Cause Of Dilated Cardiomyopathy Research Articles

Long QT interval revealing severe hypcalcemic dilated cardiomypathy : A case report

Hypcalcemia is a rare cause of dilated cardiomyopathy, but should be suspected in the presence of an obvious long QT interval on the surface ECG; we report a case of 46 years-old-woman, with surgical history of thyroidectomy 6 years ago, admited in our cardiology departement for mangement of congestive heart failure secondary to dilated cardiomyopathy, her surface ECG showed sinus rhythm with long QT interval, his blood tests showed severe hypocalcemia and low serum concentration of parathyroid hormone (PTH), cardiac magnetic resonance imaging was in favor of non ischemic dilated cardiomyopathy. Concomitant with conventionel heart failure treatement, our patient had received parenteral calcium supplementation, vitamin D, levothyrox; after four weeks, heart failure symptomes were relieved, the intervalle QT has shortened, but persistant severe left ventricular systolic dysfuction. Hypoparathyroidism is frequent after thyroidectomy, and could be responsible of severe hypocalcemia which in turn may induce irreversible dilated cardiomyopathy.

Fenofibrate Induces a Resolving Profile in Heart Macrophage Subsets and Attenuates Acute Chagas Myocarditis.

Chagas disease, caused by Trypanosoma cruzi, stands as the primary cause of dilated cardiomyopathy in the Americas. Macrophages play a crucial role in the heart's response to infection. Given their functional and phenotypic adaptability, manipulating specific macrophage subsets could be vital in aiding essential cardiovascular functions including tissue repair and defense against infection. PPARα are ligand-dependent transcription factors involved in lipid metabolism and inflammation regulation. However, the role of fenofibrate, a PPARα ligand, in the activation profile of cardiac macrophages as well as its effect on the early inflammatory and fibrotic response in the heart remains unexplored. The present study demonstrates that fenofibrate significantly reduces not only the serum activity of tissue damage biomarker enzymes (LDH and GOT) but also the circulating proportions of pro-inflammatory monocytes (CD11b+ LY6Chigh). Furthermore, both CD11b+ Ly6Clow F4/80high macrophages (MΦ) and recently differentiated CD11b+ Ly6Chigh F4/80high monocyte-derived macrophages (MdMΦ) shift toward a resolving phenotype (CD206high) in the hearts of fenofibrate-treated mice. This shift correlates with a reduction in fibrosis, inflammation, and restoration of ventricular function in the early stages of Chagas disease. These findings encourage the repositioning of fenofibrate as a potential ancillary immunotherapy adjunct to antiparasitic drugs, addressing inflammation to mitigate Chagas disease symptoms.

Dilated cardiomyopathy due to hypocalcaemia: a case report.

Hypocalcaemia is a rare, but reversible, cause of dilated cardiomyopathy causing heart failure. Several case reports have been reported on reversible cardiomyopathy secondary to hypocalcaemia. We report a case of 54-year-old female Sri Lankan patient who presented with shortness of breath and was diagnosed with heart failure with reduced ejection fraction due to dilated cardiomyopathy. The etiology for dilated cardiomyopathy was identified as hypocalcemic cardiomyopathy, secondary to primary hypoparathyroidism, which was successfully treated with calcium and vitamin D replacement therapy. This adds to literature of this rare cause of reversible cardiomyopathy secondary to hypocalcemia reported from the South Asian region of the world. This case highlights the impact of proper treatment improving the heart failure in patients with hypocalcemic cardiomyopathy.

Idiopathic Dilated Cardiomyopathy Associated with Bicavitary Thrombi: Case Report, Diagnostic Approach and Literature Review

Dilated cardiomyopathy is considered as a dysfunction of the left ventricle systolic function or even both ventricles associated with myocardial dilation. Approximately 50% of cases have an identifiable cause such as genetic mutations, infectious, autoimmune or metabolic diseases, among others. When the origin of dilated cardiomyopathy is not identified, it is considered idiopathic, which constitutes the other 50% of cardiomyopathies. The diagnostic approach is based on laboratory and image studies trying to identify the known causes of dilated cardiomyopathy, the treatment consists in those cases of known etiology cardiomyopathy in the treatment of the underlying disease as well as the heart failure if it presents, if the etiology is unknown we only focus in improve the symptoms caused by cardiomyopathy. We present a case of a 27-year-old man with history of sudden cardiac death in a second degree relative, who initially presented signs of heart failure with later pulmonary thromboembolism secondary to biventricular intracardiac thrombi. A complete diagnostic approach was performed, ruling out genetic and non-genetic causes of dilated cardiomyopathy, without being perform an endomyocardial biopsy to complete the diagnostic approach due to the risk that the procedure involved and the patient's refusal.

Dysregulated Autophagy and Sarcomere Dysfunction in Patients With Heart Failure With Co-Occurrence of P63A and P380S BAG3 Variants.

Mutations to the co-chaperone protein BAG3 (B-cell lymphoma-2-associated athanogene-3) are a leading cause of dilated cardiomyopathy (DCM). These mutations often impact the C-terminal BAG domain (residues 420-499), which regulates heat shock protein 70-dependent protein turnover via autophagy. While mutations in other regions are less common, previous studies in patients with DCM found that co-occurrence of 2 BAG3 variants (P63A, P380S) led to worse prognosis. However, the underlying mechanism for dysfunction is not fully understood. In this study, we used proteomics, Western blots, and myofilament functional assays on left ventricular tissue from patients with nonfailing, DCM, and DCM with BAG363/380 to determine how these mutations impact protein quality control and cardiomyocyte contractile function. We found dysregulated autophagy and increased protein ubiquitination in patients with BAG363/380 compared with nonfailing and DCM, suggesting impaired protein turnover. Expression and myofilament localization of BAG3-binding proteins were also uniquely altered in the BAG3,63/380 including abolished localization of the small heat shock protein CRYAB (alpha-crystallin B chain) to the sarcomere. To determine whether these variants impacted sarcomere function, we used cardiomyocyte force-calcium assays and found reduced maximal calcium-activated force in DCM and BAG363/380. Interestingly, myofilament calcium sensitivity was increased in DCM but not with BAG363/380, which was not explained by differences in troponin I phosphorylation. Together, our data support that the disease-enhancing mechanism for BAG3 variants outside of the BAG domain is through disrupted protein turnover leading to compromised sarcomere function. These findings suggest a shared mechanism of disease among pathogenic BAG3 variants, regardless of location.

Comprehensive review on gene mutations contributing to dilated cardiomyopathy.

Dilated cardiomyopathy (DCM) is one of the most common primary myocardial diseases. However, to this day, it remains an enigmatic cardiovascular disease (CVD) characterized by ventricular dilatation, which leads to myocardial contractile dysfunction. It is the most common cause of chronic congestive heart failure and the most frequent indication for heart transplantation in young individuals. Genetics and various other factors play significant roles in the progression of dilated cardiomyopathy, and variants in more than 50 genes have been associated with the disease. However, the etiology of a large number of cases remains elusive. Numerous studies have been conducted on the genetic causes of dilated cardiomyopathy. These genetic studies suggest that mutations in genes for fibronectin, cytoskeletal proteins, and myosin in cardiomyocytes play a key role in the development of DCM. In this review, we provide a comprehensive description of the genetic basis, mechanisms, and research advances in genes that have been strongly associated with DCM based on evidence-based medicine. We also emphasize the important role of gene sequencing in therapy for potential early diagnosis and improved clinical management of DCM.

Skeletal Muscle Involvement in Patients With Truncations of Titin and Familial Dilated Cardiomyopathy

BackgroundGenetic variants in titin (TTN) are associated with dilated cardiomyopathy (DCM) and skeletal myopathy. However, the skeletal muscle phenotype in individuals carrying heterozygous truncating TTN variants (TTNtv), the leading cause of DCM, is understudied. ObjectivesThis study aimed to assess the skeletal muscle phenotype associated with TTNtv. MethodsParticipants with TTNtv were included in a cross-sectional study. Skeletal muscle fat fraction was evaluated by magnetic resonance imaging (compared with healthy controls and controls with non-TTNtv DCM). Muscle strength was evaluated by dynamometry and muscle biopsy specimens were analyzed. ResultsTwenty-five TTNtv participants (11 women, mean age 51 ± 15 years, left ventricular ejection fraction 45% ± 10%) were included (19 had DCM). Compared to healthy controls (n = 25), fat fraction was higher in calf (12.5% vs 9.9%, P = 0.013), thigh (12.2% vs 9.3%, P = 0.004), and paraspinal muscles (18.8% vs 13.9%, P = 0.008) of TTNtv participants. Linear mixed effects modelling found higher fat fractions in TTNtv participants compared to healthy controls (2.5%; 95% CI: 1.4-3.7; P < 0.001) and controls with non-TTNtv genetic DCM (n = 7) (1.5%; 95% CI: 0.2-2.8; P = 0.025). Muscle strength was within 1 SD of normal values. Biopsy specimens from 21 participants found myopathic features in 13 (62%), including central nuclei. Electron microscopy showed well-ordered Z-lines and T-tubuli but uneven and discontinuous M-lines and excessive glycogen depositions flanked by autophagosomes, lysosomes, and abnormal mitochondria with mitophagy. ConclusionsMild skeletal muscle involvement was prevalent in patients with TTNtv. The phenotype was characterized by an increased muscle fat fraction and excessive accumulation of glycogen, possibly due to reduced autophagic flux. These findings indicate an impact of TTNtv beyond the heart.

GFPT1 deficiency is a novel cause of a dilated cardiomyopathy and is required for myocardial adaptation to chronic pressure-overload stress-induced heart failure

Abstract Background GFPT1 is the rate-limiting enzyme of a pathway called the hexosamine biosynthesis pathway (HBP) that turns fructose 6-phosphate derived from glucose into another monosaccharide called N-acetylglucosamine (GlcNAc). GlcNAc is an important substrate for modifying diverse cellular proteins on their serine and threonine residues termed O-GlcNAcylation often competing with phosphorylation and altering their activity or stability (Bond &amp; Hanover; 2015). Increased GFPT1 activity is known to stimulate the cellular integrated stress response improving protein quality control and cell survival (Denzel et al 2014). In the heart, GFPT1 expression and O-GlcNAcylation increases in the early stages of chronic cardiac stress but the physiological role of GFPT1 in regulating heart function including its role during chronic stress remains unclear. Identifying molecular pathways that promote adaptive cardiac remodelling is a promising approach to discover novel therapies for heart failure. Methods Cardiomyocyte-specific GFPT1 knockout mice were generated to study the effects of GFPT1 deletion in hearts. Heart function was examined by echocardiography. HBP activity was quantified using Western blotting of O-GlcNAc-modified proteins. Abdominal aortic banding (AAB) was used to induce chronic pressure-overload heart failure. Results Homozygous GFPT1 KO mice spontaneously develop a dilated cardiomyopathy (DCM) with a 30% mortality rate (ejection fraction 32% compared with 62% for floxed controls and end diastolic volume 125 microL versus 60 microL; n=5-6 per group; p &amp;lt;0.05). Hearts showed reduced levels of total protein O-GlcNAcylation suggesting impaired hexosamine biosynthesis pathway activity. Heart function could be rescued by supplementing their diets with oral glucosamine bypassing GFPT1 to provide metabolites required for hexosamine biosynthesis and normalising O-GlcNAcylation (ejection fraction improved to 40% in KO with supplementation versus KO without; n=4-6 per group; p &amp;lt;0.05). Heterozygous KO mice do not develop a DCM but when subject to pressure-overload cardiac stress, develop worse heart failure with a 50% mortality rate over 9 weeks of pressure-overload (ejection fraction 43% in het KO versus 53% in floxed control; n= 3-6 per group; p = 0.0025). Conclusion Deficiency of GFPT1 is a novel cause of a spontaneous dilated cardiomyopathy. GFPT1 is required for physiological growth of the heart that may in part involve the O-GlcNAcylation of proteins. Partial GFPT1 deficiency is associated with adverse cardiac remodelling following pressure-overload stress. Increasing GFPT1 activity may be a key therapeutic target in developing novel heart failure treatments.

Skeletal muscle involvement in patients with truncations of titin and familial dilated cardiomyopathy

Abstract Background Variants in TTN are associated with dilated cardiomyopathy (DCM) and skeletal myopathy with or without cardiac affection. However, the skeletal muscle phenotype has not been systematically evaluated in patients with predisposition to or manifest cardiac involvement due to heterozygous truncating TTN variants (TTNtv), the most common cause of DCM. Purpose Assess the skeletal muscle phenotype associated with TTNtv. Methods This cross-sectional study examined skeletal muscle involvement in individuals with TTNtv by quantifying and comparing fat fraction from muscle magnetic resonance imaging to controls (matched on body-size, sex, and age), and evaluating muscle strength by dynamometry and features from muscle biopsies. Results Twenty-five participants (11 women, age 51±15 years, left ventricular ejection fraction 45±10%) with TTNtv were included (19 had DCM). Compared to controls, participants with TTNtv had higher fat fraction in calf- (12.5% vs 9.9%, p=0.013), thigh- (12.2% vs 9.3%, p=0.004) and paraspinal muscles (18.8% vs 13.9%, p=0.008), see figure. Muscle strength was relatively intact (within 1 SD of normal values). Muscle biopsies in 21 participants showed that 13 (62%) displayed myopathic features, most notably an increased proportion of central nuclei. Electron microscopy showed well-ordered Z-lines and T-tubuli but uneven and discontinuous M-lines and excessive glycogen depositions flanked by large autophagosomes, lysosomes, and abnormal mitochondria with mitophagy. Conclusion Skeletal muscle involvement is prevalent in patients with cardiac involvement or predisposition to DCM due to TTNtv and is characterized by an increased muscle fat fraction, and excessive accumulation of glycogen, possibly due to reduced autophagic flux. This emphasizes the need for specialized diagnostic work-up in patients with TTNtv, especially if reporting symptoms or objective signs of muscle involvement.

Relation between non-sustained ventricular tachycardia and major arrhythmic events in patients with dilated cardiomyopathy caused by titin truncating variants

Abstract Background Truncating titin variants (TTNtv) are the most frequent monogenetic cause of dilated cardiomyopathy (DCM). Current data suggest that nonsustained ventricular arrhythmia is common in patients with TTVtv but its relation to the risk of major arrhythmic events (MAE) is uncertain. Purpose To investigated the relationship between NSVT recorded on Holter ECG or implanted device and MAE in patients with DCM. Methods We retrospectively studied consecutively evaluated patients with DCM (left ventricle ejection fraction (LVEF) below 50%) on echocardiography and a pathogenic TTNtv. Patients with obstructive coronary artery disease, valvular disease, ventricular tachycardia ablation during follow-up time and follow-up less than one month were excluded. Survival was modelled from the initial Holter or device implantation. NSVT was defined as ≥3 consecutive ventricular beats at a rate &amp;gt;120 beats per minute, lasting for &amp;lt;30 s. MAE was defined as sustained ventricular tachycardia (VT), ventricular fibrillation (VF), sudden cardiac death, implantable cardioverter defibrillator (ICD) treated ventricular arrhythmias (appropriate shock and ATP). The clinical endpoint was MAE (sustained VT, VF, sudden cardiac death, ICD shocks and ATP) and multivariable analysis was performed using Cox proportional hazards models. Event-free survival probabilities were estimated using the Kaplan-Meier method, and comparisons of Kaplan-Meier curves were made using log-rank tests. Results The cohort comprised 58 men and 30 women [mean age 49 ± 15 years; mean follow-up 3.5 ± 1.8 years]. Symptoms were NYHA class I in 56 patients, class II in 25 patients, class III in 7 patients and class IV in none. Holter ECGs were performed in 77 patients, 41 of whom had NSVT. Twenty five patients had pacemaker/ICD in situ; 14 had NSVT. Six patients had MAE; 4 with NSVT. Univariate analysis association between MAE and LVEF ≤35% (hazard ratio (HR), 9.03; 95% confidence interval (CI), 1.49-54.71; P=0.017), prolonged (&amp;gt;8 beats) NSVT (HR, 6.71; 95% CI, 1.22-36.98; P=0.029) and fast (&amp;gt;200 bpm) NSVT (HR, 5.09; 95% CI, 1.02-25.47; P=0.048). Kaplan-Meier showed similar differences in freedom from MAE (LVEF ≤35%; P=0.004, long NSVT; P=0.025, fast NSVT; P=0.031). Conclusion Fast and prolonged NSVT is associated with a higher risk of MAE in patients with TTNtv.Characteristics at the beginningSurvival probability for freedom

The role of TBX20 truncating variants in dilated and left ventricular non-compaction cardiomyopathy

Abstract Background The genetic cause of dilated cardiomyopathy (DCM) remains unexplained in a considerable proportion of cases. TBX20, the T-Box transcription factor 20 gene, has been linked to cardiac septal defects. Although only a few case reports have described an association between TBX20 and DCM/left ventricular non-compaction (LVNC), there are no case-control studies available, and TBX20 is still considered a gene with limited evidence for these phenotypes. Objectives This study sought to investigate the relationship between truncating variants in TBX20 (TBX20tv) and the development of DCM and LVNC. Methods TBX20 was sequenced using massive parallel sequencing in 7,463 unrelated probands with DCM/LVNC and 22,773 probands with other diagnoses (e.g., hypertrophic or arrhythmogenic cardiomyopathy, channelopathies, or aortic diseases) as internal controls. It was tested for enrichment and cosegregation of TBX20tv in DCM/LVNC, and clinical characteristics and outcomes in carriers were analyzed. Results Twenty-four probands with 22 TBX20tv were identified. Variant frequencies were significantly higher in patients with DCM/LVNC (24/7,463; 0.29%) than in internal controls (2/22,773; 0.008%) or controls from the gnomAD database (4/124,098; 0.003%), with an OR of 70.18 (CI95%: 9.48 to 519.8; p &amp;lt;0.0001) and 95.61 (CI95%: 33.06-276.55; p &amp;lt;0.0001), respectively. Cosegregation was studied in 21 families, identifying 57 carriers, of whom 43 (75.4%) had cardiac involvement. A combined LODs score of 4.41 was obtained, which is indicative of very strong segregation. Regarding clinical characteristics, the mean age at diagnosis was 37 years old, and 50% of carriers were female. Forty-six percent developed left-ventricular dysfunction, which was moderate to severe in half of the cases. Three carriers received a heart transplant, and another carrier died due to heart failure. Congenital heart defects were present in 16 patients (28.1%). Valvular involvement was the most frequent congenital abnormality (5 cases had bicuspid aortic valve, and another 5 had mitral valve defects), followed by heart septal defects (3 atrial and 3 ventricular); coronary anomalies (2) and aortic coarctation (2) were also detected. In some patients, these defects presented as complex congenital heart disease. Conclusions TBX20tv are associated with the development of dilated and non-compaction cardiomyopathy, and the presence of congenital heart defects is also common. Although some carriers, particularly younger ones, may not present the phenotype, nearly half of them experience ventricular dysfunction, and significant cardiac events, such as cardiac death or transplantation, are not uncommon. Therefore, the TBX20 gene should be routinely included in genetic testing panels for DCM and LVNC.

Abstract 19052: Interferon B1A-Induced Dilated Cardiomyopathy

Introduction: Congestive heart failure is a leading causes of morbidity and mortality. Interferon therapy is a rare cause of dilated cardiomyopathy (DCM) and Heart Failure with Reduced Ejection Fraction (HFrEF). Specifically, interferon Alpha has been associated with cardiotoxicity. Here we describe a case of interferon B1A - induced HFrEF and DCM in a patient who took subcutaneous Interferon B1A for 11 years before developing clinical signs of heart failure. To our knowledge, only four other cases have been reported. Case Description: A 70-year-old man with a history of multiple sclerosis managed with Interferon B1A presented with shortness of breath, orthopnea, and lower extremity edema for 10 days. Physical examination revealed jugular venous distension and pitting edema. Brain natriuretic peptide (BNP) was 1580 pg/mL, troponin was 49 ng/L. Lipid panel, complete blood count, complete metabolic panel, Hemoglobin A1c, and thyroid stimulating hormone were within normal limits. Urine drug screen was negative. Chest X-ray revealed pulmonary vascular congestion and small pleural effusions bilaterally. A Transthoracic echocardiogram revealed mild aortic root dilatation (4.1cm), significant four-chamber dilatation, severely reduced left ventricular (LV) systolic function with an estimated ejection fraction of 20%, diastolic LV dysfunction, and moderately reduced systolic RV function, consistent with HFrEF and DCM (LVIDD 6.1cm). Coronary angiography showed normal coronary anatomy. The patient was started on guideline-directed medical therapy for HFrEF. Close follow-up was arranged to track improvement in systolic function after cessation of interferon b1a and consideration for Cardiac MRI and possible RV biopsy to evaluate for other causes of cardiomyopathy. Discussion/Conclusions: Due to the patient’s negative ischemic workup and absence of risk factors for cardiovascular disease, we strongly suspect that the patient’s cardiomyopathy was due to interferon B1A. With only 4 other cases of interferon B1A-induced DCM reported, it is a rare cause of medication-induced DCM. Interferon B1A should be considered a potential risk factor for developing heart failure, especially in high-risk patients.

Abstract 12498: AAV-Mediated LINC Complex Uncoupling Ameliorates Pathology in a Mouse Model of LMNA Dilated Cardiomyopathy

Mutations in the LMNA gene, encoding lamin A/C, are one of the most frequent genetic causes of dilated cardiomyopathy. While gene therapy using adeno-associated virus (AAV) vectors show promise for the treatment of monogenic diseases, LMNA DCM mutations tend to be autosomal dominant and gain-of-function, precluding typical gene replacement approaches. Lamin A/C forms a filamentous network, the nuclear lamina, underlying the nuclear envelope that is thought to function in maintaining structural integrity of the nucleus by resisting cytoskeletal forces transmitted to the nucleus during cardiac contraction. Our hypothesis is that disruption to the lamin A/C network leads to nuclear envelope rupture as the weakened nuclear lamina cannot resist excess cytoskeletal force. Uncoupling the linkage between the cytoskeleton and nucleus might therefore reduce LMNA -associated pathology. This linkage is known to be mediated by the nuclear envelope-localized linker of nucleoskeleton and cytoskeleton (LINC) complex. Using AAV-mediated expression of a LINC complex uncoupling transgene, GSLA01, we were indeed able to prevent the progression of ventricular dilation, cardiac fibrosis, and decline in ejection fraction observed in a LMNA dilated cardiomyopathy mouse model. We decided to explore structure-function relationships in GSLA01 in our lead optimization studies. We generated a series of truncations of full-length GSLA01 comprising different lengths of its coiled coil domain. In vitro assays indicated that most truncations examined were able to uncouple the LINC complex. Selected truncations were delivered using AAV to LMNA DCM mice after inducing cardiac-specific deletion of Lmna with tamoxifen. Full-length GSLA01 extended the lifespan of LMNA DCM mice from 39 to ~170 days. The truncations mostly performed on par or better than full-length GSLA01 in extending the lifespan of LMNA DCM mice, to more than 250 days for certain constructs. Reducing cytoskeletal force transmission to the nucleus by uncoupling the LINC complex appears to be a viable strategy for treating LMNA -linked pathology, and multiple GSLA01 truncation variants can be used to achieve this effect.

Abstract 18674: Deep Phenotyping Arrhythmogenic MVP With Imaging and Genotyping Reveals Important Shared Genetic Etiology With Arrhythmia and Cardiomyopathy Genes

Introduction: Mitral valve prolapse (MVP) has a high population prevalence 2-4% with an arrhythmogenic subtype presenting with premature ventricular complexes (PVC) ventricular tachycardia (VT) and sudden death. There is a continued search for markers of MVP to help risk stratify patients. Hypothesis: Arrhythmogenic MVP shares genetic etiology with Mendelian causes of arrhythmia and cardiomyopathy Methods: Consecutive adult patients with arrhythmogenic MVP patients prospectively evaluated Results: A total of 33 cases (age 55±15 years, female 51.5%) presented with history of hypertension (33%), diabetes (3%), coronary disease (12%), atrial fibrillation (45%), bileaflet MVP (58%) and syncope (18%). ECG findings include inverted T-waves in inferior leads in 6%, pleomorphic PVC in 6%, Ventricular couplets in 51.5%, non-sustained VT in 73% and sustained VT in 33%; High PVC burden was seen in 55% of cases with burden 15±14%. Echocardiography noted LV ejection fraction of 55±8%, mitral regurgitations in 70% (severe 18%, moderate 27%, mild 24%), mitral annular disjunction in 39%, and Pickelhaube sign in 9% of cases. Cardiac magnetic resonance showed LVESV 113±119mm, LVEDV 117±70mm, and late Gadolinium enhancement in 48% with highest prevalence in basal inferolateral segment. PET-CT performed in 17 cases and showed fluorodeoxyglucose uptake in 24% cases, mostly in basal inferolateral segment as well. Genetic testing was performed in 23 cases and reported a putative pathogenic variant in 21.7%: FLNC (Exemplar case, Figure 1 ) cause of dilated cardiomyopathy, TBX5 cause of Holt-Oram syndrome, DSP cause of arrhythmogenic cardiomyopathy , TTN causes of dilated cardiomyopathy, MTO1 cause of mitochondrial hypertrophic cardiomyopathy. Conclusion: Full evaluation of arrhythmogenic MVP with multimodality imaging and genetic testing reveals high burden of fibrosis, inflammation, and candidate pathogenic variants.

A study of clinical profile and outcome in children with dilated cardiomyopathy

Background: Objective was to analyse the clinical profile of children diagnosed with Dilated cardiomyopathy and to correlate the same with the severity and functional status on 2-D echocardiography. Methods: It was a prospective, retrospective and observational study. A total of 150 subjects were selected from patients visiting the cardiology OPD, admitted in medical wards, paediatric Intensive Care Unit of a tertiary care referral centre. The demographic profile, symptomatology, heart functions and compliance were recorded. The cases were evaluated by detailed history, general and cardiovascular examination and laboratory investigations along with 2D echocardiography. Results: The demographic profile is significant as the age at diagnosis predicts the risk of mortality with older children having the worst outcome. A significant association observed between decreasing ejection fraction and increasing mortality with a p value (p=0.02). Signs of pedal edema and hepatomegaly are associated with unfavourable outcome with a significant p value of (p=0.03). The overall prognosis of children with Dilated cardiomyopathy steadily improved with timely use of appropriate medications. Only 1 patient in this study had undergone orthotopic heart transplant at the age of 15 years (case of chemotherapy induced Dilated cardiomyopathy). Conclusions: Dilated cardiomyopathy is a difficult entity to treat in children as most cases are idiopathic and the therapy remains mostly supportive. Hypovitaminosis-D and hypocalcemia are common treatable causes of dilated cardiomyopathy in children and must be ruled out in all cases of dilated cardiomyopathy. Patients refractory to medical therapy should be considered for ventricular assist devices and orthotopic heart transplantation.

Research progress on the expression of the RBM20 gene in dilated cardiomyopathy

Dilated cardiomyopathy (DCM) is a significant contributor to heart failure and can lead to life-threatening cardiovascular events at any stage. RNA-binding motif protein 20 (RBM20) gene mutation is known to be one of the causes of DCM. This mutation exhibits familial aggregation and is associated with arrhythmias, increasing the risk of sudden and early death. This article delves into the characteristics of the RBM20 gene, highlighting its role in regulating alternative splicing of the TTN gene and calcium/calmodulin-dependent protein kinase type II gene. Furthermore, the article provides a summary of treatment options available for DCM caused by RBM20 gene mutations, aiming to enhance clinicians' understanding of the RBM20 gene and provide new ideas for precision medicine treatment.

TCAP gene is not a common cause of cardiomyopathy in Iranian patients

BackgroundHypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) are the most frequent cardiomyopathies that cause acute heart failure and sudden cardiac death. Previous genetic reports have shown that pathogenic variants of genes encoding Z-disc components such as telethonin protein (TCAP) are the primary cause of DCM and HCM.MethodsThis study was the first investigation on the TCAP gene among the Iranian cardiomyopathies population wherein the TCAP gene was analyzed in 40 unrelated patients (17 females and 23 males) who were clinically diagnosed with HCM and DCM. In addition, we conducted a thorough review of all published articles and the databases that were the first to report novel pathogenic or likely pathogenic variants the in TCAP gene.ResultsIn the cohort of this study, we identified only one intronic variant c.111-42G > A in one of the HCM patients that were predicted as polymorphism by in-silico analysis. Moreover, a total of 44 variants were reported for the TCAP gene in the literature where a majority of mutations were found to be missense. Pathogenic mutations in TCAP may cause diseases including limb-girdle muscular dystrophy 2G (LGMD-2G), DCM, HCM, intestinal pseudo-obstruction, and telethonin deficiency. However, a large number of affected patients were clinically diagnosed with limb-girdle 2G compared to other presenting phenotypes.DiscussionThese findings suggest that the TCAP gene pathogenic mutations might not be a common cause of cardiomyopathies among Iranian patients. These gene disease-causing mutations may cause various manifestations, but it has a high prevalence among LGMD-2G, HCM, and DCM patients.

DMD-Associated Dilated Cardiomyopathy: Genotypes, Phenotypes, and Phenocopies.

Variants in the DMD gene, that encodes the cytoskeletal protein, dystrophin, cause a severe form of dilated cardiomyopathy (DCM) associated with high rates of heart failure, heart transplantation, and ventricular arrhythmias. Improved early detection of individuals at risk is needed. Genetic testing of 40 male probands with a potential X-linked genetic cause of primary DCM was undertaken using multi-gene panel sequencing, multiplex polymerase chain reaction, and array comparative genomic hybridization. Variant location was assessed with respect to dystrophin isoform patterns and exon usage. Telomere length was evaluated as a marker of myocardial dysfunction in left ventricular tissue and blood. Four pathogenic/likely pathogenic DMD variants were found in 5 probands (5/40: 12.5%). Only one rare variant was identified by gene panel testing with 3 additional multi-exon deletion/duplications found following targeted assays for structural variants. All of the pathogenic/likely pathogenic DMD variants involved dystrophin exons that had percent spliced-in scores >90, indicating high levels of constitutive expression in the human adult heart. Fifteen DMD variant-negative probands (15/40: 37.5%) had variants in autosomal genes including TTN, BAG3, LMNA, and RBM20. Myocardial telomere length was reduced in patients with DCM irrespective of genotype. No differences in blood telomere length were observed between genotype-positive family members with/without DCM and controls. Primary genetic testing using multi-gene panels has a low yield and specific assays for structural variants are required if DMD-associated cardiomyopathy is suspected. Distinguishing X-linked causes of DCM from autosomal genes that show sex differences in clinical presentation is crucial for informed family management.

OPA1, a molecular regulator of dilated cardiomyopathy.

Dilated cardiomyopathy (DCM) is a disease with no specific treatment, poor prognosis and high mortality. During DCM development, there is apoptosis, mitochondrial dynamics imbalance and changes in cristae structure. Optic atrophy 1 (OPA1) appears at high frequency in these three aspects. DCM LMNA (LaminA/C) gene mutation can activate TP53, and the study of P53 shows that P53 affects OPA1 through Bak/Bax and OMA1 (a metalloprotease). OPA1 can be considered the missing link between DCMp53 and DCM apoptosis, mitochondrial dynamics imbalance and changes in cristae structure. OPA1 regulates apoptosis by regulating the release of cytochrome c from the mitochondrial matrix through CJs (crisp linkages, located in the inner mitochondrial membrane) and unbalances mitochondrial fusion and fission by affecting mitochondrial inner membrane (IM) fusion. OPA1 is also associated with the formation and maintenance of mitochondrial cristae. OPA1 is not the root cause of DCM, but it is an essential mediator in P53 mediating the occurrence and development of DCM, so OPA1 also becomes a molecular regulator of DCM. This review discusses the implication of OPA1 for DCM from three aspects: apoptosis, mitochondrial dynamics and ridge structure.

Anesthetic management of a patient with pheochromocytoma and peripartum cardiomyopathy for cesarean section

Pheochromocytoma and peripartum cardiomyopathy is associated with significant maternal mortality. Cause of death can be heart failure, myocardial infarction, arrhythmias and thromboembolism. Pheochromocytoma can be one of the causes of dilated cardiomyopathy. Anesthesia in an obstetric patient with pheochromocytoma and peripartum cardiomyopathy is challenging. Early diagnosis and a multidisciplinary management is required to improve outcome. Elective cesarean section must be planned and epidural anesthesia should be the preferred technique. We present a case of 34 y old female patient with pheochromocytoma and peripartum cardiomyopathy who underwent cesarean section under epidural anesthesia and had uneventful recovery.&#x0D; Key words: Pheochromocytoma; Peripartum Cardiomyopathy; Cesarean Section; Epidural Anesthesia&#x0D; Citation: Ayesha K, Khan J, Sikander RI, Fatima N. Anesthetic management of a patient with pheochromocytoma and peripartum cardiomyopathy for cesarean section. Anaesth. pain intensive care 2023;27(4):596−599.&#x0D; DOI: 10.35975/apic.v27i4.2208&#x0D; Received: April 16, 2023; Reviewed: May 09, 2023; Accepted: June 06, 2023