Detection of viruses in myocardial tissues by polymerase chain reaction. evidence of adenovirus as a common cause of myocarditis in children and adults

Rationale and design of the French cohort of acute myocarditis diagnosed by cardiac magnetic resonance imaging (MyocarditIRM)

BACKGROUND

Acute myocarditis usually presents as chest pain with rising troponin and normal coronary arteries. Despite frequent favourable evolution at the acute phase, it is associated with heart failure and ventricular rhythm disorders, and is considered the leading cause of sudden cardiac death in young, apparently healthy, adults. There are no specific recommendations for acute myocarditis diagnosis and management, only expert consensus, given the lack of large databases.

AIM

The main objective is to describe the contemporary presentation of acute myocarditis, its management and in-hospital outcomes. Secondary objectives are to investigate survival and event-free survival for up to 10years of follow-up, the determinants of prognosis, the modalities of treatment and follow-up and the gaps between expert consensus and real-life management.

METHODS

MyocarditIRM is a prospective multicentre cohort that enrolled 803 consecutive patients with acute myocarditis in 49 participating centres in France between 01 May 2016 and 28 February 2019. The diagnosis of acute myocarditis was acknowledged by cardiac magnetic resonance, using the Lake Louise Criteria. Exclusion criteria were age<18years, lack of health coverage, contraindication to cardiac magnetic resonance and refusal to participate. Detailed information was collected prospectively, starting at admission. Cardiac magnetic resonance imaging (diagnosis and follow-up) is analysed centrally by the certified core laboratory IHU ICAN. Ten years of follow-up for each patient is ensured by linking with the French National Health Database, and includes information on death, hospital admissions, major clinical events and drug consumption.

CONCLUSION

This prospective cohort with long-term follow-up represents the largest database on acute myocarditis worldwide, and will improve knowledge about its presentation, management and outcomes.

Innate and adaptive immunity in acute myocarditis

Acute myocarditis is an acute inflammatory cardiomyopathy associated with cardiac damage triggered by a virus or a pathological immune activation. It may present with a wide range of clinical presentations, ranging from mild symptoms to severe forms like fulminant myocarditis, characterized by hemodynamic compromise and cardiogenic shock. The immune system plays a central role in the pathogenesis of myocarditis. In fact, while its function is primarily protective, aberrant responses can be detrimental. In this context, both innate and adaptive immunity play pivotal roles; notably, the innate system offers a non-specific and immediate defense, while the adaptive provides specialized protection with immunological memory. However, dysregulation in these systems can misidentify cardiac tissue, triggering autoimmune reactions and possibly leading to significant cardiac tissue damage. This review highlights the importance of innate and adaptive immune responses in the progression and treatment of acute myocarditis.

Infectious factors in myocarditis: a comprehensive review of common and rare pathogens

BACKGROUND

Myocarditis is a significant health threat today, with infectious agents being the most common cause. Accurate diagnosis of the etiology of infectious myocarditis is crucial for effective treatment.

MAIN BODY

Infectious myocarditis can be caused by viruses, prokaryotes, parasites, and fungi. Viral infections are typically the primary cause. However, some rare opportunistic pathogens can also damage heart muscle cells in patients with immunodeficiencies, neoplasms and those who have undergone heart surgery.

CONCLUSIONS

This article reviews research on common and rare pathogens of infectious myocarditis, emphasizing the complexity of its etiology, with the aim of helping clinicians make an accurate diagnosis of infectious myocarditis.

Acute Adenoviral Infection Elicits an Arrhythmogenic Substrate Prior to Myocarditis

BACKGROUND

Viral cardiac infection represents a significant clinical challenge encompassing several etiological agents, disease stages, complex presentation, and a resulting lack of mechanistic understanding. Myocarditis is a major cause of sudden cardiac death in young adults, where current knowledge in the field is dominated by later disease phases and pathological immune responses. However, little is known regarding how infection can acutely induce an arrhythmogenic substrate before significant immune responses. Adenovirus is a leading cause of myocarditis, but due to species specificity, models of infection are lacking, and it is not understood how adenoviral infection may underlie sudden cardiac arrest. Mouse adenovirus type-3 was previously reported as cardiotropic, yet it has not been utilized to understand the mechanisms of cardiac infection and pathology.

METHODS

We have developed mouse adenovirus type-3 infection as a model to investigate acute cardiac infection and molecular alterations to the infected heart before an appreciable immune response or gross cardiomyopathy.

RESULTS

Optical mapping of infected hearts exposes decreases in conduction velocity concomitant with increased Cx43Ser368 phosphorylation, a residue known to regulate gap junction function. Hearts from animals harboring a phospho-null mutation at Cx43Ser368 are protected against mouse adenovirus type-3-induced conduction velocity slowing. Additional to gap junction alterations, patch clamping of mouse adenovirus type-3-infected adult mouse ventricular cardiomyocytes reveals prolonged action potential duration as a result of decreased IK1 and IKs current density. Turning to human systems, we find human adenovirus type-5 increases phosphorylation of Cx43Ser368 and disrupts synchrony in human induced pluripotent stem cell-derived cardiomyocytes, indicating common mechanisms with our mouse whole heart and adult cardiomyocyte data.

CONCLUSIONS

Together, these findings demonstrate that adenoviral infection creates an arrhythmogenic substrate through direct targeting of gap junction and ion channel function in the heart. Such alterations are known to precipitate arrhythmias and likely contribute to sudden cardiac death in acutely infected patients.

T-Cell Receptor Sequences Identify Combined Coxsackievirus-Streptococci Infections as Triggers for Autoimmune Myocarditis and Coxsackievirus-Clostridia Infections for Type 1 Diabetes

Recent research suggests that T-cell receptor (TCR) sequences expanded during human immunodeficiency virus and SARS-CoV-2 infections unexpectedly mimic these viruses. The hypothesis tested here is that TCR sequences expanded in patients with type 1 diabetes mellitus (T1DM) and autoimmune myocarditis (AM) mimic the infectious triggers of these diseases. Indeed, TCR sequences mimicking coxsackieviruses, which are implicated as triggers of both diseases, are statistically significantly increased in both T1DM and AM patients. However, TCRs mimicking Clostridia antigens are significantly expanded in T1DM, whereas TCRs mimicking Streptococcal antigens are expanded in AM. Notably, Clostridia antigens mimic T1DM autoantigens, such as insulin and glutamic acid decarboxylase, whereas Streptococcal antigens mimic cardiac autoantigens, such as myosin and laminins. Thus, T1DM may be triggered by combined infections of coxsackieviruses with Clostridia bacteria, while AM may be triggered by coxsackieviruses with Streptococci. These TCR results are consistent with both epidemiological and clinical data and recent experimental studies of cross-reactivities of coxsackievirus, Clostridial, and Streptococcal antibodies with T1DM and AM antigens. These data provide the basis for developing novel animal models of AM and T1DM and may provide a generalizable method for revealing the etiologies of other autoimmune diseases. Theories to explain these results are explored.

Myocarditis mortality with and without COVID-19: insights from a national registry

BACKGROUND

Myocarditis in context of a SARS-CoV-2 infection is vividly discussed in the literature. Real-world data however are sparse, and relevance of the myocarditis diagnosis to outcome in coronavirus disease (COVID-19) is unclear.

PATIENTS AND METHODS

Retrospective analysis of 75,304 patients hospitalized in Germany with myocarditis between 2007 and 2020 is reported by DESTATIS. Patients hospitalized between 01/2016 and 12/2019 served as reference cohort for the COVID-19 patients hospitalized in 2020.

RESULTS

A total of 75,304 patients were hospitalized between 2007 and 2020 (age 42.5 years, 30.1% female, hospital mortality 2.4%). In the reference cohort, 24,474 patients (age 42.8 years, 29.5% female, hospital mortality 2.2%) were registered. In 2020, annual myocarditis hospitalizations dropped by 19.6% compared to reference (4921 vs. 6119 annual hospitalization), of which 443/4921 (9.0%) were connected to COVID-19. In 2020, hospital mortality of myocarditis in non-COVID-19 patients increased significantly compared to reference (2.9% vs. 2.2%, p = 0.008, OR 1.31, 95% CI 1.08-1.60). In COVID-19 myocarditis, hospital mortality was even higher compared to reference (13.5% vs. 2.2%, p < 0.001, OR 6.93, 95% CI 5.18-9.18).

CONCLUSION

The burden of patients with myocarditis and COVID-19 in 2020 was low. Hospital mortality was more than sixfold higher in patients with myocarditis and COVID-19 compared to those with myocarditis but without COVID-19.

Successful treatment of fulminant myocarditis due to COVID-19 in a 5-year-old girl

Reports of acute myocarditis are increasing due to the worldwide spread of coronavirus disease 2019 (COVID-19). We report a case of a 5-year-old girl with fulminant myocarditis caused by COVID-19, who was successfully treated with veno-arterial extracorporeal membrane oxygenation (VA-ECMO). The unvaccinated patient had developed fever 1 week before attending our hospital and was "presumptive positive" for COVID-19 based on the surrounding infectious situation. The fever resolved, but the day before the visit, abdominal pain appeared. The patient visited her previous physician with vomiting as the main complaint. She was transferred to our hospital due to impaired consciousness and bradycardia, with a heart rate of 40 beats/min. Immediately after transfer, she was diagnosed with complete atrioventricular (AV) block and was scheduled to undergo percutaneous pacing lead insertion. However, the patient had ventricular tachycardia, AV block and hypotension intraoperatively and required cardiopulmonary resuscitation. The patient was in an extremely unstable circulatory state, and VA-ECMO was urgently introduced. After multidisciplinary treatment for acute myocarditis, waiting for an improvement in AV block, and recovery of cardiac function, the patient was weaned from VA-ECMO on the eighth day after admission. The patient was discharged with no cardiac or neurologic sequelae.

Learning objective

The rapid introduction of veno-arterial extracorporeal membrane oxygenation for fulminant myocarditis caused by coronavirus disease 2019 (COVID-19) in young children is extremely effective. Vaccination may be important for preventing infection with COVID-19 and avoiding severe complications.

Prostaglandin E2 and myocarditis; friend or foe?

This review article summarizes the role of prostaglandin E2 (PGE2) and its receptors (EP1-EP4) as it relates to the inflammatory cardiomyopathy, myocarditis. During the COVID-19 pandemic, the onset of myocarditis in a subset of patients prompted a debate on the use of nonsteroidal anti-inflammatory drugs (NSAIDs), like ibuprofen, which act to inhibit the actions of prostaglandins. This review aims to further understanding of the role of PGE2 in the pathogenesis or protection of the myocardium in myocarditis. Inflammatory cardiomyopathies encompass a broad spectrum of disorders, all characterized by cardiac inflammation. Therefore, for the purpose of this review, the authors have placed particular emphasis on etiologies of myocarditis where effects of PGE2 have been documented.

Cardiac arrhythmias in viral infections

BACKGROUND

The current COVID-19 pandemic has led to many studies examining its arrhythmogenic effects. However, there are many other viruses that are capable of inducing arrhythmias that have not received as much attention. The objective of this study was to review common viruses and identify studies highlighting their arrhythmogenic effects.

METHODS AND RESULTS

In this review, we examined 15 viruses and the literature regarding their arrhythmogenic effects. The common mechanisms of action appear to be direct invasion of myocytes leading to immune mediated damage, infection of vascular endothelium, and alteration of cardiac ion channels.

CONCLUSIONS

This review highlights the growing evidence that supports the involvement of other viral infections in the development of arrhythmia. Physicians should be aware of these potentially life-threatening effects when caring for patients with these viruses, some of which are very common. Additional studies are required to better understand the complex mechanism and risk factors of cardiac arrhythmias in patients suffered from viral infections to determine whether the processes can be reversed or even prevented.

A teenager with adenoviral myocarditis mimicking hypertrophic cardiomyopathy

A 14-year-old previously healthy female presented with chest pain and dyspnoea for 2 days in the setting of a recent upper respiratory infection. She had elevated inflammatory markers and troponin, resulting in the diagnosis of acute myocarditis. Transthoracic echocardiography demonstrated mild systolic dysfunction and a moderate pericardial effusion. Additionally, her echocardiogram showed concentric left ventricular hypertrophy raising concern for hypertrophic cardiomyopathy. She was treated with intravenous immunoglobulin. Serial echocardiograms revealed rapid resolution of her ventricular hypertrophy. Cardiac magnetic resonance confirmed the diagnosis of myocarditis.

Detection of Parvovirus B19 genome in human heart tissue samples

OBJECTIVE

Identifying viral genomes in human heart tissues is critical for disease diagnosis and assessment of cardiovascular damage. Human heart tissue samples obtained during a biopsy procedure are routinely used to test for the presence of viruses, as guided by clinical manifestations and prognosis. Furthermore, heart tissue samples obtained post-mortem or during a cardiac transplant procedure serve as a valuable research tool, as they allow for an in-depth assessment of cardiac pathology that can aid in our understanding of molecular pathways associated with disease. Because viral nucleic acid constitutes only a small portion of each sample's genetic material, appropriate methods are necessary for positive viral genome identification.

RESULTS

Snap-frozen heart tissue samples obtained either post-mortem or during a cardiac transplant procedure were used to develop conditions for detection of Parvovirus B19. Briefly, total DNA was isolated from the heart tissue under varying conditions. A PCR-based assay with Parvovirus B19 specific primers was implemented to detect the presence of the viral genome, followed by Sanger Sequencing. The mechanical disruption of the heart tissue, as well as the cardiac tissue processing methods, had a significant effect on the DNA quality and the ability to detect the Parvovirus B19 genome.

Navigating paediatric virology through the COVID‑19 era (Review)

The present review article presents the key messages of the 8th Workshop on Paediatric Virology organised virtually by the Institute of Paediatric Virology based on the island of Euboea in Greece. The major topics covered during the workshop were the following: i) New advances in antiviral agents and vaccines against cytomegalovirus; ii) hantavirus nephropathy in children; iii) human rhinovirus infections in children requiring paediatric intensive care; iv) complications and management of human adenovirus infections; v) challenges of post‑coronavirus disease 2019 (COVID‑19) syndrome in children and adolescents; and vi) foetal magnetic resonance imaging in viral infections involving the central nervous system. The COVID‑19 era requires a more intensive, strategic, global scientific effort in the clinic and in the laboratory, focusing on the diagnosis, management and prevention of viral infections in neonates and children.

Advancing Precision Medicine in Myocarditis: Current Status and Future Perspectives in Endomyocardial Biopsy-Based Diagnostics and Therapeutic Approaches

The diagnosis and specific and causal treatment of myocarditis and inflammatory cardiomyopathy remain a major clinical challenge. Despite the rapid development of new imaging techniques, endomyocardial biopsies remain the gold standard for accurate diagnosis of inflammatory myocardial disease. With the introduction and continued development of immunohistochemical inflammation diagnostics in combination with viral nucleic acid testing, myocarditis diagnostics have improved significantly since their introduction. Together with new technologies such as miRNA and gene expression profiling, quantification of specific immune cell markers, and determination of viral activity, diagnostic accuracy and patient prognosis will continue to improve in the future. In this review, we summarize the current knowledge on the pathogenesis and diagnosis of myocarditis and inflammatory cardiomyopathies and highlight future perspectives for more in-depth and specialized biopsy diagnostics and precision, personalized medicine approaches.

Myocardial Function in Fetuses with Congenital Cytomegalovirus Infection

INTRODUCTION

The objective of this study was to investigate myocardial deformation of left (LV) and right ventricle (RV) using 2-dimensional speckle-tracking echocardiography (2D-STE) in fetuses with and without congenital cytomegalovirus (CMV) infection.

METHODS

This was a prospective single-center study. Vertical transmission was defined by a positive CMV polymerase chain reaction (PCR) test on the amniotic fluid or on the neonate's urine. Fetuses were divided into group 1 and group 2 if CMV-PCR was positive or negative, respectively. LV and RV global longitudinal strain (GLS) values were obtained and adjusted for gestational age by calculating Z-scores. Univariate analysis was carried out to compare cardiac indices between group 1 and group 2.

RESULTS

Fetuses from group 1 (n = 11) had a significantly lower LV myocardial shortening than those from group 2 (n = 32). GLS was -20.7 ± 5.2% and -26.3 ± 4.1%, respectively (p = 0.001). Similarly, GLS Z-score was lower (0.02 ± 0.72) in group 1 than in group 2 (-0.80 ± 0.59) (p = 0.001). Similarly, RV GLS Z-score was significantly impaired in group 1 compared to group 2 (-0.44 ± 1.03 vs. -1.04 ± 0.71, p = 0.041).

CONCLUSION

Fetuses with congenital CMV showed subclinical biventricular myocardial dysfunction. Further studies are needed to confirm the potential role of 2D-STE in identifying fetuses with congenital CMV at risk of postnatal cardiovascular morbidities.

Autoimmune Heart Disease: A Comprehensive Summary for Forensic Practice

Autoimmune heart disease is a non-random condition characterised by immune system-mediated aggression against cardiac tissue. Cardiac changes often exhibit nonspecific features and, if unrecognised, can result in fatal outcomes even among seemingly healthy young individuals. In the absence of reliable medical history, the primary challenge lies in differentiating between the various cardiopathies. Numerous immunohistochemical and genetic studies have endeavoured to characterise distinct types of cardiopathies, facilitating their differentiation during autopsy examinations. However, the presence of a standardised protocol that forensic pathologists can employ to guide their investigations would be beneficial. Hence, this summary aims to present the spectrum of autoimmune cardiopathies, including emerging insights such as SARS-CoV-2-induced cardiopathies, and proposes the utilisation of practical tools, such as blood markers, to aid forensic pathologists in their routine practice.

Rare case of subacute herpetic myocarditis

Viruses represent the main cause, especially in developed countries. Coxsackie and echoviruses are the most common cardiotropic viruses causing myocarditis. Herpes simplex virus-induced myocarditis is uncommon, and few cases of Herpes simplex virus (HSV) type II have been reported to date. This article presents a rare case of subacute herpetic myocarditis in a 35-year-old male patient.

Myocarditis: Etiology, Pathogenesis, and Their Implications in Clinical Practice

Myocarditis is an inflammatory disease of the myocardium caused by infectious or non-infectious agents. It can lead to serious short-term and long-term sequalae, such as sudden cardiac death or dilated cardiomyopathy. Due to its heterogenous clinical presentation and disease course, challenging diagnosis and limited evidence for prognostic stratification, myocarditis poses a great challenge to clinicians. As it stands, the pathogenesis and etiology of myocarditis is only partially understood. Moreover, the impact of certain clinical features on risk assessment, patient outcomes and treatment options is not entirely clear. Such data, however, are essential in order to personalize patient care and implement novel therapeutic strategies. In this review, we discuss the possible etiologies of myocarditis, outline the key processes governing its pathogenesis and summarize best available evidence regarding patient outcomes and state-of-the-art therapeutic approaches.

Imaging for Cardiovascular Complications of COVID-19: Cardiac Manifestations in Context

After the first confirmed case in 2019, COVID-19 rapidly spread worldwide and overwhelmed the medical community. In the intervening time, we have learned about COVID-19's clinical manifestations and have developed effective therapies and preventative vaccines. Severe COVID-19 infection is associated with many cardiovascular disorders in the acute phase, and patients recovered from illness can also manifest long-term sequelae, including long COVID syndrome. Furthermore, severe acute respiratory syndrome-related coronavirus-2 messenger RNA (mRNA) vaccination can trigger rare cases of myopericarditis. We have gained significant knowledge of the acute and long-term cardiovascular complications of COVID-19- and mRNA vaccine-associated myocarditis through clinical and investigative studies using cardiac imaging. In this review, we describe how cardiovascular imaging can be used to understand the cardiovascular complications and cardiac injury associated with acute COVID-19 infection, review the imaging findings in patients recovered from illness, and discuss the role and limitations of cardiac imaging in COVID-19 mRNA vaccine-associated myocarditis.

Associations of adenovirus-reactive immunoglobulins with atrial fibrillation and body mass index

Adenovirus (AdV) has been suggested to be involved in pathogenesis of atrial fibrillation (AF). We aimed to evaluate an association between AdV-specific immunoglobulins G in the serum (AdV-IgG) and AF. The present case-control study comprised two cohorts, including cohort 1 of patients with AF and cohort 2 of asymptomatic subjects. Initially, two groups, MA and MB, were selected from the cohorts 1 and 2, respectively, for serum proteome profiling using an antibody microarray to identify possible relevant protein targets. The data of microarray analysis indicated a possible overall increase in the total adenovirus signals in the group MA vs. group MB, suggesting potential relevance of adenoviral infection to AF. Then, the groups A (with AF) and B (control) were selected from the cohorts 1 and 2, respectively, to assay the presence and levels of AdV-IgG- by ELSA. The prevalence of AdV-IgG-positive status demonstrated a 2-fold increase in the group A (AF) compared with that in the group B (asymptomatic subjects); odds ratio 2.06 (95%CI: 1.11-3.84; P = 0.02). The prevalence of obesity demonstrated an approximately 3-fold increase in AdV-IgG-positive patients of the group A compared with that in AdV-IgG-negative patients of the same group A (odds ratio 2.7; 95% CI: 1.02-7.1; P = 0.04). Thus, AdV-IgG-positive reactivity was independently associated with AF, and AF was independently associated with BMI, indicating that adenoviral infection may be a possible etiological factor for AF.

Role of Coxsackievirus B3-Induced Immune Responses in the Transition from Myocarditis to Dilated Cardiomyopathy and Heart Failure

Dilated cardiomyopathy (DCM) is a cardiac disease marked by the stretching and thinning of the heart muscle and impaired left ventricular contractile function. While most patients do not develop significant cardiac diseases from myocarditis, disparate immune responses can affect pathological outcomes, including DCM progression. These altered immune responses, which may be caused by genetic variance, can prolong cytotoxicity, induce direct cleavage of host protein, or encourage atypical wound healing responses that result in tissue scarring and impaired mechanical and electrical heart function. However, it is unclear which alterations within host immune profiles are crucial to dictating the outcomes of myocarditis. Coxsackievirus B3 (CVB3) is a well-studied virus that has been identified as a causal agent of myocarditis in various models, along with other viruses such as adenovirus, parvovirus B19, and SARS-CoV-2. This paper takes CVB3 as a pathogenic example to review the recent advances in understanding virus-induced immune responses and differential gene expression that regulates iron, lipid, and glucose metabolic remodeling, the severity of cardiac tissue damage, and the development of DCM and heart failure.

Optimising the ECMO treatment regimen increases the survival rate for adult patients with acute fulminant myocarditis: A single-centre retrospective cohort study

Background

Applying Extracorporeal membrane oxygenation (ECMO) to patients with acute fulminant myocarditis (AFM) reduces their mortality. The survival rate is 55.6-71.9% for adult AFM patients, which is lower than that for paediatric patients (63-81%). In our centre, the survival rate of ECMO for adult patients with AFM was 66.7% from January 2003 to 2012. In January 2013, the therapeutic regimen was optimised, and then the survival rate increased to 89.1% by January 2022. This article analyses the reasons for the improved survival rate following the optimisation of treatment protocols.

Methods

The data for adult patients with AFM who underwent ECMO for a poor response conventional treatment from January 2003 to January 2022 were reviewed. According to different treatment regimens, the AFM patients were divided into an old and a new regimen group. Univariate and multivariate logistic regression analyses were performed on the data before and after ECMO.

Results

Fifty-five patients were enrolled in the age (31.2 ± 11.3), including 24 males. Forty-nine patients were weaned successfully from ECMO [duration: (4.1 ± 1.8) d], all of whom were discharged from the hospital, with a survival rate of 89.1%. Compared with the old regimen group, the new regimen group had a shorter duration of shock to ECMO, a lower proportion of patients receiving extracorporeal cardiopulmonary resuscitation (ECPR), a lower Vasoactive Inotropic Score (VIS), and lower levels of lactic acid, and high-sensitivity troponin T before ECMO (p &lt; 0.05). Compared with the old regimen group, after ECMO, the new regimen group had lower ECMO flow, lower proportion of left ventricular dilation and lower limb ischemia injury, the duration of ECMO was shorter, and significantly improved the survival rate, the difference was statistically significant (P &lt; 0.05). The duration of shock to ECMO and VIS before ECMO were independent risk factors for the survival rate (p &lt; 0.05).

Conclusion

Early ECMO initiation in adult AFM patients with a poor response to conventional therapy and low-flow ECMO to meet metabolic needs can reduce serious complications affecting the prognosis, may be associated with better outcomes.

Transcriptomic profiling of cardiac tissues from SARS-CoV-2 patients identifies DNA damage

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is known to present with pulmonary and extra-pulmonary organ complications. In comparison with the 2009 pandemic (pH1N1), SARS-CoV-2 infection is likely to lead to more severe disease, with multi-organ effects, including cardiovascular disease. SARS-CoV-2 has been associated with acute and long-term cardiovascular disease, but the molecular changes that govern this remain unknown. In this study, we investigated the host transcriptome landscape of cardiac tissues collected at rapid autopsy from seven SARS-CoV-2, two pH1N1, and six control patients using targeted spatial transcriptomics approaches. Although SARS-CoV-2 was not detected in cardiac tissue, host transcriptomics showed upregulation of genes associated with DNA damage and repair, heat shock, and M1-like macrophage infiltration in the cardiac tissues of COVID-19 patients. The DNA damage present in the SARS-CoV-2 patient samples, were further confirmed by γ-H2Ax immunohistochemistry. In comparison, pH1N1 showed upregulation of interferon-stimulated genes, in particular interferon and complement pathways, when compared with COVID-19 patients. These data demonstrate the emergence of distinct transcriptomic profiles in cardiac tissues of SARS-CoV-2 and pH1N1 influenza infection supporting the need for a greater understanding of the effects on extra-pulmonary organs, including the cardiovascular system of COVID-19 patients, to delineate the immunopathobiology of SARS-CoV-2 infection, and long term impact on health.

Pathophysiological Mechanisms of Cardiac Dysfunction in Transgenic Mice with Viral Myocarditis

Viral myocarditis is pathologically associated with RNA viruses such as coxsackievirus B3 (CVB3), or more recently, with SARS-CoV-2, but despite intensive research, clinically proven treatment is limited. Here, by use of a transgenic mouse strain (TG) containing a CVB3ΔVP0 genome we unravel virus-mediated cardiac pathophysiological processes in vivo and in vitro. Cardiac function, pathologic ECG alterations, calcium homeostasis, intracellular organization and gene expression were significantly altered in transgenic mice. A marked alteration of mitochondrial structure and gene expression indicates mitochondrial impairment potentially contributing to cardiac contractile dysfunction. An extended picture on viral myocarditis emerges that may help to develop new treatment strategies and to counter cardiac failure.

Monkeypox-Induced Myocarditis: A Systematic Review

Monkeypox virus has emerged in different parts of the world with varying clinical symptoms and outcomes. To date, only a few studies have reported cardiac manifestations among monkeypox-infected patients. We aim to systematically evaluate the symptoms, imaging findings, management, and outcomes among monkeypox-induced myocarditis patients. We conducted a systematic literature search in PubMed, Embase, and Scopus from inception till 5th January 2023 by using predefined MESH terms and "AND" and "OR." The following search terms were used: "monkeypox virus" AND "myocarditis." A total of 6 studies with 9 monkeypox-induced myocarditis patients were included in this analysis. The mean age of patients was 33.6 years, with all being male patients. The most common symptoms were fever (89%) and chest pain (100%). Electrocardiogram findings showed 44% of patients had ST-elevation, and 22% had sinus tachycardia. The echocardiographic findings show a mean ejection fraction of 52.14%, while 57% of patients had preserved ejection fraction, and 67% had normal wall motion. Cardiac magnetic resonance findings show 40% of patients had late gadolinium enhancement, and 40% had edema. Management of patients was primarily supportive (33%), and 33% of patients were administered Beta blockers and ACE inhibitors. Overall all patients survived with a good prognosis. Our study's findings show that all cases were reported among male patients with the most common symptoms of chest pain. The overall prognosis was good, with no mortality reported. Infected patients complaining of chest pain should not be ignored, and proper investigation of myocarditis must be considered.

Successful rescue of fulminant myocarditis with mechanical circulatory support and immunosuppression therapy: A case report

Myocarditis is challenging to diagnose because of its various clinical manifestations. Fulminant myocarditis (FM) is a severe type of myocarditis characterized by heart failure, malignant arrhythmia, cardiogenic shock, and cardiac arrest. Its early diagnosis and timely treatment are crucial for a positive long-term prognosis. Here we report a case of 42-year-old woman who presented with fever, chest pain, and cardiogenic shock. An initial examination showed increased myocardial enzyme levels and diffuse ST-segment elevation. Urgent coronary angiography excluded coronary artery stenosis. Echocardiography revealed decreased left ventricular systolic function. Cardiac magnetic resonance imaging revealed cardiomyocyte necrosis and interstitial inflammatory edema. The patient was diagnosed with FM and administered antiviral and anti-infective agents, glucocorticoid, immunoglobulin, and supported with temporary cardiac pacemaker and positive airway therapy, and treated with continuous renal replacement therapy. As her clinical condition deteriorated rapidly, we immediately started an intra-aortic balloon pump and veno-arterial extracorporeal membrane oxygenation. She was discharged on day 15 and recovered normally during follow-up. The early initiation of mechanical circulatory support and immunosuppression are life-saving tools for the treatment of FM.

Comparison of clinical, laboratory and radiological characteristics between Chlamydia psittaci and adenovirus pneumonias: a multicenter retrospective study

OBJECTIVES

Pneumonia caused by Chlamydia psittaci is a significant global public health issue. Symptom onset and laboratory characteristics may be confused with those of other respiratory viral infections, including adenovirus pneumonia. We aimed to determine differences in clinical presentations and establish a simple nomogram to differentiate C. psittaci and adenovirus pneumonias.

METHODS

We conducted a multicenter retrospective study in 10 tertiary general hospitals to compare patients with either C. psittaci (n = 78) or adenovirus (n = 102) pneumonia. A multivariable logistic regression model was used to identify risk factors of C. psittaci pneumonia that were used to establish a nomogram.

RESULTS

C. psittaci and adenovirus pneumonia showed certain similar clinical symptoms, including fever, dyspnea, and fatigue, but differed in other characteristics. The multivariate logistic regression showed that age, sex, nervous system symptoms, lymphocyte count, C-reactive protein level, and bilateral lung lesions were risk factors for C. psittaci pneumonia. After incorporating these six factors, the established nomogram achieved a good concordance value (0.949 [95% CI 0.917-0.982]) in differentiating the types of pneumonia, with well-fitting calibration curves.

CONCLUSION

Despite having similar clinical features, the variables of age, sex, nervous system symptoms, lymphocytes, C-reactive protein levels, and bilateral lung lesions were combined into a clinically useful nomogram for the rapid and early differentiation of C. psittaci pneumonia from adenovirus pneumonia. This nomogram may help improve treatments and clinical outcomes.

A Comprehensive Review of Dilated Cardiomyopathy in Pre-clinical Animal Models in Addition to Herbal Treatment Options and Multi-modality Imaging Strategies

Dilated cardiomyopathy (DCM) is distinguished by ventricular chamber expansion, systolic dysfunction, and normal left ventricular (LV) wall thickness, and is mainly caused due to genetic or environmental factors; however, its aetiology is undetermined in the majority of patients. The focus of this work is on pathogenesis, small animal models, as well as the herbal medicinal approach, and the most recent advances in imaging modalities for patients with dilated cardiomyopathy. Several small animal models have been proposed over the last few years to mimic various pathomechanisms that contribute to dilated cardiomyopathy. Surgical procedures, gene mutations, and drug therapies are all characteristic features of these models. The pros and cons, including heart failure stimulation of extensively established small animal models for dilated cardiomyopathy, are illustrated, as these models tend to procure key insights and contribute to the development of innovative treatment techniques for patients. Traditional medicinal plants used as treatment in these models are also discussed, along with contemporary developments in herbal therapies. In the last few decades, accurate diagnosis, proper recognition of the underlying disease, specific risk stratification, and forecasting of clinical outcome, have indeed improved the health of DCM patients. Cardiac magnetic resonance (CMR) is the bullion criterion for assessing ventricular volume and ejection fraction in a reliable and consistent direction. Other technologies, like strain analysis and 3D echocardiography, have enhanced this technique's predictive and therapeutic potential. Nuclear imaging potentially helps doctors pinpoint the causative factors of left ventricular dysfunction, as with cardiac sarcoidosis and amyloidosis.

Persistent viral infections and their role in heart disease

Viral infections are the culprit of many diseases, including inflammation of the heart muscle, known as myocarditis. Acute myocarditis cases have been described in scientific literature, and viruses, such as parvovirus B19, coxsackievirus B3, or more recently, SARS-CoV-2, were the direct cause of cardiac inflammation. If not treated, myocarditis could progress to dilated cardiomyopathy, which permanently impairs the heart and limits a person's lifespan. Accumulated evidence suggests that certain viruses may persist in cardiac tissue after the initial infection, which could open up the door to reactivation under favorable conditions. Whether this chronic infection contributes to, or initiates, cardiac damage over time, remains a pressing issue in the field of virus-induced heart pathology, and it is directly tied to patients' treatment. Previously, large case studies found that a few viruses: parvovirus B19, coxsackievirus, adenovirus, human herpesvirus 6, cytomegalovirus and Epstein-Barr virus, are most commonly found in human endomyocardial biopsy samples derived from patients experiencing cardiac inflammation, or dilated cardiomyopathy. SARS-CoV-2 infection has also been shown to have cardiovascular consequences. This review examines the role of viral persistence in cardiac inflammation and heart disease, and discusses its implications for patients' outcomes.

CMV-associated carditis in a 5-month-old child

The article presents a case of cytomegalovirus-associated carditis in a 5-month-old child. Carditis proceeded in an arrhythmic form and was manifested by frequent ventricular extrasystoles. An increase in the activity of creatine-phosphokinase was noted in the blood. The isolation of cytomegalovirus DNA from the blood, as well as IgM and IgG to cytomegalovirus, made it possible to associate the development of carditis with IgG to cytomegalovirus. Carditis in a child proceeded without signs of heart failure. After diagnostic and therapeutic procedures, the child was discharged home. This case shows that one of the possible causes of carditis in children is cytomegalovirus, which necessitates testing for markers of active cytomegalovirus infection. In this age group, it is possible to register both congenital and acquired variants of infection with heart damage, having different treatment regimens and prognosis. 

A case report of severe systemic herpes simplex virus-1 (HSV-1) infection with multi-organ involvement after a course of oral corticosteroid treatment

Background

Herpes simplex virus (HSV) rarely causes organ-invasive infection. Diagnosis and treatment for such infections are often delayed, and mortality is high. We present the first reported case of disseminated HSV-1 infection in an adult causing liver failure, myocarditis, and encephalitis in a patient who recovered after receiving parenteral acyclovir treatment.

Case presentation

A 46-year-old female presented with fever, chills, and malaise after 2 weeks of oral corticosteroid treatment for uveitis. She was diagnosed with disseminated HSV-1 infection with multi-organ involvement causing hepatitis, encephalitis, and myocarditis. Diagnosis was made timely using serum polymerase chain reaction (PCR) for HSV DNA and the patient was given intravenous acyclovir treatment promptly, which led to her survival without significant morbidity.

Conclusions

Clinicians should have a low threshold for suspecting HSV infection and ordering HSV PCR to decrease morbidity and mortality when there is a high clinical suspicion of systemic HSV infection with multi-organ involvement. Serum PCR for HSV DNA is an excellent modality for an initial diagnostic approach. Further research is warranted to elucidate causality between a course of corticosteroid therapy and systemic HSV-1 infection without major immunosuppressive comorbidities or treatments.

Successful treatment of fulminant myocarditis with intra-aortic balloon pump counterpulsation combined with immunoglobulin and glucocorticoid in a young male adult

Background

Fulminant myocarditis (FM) is a serious non-specific inflammatory disease of the myocardium. FM tends to occur in adolescents and the course of the disease progresses rapidly. It is prone to cardiogenic shock (CGS) and multiple organ failure (MOF) with high mortality. We report a case of FM with CGS and MOF in a young male who was successfully treated with intra-aortic balloon pump counterpulsation (IABP) combined with intravenous immunoglobulin (IVIG) and glucocorticoid (GC).

Case summary

A 21-year-old previously healthy man presented with fever, headache, and chest tightness. He came to the hospital for emergency treatment. The laboratory data showed that the levels of serum cardiac troponin I (cTnI), N-terminal B-type natriuretic peptide (NT-proBNP), myocardial zymogram, and neutrophils increased. Echocardiography showed pericardial effusion and decreased left ventricular systolic function. ECG showed diffuse ST-segment elevation. He was clinically diagnosed with FM and admitted to the intensive care unit for treatment. Within 48 h of admission, the clinical course of the patient deteriorated rapidly, with CGS accompanied by MOF, high atrioventricular block (AVB), and ventricular tachycardia (VT). After using mechanical circulatory support (MCS) therapy with IABP, IVIG, GC, continuous renal replacement therapy (CRRT), and mechanical ventilation complicated with a temporary cardiac pacemaker, he recovered normal cardiac function. He made a full recovery and was discharged home on day 21.

Discussion

For patients with FM, early diagnosis, close monitoring, timely use of MCS devices, and active comprehensive treatment are very important. MCS devices such as IABP can become lifesaving tools for the treatment of FM.

Influenza myocarditis in paediatric patients

Acute myocarditis is a rare but potentially fatal disease. Endomyocardial biopsy and histologic examination are key to an accurate diagnosis. Despite being an uncommon cause, Influenza A and B viruses are a well-documented aetiology. Myocarditis may complicate about 0 to 10% of influenza virus infections (0.4 to 5% in paediatric cases). The clinical presentation varies widely, from ischemic-like chest pain to fulminant myocarditis with acute hemodynamic compromise, requiring mechanical circulatory support, with high mortality in the acute phase. We report a series of paediatric patients with myocarditis due to Influenza virus, to emphasize the importance of considering this uncommon aetiology.

Myocarditis Following COVID-19 Vaccine Use: Can It Play a Role for Conditioning Immunization Schedules?

Myocarditis (MYO) is a relatively uncommon inflammatory disease that involves the heart muscle. It can be a very severe disease as it can lead to the development of acute or chronic heart failure and, in a not marginal number of cases, to death. Most of the cases are diagnosed in healthy people younger than 30 years of age. Moreover, males are affected about twice as much as females. Viruses are among the most common causes of MYO, but how viral infection can lead to MYO development is not precisely defined. After COVID-19 pandemic declaration, incidence rate of MYO has significantly increased worldwide because of the SARS-CoV-2 infection. After the introduction of anti-COVID-19 vaccines, reports of post-immunization MYO have emerged, suggesting that a further cause of MYO together with the SARS-CoV-2 infection could increase the risk of heart damage during pandemic. Main aim of this study is to discuss present knowledge regarding etiopathogenesis and clinical findings of MYO associated with COVID-19 vaccine administration and whether the risk of this adverse events can modify the initially suggested recommendation for the use of COVID-19 vaccines in pediatric age. Literature analysis showed that MYO is an adverse event that can follow the COVID-19 immunization with mRNA vaccines in few persons, particularly young adults, adolescents, and older children. It is generally a mild disease that should not modify the present recommendations for immunization with the authorized COVID-19 mRNA vaccines. Despite this, further studies are needed to evaluate presently undefined aspects of MYO development after COVID-19 vaccine administration and reduce the risk of development of this kind of vaccine complication. Together with a better definition of the true incidence of MYO and the exact role of the various factors in conditioning incidence variations, it is essential to establish long-term evolution of acute COVID-19 related MYO.

Neurological Manifestations of Myocarditis

PURPOSE OF REVIEW

The present review discusses the neurological complications associated with myocarditis of different etiologies.

RECENT FINDINGS

Myocarditis can be idiopathic or caused by different conditions, including toxins, infections, or inflammatory diseases. Clinical findings are variable and range from mild self-limited shortness of breath or chest pain to hemodynamic instability which may result in cardiogenic shock and death. Several neurologic manifestations can be seen in association with myocarditis. Tissue remodeling, fibrosis, and myocyte dysfunction can result in heart failure and arrhythmias leading to intracardiac thrombus formation and cardioembolism. In addition, peripheral neuropathies, status epilepticus, or myasthenia gravis have been reported in association with specific types of myocarditis. Multiple studies suggest the increasing risk of neurologic complications in patients with myocarditis. Neurologists should maintain a high suspicion of myocarditis in cases presenting with both cardiovascular and neurological dysfunction without a clear etiology.

Influenza virus replication in cardiomyocytes drives heart dysfunction and fibrosis

Cardiac dysfunction is a common complication of severe influenza virus infection, but whether this occurs due to direct infection of cardiac tissue or indirectly through systemic lung inflammation remains unclear. To test the etiology of this aspect of influenza disease, we generated a novel recombinant heart-attenuated influenza virus via genome incorporation of target sequences for miRNAs expressed in cardiomyocytes. Compared with control virus, mice infected with miR-targeted virus had significantly reduced heart viral titers, confirming cardiac attenuation of viral replication. However, this virus was fully replicative in the lungs and induced similar systemic inflammation and weight loss compared to control virus. The miR-targeted virus induced fewer cardiac conduction irregularities and significantly less fibrosis in mice lacking interferon-induced transmembrane protein 3 (IFITM3), which serve as a model for influenza-associated cardiac pathology. We conclude that robust virus replication in the heart is required for pathology, even when lung inflammation is severe.

Pediatric Myocarditis: What Have We Learnt So Far?

Myocarditis is an inflammatory disease of the myocardium that is troublesome to diagnose and manage, especially in children. Since the introduction of endomyocardial biopsy (EMB), new diagnostic tools have provided useful data. Especially when enhanced with immunohistochemistry and polymerase chain reaction (PCR) studies, EMB remains the gold standard for the diagnosis. Notably, cardiac magnetic resonance (MRI) is a non-invasive tool that can confirm the diagnosis and has a particular usefulness during the follow-up. The causes of myocarditis are heterogeneous (mostly viral in children). The course and outcome of the illness in the pediatric population represent a complex interaction between etiologic agents and the immune system, which is still not fully understood. The clinical presentation and course of myocarditis vary widely from paucisymptomatic illness to acute heart failure refractory to therapy, arrhythmias, angina-like presentation and sudden cardiac death. In this setting, cardiac biomarkers (i.e., troponins and BNP), although unspecific, can be used to support the diagnosis. Finally, the efficacy of therapeutic strategies is controversial and not confirmed by clinical trials. In this review, we summarized the milestones in diagnosis and provided an overview of the therapeutic options for myocarditis in children.

COVID-19 Myocarditis: An Emerging Clinical Conundrum

Coronavirus Disease 2019 (COVID-19) has been a significant cause of global mortality and morbidity since it was first reported in December 2019 in Wuhan, China. COVID19 like previous coronaviruses primarily affects the lungs causing pneumonia, interstitial pneumonitis, and severe acute respiratory distress syndrome (ARDS). However, there is increasing evidence linking COVID-19 to cardiovascular complications such as arrhythmias, heart failure, cardiogenic shock, fulminant myocarditis, and cardiac death. Given the novelty of this virus, there is paucity of data on some cardiovascular complications of COVID-19, specifically myocarditis. Myocarditis is an inflammatory disease of the heart muscle with a heterogenous clinical presentation and progression. It is mostly caused by viral infections and is the result of interaction of the virus and the host's immune system. There have been several case reports linking COVID-19 with myocarditis, however the true mechanism of cardiac injury remains under investigation. In this paper we review the clinical presentation, proposed pathophysiology, differential diagnoses and management of myocarditis in COVID-19 patients.

Predictors of relapse, death or heart transplantation in myocarditis before the introduction of immunosuppression: negative prognostic impact of female gender, fulminant onset, lower ejection fraction and serum autoantibodies

AIMS

Outcome predictors in myocarditis are not well defined; we aimed at identifying predictors of death, heart transplantation (HTx) and relapse before the introduction of immunosuppression.

METHODS AND RESULTS

From 1992 to 2012 we consecutively included 466 patients (68% male, 37±17 years, single centre recruitment, median follow-up 50 months), 216 with clinically suspected and 250 with biopsy (Bx)-proven myocarditis. Serum anti heart (AHA) and antiintercalated disk (AIDA) auto-antibodies were measured by indirect immunofluorescence. We performed univariable and multivariable analysis of clinical and diagnostic features at diagnosis. Survival free from death or HTx at 10 years was 83% in the whole group and was lower in Bx- proven vs. clinically suspected myocarditis (76% vs 94% respectively, p<0.001). Female gender (hazard ratio (HR) 2.7, 95% Confidence Intervals (CI) 1.1-6.5), fulminant presentation (HR 13.77, CI 9.7-261.73), high-titre organ-specific AHA (HR 4.2, CI 1.2-14.7) and anti-nuclear antibodies (ANA) (HR 5.2, CI 2.1-12.8) were independent predictors of death or HTx; higher echocardiographic left ventricular ejection fraction (LVEF) at diagnosis was protective, with a 0.93 times risk reduction for each 1% LVEF increase (CI 0.89-0.96). History of myocarditis at diagnosis (HR 8.5, CI 3.5-20.7) was independent predictor of myocarditis relapse at follow-up; older age was protective (HR 0.95, CI 0.91-0.99). Predictors of death, HTx and relapse did not differ in Bx-proven vs. clinically suspected myocarditis.

CONCLUSIONS

Young age and a previous myocarditis were independent relapse predictors; female gender, fulminant onset, lower LVEF at presentation and high-titre organ-specific AHA and ANA were independent predictors of death and HTx, suggesting that autoimmune features predict worse prognosis.

Immunomodulating Therapies in Acute Myocarditis and Recurrent/Acute Pericarditis

The field of inflammatory disease of the heart or "cardio-immunology" is rapidly evolving due to the wider use of non-invasive diagnostic tools able to detect and monitor myocardial inflammation. In acute myocarditis, recent data on the use of immunomodulating therapies have been reported both in the setting of systemic autoimmune disorders and in the setting of isolated forms, especially in patients with specific histology (e.g., eosinophilic myocarditis) or with an arrhythmicburden. A role for immunosuppressive therapies has been also shown in severe cases of coronavirus disease 2019 (COVID-19), a condition that can be associated with cardiac injury and acute myocarditis. Furthermore, ongoing clinical trials are assessing the role of high dosage methylprednisolone in the context of acute myocarditis complicated by heart failure or fulminant presentation or the role of anakinra to treat patients with acute myocarditis excluding patients with hemodynamically unstable conditions. In addition, the explosion of immune-mediated therapies in oncology has introduced new pathophysiological entities, such as immune-checkpoint inhibitor-associated myocarditis and new basic research models to understand the interaction between the cardiac and immune systems. Here we provide a broad overview of evolving areas in cardio-immunology. We summarize the use of new imaging tools in combination with endomyocardial biopsy and laboratory parameters such as high sensitivity troponin to monitor the response to immunomodulating therapies based on recent evidence and clinical experience. Concerning pericarditis, the normal composition of pericardial fluid has been recently elucidated, allowing to assess the actual presence of inflammation; indeed, normal pericardial fluid is rich in nucleated cells, protein, albumin, LDH, at levels consistent with inflammatory exudates in other biological fluids. Importantly, recent findings showed how innate immunity plays a pivotal role in the pathogenesis of recurrent pericarditis with raised C-reactive protein, with inflammasome and IL-1 overproduction as drivers for systemic inflammatory response. In the era of tailored medicine, anti-IL-1 agents such as anakinra and rilonacept have been demonstrated highly effective in patients with recurrent pericarditis associated with an inflammatory phenotype.

Non-Cardiac Cause of Death in Selected Group Children with Cardiac Pathology: A Retrospective Single Institute Study

Background: Pediatricians and pediatric surgeons often face children with cardiomegaly and dilatative or hypertrophic cardiomyopathies presenting with or without symptoms. Some of these patients have already been diagnosed and received medication, and some present with completely unrelated pathologies. Methods: We performed a 4-year retrospective study on the causes and mechanisms of death of children with cardiac pathology who died outside the cardiology clinic of our hospital by studying the hospital charts and necropsy reports. All children who were in this situation in our hospital were included. Results: Most children in our study group were infants (81.82%), most were boys (81.82%), and in most cases, the cause or mechanism of death was unrelated to their heart condition, whether it had already been diagnosed or not (one case probably died as a result of a malignant ventricular arrhythmia). Additionally, 27.27% of children died as a consequence of bronchopneumonia, the same percentage died as a consequence of an acquired non-pulmonary disease or after surgery, and 18.18% died as a consequence of congenital malformations. Conclusions: Cardiac disease needs to be thoroughly investigated using multiple tools for all children presenting with heart failure symptoms, those with heart murmurs, and children scheduled for surgery of any type. The intensive care specialist and surgeon need to be aware of any heart pathology before non-cardiac surgical interventions.

Spectrum of Viral Pathogens Identified in Children with Clinical Myocarditis (Pre-Coronavirus Disease-2019, 2000-2018): Etiologic Agent Versus Innocent Bystander

OBJECTIVE

To identify the etiologies of viral myocarditis in children in the pre-coronavirus disease 2019 era.

STUDY DESIGN

This was a retrospective review of all patients (age <18 years) diagnosed with myocarditis and hospitalized at Rady Children's Hospital San Diego between 2000 and 2018.

RESULTS

Twenty-nine patients met inclusion criteria. Of 28 (97%) patients who underwent testing for viruses, polymerase chain reaction was used in 24 of 28 (86% of cases), and 16 of 24 (67%) detected a virus. Pathogens were rhinovirus (6), influenza A/B (4), respiratory syncytial virus (RSV) (3), coronavirus (3), parvovirus B19 (2), adenovirus (2), and coxsackie B5 virus, enterovirus, and parainfluenza virus type 2 in one case each. Six (21%) patients had no pathogen detected but imaging and other laboratory test results were compatible with myocarditis. Age 0-2 years was associated with RSV, influenza A/B, coronavirus, and enteroviruses (P < .001). Twenty-one patients (72%) experienced full clinical recovery. Three patients (10%) required venoarterial extracorporeal membrane oxygenation (VA-ECMO), and all 3 recovered. Three others (10%) required and underwent successful cardiac transplantation without complications. Two patients (7%) died 9-10 days after hospitalization (1 had RSV and 1 had influenza A/B). Two other patients presented with complete atrioventricular block; 1 case (rhinovirus) resolved spontaneously, and 1 (coronavirus) resolved after support with VA-ECMO. Age <2 years, female sex, lower ejection fraction at admission, and greater initial and peak levels of brain natriuretic peptide were significant predictors of critical outcomes (use of VA-ECMO, listing for cardiac transplantation, and death).

CONCLUSIONS

Viral nucleic acid-based testing revealed a wider spectrum of viruses that could be associated with myocarditis in children than previously reported and traditionally anticipated. A predilection of certain pathogens in the very young patients was observed. Whether the observed range of viral agents reflects an undercurrent of change in viral etiology or viral detection methods is unclear, but the wider spectrum of viral pathogens found underscores the usefulness of polymerase chain reaction testing to explore possible viral etiologies of myocarditis in children.

Ligand-of-Numb protein X1 controls the coxsackievirus B3-induced myocarditis via regulating the stability of coxsackievirus and adenovirus receptor

Group B coxsackieviruses (CVBs) are the main cause of virus-induced myocarditis. CVBs use coxsackievirus and adenovirus receptor (CAR) for infection and targeting CAR has been shown to ameliorate CVBs-induced myocarditis. Ligand-of-Numb protein X1 (LNX1) is an E3 ubiquitin ligase that was shown to interact with CAR. However, the precise effect of LNX1 on CAR and the roles of LNX1 on CVBs-induced myocarditis remain unknown. In the present study, we generated mice deficient in LNX1 in the heart and evaluated the symptoms of myocarditis after CVB3 infection. We also monitored the expression and ubiquitination of CAR in LNX1-deficient cardiomyocytes after CVBs infection. We found that CVBs infection decreased CAR expression while promoted the expression of LNX1. Mice with deficiency of LNX1 in the heart had normal myocardial development while had deteriorated myocarditis symptoms after CVB3 infection. In LNX1-deficient cardiomyocytes, decreased ubiquitination of CAR and upregulation of CAR were observed after CVB3 infection. In summary, LNX1 controls CVB3-induced myocarditis by regulating the expression of CAR.

Isolation and molecular characterization of Adenovirus in suspected acute flaccid paralysis patients: A preliminary report from Pakistan

Human adenoviruses (HAdVs) usually cause asymptomatic or mild infection, but infrequently, they are responsible for various severe syndromes including neurological disorders. Various research studies have investigated the association of HAdVs with acute flaccid paralysis (AFP). The purpose of this study was to investigate the genetic diversity of HAdVs and their association with AFP. Stool samples from patients ≤ 12 years of age with suspected AFP were collected from all over Pakistan within the framework of poliovirus surveillance. Poliovirus- and enterovirus-negative samples were screened for HAdVs. For virus isolation, the human epithelial cell line HEp-2c was used, culture-positive samples were screened by nested PCR assay, and partial hexon gene sequences were used for genotype identification. Out of 172 samples, 94 were positive by virus isolation, 89 were positive by PCR, and 32 isolates were genotyped successfully. Phylogenetic analysis showed that the HAdVs belonged to species A (HAdV-A12 and A31), B (HAdV-B3 and B7), C (HAdV-C1 and C6), D (HAdV-D19 and D93), and F (HAdV-F41), showing 99-100% nucleotide sequence identity and 98.3-100% amino acid sequence identity). Most of these genotypes have been reported previously in AFP cases, but this is the first report of the detection of HAdV-D93 in stool samples from AFP cases. The detection of a significant fraction of the HAdVs genotypes indicates that these genetically distinct genotypes are circulating in Pakistan and suggests their possible role in the pathogenesis of AFP.

Advanced detection strategies for cardiotropic virus infection in a cohort study of heart failure patients

The prevalence and contribution of cardiotropic viruses to various expressions of heart failure are increasing, yet primarily underappreciated and underreported due to variable clinical syndromes, a lack of consensus diagnostic standards and insufficient clinical laboratory tools. In this study, we developed an advanced methodology for identifying viruses across a spectrum of heart failure patients. We designed a custom tissue microarray from 78 patients with conditions commonly associated with virus-related heart failure, conditions where viral contribution is typically uncertain, or conditions for which the etiological agent remains suspect but elusive. Subsequently, we employed advanced, highly sensitive in situ hybridization to probe for common cardiotropic viruses: adenovirus 2, coxsackievirus B3, cytomegalovirus, Epstein-Barr virus, hepatitis C and E, influenza B and parvovirus B19. Viral RNA was detected in 46.4% (32/69) of heart failure patients, with 50% of virus-positive samples containing more than one virus. Adenovirus 2 was the most prevalent, detected in 27.5% (19/69) of heart failure patients, while in contrast to previous reports, parvovirus B19 was detected in only 4.3% (3/69). As anticipated, viruses were detected in 77.8% (7/9) of patients with viral myocarditis and 37.5% (6/16) with dilated cardiomyopathy. Additionally, viruses were detected in 50% of patients with coronary artery disease (3/6) and hypertrophic cardiomyopathy (2/4) and in 28.6% (2/7) of transplant rejection cases. We also report for the first time viral detection within a granulomatous lesion of cardiac sarcoidosis and in giant cell myocarditis, conditions for which etiological agents remain unknown. Our study has revealed a higher than anticipated prevalence of cardiotropic viruses within cardiac muscle tissue in a spectrum of heart failure conditions, including those not previously associated with a viral trigger or exacerbating role. Our work forges a path towards a deeper understanding of viruses in heart failure pathogenesis and opens possibilities for personalized patient therapeutic approaches.

Viral Myocarditis-From Pathophysiology to Treatment

The diagnosis of acute and chronic myocarditis remains a challenge for clinicians. Characterization of this disease has been hampered by its diverse etiologies and heterogeneous clinical presentations. Most cases of myocarditis are caused by infectious agents. Despite successful research in the last few years, the pathophysiology of viral myocarditis and its sequelae leading to severe heart failure with a poor prognosis is not fully understood and represents a significant public health issue globally. Most likely, at a certain point, besides viral persistence, several etiological types merge into a common pathogenic autoimmune process leading to chronic inflammation and tissue remodeling, ultimately resulting in the clinical phenotype of dilated cardiomyopathy. Understanding the underlying molecular mechanisms is necessary to assess the prognosis of patients and is fundamental to appropriate specific and personalized therapeutic strategies. To reach this clinical prerequisite, there is the need for advanced diagnostic tools, including an endomyocardial biopsy and guidelines to optimize the management of this disease. The severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has currently led to the worst pandemic in a century and has awakened a special sensitivity throughout the world to viral infections. This work aims to summarize the pathophysiology of viral myocarditis, advanced diagnostic methods and the current state of treatment options.