Viral myocarditis in childhood

Intravenous immunoglobulins in children with new onset dilated cardiomyopathy

BACKGROUND

Dilated cardiomyopathy is a rare but serious disorder in children. No effective diagnostic or treatment tools are readily available. This study aimed to evaluate the efficacy of intravenous immunoglobulins in children with new onset dilated cardiomyopathy. Methods and results In this retrospective cohort study, 94 children with new onset dilated cardiomyopathy were followed during a median period of 33 months. All patients with secondary dilated cardiomyopathy - for example, genetic, auto-immune or structural defects - had been excluded. Viral tests were performed in all patients and 18 (19%) children met the criteria for the diagnosis "probable or definite viral myocarditis". Intravenous immunoglobulins were administered to 21 (22%) patients. Overall transplant-free survival was 75% in 5 years and did not differ between treatment groups. The treatment was associated with a higher recovery rate within 5 years, compared with non-treated children (70 versus 43%, log rank=0.045). After correction for possible confounders the hazard ratio for recovery with intravenous immunoglobulins was not significant (hazard ratio: 2.1; 95% CI: 1.0-4.6; p=0.056). Administration of intravenous immunoglobulins resulted in a greater improvement in the shortening fraction of the left ventricle.

CONCLUSION

In our population of children with new onset dilated cardiomyopathy, of either viral or idiopathic origin, intravenous immunoglobulins were administered to a minority of the patients and did not influence transplant-free survival, but were associated with better improvement of systolic left ventricular function and with better recovery. Our results support the concept that children with new onset dilated cardiomyopathy might benefit from intravenous immunoglobulins.

Coxsackievirus B heart infections and their putative contribution to sudden unexpected death: An 8-year review of patients and victims in the coastal region of Tunisia

Coxsackieviruses B (CV B) are known as the most common viral cause of human heart infections. Cardiac inflammations contribute to sudden unexpected death (SUD) significantly. The diagnosis remains difficult with the traditional diagnostic tests and must be substantially improved. This has prompted health professionals to seek new diagnostic procedures which may provide important clues regarding underlying etiology. The present study is based on patients with infectious heart diseases and SUD victims with no relevant pathologies. They were investigated for possible CV-B infection. Patients with coronary artery diseases and unnatural road and domestic accident victims served as controls. The samples were studied for CV-B applying PCR. Histopathology for inflammatory markers, immunohistochemistry (IHC) for immune inflammatory cells and the enteroviral VP1-capsid protein were performed. Overall, 102 patients and 87 SUD victims were studied. As controls, 100 patients and 54 SUD unnatural accident victims were enrolled. CV-B were detected in 28 patients and 15 SUD victims. The control group samples were completely virus negative. Compared to controls, IHC revealed a significant presence of T and B lymphocytes within the myocardium. Furthermore, enteroviral VP1-capsid protein were detected from samples by IHC. Applying a comprehensive combination of methods, our results demonstrate the involvement of CV-B in cases of heart infection suggesting they play a significant role in SUD. Our results emphasize the importance of opting for a combination of methods.

Postmortem diagnosis of infectious heart diseases: A mystifying cause of Sudden Infant Death

Sudden infant death (SID) is an unresolved problem of high relevance and previous studies have indicated a role of viral heart infections. The diagnosis remains difficult in clinical practice using routine diagnostic tests and must be substantially improved. A prospective study based on post-mortem samples from SID victims whose heart disease was not clinically recognized was conducted for 4 years in a Tunisian University Hospital. Pediatric cases of unnatural death served as controls. Both SID victims and controls were investigated for possible coxsackievirus-B (CV-B) infection in heart tissue. During the study period, 39 cases with a male predominance (77%) were reported. There was no positive family history of coronary artery disease among the victims. In 35 cases (90%), low birth weight and/or critical development period were reported. All SID victims had complained of mild fever and insomnia for a few days preceding death, which required infectious laboratory investigations marked with an elevated white blood cell count (WBC) and C-reactive protein (CRP). The cardiac biomarkers were also elevated. The histopathological investigations of the heart tissue samples revealed signs of myocardial and pericardial inflammation. Enterovirus was detected by immunohistochemistry (IHC) and PCR from myocardial samples from 6 cases (15.3%) having myocarditis and 3 cases (7.7%) having perimyocarditis. The current study is of great interest and is aimed at urging health professionals to adopt systematically long intensive heart care in infants with underlying vulnerability as well as new diagnostic approaches including histopathology complemented with IHC and molecular pathology.

Coxsackievirus B detection in cases of myocarditis, myopericarditis, pericarditis and dilated cardiomyopathy in hospitalized patients

Coxsackieviruses B (CV-B) are known as the most common viral cause of human heart infections. The aim of the present study was to assess the potential role of CV-B in the etiology of infectious heart disease in hospitalized patients. The present study is based on blood, pericardial fluid and heart biopsies from 102 patients and 100 control subjects. All of the samples were examined for the detection of specific enteroviral genome using the reverse transcription polymerase chain reaction (RT-PCR) and sequence analysis. Immunohistochemical investigations for the detection of the enteroviral capsid protein, VP1, from the biopsies were performed. The samples were cultured on confluent KB monolayer cell line for possible virus isolation. The epidemiological data were also collected. CV-B was detected in 28 of the 102 patients. The sequence analysis demonstrated that 27 strains were identical to CV-B3 and only one strain was identical to CV-B1. Furthermore, VP1 in the heart biopsies was detected in enterovirus-positive cases, as revealed by RT-PCR. Pericarditis infection was more frequent than myocarditis (P<0.05) or myopericarditis (P=0.05). The epidemiological data demonstrate that CV-B heart infections occur mainly during autumn and winter, and young male adults are more susceptible than adolescents or adults (P<0.5). The present findings demonstrate a higher prevalence of viral heart infections, suggesting that CV-B may significantly contribute to heart infections.

[Myocarditis exacerbation in a child undergoing inguinal herniopasty after viral infection]

INTRODUCTION

Immunosuppressive effects of general anaesthesia and surgery could have unexpected consequences in a child with recent infection. The incidence of myocarditis in childhood is unknown.

CASE OUTLINE

During general anaesthesia for inguinal hernia repair, a seven-year-old boy suddenly developed heart failure. Clinical presentation included hypotension, pulmonary oedema, drop in haemoglobin oxygen saturation, ST segment elevation and premature ventricular contractions. Haemodynamic stability and adequate oxygenation were achieved with dopamine and furosemide. Preoperative history, physical examination and complete blood count were unremarkable. Moderate cardiomegaly and pulmonary oedema were present on chest radiography. Diminished left ventricular contractility found on echocardiography increased troponin I and CK-MB levels suggested myocardial injury. Increased C-reactive protein with lymphocytosis suggested inflammation as its cause. Parents failed to report rubella 10 days before the operation. A clinical diagnosis of myocarditis as a complication of rubella was based on increased titer of IgM to rubella. With intravenous immunoglobulin, corticosteroids and symptomatic treatment for heart failure, his condition improved and ejection fraction reached 68% one month after operation.

CONCLUSION

In future, we need protocols with instructions for paediatric patients undergoing elective surgery and anaesthesia after viral infections.