly for 14 years) presented with bilateral lower extremity oedema and shortness of breath for 3 months. She was tachycardic with a troponin level of 0.07 ng/ml and a B-type natriuretic peptide (BNP) level of 2511 pg/ml. Electrocardiogram showed normal sinus rhythm and transthoracic echocardiography (TTE) showed left ventricular ejection fraction (EF) of 15%, dilated left ventricle, and severe tricuspid and mitral regurgitation. Computed tomography (CT) scan of the chest and abdomen showed bilateral pleural effusions with congestive hepatopathy and ascites. The patient was started on intravenous furosemide, metoprolol, and sacubitril/valsartan. Rheumatological workup including complement levels, and antinuclear anti-double-stranded DNA was negative. A repeat TTE 2 weeks later revealed an EF of 25% and moderate tricuspid regurgitation. Four months later, the EF was 54% with normal left ventricular cavity size.
CONCLUSION
Although ketamine use disorder is increasing, data on long-term side effects is minimal. Screening for ketamine use disorders should be considered in patients presenting with acute systolic heart failure. Long-term studies are needed to evaluate the benefits of adding ketamine screening to standard urine toxicology.
LEARNING POINTS
Ketamine use disorder can lead to severe cardiovascular complications, including acute systolic heart failure, likely due to its direct negative inotropic effects and dose-dependent impact on cardiac function.Clinicians should consider screening for ketamine use disorder in young adults presenting with acute systolic heart failure, especially when other common aetiologies have been ruled out.Early recognition and prompt treatment of ketamine-induced heart failure with diuretics and guideline-directed medical therapy can lead to significant improvement in cardiac function, but long-term management should also focus on ensuring cessation of ketamine use disorder.
PubMed: 38846645
DOI: 10.12890/2024_004470 -
Circulation Research Jun 2024Autoimmunity significantly contributes to the pathogenesis of myocarditis, underscored by its increased frequency in autoimmune diseases such as systemic lupus... (Review)
Review
Autoimmunity significantly contributes to the pathogenesis of myocarditis, underscored by its increased frequency in autoimmune diseases such as systemic lupus erythematosus and polymyositis. Even in cases of myocarditis caused by viral infections, dysregulated immune responses contribute to pathogenesis. However, whether triggered by existing autoimmune conditions or viral infections, the precise antigens and immunologic pathways driving myocarditis remain incompletely understood. The emergence of myocarditis associated with immune checkpoint inhibitor therapy, commonly used for treating cancer, has afforded an opportunity to understand autoimmune mechanisms in myocarditis, with autoreactive T cells specific for cardiac myosin playing a pivotal role. Despite their self-antigen recognition, cardiac myosin-specific T cells can be present in healthy individuals due to bypassing the thymic selection stage. In recent studies, novel modalities in suppressing the activity of pathogenic T cells including cardiac myosin-specific T cells have proven effective in treating autoimmune myocarditis. This review offers an overview of the current understanding of heart antigens, autoantibodies, and immune cells as the autoimmune mechanisms underlying various forms of myocarditis, along with the latest updates on clinical management and prospects for future research.
Topics: Myocarditis; Humans; Autoimmune Diseases; Animals; Autoantibodies; Autoimmunity; T-Lymphocytes; Autoantigens; Cardiac Myosins
PubMed: 38843292
DOI: 10.1161/CIRCRESAHA.124.323816 -
Circulation Jun 2024Dilated cardiomyopathy is characterized by left ventricular dilation and continuous systolic dysfunction. Mitochondrial impairment is critical in dilated cardiomyopathy;...
BACKGROUND
Dilated cardiomyopathy is characterized by left ventricular dilation and continuous systolic dysfunction. Mitochondrial impairment is critical in dilated cardiomyopathy; however, the underlying mechanisms remain unclear. Here, we explored the cardioprotective role of a heart-enriched long noncoding RNA, the dilated cardiomyopathy repressive transcript (DCRT), in maintaining mitochondrial function.
METHODS
The DCRT knockout (DCRT) mice and DCRT knockout cells were developed using CRISPR-Cas9 technology. Cardiac-specific DCRT transgenic mice were generated using α-myosin heavy chain promoter. Chromatin coimmunoprecipitation, RNA immunoprecipitation, Western blot, and isoform sequencing were performed to investigate the underlying mechanisms.
RESULTS
We found that the long noncoding RNA DCRT was highly enriched in the normal heart tissues and that its expression was significantly downregulated in the myocardium of patients with dilated cardiomyopathy. DCRT mice spontaneously developed cardiac dysfunction and enlargement with mitochondrial impairment. DCRT transgene or overexpression with the recombinant adeno-associated virus system in mice attenuated cardiac dysfunction induced by transverse aortic constriction treatment. Mechanistically, DCRT inhibited the third exon skipping of NDUFS2 (NADH dehydrogenase ubiquinone iron-sulfur protein 2) by directly binding to PTBP1 (polypyrimidine tract binding protein 1) in the nucleus of cardiomyocytes. Skipping of the third exon of NDUFS2 induced mitochondrial dysfunction by competitively inhibiting mitochondrial complex I activity and binding to PRDX5 (peroxiredoxin 5) and suppressing its antioxidant activity. Furthermore, coenzyme Q10 partially alleviated mitochondrial dysfunction in cardiomyocytes caused by DCRT reduction.
CONCLUSIONS
Our study revealed that the loss of DCRT contributed to PTBP1-mediated exon skipping of NDUFS2, thereby inducing cardiac mitochondrial dysfunction during dilated cardiomyopathy development, which could be partially treated with coenzyme Q10 supplementation.
PubMed: 38841852
DOI: 10.1161/CIRCULATIONAHA.123.067861 -
Interdisciplinary Cardiovascular and... Jun 2024Predictors and evaluations of continuous flow left ventricular assist device (cf-LVAD) explantation in recovered patients remain under discussion due to lack of evidence...
OBJECTIVES
Predictors and evaluations of continuous flow left ventricular assist device (cf-LVAD) explantation in recovered patients remain under discussion due to lack of evidence on long-term safety and efficacy. This study summarized our experiences regarding cf-LVAD explantation in non-ischaemic dilated cardiomyopathy patients and estimated a predictor for sufficient myocardial recovery allowing left ventricular assist device explant.
METHODS
We retrospectively identified 135 adult patients with cf-LVAD therapy as bridge to heart transplant due to non-ischaemic dilated cardiomyopathy. Of those, 13 patients underwent device explantation (recovery group) after myocardial recovery. Twelve (92%) of the explanted patients were evaluated using our weaning protocol and underwent surgical explantation. Meanwhile, the remaining 122 continued with cf-LVAD therapy (non-recovery group).
RESULTS
Multivariate logistic regression analysis revealed time interval between the first heart failure event and cf-LVAD implantation as an independent predictor for successful explantation. The optimal time interval cutoff value to predict cf-LVAD explantation was 7 months, with a sensitivity of 91.0% and specificity of 84.6%. Echocardiography in patients with successful cf-LVAD explantation showed significant improvement of left ventricular function and dimensions at 6 months postoperatively. The 13 explanted patients are currently alive at a median of 30 (interquartile range; 18-58) months after explantation. The survival rate free from rehospitalization due to heart failure following explantation was 100%. Left ventricular function and remodelling after explantation were also preserved.
CONCLUSIONS
In non-ischaemic dilated cardiomyopathy patients with a short interval between the first heart failure event and cf-LVAD therapy, left ventricular myocardium may recover in an early phase after device implantation.
PubMed: 38830049
DOI: 10.1093/icvts/ivae091 -
Clinical Case Reports Jun 2024Peripartum cardiomyopathy (PPCM) is a rare cause of heart failure associated with pregnancy without any other known cause. With a prognosis that can vary from the...
KEY CLINICAL MESSAGE
Peripartum cardiomyopathy (PPCM) is a rare cause of heart failure associated with pregnancy without any other known cause. With a prognosis that can vary from the complete recovery of left ventricular function to maternal mortality as well as recurrence with subsequent pregnancies, early diagnosis and treatment of PPCM is important in management. Bromocriptine treatment is beneficial effects on LVEF and mortality in women with severe acute PPCM in addition to standard heart failure therapy. However, further study is required to establish its effect in PPCM.
ABSTRACT
Peripartum cardiomyopathy (PPCM) is a rare cause of heart failure associated with pregnancy without any other known cause. Most of the clinical presentation is similar to symptoms of advanced pregnancy making the diagnosis difficult. Reported are three patients who developed dyspnea, orthopnea, and dry cough during the first week of puerperium. On examination, bilateral lower limb edema and bilateral basal lung crepitation were present in all patients. Chest radiograph showed pulmonary edema in cases two and three, and pleural effusion in case one. All patients had reduced left ventricular ejection fraction and raised N-terminal pro-b-type natriuretic peptide (NT-proBNP) levels. Case two developed PPCM in the background of left pyelonephritis. Case three was complicated by acute kidney injury. All patients were managed with bromocriptine, diuretics, beta-blockers, ACE inhibitors, and fluid restriction. Hence, PPCM though rare should be considered as a differential in women presenting with features of heart failure in later months of pregnancy or within 5 months of delivery.
PubMed: 38827942
DOI: 10.1002/ccr3.9043 -
BMJ Paediatrics Open May 2024This study aimed to describe the genetic and clinical characteristics of paediatric cardiomyopathy in a cohort of Chinese patients.
OBJECTIVES
This study aimed to describe the genetic and clinical characteristics of paediatric cardiomyopathy in a cohort of Chinese patients.
METHODS
We retrospectively reviewed the clinical history and mutation spectrum of 75 unrelated Chinese paediatric patients who were diagnosed with cardiomyopathy and referred to our hospital between January 2016 and December 2022.
RESULTS
Seventy-five children with cardiomyopathy were enrolled, including 32 (42.7%) boys and 43 (57.3%) girls. Dilated cardiomyopathy was the most prevalent cardiomyopathy (61.3%) in the patients, followed by hypertrophic cardiomyopathy (17.3%), ventricular non-compaction (14.7%), restrictive cardiomyopathy (5.3%) and arrhythmogenic right ventricular cardiomyopathy (1.3%). Whole-exome sequencing and targeted next-generation sequencing identified 34 pathogenic/likely pathogenic variants and 1 copy number variant in 14 genes related to cardiomyopathy in 30 children, accounting for 40% of all patients. p.Asp65Asn and p.Glu500Lys have not been reported previously. The follow-up time ranged from 2 months to 6 years. Twenty-two children died (mortality rate 29%).
CONCLUSIONS
Comprehensive genetic testing was associated with a 40% yield of causal genetic mutations in Chinese cardiomyopathy cases. We found diversity in the mutation profile in different patients, which suggests that the mutational background of cardiomyopathy in China is heterogeneous, and the findings may be helpful to those counselling patients and families.
Topics: Humans; Male; Female; Retrospective Studies; Child; Infant; Cardiomyopathies; Child, Preschool; Mutation; Genetic Testing; China; Exome Sequencing; Adolescent
PubMed: 38823802
DOI: 10.1136/bmjpo-2023-002024