Acute fulminant myocarditis in scrub typhus

Scrub typhus is a zoonotic disease caused by Orientia tsutsugamushi in which humans are accidental hosts. It is a febrile illness which is confined to rural Asia and the Western Pacific islands. Severe complications are very rare. We report four cases of acute fulminant myocarditis in children with scrub typhus. This complication led to severe cardiogenic shock and death in two of them. We believe this is the first report of fulminant myocarditis complicating scrub typhus in children.     

Acute myocarditis in infants. Initial presentation

The authors reviewed the initial presentation of seven infants with acute myocarditis. All patients presented with respiratory distress including tachypnea (respiratory rate greater than or equal to 40) and intercostal retractions. Other findings included tachycardia (heart rate greater than or equal to 120) (7/7) and grunting (6/7). Lungs were clear to auscultation in six out of the seven patients. Cardiomegaly was seen in five of the initial chest roentgenograms. Each initial electrocardiogram had abnormal findings. Initial diagnoses were sepsis and shock in three patients, pneumonia and asthma in two, and congestive heart failure in two. Six patients required tracheal intubation. All required admission to the Pediatric Intensive Care Unit (ICU). Two patients died. Myocarditis should be suspected in a child presenting with severe respiratory distress, tachycardia, cardiomegaly, and/or an abnormal electrocardiogram. Prompt stabilization and admission to a pediatric intensive care unit for further evaluation and treatment is essential.     

Acute parvovirus myocarditis with fatal outcome]

We report a new complication related to parvovirus B 19: acute lethal myocarditis in the context of a familial epidemic. Serological studies confirmed the existence of a recent infection and the B 19 structural proteins were detected by immunocytochemical techniques on myocardial sections.     

Acute myocarditis simulating myocardial infarction in a child

Pediatric chest pain usually occurs in benign conditions. However, this case portrays the dramatic electrocardiographic appearance of acute myocardial ischemia in a boy with biopsy-proven myocarditis who had only mild chest pain. This underscores the need for eliciting a detailed history when evaluating a patient with chest pain. If the pain cannot be clearly attributed to chest wall phenomena, or if there are historical or physical findings suggestive of an arrhythmia or angina, then further investigation with a chest radiograph and a 12-lead electrocardiogram is recommended. Myocarditis must be considered in the differential diagnosis of any child whose electrocardiogram is indistinguishable from an acute myocardial infarction. Finally, endomyocardial biopsy allows early diagnosis and institution of therapy, which may have beneficial effect on decreasing morbidity and mortality. Further follow-up and research is still needed to evaluate the effect of early treatment of myocarditis on long-term myocardial function and the development of chronic cardiomyopathy.     

Neonatal enterovirus myocarditis]

Enterovirus infections in neonates are difficult to diagnose. Diphasic pattern and possibly fatal myocarditis must be anticipated. CASE REPORT: A 14-day-old girl had presented a heart failure after an initial episode of gastroenteritis and supraventricular tachycardia. Investigation demonstrated global myocardial dysfunction. Diagnosis of neonatal enterovirus myocarditis was made by polymerase chain reaction detection of viral genome. Heart failure was controlled with medical treatment. CONCLUSION: Enterovirus myocarditis is typically a biphasic illness. Rapid diagnosis of enteroviral infection in neonatal period may be made by polymerase chain reaction detection of viral genome. There is anecdoctal evidence that immunoglobulin infusions may improve outcome.     

Viral myocarditis in childhood

Viral myocarditis is an important condition that may be encountered by general paediatricians, general practitioners and paediatric cardiologists alike. Its presentation varies from asymptomatic and transient ECG changes to acute, fulminant heart failure and collapse. Clinicians must therefore have a high index of suspicion to enable its prompt recognition and the prevention of serious complications. A number of investigations are useful in assessing a child or adolescent with suspected viral myocarditis. Initial treatment is supportive, and a significant proportion of patients recover spontaneously. Although the use of immune-modulatory therapies is commonplace, there is little evidence to support this, and large, randomised, controlled clinical trials are needed to clarify this issue.     

Enteroviral myocarditis in neonates

Enteroviruses are a leading cause of viral infections in children. While most enteroviral infections are mild and self‐limiting, severe disease such as a viral sepsis syndrome, myocarditis, hepatitis and meningoencephalitis may occur. We present two cases of neonatal enteroviral myocarditis. Cardiorespiratory failure occurred in both cases, and severe shock refractory to conventional treatment required support with extracorporeal membrane oxygenation (ECMO). One child with coxsackievirus B3 myocarditis failed to recover and died after 3 weeks on ECMO, while one child could be decannulated successfully after 9 days of ECMO and recovered completely subsequently. In conclusion, neonatal myocarditis has a very high mortality, and ECMO should be considered early in neonates with rapid clinical and echocardiographic deterioration despite adequate inotropic support.     

心肌炎的免疫学作用机制

病毒感染引起的心肌炎临床最为常见,其中半数以上由柯萨奇B组病毒所致。然而,迄今为止,其发病机制尚未完全明了,病毒感染对心肌细胞的直接损伤作用及病毒介导的免疫损伤作用是目前认为最有可能的机制,因此,了解心肌炎的免疫学机制具有重要的理论和实践意义。     

病毒性心肌炎与心肌纤维化

心肌纤维化是由心肌间质胶原过多蓄积引起,在病毒性心肌炎各期均不同程度地存在,尤其以恢复期与慢性期改变明显.心肌纤维化受多种因素调控,包括病毒直接损伤、转化生长因子-β1(TGF-β1)、肾素-血管紧张素-醛固酮系统、一氧化氮和内皮素、哺乳动物雷帕霉素靶蛋白(mTOR)等.临床表现缺乏特征性.病毒性心肌炎慢性期可行抗纤维化治疗.