REVIEW | doi:10.20944/preprints202203.0265.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: Restrictive Cardiomyopathy; Cardiomyopathy; Cardiovascular Genetics; Desmin; Troponin; Filamin-C
Online: 18 March 2022 (09:05:21 CET)
Restrictive cardiomyopathy is a rare cardiac disease causing severe diastolic dysfunction, ventricular stiffness and dilated atria. In consequence, it induces heart failure often with preserved ejection fraction and is associated with a high mortality. Since a poor clinical prognosis, patients with restrictive cardiomyopathy require frequently heart transplantation. Genetic as well as non-genetic factors contribute to restrictive cardiomyopathy and a significant portion of cases remains of unknown etiology. However, the genetic forms of restrictive cardiomyopathy and the involved molecular pathomechanisms are only partially understood. In this review, we summarize the current knowledge about primary genetic restrictive cardiomyopathy and describe its genetic landscape, which might be of interest for geneticists as well as for cardiologists.
REVIEW | doi:10.20944/preprints201912.0385.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: dilated cardiomyopathy (DCM); hypertrophic cardiomyopathy (HCM); restrictive cardiomyopathy (RCM); arrhythmogenic right ventricular cardiomyopathy (ARVC); left ventricular non-compaction cardiomyopathy (LVNC); Duchenne muscular dystrophy; dystrophin; genome editing; CRISPR/Cas9; Cpf1 (Cas12a)
Online: 29 December 2019 (13:41:48 CET)
Cardiomyopathies are diseases of heart muscle, a significant percentage of which are genetic in origin. Cardiomyopathies can be classified as dilated, hypertrophic, restrictive, arrhythmogenic right ventricular or left ventricular non-compaction, although mixed morphologies are possible. A subset of neuromuscular disorders, notably Duchenne and Becker muscular dystrophies, are also characterized by cardiomyopathy aside from skeletal myopathy. The global burden of cardiomyopathies is certainly high, necessitating further research and novel therapies. Genome editing tools, which include zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeats (CRISPR) systems have emerged as increasingly important technologies in studying this group of cardiovascular disorders. In this review, we discuss the applications of genome editing in the understanding and treatment of cardiomyopathy. We also describe recent advances in genome editing that may help improve these applications, and some future prospects for genome editing in cardiomyopathy treatment.
ARTICLE | doi:10.20944/preprints202310.0269.v1
Subject: Medicine And Pharmacology, Endocrinology And Metabolism Keywords: Diabetes mellitus; diabetes cardiomyopathy; echocardiography
Online: 5 October 2023 (10:57:29 CEST)
Background and Objectives: Cardiovascular disease is one of the leading causes of morbidity and mortality among the diabetic population. Given the high prevalence of diabetes mellitus (DM) in Saudi Arabia and the high prevalence of heart failure in the diabetic population, this study assesses the echocardiographic changes in Saudi patients with type 2 DM (T2DM) compared with healthy controls. Materials and Methods: In this retrospective case control study, 80 patients with diabetes (45 males, age: 58.78±10.2 years) were compared with 80 controls (45 males, age: 58.6±10 years) who underwent an echocardiographic study in the King Saud University Medical City, Riyadh, Saudi Arabia. Results: There were no significant differences between patients with diabetes and controls in terms of aortic root diameter, left atrium diameter, posterior wall, interventricular wall thickness, left ventricular diameters and ejection fraction. However, diastolic dysfunction was statistically significantly higher in the diabetic group compared with the control group (P <0.05). Conclusions: This is the first case control study in Saudi Arabia that assesses echocardiographic parameters in T2DM patients. DM is an independent risk factor for diastolic dysfunction regardless of its association with hypertension and dyslipidemia.
ARTICLE | doi:10.20944/preprints202306.0800.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: hypertrophic cardiomyopathy; cardiomyopathies; heart failure
Online: 12 June 2023 (08:41:43 CEST)
Background: Hypertrophic Cardiomyopathy (HCM) is the most common inherited Cardiomyopathy. The hallmark of HCM is myocardial fibrosis which contributes to heart failure, arrhythmias, and sudden cardiac death (SCD). Objective: To identify the factors implicated in heart failure symptoms and functional capacity of patients with HCM. Methods: In this cohort study, 43 patients with HCM were recruited. According to functional capacity and symptoms presentation, patients were categorized according to NYHA classification, and echocardiographic measurements of left ventricle systolic and diastolic function have been conducted. The echocardiographic assessment of right vetriculo-arterial coupling (RVAC) has been made by calculating the tricuspid annular peak systolic tissue Doppler velocity (TASV)/estimated RV systolic pressure (RVSP) ratio. Results: Almost half, 22 (51%) of our study population present symptoms of heart failure and were categorized as the symptomatic group - NYHA 2 or higher. Maximum LVOT gradient, RVSP, and the ratio of E/e’ were higher in the “symptomatic” compared to the “asymptomatic” group. TASV was lower in the “symptomatic” compared to the asymptomatic group (11±1cm/sex vs. 13±2cm/sec, p=0.04). However, there was no difference in other potentially influential factors, such as heart rate or systemic blood pressure. The SCD risk score does not differ between the two studied groups. The RVAC (estimated with the TASV/RVSP ratio) was lower in the “symptomatic” compared with the “asymptomatic” group (0.32±0.09 vs. 0.46±0.11, p<0.001). Conclusion: A low RVAC (as TASV/RVSP ratio) value could represent an echocardiographic marker of right ventricular-arterial uncoupling in patients with HCM and may impaired functional status.
CASE REPORT | doi:10.20944/preprints202306.0239.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: Cardiomyopathy; Genetic disorders; Cardiovascular Imagen
Online: 5 June 2023 (05:02:25 CEST)
A 52-y/o asymptomatic male with history of hypertension, was referred to our Heart Failure Clinic due to report of hypertrophic cardiomyopathy, TTE with an increased end-diastolic thick-ness (basal inferoseptal of 23 mm, and basal anteroseptal of 21 mm). CMR demonstrated late gadolinium enhancement at the septum, anterior, inferolateral, and inferior walls with a mid-myocardial distribution, T1 mapping which reported an average T1 of 929 ms. A next-generation sequencing panel was requested. Results demonstrated hemizygosis, in the ga-lactosidase alpha gene, consistent with Fabry Disease. The replacement of the enzyme was start-ed. Extended familial genetic counseling and testing were done.
REVIEW | doi:10.20944/preprints201910.0040.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: diabetes; exercise; cardiomyopathy; heart failure
Online: 3 October 2019 (13:59:22 CEST)
Diabetes mellitus is associated with cardiovascular, ophthalmic, and renal comorbidities. Among these, diabetic cardiomyopathy (DCM) causes the most severe symptoms and is considered to be a major health problem worldwide. Exercise is widely known as an effective strategy for the prevention and treatment of many chronic diseases. Importantly, the onset of complications arising from diabetes can be delayed or even prevented by exercise. Regular exercise is reported to have positive effects on diabetes mellitus and the development of DCM. The protective effects of exercise include the prevention of cardiac apoptosis, fibrosis, oxidative stress, and microvascular diseases, as well as improvement in cardiac mitochondrial function, and calcium regulation. The present review summarizes the recent findings to describe the potential mechanisms by which exercise may prevent DCM and heart failure.
ARTICLE | doi:10.20944/preprints201805.0082.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: obesity, diabetes, cardiomyopathy, echocardiography, ultrasound
Online: 3 May 2018 (16:06:24 CEST)
Cardiomyopathy is the leading cause of morbidity and mortality among all complications of type 2 diabetes (T2D) and obese patients. Diabetic cardiomyopathy (DC) is characterized by changes in cardiac morphology with declines in both systolic and diastolic functions. No rodent models fully captured phenotypes of DC. The ZDSD rat, a new generation of T2D rat model with intact leptin signaling features with slow onset of diabetes and obesity, which closely mimics the development of the disease in patients. Age-matched male ZDSD and SD rats were monitored for blood pressure, glucose and cardiac function using echocardiography. Animals were also challenged with 1 mg/kg dobutamine for the assessment of cardiac reserve. ZDSD rats developed hypertension from age of 18 weeks with blood pressure significantly higher than controls. At resting state, ZDSD rats showed biphasic changes in left ventricular posterior wall thickness and cavity volume. Concomitantly, both ejection fraction (EF) and transmitral E/A ratio of LV declined at 34 weeks old. Upon treatment with dobutamine, ZDSD lost cardiac contractility. Therefore, ZDSD rats may serve as a suitable preclinical model to study potential therapeutic approaches to treat cardiomyopathy with presence of metabolic syndromes.
ARTICLE | doi:10.20944/preprints202106.0246.v1
Subject: Medicine And Pharmacology, Pathology And Pathobiology Keywords: Arrhythmogenic cardiomyopathy; arrhythmogenic right ventricular cardiomyopathy; cardiac conduction system; sudden unexpected cardiac death; autopsy
Online: 9 June 2021 (08:49:09 CEST)
A retrospective study was conducted on pathologically diagnosed arrhythmogenic cardiomyopathy (ACM) from consecutive cases over the past 34 years (n = 1,109). The cardiac conduction system (CCS) was removed in two blocks, containing the following structures: Sino-atrial node (SAN), atrio-ventricular junction (AVJ) including the atrio-ventricular node (AVN), the His bundle (HB), the bifurcation (BIF), the left bundle branch (LBB) and the right bundle branch (RBB). The ACM cases (2.07% of the total cases) consisted of 20 (86.96%) sudden unexpected cardiac death (SUCD) and 3 (13.04%) native explanted hearts; 16 (69.56%) were males and 7 (30.44%) were females, ranging in age from 5 to 65 (mean age ± SD, 36.13 ± 16.06) years. The following anomalies of the CCS, displayed as percentages of ACM SUCD cases, have been detected: Hypoplasia of SAN (80%) and/or AVJ (86.67%) due to fatty-fibrous involvement, AVJ dispersion and/or septation (46.67%), central fibrous body (CFB) hypoplasia (33.33%), fibromuscular dysplasia of SAN (20%) and/or AVN (26.67%) arteries, hemorrhage and infarct-like lesions of CCS (13.33%), islands of conduction tissue in CFB (13.33%), Mahaim fibers (13.33%), LBB block by fibrosis (13.33%), AVN tongue (13.33%), HB duplicity (6.67%%), CFB cartilaginous meta-hyperplasia (6.67%), and right sided HB (6.67%). Arrhythmias are the hallmark of ACM, not only from the fatty-fibrous disruption of the ventricular myocardium that accounts for reentrant ventricular tachycardia, but also from the fatty-fibrous involvement of CCS itself. The careful examination of the cardiac conduction system on serial sections was crucial in documenting the fatty-fibrous infiltration of CCS in ACM.
ARTICLE | doi:10.20944/preprints202305.1628.v1
Subject: Public Health And Healthcare, Other Keywords: myocarditis; psoriasis; dilated cardiomyopathy; IL-17A
Online: 23 May 2023 (08:46:46 CEST)
Background. Psoriasis (PS) is a common immune-mediated disease of the skin with pos-sible extension to joints, aorta and eye. Myocardial inflammation has been rarely sug-gested. Aims: Report of PS-related myocarditis Methods and Results: One hundred consecutive patients with PS were screened for car-diac involvement. Among them, five male patients (aged 56 ± 9.5 years) with moder-ate-severe form showed a dilated cardiomyopathy (LVEF <35%) with normal coronary ar-teries and valves. They underwent a left ventricular endomyocardial biopsy for evaluation of myocardial substrate. Endomyocardial samples were processed for histology and im-munohistochemistry, including myocardial expression of Toll-Like Receptor 4 (TLR4) and interleukin-17A (IL-17A), which plays a major role in psoriasis pathogenesis; real-time PCR for cardiotropic viruses and Western blot analysis for myocardial expression of IL-17A. Patients’ sera were tested for anti-heart autoantibodies.An active lymphocytic myocarditis was revealed in all 5 patients, characterized by absence of viral genomes at PCR, positive anti-heart autoantibodies, overexpression of TLR-4 and enhancement of IL-17-A at western blot analysis showing a 2,48-fold increase in psoriatic myocarditis compared with no psoriatic myocarditis and a 6-fold increase compared to myocardial controls. Treatment included combination of prednisone (1 mg/Kg daily for 4 weeks, ta-pered to 0.33 mg/Kg) + azathioprine (2 mg/Kg, daily) in 3 pts or secukinumab (SK, 100 mg/monthly) in 2 pts for 6 months. LVEDD and LVEF improved in the first 3 pts (-14% and + 118%, respectively) while completely recovered (LVEF> 50%) in the last 2 pts on SK. Conclusion. IL-17A-related myocarditis can occur in up-to 5% of patients with psoriasis. It manifests as a progressive dilated cardiomyopathy. It may completely recover following SK administration.
ARTICLE | doi:10.20944/preprints202108.0565.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: primary prevention of sudden cardiac death; non-ischemic cardiomyopathy; ischemic cardiomyopathy; appropriate ICD therapy; mortality rate comparison
Online: 31 August 2021 (11:26:43 CEST)
(1) Background: In patients suffering from heart failure, the main causes of death are either he-modynamic failure, or ventricular arrhythmias. The only tool to significantly reduce arrhythmic sudden death is the implantable cardioverter defibrillator (ICD), but not all patients benefit to the same extend of these devices. (2) Methods: The primary outcome of this single center study was defined as cardiovascular death in patients with ischemic and non-ischemic heart failure who have benefited from ICD therapy. The secondary outcomes were death from any cause, sudden cardiac death, ICD-related therapies (appropriate antitachycardia pacing or shock therapy for ventricular tachycardia or fi-brillation) and recurrences of ventricular tachyarrhythmias. (3) Results: A total of 403 consecutive ICD recipients – symptomatic heart failure patients with ICD for the primary prevention of sudden cardiac death – were included retrospectively: 59% is-chemic cardiomyopathy (ICMP) and 41% non-ischemic cardiomyopathy (NICMP). Within a median follow-up period of 36 months, the incidence of cardiovascular mortality was not signif-icantly different in patients with NICMP and ICMP: the primary outcome had occurred in 9 pa-tients (5.4%) in the NICMP group and in 14 patients (5.9%) in the ICMP group (hazard ratio 1; 95%confidence interval [CI] 0.45 to 2.28; p =0.97). All-cause mortality occurred in 14 of 166 pa-tients (8.4%) in NICMP group and 18 of 237 patients (7.6%) in ICMP group. Sudden cardiac death occurred in 2 patients (1.2%) in the NICMP group and in 4 patients (1.7%) in the ICMP group (hazard ratio 0.71; 95% CI, 0.13 to 3.88; P=0.69). The rate of appropriate device therapies was comparable in both groups. (4) Conclusion: In this study, ICD implantation for primary prevention of sudden cardiac death in patients with symptomatic systolic heart failure was associated with similar rates of cardiovas-cular and all-cause mortality in patients with ischemic heart disease, and in patients with heart failure from other causes. NICMP and ICMP showed comparable rates of recurrent ventricular tachyarrhythmias and appropriate ICD therapies.
ARTICLE | doi:10.20944/preprints202310.0829.v1
Subject: Biology And Life Sciences, Parasitology Keywords: chagas; cardiomyopathy; mitochondria; haplgroups; variants; copy-number
Online: 13 October 2023 (03:03:37 CEST)
Cardiomyopathies are major causes of heart failure. Chagas disease (CD) is caused by the parasite Trypanosoma cruzi, and it is endemic in Central, South America. Thirty percent of the cases evolve into chronic cardiomyopathy (CCC) with worse prognosis as compared with other cardiomyopathies. In vivo bioenergetic analysis and ex vivo proteomic analysis of myocardial tissues highlighted worse mitochondrial dysfunction in CCC, and previous studies identified nuclear-encoded mitochondrial gene variants segregating with CCC. Here, we assessed the role of the mitochondrial genome through mtDNA copy number variations and mtDNA haplotyping and sequencing from heart or blood tissues of severe, moderate CCC and asymptomatic/indeterminate Chagas disease as well as healthy controls as an attempt to help decipher mitochondrial-intrinsic genetic involvement in Chagas disease development. We have found that mtDNA copy number was significantly lower in CCC than in heart tissue from healthy individuals, while blood mtDNA content was similar among asymptomatic Chagas disease, moderate and severe CCC patients. MtDNA haplogrouping study has indicated that African haplogroups were over represented in the Chagas subject groups in comparison with Brazilian healthy individuals. The European lineage is associated to protection against cardiomyopathy and the macro haplogroup H is associated with increased risk towards CCC. By mitochondria DNA sequencing, 84 mtDNA-encoded protein sequence pathogenic variants were associated with CCC. Among them, two variants were associated to left ventricular non-compaction and two to hypertrophic cardiomyopathy. The finding that mitochondrial protein-coding SNPs and mitochondrial haplogroups associate with risk of evolving to CCC is consistent with a key role of mitochondrial DNA in the development of Chronic Chagas disease Cardiomyopathy.
ARTICLE | doi:10.20944/preprints202309.0373.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: cardioprotection; ischemic cardiomyopathy; miR-30d; myocardial infarction
Online: 6 September 2023 (10:17:11 CEST)
Abstract: (1) Background and Objective: MicroRNAs (miR) are biomarkers for assessing the extent of cardiac remodeling after myocardial infarction (MI) and important predictors of clinical outcome in heart failure. Overexpression of miR-30d appears to have a cardioprotective effect. The aim of the present study was to demonstrate whether miR-30d could be used as a potential therapeutic target to improve post-MI adverse remodeling. (2) Methods and Results: MiR profiling was performed by next generation sequencing to assess different expression patterns in ischemic vs. healthy myocardium in a rat model of MI. MiR-30d was significantly downregulated (p<0.001) in ischemic myocardium and was selected as promising target. A mimic of miR-30d was administered in the respective treatment group, whereas control group received non-functional, scrambled siRNA. To measure the effect of miR-30d on infarct area size of left ventricle, rats were randomized and treated with miR-30d or scrambled siRNA. Histological planimetry was performed 72 hours and 6 weeks after induction of MI. Infarct area was significantly reduced at 72 hours and at 6 weeks by using the miR-30d (72 hours: 22.89±7.66% vs. 35.96±9.27%, p=0.0136; 6 weeks: 6.93±4.58% vs. 12.48±7.09%; p=0.0172). To gain insight into infarct healing, scratch assays were used to obtain information on cell migration in human umbilical vein endothelial cells (HUVEC). Gap closure was significantly faster in the mimic-treated cells 20h post-scratching (12.4% more than scrambled control after 20h; p=0.013). To analyze anti-apoptotic quality of miR-30d, the ratio between phosphorylated p53 and total p53 was evaluated in human cardiomyocytes using ELISA. Under the influence of miR-30d mimic, cardiomyocytes demonstrated a decreased pp53/total p53 ratio (0.66±0.08 vs. 0.81±0.17), showing a distinct tendency (p=0.055) to decrease apoptosis rate compared to the control group. (3) Conclusion: Using a mimic of miR-30d underlines the cardioprotective effect of miR-30d in MI and could reduce the risk for development of ischemic cardiomyopathy.
CASE REPORT | doi:10.20944/preprints202305.0074.v1
Subject: Biology And Life Sciences, Neuroscience And Neurology Keywords: desmin; myofibrillar myopathy; cardiomyopathy; ribonucleic acid sequencing
Online: 2 May 2023 (08:45:01 CEST)
Desmin is a class III intermediate filament highly expressed in cardiac, smooth and striated muscle Autosomal dominant or recessive mutations in the desmin gene (DES) result in a variety of diseases, including cardiomyopathies and myofibrillar myopathy, collectively called desminopathies. Here we describe the clinical, histological and radiological features of a Greek patient with a myofibrillar myopathy and cardiomyopathy linked to the c.734A>G,p.(Glu245Gly) heterozygous variant in the DES gene. Moreover, through ribonucleic acid sequencing analysis in skeletal muscle we show that this variant provokes a defect in exon 3 splicing and thus should be considered clearly pathogenic
ARTICLE | doi:10.20944/preprints202104.0629.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Hypertrophic Cardiomyopathy; metabolomics; cardiovascular disease; myectomy surgery
Online: 23 April 2021 (10:28:18 CEST)
Hypertrophic cardiomyopathy (HCM) is a common inherited heart disorder complicated by left ventricle outflow tract (LVOT) obstruction, which can be treated with surgical myectomy. To date, no reliable biomarkers for LVOT obstruction exist. To determine whether metabolomic biomarkers for obstruction can be identified, we conducted metabolomic profiling on plasma samples of 18 HCM patients before and after undergoing surgical myectomy to measure changes in the plasma metabolome in the postoperative state. Plasma was collected approximately 4 weeks before surgery at the preoperative visit and approximately 3 months after the surgery at the postoperative visit. We found that 215 metabolites were altered in the postoperative state (p-value < 0.05). Identified metabolites that were significantly reduced post-myectomy included metabolites of heme, such as bilirubin, and phenylacetylglutamine, a biomarker of urea cycle disorders, which suggests that liver and kidney function are improved in the postoperative state. Markers of arginine metabolism such as homoarginine and dimethylarginine are also decreased in the postoperative state, suggestive of reduction in nitric oxide production, inflammation and heart failure after surgery. 3-hydroxybutyrate (BHBA) was also decreased, suggesting possible increased fatty acid utilization and a return to normal heart function. 12 of these metabolites were notably significant after adjusting for multiple comparisons (q-value < 0.05), including bilirubin, PFOS, PFOA, 3,5-dichloro-2,6-dihydroxybenzoic acid, 2-hydroxylaurate, trigonelline and 6 unidentified compounds, which support improved kidney and liver function and increased lean soft tissue mass. These findings suggest improved organ metabolic function after surgical relief of LVOT obstruction in HCM and further underscore the beneficial systemic effects of surgical myectomy.
CASE REPORT | doi:10.20944/preprints202311.1692.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: mavacamten; cardiac myosin inhibitor; hypertrophic cardiomyopathy; heart failure
Online: 27 November 2023 (11:50:17 CET)
We describe real-world use of mavacamten in 50 patients with oHCM. Consistent with EXPLORER-HCM and VALOR-HCM, we report significant improvement in wall thickness, mitral regurgitation, left ventricular outflow tract obstruction and NYHA class. Moreover, in our center’s experience, neither arrhythmia burden, nor contractility have worsened in the vast majority of patients: We note a clinically insignificant mean decrease in left ventricular ejection fraction (LVEF), with only two patients requiring temporary mavacamten discontinuance for LVEF < 50%. Adverse events were rare, unrelated to mavacamten itself, and seen solely in patients with disease too advanced to have been represented in clinical trials. Our multidisciplinary pathway enabled us to provide a large number of patients with a novel closely-monitored therapeutic within just a few months of commercial availability. These data lead us to conclude that mavacamten, as a first-in-class cardiac myosin inhibitor, is safe and efficacious in real-world settings.
REVIEW | doi:10.20944/preprints202306.0470.v1
Subject: Public Health And Healthcare, Health Policy And Services Keywords: Cardiac resynchronisation therapy; Pacemaker; implantable cardioverter defibrillator; Cardiomyopathy
Online: 7 June 2023 (02:32:17 CEST)
Background: This is a comparative analysis of upgrade to cardiac resynchronisation therapy (CRT) of an existing pacemaker implanted for bradyarrhythmia or an implantable cardioverter defibrillator (ICD). International guidelines recommend an upgrade to CRT for both groups based on the same criteria; this may lead to a hypothesis of whether we are under-treating a population that would otherwise benefit more from a CRT than the other. Methods: So far, this is the largest multicentre retrospective study that includes in total, 151 (93 upgrades to CRT-P and 58 upgrades to CRT-D) participants who had an upgrade to a CRT device between January 2010 and January 2020. Clinical and echocardiographic parameters were analysed both, before and after an upgrade to CRT. Results: EF was greater in patients with PPM, both before and after upgrade. Moreover, the post upgrade increase in EF was significantly greater in patients with PPM. Patients with ICD have, on average, an NYHA class ranking greater than PPM patients, both before and after upgrade. Conclusions: These data show that the PPM group patients have a greater response to upgrade to CRT compared to those from the ICD group. It also demonstrates that patients with non-ischaemic cardiomyopathy are better responders compared to those with ischaemic aetiology.
ARTICLE | doi:10.20944/preprints202212.0376.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: Sport; Cardiomyopathy; Heart Rate; Monitoring; Functional; Athlete Readiness
Online: 21 December 2022 (02:48:03 CET)
The syndrome of heart chronic physical overstrain is the condition of functional disadaptation, which a coach must diagnosis by himself. If he misses the development of this condition (especially for juniors) then subsequent training or competitive activities may cause development of hypertrophic cardiomyopathy and increase the risk of sudden cardiac death. The syndrome of heart chronic physical overstrain is the main reason of «professional sports aging».
ARTICLE | doi:10.20944/preprints202102.0191.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Hypertrophic Cardiomyopathy; proteomics; aptamer; cardiovascular disease; myectomy surgery
Online: 8 February 2021 (11:18:59 CET)
Left Ventricular Outflow Tract (LVOT) obstruction occurs in approximately 70% of Hypertrophic Cardiomyopathy (HCM) patients and currently requires imaging or invasive testing for diagnosis, sometimes in conjunction with provocative physiological or pharmaceutical stimuli. To identify potential biomarkers of LVOT obstruction, we performed proteomics profiling of 1305 plasma proteins in 12 HCM patients with documented LVOT obstruction referred for surgical myectomy. Plasma was collected at the surgical preoperative visit approximately one month prior to surgery and then at the post surgical visit approximately 3 months later. Proteomic profiles were generated using the aptamer-based SOMAscan assay. Principal Component Analysis using the highest statistically significant proteins separated all preoperative samples from all postoperative samples. Further analysis revealed a set of 25 proteins that distinguished the preoperative and postoperative states with a paired t-test p value of <0.01. Ingenuity Pathway analysis facilitated the generation of protein interaction networks and the elucidation of key upstream regulators of the differentially expressed proteins such as interferon-, TGF-1 and TNF. Biological pathways affected by the surgery included organ inflammation, migration and motility of leukocytes, fibrosis, vasculogenesis, angiogenesis, acute coronary events, endothelial proliferation, eicosanoid metabolism, calcium flux, apoptosis and morphology of the cardiovascular system. Our results indicate that surgical relief of dynamic outflow tract obstruction in HCM patients is associated with unique alterations in plasma proteomic profiles that likely reflect improvement in organ inflammation and physiological function.
REVIEW | doi:10.20944/preprints201811.0075.v1
Subject: Medicine And Pharmacology, Pathology And Pathobiology Keywords: sepsis cardiomyopathy; left ventricular function; global longitudinal strain
Online: 5 November 2018 (02:51:26 CET)
Myocardial deformation imaging (strain imaging) is a technique to directly quantify the extent of myocardial contractility and overcomes several of the limitations of ejection fraction. The application of the most commonly used strain imaging method; speckle-tracking echocardiography to patients with sepsis cardiomyopathy heralds an exciting development to the field. However; the body of evidence and knowledge on the utility, feasibility and prognostic value of left ventricular global longitudinal strain in sepsis cardiomyopathy is still evolving. We conducted a review of literature on utility of left ventricular global longitudinal strain in sepsis cardiomyopathy. We discuss the role of left ventricular global longitudinal strain in mortality prediction, utility and limitations of the technique in the context of sepsis cardiomyopathy.
ARTICLE | doi:10.20944/preprints201611.0094.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: diabetes mellitus; hyperglycemia; cardiomyopathy; lipid toxicity; polyphenols; aspalathin
Online: 17 November 2016 (11:19:37 CET)
Aspalathin, a C-glucosyl dihydrochalcone, has previously been shown to protect cardiomyocytes against hyperglycemia-induced shifts in substrate preference and subsequent apoptosis. However, the precise gene regulatory network remains to be elucidated. To unravel the mechanism and provide insight into this supposition, the direct effect of aspalathin in an isolated cell-based system, without the influence of any variables, was tested using an H9c2 cardiomyocytes model. Cardiomyocytes were exposed to high glucose (33 mM) for 48 hours before post-treatment with or without aspalathin. Thereafter, RNA was extracted and RT2 PCR Profiler Arrays were used to profile the expression of 336 genes. Results showed that, 57 genes were differentially regulated in the high glucose or high glucose and aspalathin treated groups. STRING analysis revealed lipid metabolism and molecular transport as the biological processes altered after high glucose treatment, followed by inflammation and apoptosis. Aspalathin was able to modulate key regulators associated with lipid metabolism (Adipoq, Apob, Cd36, Cpt1, Pparγ, Srebf1/2, Scd1 and Vldlr), insulin resistance (Igf1, Akt1, Pde3 and Map2k1), inflammation (Il3, Il6, Jak2, Lepr, Socs3, and Tnf13) and apoptosis (Bcl2 and Chuk). Collectively, our results propose that aspalathin could reverse metabolic abnormalities by activating Adipoq while modulating the expression of Pparγ and Srebf1/2, decreasing inflammation via Il6/Jak2 pathway, which together with an observed increased expression of Bcl2 prevents myocardium apoptosis.
ARTICLE | doi:10.20944/preprints201611.0093.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: diabetes mellitus; cardiomyopathy; hyperglycemia; oxidative stress; aspalathin; Nrf2
Online: 17 November 2016 (11:07:56 CET)
Aspalathin (ASP) can protect H9c2 cardiomyocytes against high glucose (HG)-induced shifts in myocardial substrate preference, oxidative stress and apoptosis. While the protective mechanism of aspalathin remains unknown, nuclear factor (erythroid-derived 2)-like 2 (Nrf2) has emerged as a key factor for intracellular responses against oxidative stress. Therefore, we hypothesized that aspalathin protects the myocardium against hyperglycemia-induced oxidative damage by up-regulating Nrf2 expression in H9c2 cardiomyocytes and diabetic (db/db) mice. Using an oxidative stress RT2 Profiler PCR array, ASP at a dose of 1 µM was demonstrated to protect H9c2 cardiomyocytes against HG-induced oxidative stress, but silencing of Nrf2 abolished this protective response of ASP and exacerbated cardiomyocyte apoptosis. Db/db mice and their non-diabetic (db/+) littermate controls were subsequently treated daily for 6 weeks with either a low (13 mg/kg) or high (130 mg/kg) ASP dose. Compared to nondiabetic mice the db/db mice presented increased cardiac remodeling and enlarged left ventricular wall that occurred concomitant to enhanced oxidative stress. Daily treatment of mice with ASP at a dose of 130 mg/kg for 6 weeks was more effective at reversing complications than both a low dose ASP or metformin, eliciting enhanced expression of Nrf2 and its downstream antioxidant genes. These results indicate that ASP maintains cellular homeostasis and protects the myocardium against hyperglycemia-induced stress through activation of Nrf2 and its downstream target genes.
REVIEW | doi:10.20944/preprints202308.1645.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: dilated cardiomyopathy; heart failure; cardiac device therapy; genetic analysis
Online: 23 August 2023 (09:20:43 CEST)
Dilated cardiomyopathy (DCM) is a common form of cardiomyopathy, characterized by ventricular chamber dilatation and systolic dysfunction, in the absence of coronary artery disease, arterial hypertension, valvular or congenital diseases. DCM is a heterogeneous group of disorders of the myocardium caused by genetic factors, environmental factors, or a combination of both. DCM affects mainly men aged between 20 and 50 years, being considered one of the main causes of heart failure (HF) and the main indication for heart transplantation. Guideline-based HF treatment is the mainstay of management for patients with DCM. In recent years, gene therapy and induced pluripotent stem cells have become promising strategies. In this review, we summarize the relevant clinical issues, and current treatment of DCM patients, including the role of genetic evaluation.
ARTICLE | doi:10.20944/preprints202306.2009.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: heart failure; cardiomyopathy; ischemic heart disease; prognosis; women; men
Online: 29 June 2023 (07:27:12 CEST)
Background: Limited research has explored sex-specific differences in death predictors of HF pa-tients with ischemic (iCMP) and nonischemic (niCMP) cardiomyopathy. This study assessed sex differences in niCMP and iCMP prognosis. Methods: We studied 7,487 patients with HF between February 2017 and September 2020. Clini-cal features and echocardiographic findings were collected. We used Kaplan-Meier, Cox propor-tional hazards models, and score chi-square of Cox regression to determine death predictors in women and men. Results: mean age was 64.3±14.2 years, with 4,417 (59%) males. Women with iCMP and niCMP exhibited significantly higher mean age, higher mean left ventricular ejection fraction, and smaller left ventricular diastolic diameter than men. Over 2.26 years of follow-up, 325 (14.7%) women and 420 (15.7%) men, and 211 women (24.5%) and 519 men (29.8%) died in niCMP (p=NS) and iCMP (p=0.004), respectively. Cumulative incidence of death was higher in men with iCMP (log-rank p<0.0001) but similar in niCMP. Cox regression showed chronic kidney disease, dia-betes, stroke, atrial fibrillation, age, and myocardial infarction, as main predictors of death for iCMP in women and men. Conclusion: Women exhibited a better prognosis than men in iCMP, but similar for niCMP. Nevertheless, sex was not an independent predictor of death for both CMP.
ARTICLE | doi:10.20944/preprints202302.0398.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: liver fibrosis; liver cirrhosis; levosimendan; cirrhotic cardiomyopathy; hepatic encephalopathy
Online: 23 February 2023 (04:46:34 CET)
Introduction: Levosimendan is a positive inotropic molecule that does not reduce splanchnic circulation and has anti ischemic properties by opening mito KATP channels. Cirrhosis is a chronic and diffuse process characterized by fibrosis and the conversion of typical liver architecture into structurally abnormal nodules. In the late stages of the disease, cirrhosis is responsible for organ failure and complications such as cirrhotic cardiomyopathy and hepatic encephalopathy. Material and methods: We examined the effect of levosimendan in rat models of liver cirrhosis. Male Wistar rats were divided into four groups: Group A: cirrhotic rats 14 days after bile duct ligation (BDL); Group B: control (intact rats); Group A1: BDL and levosimendan (liver cirrhosis induced by bile duct ligation plus intraperitoneal administration of levosimendan); Group B1: control and levosimendan (intact animals with normal liver function treated with an intraperitoneal injection of levosimendan). Each group was subjected to blood sampling to determine GOT, GPT, and bilirubin at baseline, two weeks after surgery, and four days after treatment. In addition, echocardiography was performed in all the groups simultaneously. At the end of the experiments, the rats were subjected to cerebral and hepatic microdialysis and sacrificed. Results: Serum GOT, GPT, and bilirubin in Group A1 (GOT 304 UI/L, GPT 60 UI/L, BIL 3,9 mg/dl) were considerably lower than in Group A (GOT 320 UI/L, GPT 67,16 UI/L, BIL 6,4 mg/dl). The Ejection fraction value decreased significantly postoperatively in Group A (preop 55,66%, BDL 38,85%) and was highest after treatment with levosimendan (Group A1 48,38%). Significant histological differences were detected between the experimental groups (Group A Sheuer staging 3, severe fibrosis, Group A1 Sheuer staging 0-2 no, mild and moderate fibrosis). Group A had a higher value of Lactate, Pyruvate, Glycerol, and Glutamate cerebral microdialysate concentrations (Lac 0.37mM, Pyr 16.25 mcM, Glyc 15.72 mcM, Glut 15.8 mcM) in comparison with BDL rats treated with levosimendan (Group A1 - Lac 0.31 mM, Pyr 6.3 mcM, Glyc 13.66 mcM, Glut 11.15 mcM). Glucose concentrations in cerebral dialysate from Group A were significantly lower (0.13 mM) than in Group A1 (0.25 mM). Glucose and Glycerol concentrations in liver microdialysate from Group A were significantly lower (Gluc 0.95 mM, Glyc 1 mcM) than in Group A1 (Gluc 1.6 mM, Glyc 3.4 mcM). Conversely, in liver dialysate from Group A (0.52 mM), lactate was significantly higher than in Group A1 (0.35 mM). Conclusions: Our results suggest that levosimendan can be potentially protective for fibrotic liver and probably can prevent cirrhosis complication as cirrhotic cardiomyopathy and hepatic encephalopathy.
ARTICLE | doi:10.20944/preprints202104.0434.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: environmental exposures; heavy metals; idiopathic dilated cardiomyopathy; Katanga Copperbelt
Online: 16 April 2021 (10:43:32 CEST)
Blood and/or urine levels of 27 heavy metals were determined by ICPMS in 41 patients with dilated cardiomyopathy (DCM) and 29 presumably healthy subjects from the Katanga Copperbelt (KC), in the Democratic Republic of Congo (DRC). After adjusting for age, gender, education level, and renal function, DCM probability was almost maximal for blood concentrations above 0.75 and 150 µg/dl for arsenic and copper, respectively. Urinary concentrations above 1 for chromium, 20 for copper, 600 for zinc, 30 for selenium, 2 for cadmium, 0.2 for antimony, 0.5 for thallium and 0.05 for uranium, all in μg/g of creatinine, were also associated with increased DCM probability. Concurrent and multiple exposures to heavy metals, well beyond permissible levels, are associated with increased probability for DCM. Study findings warrant screening for metal toxicity in case of DCM and prompt public health measures to reduce exposures in the KC, DRC.
CASE REPORT | doi:10.20944/preprints202012.0704.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: left ventricular noncompaction; apical hypertrophic cardiomyopathy; next generation sequencing
Online: 28 December 2020 (13:19:41 CET)
Left ventricular noncompaction (LVNC) and hypertrophic cardiomyopathy (HCM) commonly occur as separate disorders with distinct clinical and pathoanatomical features. However, these cardiomyopathies may have a similar genetic origin with mutations encoding sarcomeric proteins. The described case demonstrates an example, in which phenotypic expression of both diseases occurs in the same patient.
ARTICLE | doi:10.20944/preprints202011.0240.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Post-mortem Cardiac magnetic resonance; hypertrophic cardiomyopathy; sudden death
Online: 6 November 2020 (10:44:52 CET)
Post-mortem cardiac magnetic resonance (PMCMR) is an emerging tool supporting forensic medicine for the identification of the causes of cardiac death, as hypertrophic cardiomyopathy (HCM). We proposed a new method of PMCMR to diagnose HCM despite myocardial rigor mortis. Methods: we performed CMR in 49 HCM patients, 30 non-HCM hypertrophy and 32 healthy controls. In cine images, rigor mortis was simulated by the analysis of the cardiac phase corresponding to the 25% of diastole. Left ventricular mass, mean and standard deviation (SD) of WT, maximal WT, minimal WT and their difference, were compared for the identification of HCM. These parameters were validated at PMCMR, evaluating 8 hearts with HCM, 10 with coronary artery disease and 10 with non-cardiac death. Results: The SD of WT with a cut-off of > 2.4 had the highest accuracy to identify HCM (AUC 0.95, 95%CI 0.89-0.98). This was particularly evident in female population of HCM (AUC=0.998), with 100% specificity (95%CI 85-100%) and 96% sensitivity (95%CI 79-99%). Using this parameter, at PMCMR all the 8 patients with HCM were correctly identified with no false positive. Conclusions: PMCMR allows to identify HCM as cause of sudden death using the SD of WT >2.4 as diagnostic parameter.
SHORT NOTE | doi:10.20944/preprints201910.0067.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Calcium; Actomyosin Kinetics; Myosin Binding Protein-C; Hypertrophic Cardiomyopathy
Online: 7 October 2019 (12:12:35 CEST)
In an attempt to correct misunderstandings this article brings together the observations on Calcium, Myosin Binding Protein-C and Hypertrophic Cardiomyopathy in the basic function of cardiac muscle. A finding of many years ago is reiterated in a novel enzyme kinetic format with defined rate limiting step which makes CaATP the apparent substrate of the actomyosin cross-bridge. The relationship of these kinetics to recent observations on disruption of myosin binding protein-C is described along with how this bears on the understanding of the related cardiomyopathies.
ARTICLE | doi:10.20944/preprints201804.0350.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: 1-DNJ; diabetic cardiomyopathy; fibrosis; N-glycosylation; α1,6-fucosylation
Online: 27 April 2018 (06:13:25 CEST)
The traditional Chinese drug Bombyx Batryticatus mori.L (BBm) which is also named the white stiff silkworm has been widely used in Chinese clinics for thousands of years. It is famous for its antispasmodic and blood circulation promoting effects. Cardiomyocyte hypertrophy, interstitial cell hyperplasia and myocardial fibrosis are closely related to the N-glycosylation of key proteins. To examine the alterations of N-glycosylation that occur in diabetic myocardium during the early stage of the disease and clarify the therapeutic effect of 1-DNJ extracted from BBm, we used the db/db mouse model and an approach based on hydrophilic chromatography solid-phase extraction integrated with an LC-MS/MS identification strategy to perform a site-specific N-glycosylation analysis of left ventricular cardiomyocyte proteins. AGEs, hydroxyproline, CTGF and other serum biochemical indicators were measured with ELISA. In addition, the α1,6-fucosylation of N-glycans was profiled with LCA lectin blots and FITC-labelled lectin affinity histochemistry. The results indicated that 1-DNJ administration obviously downregulated myocardium protein N-glycosylation in db/db mice. The expression levels of serum indicators and fibrosis-related cytokines were reduced significantly by 1-DNJ in a dose-dependent manner. The glycan α1,6-fucosylation level of the db/db mouse myocardium was elevated, and the intervention effect of 1-DNJ administration on N-glycan α1,6-fucosylation was significant. To verify this result, the well-known TGF-β/smad2/3 pathway was selected, and core α1,6-fucosylated TGFR-βⅡ was analysed semi-quantitatively with western blotting. The result supported the conclusions obtained from LCA lectin affinity histochemistry and lectin blot analysis. The expression level of FUT8 mRNA was also detected, and the results showed that 1-DNJ administration did not cause obvious inhibitory effects on FUT8 expression. Therefore, the mechanism of 1-DNJ to relieve the DCM-associated fibrosis can be concluded as the inhibition of N-GlcNAc formation and the reduction of substrate concentration.
ARTICLE | doi:10.20944/preprints202310.0971.v1
Subject: Biology And Life Sciences, Parasitology Keywords: Trypanosoma cruzi; electrocardiography (ECG); Chronic Chagas Cardiomyopathy; Chagas heart disease
Online: 16 October 2023 (12:36:35 CEST)
Chronic Chagas Cardiomyopathy (CCC) results from infection with the protozoan parasite Trypanosoma cruzi and is a prevalent cause of heart disease in endemic countries. We previously found that cardiac fibrosis can vary widely in C3H/HeN mice chronically infected with T. cruzi JR strain, mirroring the spectrum of heart disease in humans. In this study, we examined functional cardiac abnormalities in this host:parasite combination to determine its potential as an experimental model for CCC. We utilized electrocardiography (ECG) to monitor T. cruzi-infected mice and determine whether ECG markers could be correlated with cardiac function abnormalities. We found that the C3H/HeN:JR combination frequently displayed early onset CCC indicators, such as sinus bradycardia and right bundle branch block, as well as prolonged PQ, PR, RR, ST and QT intervals in the acute stage. Our model exhibited high levels of cardiac inflammation and enhanced iNOS expression in the acute stage, but denervation did not appear to have a role in pathology. These results demonstrate the potential of the C3H/HeN:JR host:parasite combination as a model for CCC that could be used for screening new compounds targeted at cardiac remodeling and for examining the potential of anti-parasitic drugs to prevent or alleviate CCC development and progression.
ARTICLE | doi:10.20944/preprints202305.0784.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: Arrhythmogenic Cardiomyopathy; PKP2; Founder pathogenic variant; Arrhythmic events; Heart Failure
Online: 11 May 2023 (04:38:37 CEST)
Introduction and objectives: arrhythmogenic cardiomyopathy (ACM) is a hereditary heart disease defined by the progressive replacement of the ventricular myocardium with fibroadipose tissue, which can act as a substrate for arrhythmias, sudden death, or even give rise to heart failure (HF). Sudden death is frequently the first manifestation of the disease, particularly among young patients. The aim of this study is to describe a new pathogenic variant in the PKP2 gene. Methods: A descriptive observational study that included 8 initially non-interrelated families with a diagnosis of ACM undergoing follow-up at our HF and Familial Cardiomyopathies Unit, who were carriers of the NM_004572.3:c.775_776insG; p. (Glu259Glyfs*77) variant in PKP2 gene. The genetic testing employed next-generation sequencing for the index cases, and the Sanger method for the targeted study with family members. We compiled personal and family histories, demographic and clinical characteristics, data from the additional tests at the time of diagnosis, and arrhythmic events at diagnosis and during follow-up. Results: We included 47 subjects, of whom 8 were index cases (17%). Among the evaluated family members, 16 (34%) were carriers of the genetic variant, 3 of whom also had a diagnosis of ACM. The majority were women (26 patients; 55.3%), with a mean age on diagnosis of 48.9 ± 18.6 years, and a median follow-up of 39 [24-59] months. Worthy of note are the high incidence of arrhythmic events as the form of presentation and in follow-up (21.5% and 20.9% respectively), and the onset of HF in 25% of the sample. The most frequent ventricular involvements were right (4 patients 16.7%) and biventricular (4 patients 16.7%); we found no statistical differences in any of the variables analysed. Conclusions: This variant is a pathogenic variant of gene PKP2 that has not previously been described and is not present in the control groups associated with ACM. It has incomplete penetrance, a highly variable phenotypic expressivity, and was identified in 8 families of our geographical area in Malaga (Andalusia, Spain), where we can establish a founder effect and describe the clinical and risk characteristics.
ARTICLE | doi:10.20944/preprints202201.0358.v1
Subject: Medicine And Pharmacology, Pediatrics, Perinatology And Child Health Keywords: left ventricular noncompaction; cardiomyopathy; imaging; echocardiography; cardiovascular magnetic resonance; children
Online: 24 January 2022 (13:59:45 CET)
Background: Left ventricular noncompaction (LVNC) is a distinct cardiomyopathy characterized by the presence of a two-layer myocardium with prominent trabeculation and deep intertrabecular recesses. The diagnosis of LVNC can be challenging because the diagnostic criteria are not uniform. The aim of our study was to evaluate echocardiographic and CMR findings in a group of children with isolated LVNC. Methods: From February 2008 to July 2021, pediatric patients under 18 years of age at the time of diagnosis with echocardiographic evidence of isolated LVNC were prospectively enrolled. The patients underwent echocardiography and contrast-enhanced cardiovascular magnetic resonance (CMR) with late gadolinium enhancement to assess myocardial noncompaction, ventricular size, and function. Results: A total of 34 patients with a median age of 11.9 years were recruited. Patients were followed prospectively for a median of 5.1 years. Of the 31 patients who met Jenni’s criteria in echocardiography, CMR was performed in 27 (79%). Further comprehensive analysis was performed in the group of 25 patients who met the echocardiographic and CMR criteria for LVNC. In echocardiography, the median NC/C ratio in systole was 2.60 and in diastole 3.40. In 25 out of 27 children (93%), LVNC was confirmed by CMR according to Petersen’s criteria, with a median NC/C ratio of 3.27. Conclusions: 1) Echocardiography precisely identifies patients with LVNC. 2) Echocardiography is a good method for monitoring LV systolic function, but CMR is indicated for the precise assessment of LV remodeling and RV size and function as well as for the detection of myocardial fibrosis.
ARTICLE | doi:10.20944/preprints201808.0059.v1
Subject: Biology And Life Sciences, Neuroscience And Neurology Keywords: chagas disease; cardiomyopathy; mitochondrial stress; endoplasmic reticulum stress; 2-aminopurine
Online: 3 August 2018 (04:36:58 CEST)
Trypanosoma cruzi infection results in debilitating cardiomyopathy, which is a major cause of mortality and morbidity in the endemic regions of Chagas disease (CD). The pathogenesis of Chagasic cardiomyopathy (CCM) has been intensely studied as a chronic inflammatory disease until recent observations reporting the role of cardio-metabolic dysfunctions. In particular, we demonstrated accumulation of lipid droplets and impaired cardiac lipid metabolism in the hearts of cardiomyopathic mice and patients, and their association with impaired mitochondrial functions and endoplasmic reticulum (ER) stress in CD mice. In the present study, we examined whether treating infected mice with an ER stress inhibitor can modify the pathogenesis of cardiomyopathy during chronic stages of infection. T. cruzi infected mice were treated with an ER stress inhibitor 2-Aminopurine (2AP) during the indeterminate stage and evaluated for cardiac pathophysiology during the subsequent chronic stage. Our study demonstrates that inhibition of ER stress improves cardiac pathology caused by T. cruzi infection by reducing ER stress and downstream signaling of phosphorylated eukaryotic initiation factor (P-elF2α) in the hearts of chronically infected mice. Importantly, cardiac ultrasound imaging showed amelioration of ventricular enlargement, suggesting that inhibition of ER stress may be a valuable strategy to combat the progression of cardiomyopathy in Chagas patients.
ARTICLE | doi:10.20944/preprints201803.0030.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: 1-DNJ; diabetic cardiomyopathy; fibrosis; N-glycosylation; α 1,6-Fucosylation
Online: 5 March 2018 (04:08:49 CET)
The Chinese drug Bombyx Batryticatus mori.L which also named as the white stiff silkworm is widely used in clinics, due to the significant antispasmodic and promotional blood circulation effects. In addition, its hypoglycemic effect is also recognized in recent years. From a pathological point of view, the enzymatic glycosylation and non-enzymatic glycation both have important roles in regulating properties of proteins and are associated with Diabetes. With the db/db mouse model, we examined the alterations of N-glycosylation of diabetic myocardium at primary stage and clarify the differences in glycosylation of myocardium before and after with 1-DNJ treatment. Hydrophilic chromatography solid phase extraction enrichment and LC-MS/MS identification was applied to profile the alternations in protein glycosylation. Meanwhile, N-glycan α1, 6-fucosylation alterations were profiled with LCA lectin blot and FITC-labelled lectin affinity histochemistry. Our results showed that AGES, hydroxyproline, CTGF and other serum indicators and fibrosis related cytokines expressional levels were reduced significantly by 1-DNJ in a dose-dependent manner. In order to verify this result, the well-known pathway of TGF-β/smad2/3 was picked out and α1, 6-core fucosylated TGFR-βⅡwas semi-quantified with western blot method. The result sustained the conclusion from LCA lectin affinity histochemistry and lectin blot analysis. The expressional level of α1, 6-fucosyltransferase mRNA was increased in the myocardium of db/db mice, however, the 1-DNJ administration did not show obvious inhibitory effect on FU8 expression. This unexpected result can be interpreted as 1-DNJ plays the roles by reducing the concentration of substrate rather than inhibiting α1，6-fucose glycosyltransferase expression. Meanwhile, 1-DNJ crude extract from BBm with some flavonoids accompany can also play the roles of anti-oxidant, and all the chemicals protect the diabetic myocardium from hyperglycemia damage commonly.
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: Diabetic Cardiomyopathy; Hyperglycemia; Ischemia/Reperfusion Injury; Metabolism; Mitochondria; Remote Conditioning; Exercise
Online: 17 March 2020 (08:52:25 CET)
Metabolic syndrome, diabetes and ischemic heart disease are among the leading causes of death and disability in Western countries. Diabetic cardiomyopathy is responsible for the most severe signs and symptoms. An important strategy for reducing the incidence of cardiovascular disease is regular exercise. Remote ischemic conditioning has some similarity with exercise, and can be induced by short periods of ischemia and reperfusion of a limb, and it can be performed in people who cannot exercise. There is abundant evidence that exercise is beneficial in diabetes and ischemic heart disease, but there is a need to elucidate the specific cardiovascular effects of emerging and unconventional forms of exercise in people with diabetes. Also, remote ischemic conditioning may be considered among the options to induce beneficial effects in these patients. The characteristics and interactions of diabetes and ischemic heart disease, and the known effects of exercise and remote ischemic conditioning in the presence of metabolic syndrome and diabetes, are analyzed in this brief review.
CASE REPORT | doi:10.20944/preprints201910.0112.v1
Subject: Biology And Life Sciences, Cell And Developmental Biology Keywords: heterotaxy syndromes; cardiac isomerism; chick embryo; Pitx2; proepicardium; non-compaction cardiomyopathy
Online: 10 October 2019 (05:54:08 CEST)
Except for a few species, the outer shape of vertebrates normally is characterized by bilateral symmetry. The inner organs, on the other hand, normally are arranged in bilaterally asymmetric patterns, which are of special importance for the normal function of the cardiovascular system of lung-breathing vertebrates. Deviations from the normal organ asymmetry can occur in the form of mirror imagery of the normal arrangement (situs inversus), or in the form of arrangements that have the tendency for development of bilateral symmetry, either in a pattern of bilateral left-sideness (left isomerism) or bilateral right-sidedness (right isomerism). The latter two forms of visceral situs anomalies are called “heterotaxy syndromes”. During the past 30 years, remarkable progress has been made in uncovering of the genetic etiology of heterotaxy syndromes. However, the pathogenetic mechanisms causing the spectrum of cardiovascular defects found in these syndromes remain poorly understood. In the present report, a spontaneous case of left cardiac isomerism found in a HH-stage 23 chick embryo is described. The observations made in this case suggest that hearts with left cardiac isomerism may have the tendency for development of a non-compaction cardiomyopathy caused by defective development of the proepicardium.
ARTICLE | doi:10.20944/preprints202306.1603.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: Tafazzin; Barth Syndrome; Single-Nucleus RNA-sequencing; Cardiomyopathy; Mitochondria; Gene Expression; Metabolism
Online: 22 June 2023 (11:31:02 CEST)
Barth Syndrome, a rare X-linked disorder affecting 1:300,000 live births, results from defects in Tafazzin, an acyltransferase that remodels cardiolipin and is essential for mitochondrial respiration. Barth Syndrome patients develop cardiomyopathy, muscular hypotonia and cyclic neutropenia during childhood, rarely surviving to middle age. At present, no effective therapy exists and downstream transcriptional effects of Tafazzin dysfunction are incompletely understood. To identify novel, cell-specific, pathological pathways that mediate heart dysfunction, we performed single-nucleus RNA-sequencing (snRNA-seq) on wild-type (WT) and Tafazzin-knockout (Taz-KO) mouse hearts. We determined differentially expressed genes (DEGs) and inferred predicted cell-cell communication networks from these data. Surprisingly, DEGs were distributed heterogeneously across the cell types, with fibroblasts, cardiomyocytes, endothelial cells, macrophages, adipocytes and pericytes exhibiting the greatest number of DEGs between genotypes. One differentially expressed gene was detected for the lymphatic endothelial and mesothelial cell types, while no significant DEGs were found in the lymphocytes. A Gene Ontology (GO) analysis of these DEGs showed cell-specific effects on biological processes such as fatty acid metabolism in adipocytes and cardiomyocytes, increased translation in cardiomyocytes, endothelial cells and fibroblasts, in addition to other cell-specific processes. Analysis of ligand-receptor pair expression, to infer intercellular communication patterns, revealed the strongest dysregulated communication involved adipocytes and cardiomyocytes. For the knockout hearts, there was a strong loss of ligand-receptor pair expression involving adipocytes, and cardiomyocyte expression of ligand-receptor pairs underwent reorganization. These findings suggest that adipocyte and cardiomyocyte mitochondria may be most sensitive to mitochondrial Tafazzin deficiency and that rescuing adipocyte mitochondrial dysfunction, in addition to cardiomyocyte mitochondrial dysfunction, may provide therapeutic benefit in Barth Syndrome patients.
ARTICLE | doi:10.20944/preprints202106.0276.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: left ventricular noncompaction; cardiomyopathy; heart failure; arrhythmia; conduction disturbances; molecular etiology; children
Online: 10 June 2021 (08:06:33 CEST)
Background: Left ventricular noncompaction (LVNC) is a genetically determined cardiomyopathy, that occurs following a disruption of endomyocardial morphogenesis. The purpose of this study was to identify the clinical characteristics and genetic profile of children with LVNC. Methods: From February 2008 to July 2020, a total of 32 children (median 11.5 years) with LVNC were prospectively enrolled and followed up for the median of 4.02 years. Diagnosis was made based on characteristic features of LVNC in echocardiography and cardiovascular magnetic resonance (CMR). Patients’ clinical symptoms, family history, ECG, Holter ECG and genetic tests were also evaluated. Results: The most common presenting symptom was heart failure (31% of children). ECG abnormalities were noted in 56% of patients. The most prominent features were ventricular arrhythmias, sinus bradycardia and paroxysmal third-degree atrioventricular block. Most of the patients (94%) met the criteria for LVNC and CMR confirmed this diagnosis in 82% of cases. The molecular etiology was found in 53% of children. Conclusion: Although heart failure and arrhythmias were very frequent in our study group, thromboembolic events and genetic syndromes were rare. For accurate and reliable assessment of children with LVNC, it is necessary to get to know their family history and detailed clinical profile.
ARTICLE | doi:10.20944/preprints202309.1503.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: hypertrophic cardiomyopathy; Russian; Slavic; underrepresented population; specific characteristics; genetics; MYBPC3; MYH7; TPM1; FLNC
Online: 22 September 2023 (05:31:18 CEST)
Hypertrophic cardiomyopathy (HCM) is a common inherited cardiac disorder characterized by marked clinical and genetic heterogeneity. Ethnic groups underrepresented in studies may have distinctive characteristics. We sought to evaluate the clinical and genetic landscape of Russian HCM patients. A total of 193 patients (52% male; 95% Eastern Slavic origin; median age 56 years) were clinically evaluated, including genetic testing, and prospectively followed to document outcomes. As a result, 48% had obstructive HCM, 25% had HCM in family, 21% were asymptomatic, and 68% had comorbidities. During 2.8 years of follow-up, the all-cause mortality rate was 2.86%/year. A total of 5.7% received an implantable cardioverter-defibrillator (ICD), 21% septal reduction therapy. Sequencing analysis of 176 probands identified 64 causative variants in 66 patients (38%); recurrent variants were MYBPC3 p.Q1233* (8), MYBPC3 p.R346H (2), MYH7 p.A729P (2), TPM1 p.Q210R (3) and FLNC p.H1834Y (2); 10 were multiple variant carriers (5.7%); 5 had non-sarcomeric HCM, ALPK3, TRIM63 and FLNC; thin filament variant carriers had a worse prognosis for heart failure (HR = 7.9, p=0.007). In conclusion, in the Russian HCM population, the low use of ICD and relatively high mortality should be noted by clinicians; some distinct recurrent variants are suspected to have a founder effect; family studies on some rare variants enriched the worldwide knowledge in HCM.
ARTICLE | doi:10.20944/preprints202208.0152.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Desmin; Myopathy; Cardiomyopathy; Intermediate Filaments; Cytoskeleton; Myofibrillar Myopathy (MFM); Desminopathy; Desmosomes; Protein Aggregation.
Online: 8 August 2022 (10:48:45 CEST)
Desmin is the major intermediate filament protein of all three muscle cell types and connects different cell organelles and multi-protein complexes like the cardiac desmosomes. Several pathogenic mutations in the DES gene cause different skeletal and cardiac myopathies. However, the significance of the majority of DES missense variants is currently unknown since functional data are lacking. To determine whether desmin missense mutations within the highly conserved 1A coil domain cause a filament assembly defect, we generated a set of variants with unknown significance and analyzed systematically the filament assembly in transfected SW13 and H9c2 cells using confocal microscopy. We found that mutations in the N-terminal part of the 1A coil domain affect the filament assembly leading to the cytoplasmic desmin aggregation. In contrast, mutant desmin in the C-terminal part of the 1A coil domain form filamentous structures comparable to wild-type desmin. Our findings suggest that the N-terminal part of the 1A coil domain is a hot spot for pathogenic desmin mutations, which affect the desmin filament assembly leading in consequence to skeletal and/or cardiac myopathies. This study may have relevance for the genetic counselling of patients carrying variants in the 1A coil domain of the DES gene.
ARTICLE | doi:10.20944/preprints202202.0243.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: left ventricular noncompaction; cardiomyopathy; sinus bradycardia; HCN4 mutation; late gado-linium enhancement; children
Online: 21 February 2022 (03:16:22 CET)
Background: Left ventricular noncompaction (LVNC) is a genetically and phenotypically heterogeneous cardiomyopathy characterized by a two-layered myocardium consisting of compacted and noncompacted segments, prominent ventricular trabeculations, and intertrabecular recesses. Patients with LVNC are at increased risk to develop heart failure, atrial and ventricular arrhythmias, and/or systemic thromboembolic events. Familial forms of primary sinus bradycardia have been attributed to mutations in HCN4. There are very few reports about the association between HCN4 mutations and LVNC. The aim of our study was to characterize the clinical phenotype of families with LVNC and sinus bradycardia caused by mutation of the HCN4 gene. Methods: From March 2008 to July 2021 we prospectively enrolled 6 patients from 4 families with diagnosed isolated LVNC based on the clinical presentation, family history and echocardiographic and cardiovascular magnetic resonance (CMR) evidence of LVNC. Next generation sequencing (NGS) analysis was undertaken for evaluation of the molecular basis of the disease in each family. Results: A total of 6 children (median age 11 years) were enrolled and followed prospectively for the median of 12 years. All 6 patients were diagnosed with LVNC by echocardiography and 5 participants additionally by CMR. The presence of LGE was found in 3 children. Sinus bradycardia and dilation of the ascending aorta occurred in 5 studied patients. In 4 patients from 3 families the molecular studies demonstrated the presence of rare heterozygous HCN4 mutations. Conclusion: (1) The HCN4 mutation influences the presence of a complex LVNC phenotype, sinus bradycardia and dilation of the ascending aorta. (2) HCN4 mutation may be associated with the early presentation of clinical symptoms and the severe course of the disease. (3) It is particularly important to assess myocardial fibrosis not only within the ventricles, but also in the atria in patients with LVNC and sinus bradycardia.
ARTICLE | doi:10.20944/preprints202306.1296.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Lamin A/C; laminopathies; dilated cardiomyopathy; vascular smooth muscle cell; vascular dysfunction; transgenic mice
Online: 19 June 2023 (05:14:51 CEST)
Mutations in the LMNA gene (encoding lamin A/C proteins) cause several human cardiac diseases, including dilated cardiomyopathies (LMNA-DCM). The main clinical risks in LMNA-DCM patients are sudden cardiac death and progressive left ventricular ejection fraction deterioration, and therefore most human and animal studies have sought to define the mechanisms through which LMNA mutations provoke cardiac alterations, with particular focus on cardiomyocytes. To investigate if LMNA mutations also cause vascular alterations that might contribute to the etiopathogenesis of LMNA-DCM, we generated and characterized Lmnaflox/floxSM22αCre mice, which constitutively lack lamin A/C in vascular smooth muscle cells (VSMCs), cardiac fibroblasts, and cardiomyocytes. Like mice with whole body or cardiomyocyte-specific lamin A/C ablation, Lmnaflox/floxSM22αCre mice recapitulated the main hallmarks of human LMNA-DCM, including ventricular systolic dysfunction, cardiac conduction defects, cardiac fibrosis, and premature death. These alterations were associated with hyperactivation of Smad3 and elevated expression of the proapoptotic protein caspase 3 in the heart. Lmnaflox/floxSM22αCre mice also exhibited perivascular fibrosis in the coronary arteries, and a switch of aortic VSMCs from the ‘contractile’ to the ‘synthetic’ phenotype. Ex vivo wire myography in isolated aortic rings revealed impaired maximum contraction capacity and an altered response to vasoconstrictor and vasodilator agents in Lmnaflox/floxSM22αCre mice. To our knowledge, our results provide the first evidence of phenotypic alterations in VSMCs that might contribute significantly to the pathophysiology of some forms of LMNA-DCM. Future work addressing the mechanisms underlying vascular defects in LMNA-DCM may open new therapeutic avenues for these diseases.
ARTICLE | doi:10.20944/preprints201807.0093.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: cardiomyopathy; hemodynamic and biochemical parameters; epidemiological and clinical Parameters; phospholamban angiotensin-1-converting enzyme
Online: 5 July 2018 (10:43:43 CEST)
Background: Cardiomyopathy is commonly observed disease that may occurs due to mutations in either susceptible genes or modifier gene. People with broad age group are affected either attributable to spontaneous or inherited mutations of these genes. Various gene mutations are reported so far but only few of them were studied in detail. Methods: In the current study, we evaluated epidemiological variables like age, sex, familial status, parental consanguinity. We also described specific clinical symptoms associated with the cardiomyopathy condition in Indian population. Results: Our studies on mutation screening of phospholamban gene revealed two transitions (4880 C/T, 4887 T/G) in 5’ flanking region which might cause inherited dilated cardiomyopathy with refractory congestive heart failure are We further deliberated the gene polymorphism of renin angiotensin system gene angiotensin-1-converting enzyme as an associated marker/ modifier in cardiomyopathy patients and their family members. Conclusions: Information on epidemiological, clinical statistics, phospholamban gene mutation analysis and angiotensin-1-converting enzyme gene polymorphism is essential to guide the successful execution for future therapies and benefits us to identify those patients at risk for faster disease progression, congestive heart failure, and arrhythmia.
ARTICLE | doi:10.20944/preprints202307.0139.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: Hypertrophic Cardiomyopathy; spatial transcriptomics; single nucleus RNA-sequencing; gene expression; bioinformatics; cardiovascular disorder; genetic disorder
Online: 4 July 2023 (05:18:51 CEST)
Hypertrophic Cardiomyopathy (HCM) is a common inherited disorder that can lead to heart failure and sudden cardiac death, characterized at the histological level by focal areas of myocyte disarray, hypertrophy and fibrosis, and few disease-targeted therapies exist. To identify, focal, spatially restricted alterations in transcriptional pathways and reveal novel therapeutic targets, we performed a spatial transcriptomic analysis of areas of focal myocyte disarray compared to areas of normal tissue, using a commercially available platform (GeoMx, nanoString). We analyzed surgical myectomy tissue from four patients with HCM and control interventricular septum tissue from two unused organ donor hearts that were free of cardiovascular disease. Histological sections were reviewed by an expert pathologist and 72 focal areas with varying degrees of myocyte disarray (normal, mild, moderate, severe) were chosen for analysis. Areas of interest were interrogated with the Human Cancer Transcriptome Atlas designed to profile 1800 transcripts. Differential expression analysis revealed significant changes in gene expression between HCM and Control tissue, and functional enrichment analysis indicated these genes were primarily involved in interferon production and mitochondrial energetics. Within HCM tissue, differentially expressed genes between areas of mild and moderate disarray were enriched for genes related to mitochondrial energetics (moderate disarray) and response to oxygen/cytokine levels (mild disarray). The comparison between areas of moderate and severe disarray were enriched for genes related to the c-Jun N-terminal kinase (JNK) cascade in severe disarray. Analysis of ligand-receptor pair gene expression revealed that HCM tissue exhibited downregulation of platelet-derived growth factor (PDGF), NOTCH, junctional adhesion molecule, and CD46 signaling, while showing upregulation of fibronectin, CD99, cadherin, and amyloid precursor protein signaling. A deconvolution analysis utilizing the matched single nuclei RNA-sequencing (snRNA-seq) data to determine cell type composition in areas of interest revealed significant differences in fibroblast and vascular cell composition in areas of severe disarray when compared to normal areas in HCM samples. Cell composition in normal areas from control tissue was also divergent from normal areas in HCM samples, which was consistent with the differential expression results. Overall, our data identify novel and potential disease-modifying targets for therapy in HCM.
ARTICLE | doi:10.20944/preprints202112.0461.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: Hypertrophic Cardiomyopathy; Left ventricular outflow tract obstruction; single nucleus RNA-sequencing; dendritic cells; integrin-b1.
Online: 29 December 2021 (09:43:00 CET)
Hypertrophic Cardiomyopathy (HCM) is a common inherited disorder characterized by unexplained left ventricular hypertrophy, with or without left ventricular outflow tract (LVOT) obstruction. Single nuclei RNA-sequencing (snRNA-seq) of both obstructive and nonobstructive HCM patient samples have revealed alterations in communication between various cell types but a direct and integrated comparison between the two HCM phenotypes has not been reported. We performed a bioinformatic analysis of HCM snRNA-seq datasets from obstructive and nonobstructive patient samples to identify differentially expressed genes and distinctive patterns of intercellular communication. Differential gene expression analysis revealed 37 differentially expressed genes, predominantly in cardiomyocytes but also in other cell types, relevant to aging, muscle contraction, cell motility and the extracellular matrix. Intercellular communication was generally reduced in HCM, affecting the extracellular matrix, growth factor binding, integrin binding, PDGF binding and SMAD binding, but with increases in adenylate cyclase binding, calcium channel inhibitor activity, and serine-threonine kinase activity in nonobstructive HCM. Increases in neuron to leukocyte and dendritic cell communication, in fibroblast to leukocyte and dendritic cell communication and in endothelial cell communication to other cell types, largely through changes in expression of integrin-b1 and its cognate ligands, were also noted. These findings indicate both common and distinct physiological mechanisms affecting the pathogenesis of obstructive and nonobstructive HCM and provide opportunities for personalized management of different HCM phenotypes.
ARTICLE | doi:10.20944/preprints202305.0993.v1
Subject: Public Health And Healthcare, Other Keywords: Sepsis-induced cardiomyopathy; Gene sequencing; Whole transcriptome profiles; Septic animal models; Cecal ligation and puncture; Lipopolysaccharide
Online: 15 May 2023 (07:36:05 CEST)
Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection, with septic cardiomyopathy being a common and severe complication. Despite its significant clinical impact, the molecular mechanisms underlying sepsis-induced cardiomyopathy (SICM) remain incompletely understood. In this study, we performed a comparative analysis of whole transcriptome profiles in two widely used mouse models of septic cardiomyopathy, the cecal ligation and puncture (CLP) model and the lipopolysaccharide (LPS) model. Our aim was to identify key genes and pathways involved in the development of septic cardiomyopathy and to evaluate the similarities and differences between the two models. Our findings suggested that 1) both methods can induce septic heart dysfunction within 24 hours; 2) distinct whole transcriptome expression profiles are revealed; 3) potentially different pathways are involved in causing heart failure in sepsis. The comprehensive comparison provides valuable insights into the molecular basis of septic cardiomyopathy and contributes to the ongoing search for effective treatment strategies, triggered by different factors for SICM.
ARTICLE | doi:10.20944/preprints202110.0178.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: cardiac muscle; cardiac contractility; force generation; enhanced molecular dynamics simulations; allostery; protein folding; disease; hypertrophic cardiomyopathy
Online: 12 October 2021 (12:20:26 CEST)
Cardiac myosin-binding protein C (MyBPC) is a thick-filament associated regulatory protein in the sarcomere. It regulates the sensitive contractile system of the myocardium by acting as a mechanical tether, sensitizing the thin filament or modulating myosin motor activity. Mutations in the MYBPC3 gene are a frequent cause for the development of hypertrophic cardiomyopathy, the most frequent cardiac disorder. Recently, the monoallelic double mutation MYBPC3Δ25bp/D389V has been discovered as a subset of the common MYBPC3Δ25bp variant in South Asia. MYBPC3Δ25bp/D389V carriers exhibit hyperdynamic features, which are considered an early finding for the development of hypertrophic cardiomyopathy. Using correlation-guided molecular dynamics simulations sampling, we show that the D389V mutation shifts the conformational distribution of the C2 domain of MyBPC. We further applied biochemical approaches to probe the effects of the D389V mutation on structure, thermostability and protein-protein interactions of MyBPC C2. The melting temperature (Tm) of MyBPC C2 D389V is decreased by 4 to 7 °C compared to wild type while the interaction of the C0-C2 domains with myosin and actin remains unchanged. Additionally, we utilized steered molecular dynamics (SMD) simulations to investigate the altered unfolding pathway of MyBPC C2 D389V. Based on our data, we propose a pathomechanism for the development of HCM in MYBPC3Δ25bp and MYBPC3Δ25bp/D389V carriers.
REVIEW | doi:10.20944/preprints202107.0635.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Takotsubo cardiomyopathy (TTS); biomarkers; specific and effective treatments; TTS management; genetic and epigenetic factors; systematic review
Online: 28 July 2021 (17:07:01 CEST)
Takotsubo syndrome (TTS), recognized as stress’s cardiomyopathy, or better as left ventricular apical balloon syndrome in the recent years, is a rare pathology, described for the first time by Japanese researchers in 1990. TTS is characterized by an interindividual heterogeneity in onset and progression, and by the strong predominance in postmenopausal women. The clear causes of these TTS features are uncertain, given the reduced understanding of this intriguing syndrome until now. However, the increasing frequency of TTS cases in the last years, and particularly correlated to SARS-CoV-2 pandemic, leads us to imperative necessity both of a complete knowledge of TTS pathophysiology for identifying biomarkers facilitating its management, and targets for specific and effective treatments. The suspect of a genetic basis in TTS pathogenesis has been evidenced. Accordingly, familial form of TTS has been described. But a systematic and comprehensive characterization of the genetic or epigenetic factors significantly associated with TTS is lacking. Thus, we, here, conducted a systematic review of literature before June 2021, to contribute to identify potential genetic and epigenetic factors associated with TTS. Interesting data were evidenced, but of reduced number and with diverse limitations. Consequently, we concluded further work is needed to address the gaps discussed, and probably a clear evidence may arrive using multi-omics investigations.
REVIEW | doi:10.20944/preprints202308.2203.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: arrhythmic sudden cardiac death; risk stratification; non-invasive risk factors; NIRFs; electrophysiology study; two-step approach; cardiomyopathy
Online: 1 September 2023 (03:36:09 CEST)
Arrhythmic sudden cardiac death (SCD) has an annual prevalence of 1 per 1000 while 75% of the victims suffer from ischemic and 10% from non-ischemic or hypertrophic cardiomyopathy. Altogether, these three entities account for more than 80% of the total SCD victims. Guidelines for implantable cardiac defibrillators are still dominated by LVEF<30% from the MADIT II study. In terms of arrhythmic risk stratification, the PRESERVE-EF study restored in clinical practice the two-step arrhythmic risk stratification approach based on Electrocardiographic non-invasive risk factors (NIRFs) guiding to electrophysiological study. In our times with the multiple cardiac imaging methods and artificial intelligence applications availability, this two-step approach based on integrated arrhythmia mechanisms detection, emerges as an efficient SCD risk stratification paradigm for these three entities but also for the patients with congenital heart disease.
ARTICLE | doi:10.20944/preprints202307.1889.v1
Subject: Biology And Life Sciences, Life Sciences Keywords: Obstructive sleep apnea, Coronary artery disease, QT dispersion, T peak to T end, multivessel coronary disease, cardiomyopathy
Online: 27 July 2023 (08:38:28 CEST)
Introduction: Obstructive sleep apnea (OSA) is the most common sleep-breathing disorder. OSA is associated with cardiovascular diseases such as coronary artery disease (CAD) and arrhythmias with an increased risk of sudden cardiac death. Some changes in ECG markers are seen as an indicator of arrhythmogenicity, especially ventricular arrhythmias. The goal of this study was to investigate if OSA patients with CAD have QT dispersion and T peak to T end (TpTe) changes as a surrogate of arrhythmogenicity. Methods: We studied 75 patients with CAD who underwent polysomnographic studies. Patients were categorized into mild, moderate, and severe OSA according to the Apnea hypopnea index (AHI). Baseline ECG and echocardiography for assessing LV function and valvular heart disease were done for all of them. Results: Results showed that in patients with moderate and severe sleep apnea QT dispersion was higher in a group with more involvement of coronary artery disease, reduced ejection fraction, and a history of old MI. However, we didn’t find any significant statistical relationship between OSA and TpTe marker. Conclusion: Our results showed a positive relation between ECG arrhythmic indices such as QT dispersion and OSA severity in patients with CAD.
REVIEW | doi:10.20944/preprints202107.0256.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: hypertrophic cardiomyopathy; pathological cardiac hypertrophy; sarcomere; cardiac myocyte; cardiac fibroblast; cardiac fibrosis; myocyte-fibroblast interaction; extracellular matrix
Online: 12 July 2021 (12:13:53 CEST)
Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiovascular disorder affecting 1 in 500 people in the general population. Although characterized by asymmetric left ventricular hypertrophy, cardiomyocyte disarray and cardiac fibrosis, HCM is in fact a highly complex disease with heterogenous clinical presentation, onset and complications. While HCM is generally accepted as a disease of the sarcomere, variable penetrance in families with identical genetic mutations challenges the monogenic origin of HCM and instead implies a multifactorial cause. Furthermore, large scale genome sequencing studies revealed that many genes previously reported as causative of HCM in fact have little or no evidence of disease association. These findings thus call for a re-evaluation of the sarcomere-centered view of HCM pathogenesis. Here, we summarize our current understanding of sarcomere-independent mechanisms of cardiomyocyte hypertrophy, highlight the role of extracellular signals in cardiac fibrosis, and propose an alternative but integrated model of HCM pathogenesis.
ARTICLE | doi:10.20944/preprints202306.0357.v1
Subject: Biology And Life Sciences, Life Sciences Keywords: Cardiomyopathy; myosin RLC; myosin ELC; N-terminal protein modification, S15D-RLC phosphomimetic, super-relaxed state (SRX); Tg mice
Online: 5 June 2023 (16:43:56 CEST)
This study focuses on mimicking constitutive phosphorylation in the N-terminus of the myosin regulatory light chain (S15D-RLC) as a rescue strategy for the mutation-induced cardiac dysfunction in transgenic (Tg) models of restrictive (RCM) and dilated (DCM) cardiomyopathy caused by mutations in myosin essential (ELC) or regulatory (RLC) light chains. S15D-RLC phosphomimetic was reconstituted in left ventricular papillary muscle (LVPM) fibers from two mouse models of cardiomyopathy, RCM-E143K ELC and DCM-D94A RLC, along with their corresponding Tg-ELC and Tg-RLC wild type (WT) mice. The beneficial effects of S15D-RLC in rescuing cardiac function were manifested by S15D-RLC-induced destabilization of the super-relaxed (SRX) state that was observed in both models of cardiomyopathy. S15D-RLC promoted a shift from the SRX state to the disordered relaxed (DRX) state, increasing the number of heads readily available to interact with actin and produce force. Additionally, S15D-RLC reconstituted fibers demonstrated significantly higher maximal isometric force per cross-section of muscle compared with reconstitution with WT-RLC protein. The effects of the phosphomimetic S15D-RLC were compared to those observed for Omecamtiv Mecarbil (OM), a myosin activator shown to bind to the catalytic site of cardiac myosin and increase myocardial contractility. A similar SRX↔DRX equilibrium shift was observed in OM=treated fibers as in S15D-RLC-reconstituted preparations. Additionally, treatment with OM resulted in significantly higher maximal pCa 4 force per cross-section of muscle fibers in both cardiomyopathy models. Our results suggest that both treatments with S15D-RLC and OM may improve the function of myosin motors and cardiac muscle contraction in RCM-ELC and DCM-RLC mice.
CASE REPORT | doi:10.20944/preprints202009.0659.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: arrhythmogenic right ventricular dysplasia; arvd; arrhythmogenic right ventricular cardiomyopathy; ARVC; VT storm; revised task force criteria 2010; ICD
Online: 27 September 2020 (03:13:29 CEST)
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a rare inherited disorder which is characterized by fibrofatty degeneration of cardiac muscles mainly in the right ventricular myocardium. It may cause tachyarrhythmias or right-heart failure or may cause sudden death, especially in young athletes. In our case report, we present a case of young age male patient who presented at a local community hospital with the complaint of atypical chest pain, palpitations, and vomiting and sustained ventricular tachycardia (VT) on electrocardiograph (ECG) showing sustained ventricular tachycardia, left bundle branch morphology with the superior axis. The normal sinus rhythm was achieved after multiple DC cardioversion attempts and he was referred to our tertiary care hospital. Later ECG demonstrated epsilon waves and T wave inversion in v1 to v4 and RBBB morphology. The echocardiography showed a severely dilated right ventricle with dysfunction and right ventricle ventricular apical aneurysm. The definitive diagnosis of ARVC was made as per Revised Task Force Criteria 2010 and the electrophysiology review suggested implantable cardiac defibrillator (ICD) device placement. The patient successfully received a dual-chamber ICD device and he remained asymptomatic.
REVIEW | doi:10.20944/preprints202012.0441.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: dystrohinopathy; Duchenne muscular disease; Becker muscular disease; dystrophic deficient cardiomyopathy; cardiac fibrosis; renin angiotensin system; angiotensin 2; angiotensin converter enzyme inhibitors; angiotensin receptor blockers; heart failure
Online: 18 December 2020 (07:18:16 CET)
Dystrophin-deficient cardiomyopathy (DDC) is currently the leading cause of death in patients with dystrophinopathies. Targeting myocardial fibrosis (MF) has become a major therapeutic goal in order to prevent the occurrence of DDC. We aimed to review and summarize the current evidence about the role of the renin-angiotensin-aldosterone system (RAAS) in the development and perpetuation of MF in DCC. We conducted a comprehensive search of peer-reviewed English literature on PubMed about this subject. We found increasing preclinical evidence from studies in animal models during the last 20 years pointing out a central role of RAAS in the development of MF in DDC. Local tissue RAAS acts directly mainly through its main fibrotic component angiotensin II (ANG2) and its transducer receptor (AT1R) and downstream TGF-b pathway. Also, it modulates the actions of most of the remaining pro-fibrotic factors involved in DDC. Despite limited clinical evidence, RAAS blockade constitutes the most studied, available and promising therapeutic strategy against MF and DDC. Conclusion: Based on the evidence reviewed, it would be recommendable to start RAAS blockade therapy through angiotensin converter enzyme inhibitors (ACEI) or AT1R blockers (ARBs) alone or in combination with mineralocorticoid receptor antagonists (MRa) at the youngest age after the diagnosis of dystrophinopathies, in order to delay the occurrence or slow the progression of MF, even before the detection of any cardiovascular alteration.