Post-COVID Myocarditis in Patients with Primary Cardiomyopathies: Diagnosis, Clinical Course and Outcomes.

The aim of this study was to evaluate the clinical course and outcomes of post-COVID myocarditis in patients with cardiomyopathies (CMP). This case series includes 10 patients with different CMPs who had COVID-19 (seven men; 48.4 ± 11.4 yr.): left ventricular non-compaction (n = 2), arrhythmogenic right ventricular CMP in combination with a heterozygous form of hemochromatosis (n = 1, HFE), restrictive CMP (n = 1, MyBPC3), laminopathy (n = 1, LMNA), dilated cardiomyopathy (n = 1, MYH7 + MyBPC3), Danon's disease (n = 1, LAMP2) and AL cardiac amyloidosis (n = 3). Myocardial morphological examination with immunohistochemical staining and PCR for SARS-CoV-2 and cardiotropic viruses was performed in six patients, while cardiac MRI and anti-cardiac antibody titres were evaluated in all patients. Post-COVID lymphocytic myocarditis was confirmed morphologically in six patients (with LVNC, RCM, ARCV, Danon's disease, and AL amyloidosis). Spike and nucleocapsid coronavirus proteins were detected in cell infiltrates, endothelium and cardiomyocytes in all biopsies; SARS-CoV-2 RNA was found in five out of six. In four patients, the diagnosis of myocarditis was based on MRI, high titres of anti-cardiac antibodies and clinical data. The mean time from COVID-19 to the diagnosis of myocarditis was 7 (5; 10.5) months. Myocarditis manifested with the onset/increase of arrhythmias and heart failure. Immunosuppressive therapy with corticosteroids was administered to six patients and led to an increase in ejection fraction and improvement of heart failure symptoms in five of them. CMPs are a favourable background for the development of post-COVID myocarditis. The onset or deterioration of heart failure and/or arrhythmias in patients with CMPs after COVID-19 requires the exclusion of myocarditis and, if present, the administration of immunosuppressive therapy.

Hypertrophic Cardiomyopathy Complicated by Post-COVID-19 Myopericarditis in Patient with ANO5-Related Distal Myopathy.

A 60-year-old male with hypertrophic cardiomyopathy, conduction disorders, post-COVID-19 myopericarditis and heart failure was admitted to the hospital's cardiology department. Blood tests revealed an increase in CPK activity, troponin T elevation and high titers of anticardiac antibodies. Whole exome sequencing showed the presence of the pathogenic variant NM_213599:c.2272C>T of the ANO5 gene. Results of the skeletal muscle biopsy excluded the diagnosis of systemic amyloidosis. Microscopy of the muscle fragment demonstrated sclerosis of the perimysium, moderate lymphoid infiltration, sclerosis of the microvessels, dystrophic changes and a lack of cross striations in the muscle fibers. Hypertrophy of the LV with a low contractile ability, atrial fibrillation, weakness of the distal skeletal muscles and increased plasma CPK activity and the results of the skeletal muscle biopsy suggested a diagnosis of a late form of distal myopathy (Miyoshi-like distal myopathy, MMD3). Post-COVID-19 myopericarditis, for which genetically modified myocardium could serve as a favorable background, caused heart failure decompensation.

Modified chordal sparing mitral valve replacement as effective technique for both stenotic and insufficient mitral valves.

BACKGROUND: Chordal apparatus preservation is important for preserving left ventricular (LV) function in the long-term perspective. We present results of originally modified chordal-sparing mitral valve replacement (MVR) successfully used in patients with mitral stenosis and mitral insufficiency. METHODS: The modified surgical method involves preserving only four strut chords with portions of the mitral valve leaflets, which are later fixed to the fibrous ring. The rest of the leaflets and marginal chords are removed. RESULTS: Starting from 1998, 484 modified universal chordal-sparing MVR were performed including 270 (55.79%) in patients with rheumatic mitral stenosis and 214 (44.21%) in patients with mitral valve insufficiency. Overall, 116 patients underwent isolated MVR, and 368 patients underwent MRV with concomitant surgical procedures. The overall in-hospital mortality was 2.5% (12 patients). Long-term efficiency was assessed in patients discharged after isolated MVR (114 patients), average follow-up period was 3.1±0.6 years. Preservation of strut chords ensured normalization of intraventricular anatomy and prevented LV dilatation; the LV Sphericity Index is maintained at 0.44-0.63. Heart failure functional class (NYHA) was improved in all patients. Non-fatal prosthesis-related complications were observed in 11 patients (9.65%). Three patients (2.63%) died due to extracardiac causes. CONCLUSIONS: The proposed modification of the strut chordal-sparing mitral valve replacement technique allows preserving functionally complete annulo-papillary apparatus, regardless of the nature of valvular dysfunction, and provides parallel movement to the mechanical prosthesis. This modified surgical technique is safe and effective and eliminates the risk of jamming of the prosthesis disk and left ventricular outflow tract obstruction.

Mixed-Etiology Restrictive Cardiomyopathy (Desminopathy and Hemochromatosis) with Complex Liver Lesions.

A 28 year-old male with restrictive cardiomyopathy (RCM) and endocardium thickening, conduction disorders, heart failure, and depressive disorder treated with paroxetine was admitted to the clinic. Blood tests revealed an increase in serum iron level, transferrin saturation percentage, and slightly elevated liver function tests. Sarcoidosis, storage diseases and Loeffler endocarditis were ruled out. Mutations in desmin (DES) and hemochromatosis gene (HFE1) were identified. Liver biopsy was obtained to verify the hemochromatosis, assess its possible contribution to the RCM progression and determine indications for treatment. Biopsy revealed signs of drug-induced injury, subcompensated heart failure, and hemosiderin accumulation. Thus, even if one obvious cause (desmin mutation) of RCM has been identified, other less likely causes should be taken into consideration.

Scintigraphy false-positive results for cardiac amyloidosis in a patient with Danon disease.

Common diagnostic approach in patients with suspected cardiac amyloidosis includes cardiac magnetic resonance imaging and scintigraphy. We report the first clinical case of false-positive results of scintigraphy in a patient with Danon disease.

Mixed Hypertrophic and Dilated Phenotype of Cardiomyopathy in a Patient With Homozygous In-Frame Deletion in the MyBPC3 Gene Treated as Myocarditis for a Long Time.

Hypertrophic cardiomyopathy (HCM) is the most common inherited disease, with a prevalence of 1:200 worldwide. The cause of HCM usually presents with an autosomal dominant mutation in the genes encoding one of more than 20 sarcomeric proteins, incomplete penetrance, and variable expressivity. HCM classically manifests as an unexplained thickness of the interventricular septum (IVS) and left ventricular (LV) walls, with or without the obstruction of the LV outflow tract (LVOT), and variable cardiac arrhythmias. Here, we present a rare case of mixed cardiomyopathy (cardiac hypertrophy and dilation) and erythrocytosis in a young patient. A 27-year-old man was admitted to the clinic due to biventricular heart failure (HF) NYHA class III. Personal medical records included a diagnosis of dilated cardiomyopathy (DCM) since the age of 4 years and were, at the time, considered an outcome of myocarditis. Severe respiratory infection led to circulatory decompensation and acute femoral thrombosis. The combination of non-obstructive LV hypertrophy (LV walls up to 15 mm), LV dilatation, decreased contractility (LV EF 24%), and LV apical thrombosis were seen. Cardiac MRI showed a complex pattern of late gadolinium enhancement (LGE). Endomyocardial biopsy (EMB) revealed primary cardiomyopathy with intravascular coagulation and an inflammatory response. No viral genome was detected in the plasma or EMB samples. Whole exome sequencing (WES) revealed a homozygous in-frame deletion p.2711_2737del in the MyBPC3 gene. The clinically unaffected mother was a heterozygous carrier of this deletion, and the father was unavailable for clinical and genetic testing. Essential erythrocytosis remains unexplained. No significant improvement was achieved by conventional treatment, including prednisolone 40 mg therapy. ICD was implanted due to sustained VT and high risk of SCD. Orthotopic heart transplantation (HTx) was considered optimal. Early manifestation combined hypertrophic and dilated phenotype, and progression may reflect a complex genotype with more than one pathogenic allele and/or a combination of genetic diseases in one patient.

Clinical Classification of Arrhythmogenic Right Ventricular Cardiomyopathy.

INTRODUCTION: Commonly accepted clinical classification of arrhythmogenic right ventricular cardiomyopathy (ARVC) is still not developed. OBJECTIVE: To study the clinical forms of ARVC. METHODS: Fifty-four patients (38.7 ± 14.1 years, 42.6% men) with ARVC. Follow-up period: 21 (6-60) months. All patients underwent electrocardiography, 24 h-Holter monitoring, echocardiography, and DNA diagnostic. Magnetic resonance imaging was performed in 49 patients. RESULTS: According to the features of clinical course of ARVC, 4 clinical forms were identified. (I) Latent arrhythmic form (n = 27) - frequent premature ventricular contractions and/or nonsustained ventricular tachycardia (VT) in the absence of sustained VT and syncope; characterized by absence of fatal arrhythmic events. (II) Manifested arrhythmic form (n = 11) - sustained VT/ventricular fibrillation; the high incidence of appropriate implantation of cardioverter-defibrillator (ICD) interventions (75%) registered. (III) ARVC with progressive chronic heart failure (CHF, n = 8) as the main manifestation of the disease; incidence of appropriate ICD interventions was 50%, mortality rate due to CHF was 25%. (IV) Combination of ARVC with left ventricular noncompaction (n = 8); characterized by mutations in desmosomal or sarcomere genes, aggressive ventricular arrhythmias, appropriate ICD interventions in 100% patients. Described 4 clinical forms are stable in time, do not transform into each other, and they are genetically determined. CONCLUSIONS: The described clinical forms of ARVC are determined by a combination of genetic and environmental factors and do not transform into each other. The proposed classification could be used in clinical practice to determine the range of diagnostic and therapeutic measures and to assess the prognosis of the disease in a particular patient.

New genetic variant in the SERPINC1 gene: hereditary Antithrombin deficiency case report, familial thrombosis and considerations on genetic counseling.

BACKGROUND: Inherited deficiency of the antithrombin (hereditary antithrombin deficiency, AT deficiency, OMIM #613118) is a relatively rare (1:2000-3000) autosomal-dominant disorder with high risk of venous thromboembolism. Mutations in the serpin family C member 1 gene (SERPINC1) can lead to Quantitative (type I) and Qualitative (type II) types of antithrombin deficiency. We describe a new genetic variant in the SERPINC1 gene and our approach to variant interpretation. CASE PRESENTATION: We observed a 29 y.o. female proband with the episode of venous thrombosis at the age of 18 and family history of thrombosis. The antithrombin level in our patient was low, 44-48% (AT deficiency type I). A new genetic variant c.662G > C (p.W221S) in the SERPINC1 gene was detected in proband and affected father but was absent in healthy sister. We used in silico tools to evaluate the possible impact of p.W221S variant on protein structure and function. In mutated SERPINC1 protein a new N-linked glycosylation site is formed, however, it is unclear if the glycosylation at 219-221 site is possible. CONCLUSION: The proband was provided with appropriate genetic counseling and referred to a hematologist. Based on all the evidence we classify the p.W221S variant as variant of unknown clinical significance. In this paper we discuss some aspects of genetic counseling, variant interpretation and thromboembolic prophilaxis.

Common pathogenic mechanism in patients with dropped head syndrome caused by different mutations in the MYH7 gene.

Mutations in the MYH7 gene are the source of an allelic series of diseases, including various cardiomyopathies and skeletal myopathies that usually manifest in adulthood. We observed a 1.5 y.o. male patient with congenital weaknesses of the axial muscles, "dropped head" syndrome, and dilated cardiomyopathy. The clinical evaluation included medical history, an echocardiogram, electromyography, and a histopathological study. The genetic evaluation included whole exome sequencing. Muscle biopsy samples from the proband were used for mRNA extraction. We revealed a novel genetic variant c.5655 + 5G > C in the MYH7 gene. The analysis of the cDNA showed an in-frame skipping of exon 38 (p.1854_1885del). This variant and two previously published mutations (c.5655G > A and c.5655 + 1G > A), also presumably leading to exon 38 skipping, were studied by expression analysis in the HEK293T cell line transfected with 4 plasmids containing the MYH7 minigene (wt, c.5655G > C, c.5655 + 1G > A and c.5655 + 5G > A). A quantitative difference in expression was shown for cell lines with each of the three mutant plasmids. All mutation carriers had a similar phenotype and included congenital axial myopathy and variable cardiac involvement. Prominent dropped head syndrome was mentioned in all patients. Early-onset axial myopathy with a dropped head syndrome is a distinct clinical entity within MYH7-related disorders. We suggest that mutations in the MYH7 gene affecting the C-terminal domain of beta-myosin heavy chain should also be considered as a possible cause in cases of early-onset myopathy with "dropped head" syndrome.

Sodium current and potassium transient outward current genes in Brugada syndrome: screening and bioinformatics.

BACKGROUND: Brugada syndrome (BrS) is a primary arrhythmia syndrome characterized by the occurrence of malignant ventricular arrhythmias. Previously, the genes SCN1B, SCN3B, MOG1, and KCND3 have been associated with BrS. Recent data from exome screening efforts permit better discrimination between low-frequency genetic variants and true monogenetic disease-causing variants. We aimed to screen the genes SCN1B through SCN4B, MOG1, CAV3, and KCND3 for variations in a population of SCN5A negative Danish and Iranian BrS patients, as well as research prior associations using newly released exome data. METHODS: Screening of all exons and splice sites was performed using Sanger sequencing. Bioinformatic searches were performed in the Single-nucleotide polymorphism database (build 132) and in the National Heart, Lung, and Blood Institute Grand Opportunity Exome Sequencing Project (ESP) for both previously published variant-BrS associations and newly uncovered variations within the noted genes. RESULTS: A total of 42 BrS patients were screened, and 2 different nonsynonymous mutations in SCN1Bb (H162P and R214Q) were found in 2 different Danish patients. The variants were not found in 216 Danish controls, but R214Q was present in ESP data (5 of 841 alleles). No other mutations were found. Previously BrS-associated mutations in KNCD3 and SCN3B were also present in ESP data. This was not the case for MOG1, but a nonsense polymorphism was present in 0.5% of alleles. CONCLUSIONS: Our study supports the association of SCN1Bb with BrS. However, recently released exome data make some of the prior associations of BrS with genes SCN3B, MOG1, and KCND3 less likely.