Tracheal aspirate as a substrate for polymerase chain reaction detection of viral genome in childhood pneumonia and myocarditis

Comparing inhaled colistin with inhaled fosfomycin/tobramycin as an adjunctive treatment for ventilator-associated pneumonia: An open-label randomized controlled trial

PURPOSE

Although investigations are limited, adjunctive aerosolized antibiotics have been advised in the setting of gram-negative ventilator-associated pneumonia (VAP). This study aimed to compare the efficiency of inhaled colistin with inhaled fosfomycin/tobramycin in treating VAP due to extensively drug-resistant (XDR) Acinetobacter baumannii.

METHODS

This single center open-label randomized controlled trial included 60 patients who developed XDR A. bumannii VAP. Eligible participants were randomly assigned to two groups (no. 30). Regardless of the assignment, all participants received meropenem (2 g as a 3-h extended infusion every 8 h) plus intravenous colistin (a loading dose of 9 million IU and then 4.5 million IU every 12 h). The control group was given inhaled colistin (1 million IU every 8 h), and the case group received inhaled tobramycin/fosfomycin (300 mg every 12 h/80 mg every 12 h) as adjunctive therapy. The primary outcome was treatment duration, and the secondary outcomes were Clinical Pulmonary Infection Score (CPIS) trend and mortality rate in the groups. The decision to stop treatment was made by the treating physician.

RESULTS

The mean treatment duration was 13.73 ± 3.22 days in the colistin group and 10.85 ± 2.84 days in the tobramycin/fosfomycin group; the mean treatment duration in the latter group was lower significantly (P = 0.001). CPIS was decreased in the groups significantly (P < 0.001), but the mean changes of CPIS were significantly different between the groups, and in the inhaled tobramycin/fosfomycin group, a greater reduction (P = 0.005) was observed. Two (6.67%) patients in the control group and three (10%) patients in the case group died.

CONCLUSION

The use of inhaled tobramycin/fosfomycin in cases with XDR A. bumannii VAP was associated with a shorter treatment duration in this open-label trial.

Cardiac Complications Caused by Respiratory Syncytial Virus Infection: Questionnaire Survey and a Literature Review

We investigated 22 cases of patients with myocarditis during respiratory syncytial virus (RSV) infection by a questionnaire survey, and performed a literature search to clarify their characteristics. The age distribution was divided into 2 groups, that is, 1 group comprised of patients younger than 4-years old and the other comprised patients older than 15 years. ECG demonstrated disturbance of the conduction system (AV block) in 7 out of 18 patients (38.8%), myocardial damage (ST-T change) in 9 out of 18 patients (50.0%), and tachycardia in 3 out of 18 patients (16.6%). Echocardiography displayed a robust decrease in left-heart function in 12 out of 14 patients. The outcome was 2 deaths, 1 pacemaker placement, 4 patients with mild sequel. Our data suggest that RSV myocarditis caused by RSV infection can be divided into 3 different pathophysiologies, characterized by disturbance of the conduction system, myocardial damage, and increase of autonomy.

A standardized postmortem protocol to assess the real burden of sudden infant death syndrome

Sudden unexpected infant death (SUID) is a major cause of death in infants < 1 year of age. Sudden infant death syndrome (SIDS) is a SUID still unexplained after post-mortem examination. In 2014, a protocol of post-mortem investigation was introduced to assess both the prevalence and the etiopathogenesis of SUID. Our aim was to compare SUID data before and after the application of a standardized autopsy protocol of investigation. In the time interval 2004-2018, SUID cases occurring in the Veneto Region, North-East Italy, were referred to our Core Lab. Since 2014, a complete autopsy was performed, including gross and histological study with toxicologic and molecular analysis carried out at the referral center. A total of 36 SUIDs (22 M, mean age 95.5 ± 80 days), 17 before (group A) and 19 after (group B) 2014, were collected. In group A, only 1 (6%) resulted as explained SUID, due to lymphocytic myocarditis and 16 (94%) were SIDS. In group B, 8 were SIDS (42%) and 11 (58%) explained SUID cases (p < 0.01), consisting of interstitial pneumonia and bronchiolitis in 9 and lymphocytic myocarditis in 2 cases. Molecular analysis was positive for viruses in 8 of them (73%). In conclusion, since the application of a standardized protocol of post-mortem investigation, inflammatory, mostly infective, cardio-pulmonary diseases have been identified as the most common cause of SUID, with SIDS falling from 94 to 42% of SUID. Efforts must be made to implement a uniform autopsy protocol to provide reliable epidemiological data on SIDS.

Fulminant myocarditis due to the influenza B virus in adults: Report of two cases and literature review

La miocarditis es una enfermedad inflamatoria del miocardio. Las infecciones virales son la causa más común, aunque también puede deberse a reacciones de hipersensibilidad y de etiología autoinmunitaria, entre otras. El espectro clínico de la enfermedad es variado y comprende desde un curso asintomático, seguido de dolor torácico, arritmias y falla cardiaca aguda, hasta un cuadro fulminante. El término 'fulminante' se refiere al desarrollo de un shock cardiogénico con necesidad de soporte vasopresor e inotrópico o dispositivos de asistencia circulatoria, ya sea oxigenación por membrana extracorpórea o balón de contrapulsación intraaórtico. Cerca del 10 % de los casos de falla cardiaca por miocarditis corresponde a miocarditis fulminante. La miocarditis por influenza se considera una condición infrecuente; no obstante, su incidencia ha aumentado desde el 2009 a raíz de la pandemia de influenza por el virus AH1N1. Por su parte, la miocarditis por influenza de tipo B sigue siendo una condición infrecuente. Se describen aquí dos casos confirmados de miocarditis fulminante por el virus de la influenza B atendidos en un centro cardiovascular, que requirieron dispositivos de asistencia circulatoria mecánica.

Enteroviruses and Parechoviruses

Infections with enteroviruses and human parechoviruses are highly prevalent, particularly in neonates, where they may cause substantial morbidity and mortality. Individuals with B-cell-related immunodeficiencies are at risk for severe enteroviral infections, usually a chronic and fatal meningoencephalitis. In transplant recipients and patients with malignancy, enterovirus infections typically involve the respiratory tract, but cases of severe, disseminated infection have been described. The mainstay of diagnosis for enterovirus and human parechovirus infections involves the use of molecular diagnostic techniques. However, routine nucleic acid-detection methods for enteroviruses will not detect human parechoviruses. Laboratory diagnosis of these viral infections is important in determining a patient's prognosis and guiding clinical management.

Complete Genome Sequence of Human Respiratory Syncytial Virus Isolated in Mexico

Human respiratory syncytial virus (HRSV) is a member of the Paramyxoviridae family, which causes lower respiratory tract infections in neonates and children younger than 5 years. Here, we report the complete genome sequence of HRSV, isolated from a nasopharyngeal swab of a pregnant woman with cardiac complications.

Classification and histological, immunohistochemical, and molecular diagnosis of inflammatory myocardial disease

In the WHO 1996 classification of cardiomyopathies, myocarditis is defined as an "inflammatory disease of the myocardium associated with cardiac dysfunction" and is listed among "specific cardiomyopathies". Myocarditis is diagnosed on endomyocardial biopsy (EMB) by established histological, immunological, and immunohistochemical criteria, and molecular techniques are recommended to identify viral etiology. Infectious, autoimmune, and idiopathic forms of inflammatory cardiomyopathy are recognized that may lead to dilated cardiomyopathy. According to Dallas criteria, myocarditis is diagnosed in the setting of an "inflammatory infiltrate of the myocardium with necrosis and/or degeneration of adjacent myocytes, not typical of ischemic damage associated with coronary artery disease". The majority of experts in the field agree that an actual increase in sensitivity of EMB has now been reached by using immunohistochemistry together with histology. A value of >14 leukocytes/mm(2) with the presence of T lymphocytes >7 cells/mm(2) has been considered a realistic cut off to reach a diagnosis of myocarditis. The development of molecular biological techniques, particularly amplification methods like polymerase chain reaction (PCR) or nested-PCR, allows the detection of low copy viral genomes even from an extremely small amount of tissue such as in EMB specimens. Positive PCR results obtained on EMB should always be accompanied by a parallel investigation on blood samples collected at the time of the EMB. According to the recent Association for European Cardiovascular Pathology guidelines, optimal specimen procurement and triage indicates at least three, preferably four, EMB fragments, each 1-2 mm in size, that should immediately be fixed in 10 % buffered formalin at room temperature for light microscopic examination. In expected focal myocardial lesions, additional sampling is recommended. Moreover, one or two specimens should be snap-frozen in liquid nitrogen and stored at -80 °C or alternatively stored in RNA-later for possible molecular tests or specific stains. A sample of peripheral blood (5-10 ml) in EDTA or citrate from patients with suspected myocarditis allows molecular testing for the same viral genomes sought in the myocardial tissue.

Differential expression of coxsackievirus and adenovirus receptor on alveolar epithelial cells between fetal and adult mice determines their different susceptibility to coxsackievirus B infection

Coxsackievirus B (CVB) can cause aseptic meningitis, myocarditis and respiratory disease, especially in newborn infants. To compare the susceptibility to CVB infection of fetal and adult mice, we prepared primary alveolar epithelial cells (AECs) from lungs of BALB/c mice. In contrast to fetal mouse AECs, those of adults were less susceptible to CVB3 infection, as indicated by decreased cytopathic effects, and reduced levels of viral particles bound at the cell surface. In adult mouse AECs, amplification of the viral genome and virus capsid protein VP1 synthesis were concomitantly reduced. In addition, the cell-surface expression of coxsackievirus and adenovirus receptor (CAR), which plays a key role in the initiation of CVB and pulmonary infection, was downregulated in adult mouse AECs. These findings demonstrate that adult mouse AECs are less susceptible to CVB3 due to decreased CAR levels. Thus, these findings strongly indicate that the level of virus receptors on AECs is one of the crucial determinants for the age-dependence of CVB virulence in the mouse lung.

Clinical outcome of acute myocarditis in children according to treatment modalities

PURPOSE

There is currently little evidence to support intravenous immune globulin (IVIG) therapy for pediatric myocarditis. The purpose of our retrospective study was to assess the effects of IVIG therapy in patients with presumed myocarditis on survival and recovery of ventricular function and to determine the factors associated with its poor outcome.

METHODS

We reviewed all consecutive cases of patients with myocarditis with left ventricular dysfunction verified by echocardiogram who had visited 3 university hospitals between January 2000 and September 2009. These patients were divided into 2 groups. Group 1 consisted of 23 patients (69.6%) who received IVIG alone or IVIG in combination with steroids, and group 2 consisted of 10 patients (30.3%) who received neither IVIG nor other immunosuppressive agents. Clinical manifestations, laboratory results, echocardiographic findings, and outcomes were compared between these 2 groups.

RESULTS

One year after the initial presentation, the difference in the probability of survival did not show statistical significance in IVIG-treated patients (P=0.607). Of the echocardiographic parameters on admission, a shortening fraction of less than 15% was associated with unremitting cardiac failure. Furthermore, anemic patients were more likely to have elevated N-terminal fragment levels of the B-type natriuretic peptide (NT-proBNP) in the progressed group (P=0.036).

CONCLUSION

There was no difference between the IVIG-treated patients and the control patients in the degree of recovery of left ventricular function and survival. Prospective, randomized, clinical studies are needed to elucidate the effects of IVIG treatment during the acute stage of myocarditis on ultimate outcomes.

Molecular diagnosis of the viral component in cardiomyopathies: pathophysiological, clinical and therapeutic implications

BACKGROUND

Myocarditis is defined as the inflammation of myocardium associated with cardiac dysfunction. Despite this clear-cut definition, diagnosis and etiologic treatment continue to create considerable debate. Viral infections are frequent causes of myocarditis and there is evidence that persistent viral infection is associated with poor prognosis in different subtypes of cardiomyopathy.

OBJECTIVE

To review methods for diagnosis of viral myocarditis and present the use of polymerase chain reaction (PCR)-based protocols for evaluating viral infection in myocarditis/cardiomyopathies.

METHODS

A review of published literature.

RESULTS/CONCLUSION

There is increasing evidence that PCR-based protocols can provide reliable molecular evidence for the presence of viral infection in myocardium. Thus application of molecular techniques will allow collection and analysis of more information on the epidemiology of viral cardiomyopathies, patient risk stratification and appropriate medical treatment.

Diagnostic value of real-time polymerase chain reaction to detect viruses in young children admitted to the paediatric intensive care unit with lower respiratory tract infection

INTRODUCTION

The aetiology of lower respiratory tract infections in young children admitted to the paediatric intensive care unit (PICU) is often difficult to establish. However, most infections are believed to be caused by respiratory viruses. A diagnostic study was performed to compare conventional viral tests with the recently developed real-time PCR technique.

METHOD

Samples from children aged under 5 years presenting to a tertiary PICU suspected of having a lower respiratory tract infection were tested using conventional methods (viral culture and immunofluorescence) and real-time PCR during the winter season from December 2004 to May 2005. Conventional methods were used to check for respiratory syncytial virus, influenzavirus, parainfluenzavirus 1-3, rhinoviruses and adenoviruses. Real-time PCR was used to test for respiratory syncytial virus, influenzavirus, parainfluenzavirus 1-4, rhinoviruses, adenoviruses, human coronaviruses OC43, NL63 and 229E, human metapneumovirus, Mycoplasma pneumoniae and Chlamydia pneumoniae.

RESULTS

A total of 23 patients were included, of whom 11 (48%) were positive for a respiratory virus by conventional methods. Real-time PCR confirmed all of these positive results. In addition, real-time PCR identified 22 more viruses in 11 patients, yielding a total of 22 (96%) patients with a positive sample. More than one virus was detected in eight (35%) children.

CONCLUSION

Real-time PCR for respiratory viruses was found to be a sensitive and reliable method in PICU patients with lower respiratory tract infection, increasing the diagnostic yield twofold compared to conventional methods.

Factors associated with establishing a causal diagnosis for children with cardiomyopathy

OBJECTIVE

The goal was to identify the clinical variables associated with establishing a cause of cardiomyopathy in children.

METHODS

The Pediatric Cardiomyopathy Registry contains clinical and causal testing information for 916 children who were diagnosed as having cardiomyopathy in North America between 1990 and 1995. Children with a causal diagnosis were compared with those without with respect to several demographic, clinical, and causal testing variables.

RESULTS

Cardiomyopathy was 1 of 4 types, hypertrophic (34.2%), dilated (53.8%), restrictive (3.2%), or other or mixed (8.9%). Only one third of cases had a known cause. Children with a known cause for hypertrophic cardiomyopathy were more likely to be female, to be relatively smaller, to present with congestive heart failure, and to have increased left ventricular posterior wall thickness without outflow tract obstruction. For dilated cardiomyopathy, a known cause was associated with older age, lower heart rate, smaller left ventricular dimensions, and greater shortening fraction. Family history of cardiomyopathy predicted a significantly higher rate of causal diagnoses for all cardiomyopathy types, whereas family histories of genetic syndromes and sudden death were also predictive of a cause for hypertrophic and dilated cardiomyopathies. For hypertrophic cardiomyopathy, only blood and urine testing was associated with a causal diagnosis, whereas both viral serologic testing or culture and endomyocardial biopsy were independent predictors of a causal diagnosis in dilated cardiomyopathy.

CONCLUSIONS

Certain patient characteristics, family history, echocardiographic findings, laboratory testing, and biopsy were associated significantly with establishing a cause of pediatric cardiomyopathy. Early endomyocardial biopsy should be considered strongly for children with dilated cardiomyopathy, for definitive diagnosis of viral myocarditis. Although not widely used, skeletal muscle biopsy may yield a cause for some patients with hypertrophic cardiomyopathy and for patients suspected of having a mitochondrial disorder.

Enhanced identification of viral and atypical bacterial pathogens in lower respiratory tract samples with nucleic acid amplification tests

The advantages of nucleic acid amplification tests (NAT) over conventional methods for the detection of pathogens in lower respiratory tract samples have not been established. NAT for respiratory pathogens were performed on 439 endotracheal tube (ETT) and bronchoalveolar lavage (BAL) samples. A potential pathogen was detected in 87 samples. Of 22 samples that tested positive by conventional methods, 15 tested positive for the same pathogen by NAT, 1 tested positive for a different pathogen, 2 had co‐infections identified only by NAT, and 4 tested negative by NAT. An additional 73 pathogens were detected by NAT in 65 samples including 30 pathogens that were missed by conventional methods (19 adenovirus, 6 respiratory syncytial virus, 3 parainfluenza virus 1–4, 2 influenza A), 41 pathogens not routinely identified by conventional methods in most laboratories (23 rhinovirus, 8 human coronavirus OC43, 5 human metapneumovirus (hMPV), 2 human coronavirus 229E, 2 human coronavirus NL63, 1 Chlamydophila pneumoniae) and 2 pathogens from samples where no respiratory virus testing was requested (1 influenza A, 1 parainfluenza virus). Four of 52 patients who had multiple BAL samples submitted on the same day had negative and positive results by NAT on different samples. NAT improves detection of potential pathogens from ETT and BAL samples. J. Med. Virol. 78:702–710, 2006. © 2006 Wiley‐Liss, Inc.

Serious and lethal respiratory tract infections of viral etiology in children

Viruses may lead to serious and lethal pulmonary infections in immunocompetent and immunocompromised children. Series of children with acute respiratory distress syndrome and series of children requiring extracorporeal membrane oxygenation, as well as reported series of nosocomial viral illness, offer an insight into the extent of serious viral disease documented in the medical literature. Series of children with specific viral respiratory illness also will be reviewed, as will the means of diagnosis in these groups of patients. Copyright © 2000 by W.B. Saunders Company

Nosocomial viral ventilator-associated pneumonia in the intensive care unit: a prospective cohort study

Objective

To determine the incidence, risk factors, and clinical relevance of viral ventilator-associated pneumonia (VAP) in an adult intensive care unit (ICU).

Design

Prospective observational study.

Setting

A 22-bed adult medical ICU in a university hospital.

Patients

All consecutive adult patients ventilated more than 48 h in a 9-month period including regular seasonal viral infections.

Interventions

A tracheobronchial aspirate upon enrollment and at the time of VAP suspicion.

Measurements and results

All respiratory specimens were tested in culture, indirect immunofluorescence assay, and PCR or RT-PCR for virological assessment. Patients were followed until ICU discharge or death. One hundred thirty-nine patients were included. Upon enrollment, a respiratory virus was detected in the tracheobronchial aspirate in 25% of patients (35 of 139). The incidence of VAP, defined according to clinical daily evaluation, was 28% (39 of 139 patients). A bacteria was documented in 74% of cases, whereas no case of a causative viral infection was encountered among VAP patients; however, herpes simplex virus type-1 (HSV 1) infection was detected in respiratory specimens of 31% of VAP (12 of 39).

Conclusions

We found a high incidence of HSV-1 infection in VAP patients; however, nosocomial viral VAP is likely to be rare in ICU, as assessed by the absence of respiratory virus-induced VAP identified in this prospective cohort study.

A formidable challenge: the diagnosis and treatment of viral myocarditis in children

It is generally well accepted that one third of patients with viral myocarditis experience a complete recovery of normal cardiac function, one third improve clinically but show residual cardiac dysfunction, and one third experience chronic heart failure and die or require heart transplantation. It is hoped that a better understanding of the underlying cause and pathogenesis of this disease will increase the number of patients who experience a complete recovery. New advances in both the diagnosis and treatment of viral myocarditis continue to enter clinical practice at a rapid pace, and it is likely that a genomic approach to the diagnostic evaluation and treatment of this disease will become possible in the near future. Viral myocarditis, however, will remain a significant diagnosticand therapeutic challenge to both physicians and scientists alike.

An approach to the treatment of pediatric myocarditis

The newest treatment strategies for pediatric myocarditis have evolved from an understanding of the pathophysiology of myocyte damage. Although the initial stages of viral myocarditis apparently result from the direct cytopathic effects on the atrial and ventricular myocardium, later stages of progressive decompensation result from immune-mediated myocyte destruction common to many forms of myocarditis. Despite advances in the understanding of the role of genetics, immunologic mechanisms, and infectious causes of myocarditis, supportive therapy continues to remain the cornerstone of treatment. Presently, therapies include supportive management with anticongestive agents, antiviral medications, and therapies that attempt to interrupt the immunologic cascade. Clinical studies have yet to provide convincing evidence that the use of immunosuppressants and gamma-globulin favorably alters the outcome for pediatric patients with acute myocarditis. Ventricular assist devices and heart transplantation remain as treatment options for all pediatric patients with severe myocarditis resistant to all other therapies. Although this review will focus on viral myocarditis, the supportive strategies and surgical treatment options apply to most forms of cardiomyopathy.

Toward testing the hypothesis that group B coxsackieviruses (CVB) trigger insulin-dependent diabetes: inoculating nonobese diabetic mice with CVB markedly lowers diabetes incidence

Insulin-dependent (type 1) diabetes mellitus (T1D) onset is mediated by individual human genetics as well as undefined environmental influences such as viral infections. The group B coxsackieviruses (CVB) are commonly named as putative T1D-inducing agents. We studied CVB replication in nonobese diabetic (NOD) mice to assess how infection by diverse CVB strains affected T1D incidence in a model of human T1D. Inoculation of 4- or 8-week-old NOD mice with any of nine different CVB strains significantly reduced the incidence of T1D by 2- to 10-fold over a 10-month period relative to T1D incidences in mock-infected control mice. Greater protection was conferred by more-pathogenic CVB strains relative to less-virulent or avirulent strains. Two CVB3 strains were employed to further explore the relationship of CVB virulence phenotypes to T1D onset and incidence: a pathogenic strain (CVB3/M) and a nonvirulent strain (CVB3/GA). CVB3/M replicated to four- to fivefold-higher titers than CVB3/GA in the pancreas and induced widespread pancreatitis, whereas CVB3/GA induced no pancreatitis. Apoptotic nuclei were detected by TUNEL (terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling) assay in CVB3/M-infected pancreata but not in CVB3/GA-infected pancreata. In situ hybridization detected CVB3 RNA in acinar tissue but not in pancreatic islets. Although islets demonstrated inflammatory infiltrates in CVB3-protected mice, insulin remained detectable by immunohistochemistry in these islets but not in those from diabetic mice. Enzyme-linked immunosorbent assay-based examination of murine sera for immunoglobulin G1 (IgG1) and IgG2a immunoreactivity against diabetic autoantigens insulin and HSP60 revealed no statistically significant relationship between CVB3-protected mice or diabetic mice and specific autoimmunity. However, when pooled sera from CVB3/M-protected mice were used to probe a Western blot of pancreatic proteins, numerous proteins were detected, whereas only one band was detected by sera from CVB3/GA-protected mice. No proteins were detected by sera from diabetic or normal mice. Cumulatively, these data do not support the hypothesis that CVB are causative agents of T1D. To the contrary, CVB infections provide significant protection from T1D onset in NOD mice. Possible mechanisms by which this virus-induced protection may occur are discussed.

Molecular diagnosis of myocarditis and dilated cardiomyopathy in children: clinicopathologic features and prognostic implications

Myocarditis is the most common cause of heart failure in children. We investigated viral etiology of myocarditis/dilated cardiomyopathy (DCM) in children and correlated molecular findings with pathologic and clinical data. Polymerase chain reaction (PCR) or reverse transcription (RT)-PCR were used to analyze 59 endomyocardial biopsies from 48 consecutive young (<18 yrs) patients (pts) with clinical and histologic diagnosis of myocarditis and DCM, employing primers designed to amplify specific sequences of various DNA and RNA viruses. Nucleic acids were successfully extracted in 41 pts and viral genomes were found in 20 (49%): 12 out of 26 pts (46%) with myocarditis, 6 out of 13 (46%) pts with DCM, and both patients with endocardial fibroelastosis. Enteroviruses were more common in DCM (72%), whereas adenoviruses and enteroviruses shared the same rate (36%) in myocarditis. The mumps virus genome was detected in the two pts with endocardial fibroelastosis. More diffuse inflammatory infiltrates and myocyte damage as well as more impaired left ventricular end diastolic volume and shortening fraction were noted in viral positive cases. PCR positive pts had a worse outcome, resulting in transplantation or death. Three out of 8 pts with viral myocarditis who underwent cardiac transplantation had recurrent PCR-proven graft viral infection. Viral myocarditis/DCM appeared to be a more severe disease than nonviral forms. Enteroviruses were more common in DCM, whereas adenoviruses were as frequent as enteroviruses in myocarditis. Persistence of viral infection was associated with disease deterioration. Viral myocarditis relapsed after transplantation.

Diagnosis and management of pediatric myocarditis

Myocarditis is an insidious inflammatory disorder of the myocardium. As a clinical entity, it has been recognized for two centuries, but it defies traditional diagnostic tests. A greater understanding of the immune response underlying the pathobiology of the disorder can lead to a more rational therapeutic approach. The presentation, course and therapeutic options appear to be different in the pediatric compared with the adult population. An understanding of the difference between fulminant and acute progressive myocarditis has led to successful treatment strategies. A variety of new therapies are available, including antiviral agents, immunosuppression, and modulation of the biological response to inflammation. The specific question for patients with myocarditis is whether regimens designed to reduce or eliminate inflammation can provide clinical benefits compared with conventional heart failure therapy. This review highlights pathological mechanisms, modalities of diagnosis, and novel therapies which may improve outcomes.

[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.

[Transient left myocardial dysfunction: a cause of neonatal hypoxemia]

Refractory hypoxemia in the newborn requires an accurate diagnostic investigation for an optimal and prompt management.

CASE REPORT

After a short delivery, a post-term newborn developed a severe hypoxemia with patchy pulmonary alveolar opacities and systolic right-to-left extrapulmonary shunting through the ductus arteriosus. Echocardiography ruled out a cardiac malformation and showed dilated left atrium with left-to-right shunting by the ovale foramen due to left ventricular dysfunction. Inotropic support associated with mechanical ventilation allowed a rapid improvement.

CONCLUSION

A pathophysiological analysis is needed in case of severe neonatal hypoxemia. Doppler ultrasound is a non invasive and rapid method allowing the adjustment of the therapeutic strategy.

Enterovirus infections: diagnosis and treatment

Enteroviruses cause infections that present in diverse ways and affect people of all ages. Infections peak during summer and fall epidemics and cause 10 to 15 million symptomatic infections annually in the United States. The 70 enteroviral serotypes cause illness that ranges from nonspecific fevers and rashes to life-threatening myocarditis or central nervous system disease. These common infections create a significant burden on our society and healthcare system. New developments in rapid diagnosis of enterovirus infections using polymerase chain reaction (PCR) positively affect patient management and have the potential to reduce the healthcare impact of enterovirus infection. The future holds promise for effective antiviral drugs that can treat enterovirus infections and decrease their significant morbidity and mortality.

Acute myocarditis

Myocarditis is defined as inflammation of the myocardium accompanied by myocellular necrosis. Acute myocarditis must be considered in patients who present with recent onset of cardiac failure or arrhythmia. Often there is a history of an antecedent flu-like illness. Fulminant myocarditis is a distinct entity characterized by sudden onset of severe congestive heart failure or cardiogenic shock, usually following a flu-like illness. Giant cell myocarditis is a rare, frequently fatal disorder of unknown origin characterized by presence of giant cell inflammatory infiltrate in the myocardium. In recent years we have made good progress in understanding the causes, pathogenesis, natural history, diagnosis, and treatment of myocarditis. However, our knowledge is still far from complete. New information that extends our understanding of myocarditis is being reported constantly. This review summarizes recent advances in myocarditis, with an emphasis on the literature during the last year.

Association of viral genome with graft loss in children after cardiac transplantation

BACKGROUND

The survival of recipients of cardiac allografts is limited by rejection, lymphoproliferative disease, and coronary vasculopathy. The purpose of this study in children who had received heart transplants was to evaluate the cardiac allografts for myocardial viral infections and to determine whether the presence of viral genome in the myocardium correlates with rejection, coronary vasculopathy, or graft loss.

METHODS

We enrolled heart-transplant recipients 1 day to 18 years old who were undergoing evaluation for possible rejection and coronary vasculopathy. Endomyocardial-biopsy specimens were evaluated for evidence of rejection with the use of standard criteria and were analyzed for the presence of virus by the polymerase chain reaction (PCR).

RESULTS

PCR analyses were performed on 553 consecutive biopsy samples from 149 transplant recipients. Viral genome was amplified from 48 samples (8.7 percent) from 34 patients (23 percent); adenovirus was found in 30 samples, enterovirus in 9 samples, parvovirus in 5 samples, cytomegalovirus in 2 samples, herpes simplex virus in 1 sample, and Epstein-Barr virus in 1 sample. In 29 of the 34 patients with positive results on PCR (85 percent), an adverse cardiac event occurred within three months after the positive biopsy, and 9 of the 34 patients had graft loss due to coronary vasculopathy, chronic graft failure, or acute rejection. In 39 of the 115 patients with negative results on PCR (34 percent), an adverse cardiac event occurred within three months of the negative PCR finding; graft loss did not occur in any of the patients in this group. The odds of graft loss were 6.5 times as great among those with positive results on PCR (P=0.006). The detection of adenovirus was associated with considerably reduced graft survival (P=0.002).

CONCLUSIONS

Identification of viral genome, particularly adenovirus, in the myocardium of pediatric transplant recipients is predictive of adverse clinical events, including coronary vasculopathy and graft loss.

Diagnosis and treatment of pediatric viral myocarditis

Acute myocarditis is characterized by the rapid development of life-threatening congestive heart failure and arrhythmias. Although the initial stages of this disorder apparently result from direct cytopathic effects on the atrial and ventricular myocardium, later stages of progressive decompensation may result from immune-mediated myocyte destruction. There has been recent improvement in understanding the role of this immunologic cascade. As a result, treatment now begins earlier in the course of the disease and can target both the virus and the immune response. Our ability to implement mechanical support in children as a bridge to transplant or recovery, even in children presenting in the final stages of their disease, has led to an improved outcome regarding morbidity and mortality.

Ventricular dysfunction clinical research in infants, children and adolescents

These two issues of Progress in Pediatric Cardiology comprehensively illustrate the wealth of currently available information on the pathophysiology of heart failure, age-related myocardial responsiveness, energy metabolism, cardiopulmonary interactions, the pressure-volume relationship, the systemic inflammatory response, the management of heart failure, pediatric pharmacology, the use of heart failure therapies including digoxin, ACE inhibitors, beta-adrenergic blockers, inotropic agents, diuretics, vasodilators, calcium sensitizers, angiotensin and aldosterone receptor blockers, growth hormone, and future gene therapy. The etiology and course of ventricular dysfunction in children is poorly characterized. Furthermore, many changing developmental properties of the pediatric myocardium and differences in the etiologies of ventricular dysfunction in children compared with adults are illustrated in these articles, invalidating the concept that children can safely be considered small adults for the purpose of understanding heart failure pathophysiology and treatment. However, these articles reveal that strikingly little research in children with ventricular dysfunction exists in terms of well-designed large-scale studies of the epidemiology or multicenter controlled clinical therapeutic trials. A future research agenda is proposed to improve understanding etiologies, course and treatment of ventricular dysfunction in children that is based on organized and funded cooperative groups since no one pediatric cardiac center treats enough children with a particular etiology of ventricular dysfunction. In conclusion, significant understanding of basic mechanisms of pediatric ventricular dysfunction and effective therapies for adults with ventricular dysfunction exist. A multicenter pediatric cardiac ventricular dysfunction network would allow improved understanding of diseases and treatments, and result in evidence-based medicine for pediatric patients with ventricular dysfunction.

Molecular Aspects of Myocarditis

Myocarditis is an acquired form inflammatory heart muscle disease, manifested as acute and chronic conditions. While many etiologies have been reported, the most common cause of this disease is infection, primarily viral. Typically, the specific causative agent(s) and mechanism(s) are elusive. Over the past several years, various new findings have added to our understanding of myocarditis. These include the identification of adenoviruses as important causative agents, a new receptor protein likely to play an important role in the virulence of certain agents affecting the myocardium, and the effect of viruses on the cardiac cytoskeleton. This report reviews the current understanding of myocarditis, proposes a hypothesis about the long-term sequelae, and suggests possible new therapeutic strategies.

Hepatitis C virus infection in a patient with dermatomyositis and left ventricular dysfunction

Hepatitis C virus (HCV) infection is frequently associated with autoimmune disease. We present here a case of dermatomyositis manifested as heart failure in which HCV was detected from an endomyocardial biopsy sample. HCV infection may have contributed to the left ventricular dysfunction in this patient with dermatomyositis.

Pediatric cardiac intensive care: current state of the art and beyond the millennium

Pediatric cardiac intensive care has emerged as a distinct clinical entity to meet the unique needs of pediatric patients with congenital and acquired heart disease. This new subspecialty demands expertise and experience in the pediatric subspecialties of cardiology, intensive care, cardiac surgery, cardiac anesthesia, neonatology, and others. Ten recent developments will have an impact on pediatric cardiac intensive care for the coming decades: 1) emergence of new patient populations; 2) new clinical methodologies in the treatment of pulmonary hypertension; 3) innovations in techniques of respiratory support; 4) expanding research of single ventricle physiology; 5) advances in the treatment of heart failure; 6) improved noninvasive imaging; 7) new directions in interventional cardiac catheterization; 8) new techniques in pediatric cardiac surgery; 9) use of computer technology and intensive care monitoring; and 10) appreciation for global economics of intensive care. Finally, a multidisciplinary approach with a team esprit de corps remains vital to a successful pediatric cardiac intensive care program.