scholarly journals Severe T-System Remodeling in Pediatric Viral Myocarditis

2021 ◽  
Vol 7 ◽  
Author(s):  
Dominik J. Fiegle ◽  
Martin Schöber ◽  
Sven Dittrich ◽  
Robert Cesnjevar ◽  
Karin Klingel ◽  
...  
Keyword(s):  
Heart Failure ◽  
Chronic Heart Failure ◽  
Acute Myocarditis ◽  
Viral Myocarditis ◽  
Left Ventricular ◽  
Length Ratio ◽  
Transverse Tubular System ◽  
Ec Coupling ◽  
T Tubules ◽  
T System

Chronic heart failure (HF) in adults causes remodeling of the cardiomyocyte transverse tubular system (t-system), which contributes to disease progression by impairing excitation-contraction (EC) coupling. However, it is unknown if t-system remodeling occurs in pediatric heart failure. This study investigated the t-system in pediatric viral myocarditis. The t-system and integrity of EC coupling junctions (co-localization of L-type Ca2+ channels with ryanodine receptors and junctophilin-2) were analyzed by 3D confocal microscopy in left-ventricular (LV) samples from 5 children with myocarditis (age 14 ± 3 months), undergoing ventricular assist device (VAD) implantation, and 5 children with atrioventricular septum defect (AVSD, age 17 ± 3 months), undergoing corrective surgery. LV ejection fraction (EF) was 58.4 ± 2.3% in AVSD and 12.2 ± 2.4% in acute myocarditis. Cardiomyocytes from myocarditis samples showed increased t-tubule distance (1.27 ± 0.05 μm, n = 34 cells) and dilation of t-tubules (volume-length ratio: 0.64 ± 0.02 μm2) when compared with AVSD (0.90 ± 0.02 μm, p < 0.001; 0.52 ± 0.02 μm2, n = 61, p < 0.01). Intriguingly, 4 out of 5 myocarditis samples exhibited sheet-like t-tubules (t-sheets), a characteristic feature of adult chronic heart failure. The fraction of extracellular matrix was slightly higher in myocarditis (26.6 ± 1.4%) than in AVSD samples (24.4 ± 0.8%, p < 0.05). In one case of myocarditis, a second biopsy was taken and analyzed at VAD explantation after extensive cardiac recovery (EF from 7 to 56%) and clinical remission. When compared with pre-VAD, t-tubule distance and density were unchanged, as well as volume-length ratio (0.67 ± 0.04 μm2 vs. 0.72 ± 0.05 μm2, p = 0.5), reflecting extant t-sheets. However, junctophilin-2 cluster density was considerably higher (0.12 ± 0.02 μm−3 vs. 0.05 ± 0.01 μm−3, n = 9/10, p < 0.001), approaching values of AVSD (0.13 ± 0.05 μm−3, n = 56), and the measure of intact EC coupling junctions showed a distinct increase (20.2 ± 5.0% vs. 6.8 ± 2.2%, p < 0.001). Severe t-system loss and remodeling to t-sheets can occur in acute HF in young children, resembling the structural changes of chronically failing adult hearts. T-system remodeling might contribute to cardiac dysfunction in viral myocarditis. Although t-system recovery remains elusive, recovery of EC coupling junctions may be possible and deserves further investigation.

scholarly journals Acute myocarditis in a patient with parainfluenza infection, seven years after bone marrow transplantation

2020 ◽  
Vol 26 (2) ◽  
pp. 79-88
Author(s):  
Nikolay Marinov ◽  
Iana Simova ◽  
Ivo Petrov
Keyword(s):  
Heart Failure ◽  
Clinical Course ◽  
Acute Myocarditis ◽  
Influenza Infection ◽  
Systolic Dysfunction ◽  
Viral Myocarditis ◽  
Left Ventricular ◽  
Current Guideline ◽  
Timely Initiation ◽  
Viral Testing

Myocarditis is an inflammatory disease of the myocardium, with heterogeneous etiology.  Although rare, myocarditis can be a complication of the influenza infection. In the majority of cases, viral myocarditis is a self-limiting infection passing without permanent changes in the myocardium. We present a clinical case of a 30-year-old woman with acute heart failure in the course of respiratory infection accompanied by severe systolic dysfunction (left ventricular (LV) ejection fraction (EF) 16%). The patient was treated according to the current guideline recommendations for the treatment of acute and chronic heart failure with the conjunction of immunomodulating and metabolic therapy. During hospitalization from microbial and viral testing, acute-phase antibodies to parainfluenza virus were identified. Following the treatment, a complete resolution of heart failure symptoms and restoration of LVEF to baseline (40%) was observed. Timely initiation of treatment in myocarditis, followed by good clinical course and regression of LV systolic dysfunction, in some cases may cancel invasive procedures such as endomyocardial biopsy.

Efficacy of Vitamin D on Chronic Heart Failure Among Adults

2020 ◽  
Vol 90 (1-2) ◽  
pp. 49-58 ◽  
Author(s):  
Wang Chunbin ◽  
Wang Han ◽  
Cai Lin
Keyword(s):  
Heart Failure ◽  
Vitamin D ◽  
Chronic Heart Failure ◽  
Left Ventricular Ejection Fraction ◽  
Confidence Interval ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Controlled Trials ◽  
Ventricular Ejection Fraction ◽  
Randomized Controlled

Abstract. Vitamin D deficiency commonly occurs in chronic heart failure. Whether additional vitamin D supplementation can be beneficial to adults with chronic heart failure remains unclear. We conducted a meta-analysis to derive a more precise estimation. PubMed, Embase, and Cochrane databases were searched on September 8, 2016. Seven randomized controlled trials that investigated the effects of vitamin D on cardiovascular outcomes in adults with chronic heart failure, and comprised 592 patients, were included in the analysis. Compared to placebo, vitamin D, at doses ranging from 2,000 IU/day to 50,000 IU/week, could not improve left ventricular ejection fraction (Weighted mean difference, WMD = 3.31, 95% confidence interval, CL = −0.93 to 7.55, P < 0.001, I2 = 92.1%); it also exerts no beneficial effects on the 6 minute walk distance (WMD = 18.84, 95% CL = −24.85 to 62.52, P = 0.276, I2 = 22.4%) and natriuretic peptide (Standardized mean difference, SMD = −0.39, 95% confidence interval CL = −0.48 to 0.69, P < 0.001, I2 = 92.4%). However, a dose-response analysis from two studies demonstrated an improved left ventricular ejection fraction with vitamin D at a dose of 4,000 IU/day (WMD = 6.58, 95% confidence interval CL = −4.04 to 9.13, P = 0.134, I2 = 55.4%). The results showed that high dose vitamin D treatment could potentially benefit adults with chronic heart failure, but more randomized controlled trials are required to confirm this result.

A translational model of chronic heart failure in rats

2018 ◽  
pp. 136-148
Author(s):  
С.А. Крыжановский ◽  
И.Б. Цорин ◽  
Е.О. Ионова ◽  
В.Н. Столярук ◽  
М.Б. Вититнова ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Heart Failure ◽  
Chronic Heart Failure ◽  
Left Ventricular ◽  
Compensatory Hypertrophy ◽  
Experimental Myocardial Infarction ◽  
Left Ventricular Ejection ◽  
Translational Model ◽  
Innovative Drug ◽  
Ventricular Ejection Fraction

Цель исследования - разработка трансляционной модели хронической сердечной недостаточности (ХСН) у крыс, позволяющей, с одной стороны, изучить тонкие механизмы, лежащие в основе данной патологии, а с другой стороны, выявить новые биомишени для поиска и изучения механизма действия инновационных лекарственных средств. Методика. Использован комплекс эхокардиографических, морфологических, биохимических и молекулярно-биологических исследований, позволяющий оценивать и дифференцировать этапы формирования ХСН. Результаты. Динамические эхокардиографические исследования показали, что ХСН формируется через 90 дней после воспроизведения переднего трансмурального инфаркта миокарда. К этому времени у животных основной группы отмечается статистически значимое по сравнению со 2-ми сут. после воспроизведения экспериментального инфаркта миокарда снижение ФВ левого желудочка сердца (соответственно 55,9 ± 1,4 и 63,9 ± 1,6%, р = 0,0008). Снижение насосной функции сердца (на 13% по сравнению со 2-ми сут. после операции и на ~40% по сравнению с интактными животными) сопровождается увеличением КСР и КДР (соответственно с 2,49 ± 0,08 до 3,91 ± 0,17 мм, р = 0,0002, и с 3,56 ± 0,11 до 5,20 ± 0,19 мм, р = 0,0001), то есть к этому сроку развивается сердечная недостаточность. Результаты эхокардиографических исследований подтверждены данными морфометрии миокарда, продемонстрировавшими дилатацию правого и левого желудочков сердца. Параллельно проведенные гистологические исследования свидетельствуют о наличии патогномоничных для данной патологии изменений миокарда (постинфарктный кардиосклероз, компенсаторная гипертрофия кардиомиоцитов, очаги исчезновения поперечной исчерченности мышечных волокон и т.д.) и признаков венозного застоя в легких и печени. Биохимические исследования выявили значимое увеличение концентрации в плазме крови биохимического маркера ХСН - мозгового натрийуретического пептида. Данные молекулярно-биологических исследований позволяют говорить о наличии гиперактивности ренин-ангиотензин-альдостероновой и симпатоадреналовой систем, играющих ключевую роль в патогенезе ХСН. Заключение. Разработана трансляционная модель ХСН у крыс, воспроизводящая основные клинико-диагностические критерии этого заболевания. Показано наличие корреляции между морфометрическими, гистологическими, биохимическими и молекулярными маркерами прогрессирующей ХСН и эхокардиографическими диагностическими признаками, что позволяет использовать неинвазивный метод эхокардиографии, характеризующий состояние внутрисердечной гемодинамики, в качестве основного критерия оценки наличия/отсутствия данной патологии. Aim. Development of a translational model for chronic heart failure (CHF) in rats to identify new biotargets for finding and studying mechanisms of innovative drug effect in this disease. Methods. A set of echocardiographic, morphological, biochemical, and molecular methods was used to evaluate and differentiate stages of CHF development. Results. Dynamic echocardiographic studies showed that CHF developed in 90 days after anterior transmural myocardial infarction. By that time, left ventricular ejection fraction was significantly decreased in animals of the main group compared with rats studied on day 2 after experimental myocardial infarction (55.9 ± 1.4% vs . 63.9 ± 1.6%, respectively, p<0.0008). The decrease in heart’s pumping function (by 13% compared with day 2 after infarction and by approximately 40% compared to intact animals) was associated with increased ESD and EDD (from 2.49 ± 0.08 to 3.91 ± 0.17 mm, p = 0.0002, and from 3.56 ± 0.11 to 5.20 ± 0.19 mm, respectively, p = 0.0001); therefore, heart failure developed by that time. The results of echocardiographic studies were confirmed by myocardial morphometry, which demonstrated dilatation of both right and left ventricles. Paralleled histological studies indicated presence of the changes pathognomonic for this myocardial pathology (postinfarction cardiosclerosis, compensatory hypertrophy of cardiomyocytes, foci of disappeared transverse striation of muscle fibers, etc.) and signs of venous congestion in lungs and liver. Biochemical studies demonstrated a significant increase in plasma concentration of brain natriuretic peptide, a biochemical marker of CHF. Results of molecular studies suggested hyperactivity of the renin-angiotensin-aldosterone and sympathoadrenal systems, which play a key role in the pathogenesis of CHF. Conclusions. A translational model of CHF in rats was developed, which reproduced major clinical and diagnostic criteria for this disease. Morphometric, histological, biochemical, and molecular markers for progressive CHF were correlated with echocardiographic diagnostic signs, which allows using this echocardiographic, noninvasive method characterizing the intracardiac hemodynamics as a major criterion for the presence / absence of this pathology.

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