Management of acute myocarditis in children

Myocarditis is defined as the inflammation of the myocardium. It continues to be a significant cause of morbidity and mortality in the paediatric population and is the commonest cause of cardiac failure in a healthy child. Some studies estimate the incidence of myocarditis to be around 1 per 100 000. PubMed search was performed using the term 'myocarditis.' The search was limited to age 0-19 years. A total of 50 articles were identified between 1966 to date and reviewed. Myocarditis is a challenging diagnosis to make on clinical grounds and requires high index of suspicion. The cornerstone of treatment remains supportive though therapeutic modalities such as immunosuppressive and intravenous immunoglobulin therapies are being studied extensively. The overall prognosis of the disease is good with survival rates up to 80%.

[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. Fulminant myocarditis is a distinct entity characterized by sudden onset of severe congestive heart failure or cardiogenic shock, usually following a flu-like illness, parvovirus B19, human herpesvirus 6, coxsackievirus and adenovirus being the most frequently viruses responsible for the disease. Treatment of myocarditis remains largely supportive, since immunosuppression has not been proven to be beneficial for acute lymphocytic myocarditis. Trials of antiviral therapies, or immunostimulants such as interferons, suggest a potential therapeutic role but require further investigation. Lastly, early recognition of patients rapidly progressing to refractory cardiac failure and their immediate transfer to a medical-surgical center experienced in mechanical circulatory support is warranted. In this setting, ECMO should be the first-line mechanical assistance. For highly unstable patients, a Mobile Cardiac Assistance Unit, that rapidly travels to primary care hospitals with a portable ECMO system and hooks it up before refractory multiorgan failure takes hold, is the preferred option.

Prediction of residual valvular lesions in rheumatic heart disease: role of adhesion molecules

Rheumatic heart disease (RHD) is a chronic condition characterized by fibrosis and scarring of the cardiac valves and damage to the heart muscle, leading to congestive heart failure and death. This prospective cohort study was conducted to investigate the possible relation between the levels of serum adhesion molecules and acute rheumatic fever (ARF) carditis, valvular insult severity, and residual valvular lesion after improvement of rheumatic activity. Serum levels of intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin were assayed by enzyme-linked immunoassay (ELISA) for 50 children with ARF carditis during activity and after improvement and for 50 healthy children as control subjects. After the acute attack, patients were followed up regularly to detect residual valvular lesion. The serum levels of these adhesion molecules were significantly higher in the patients than in the control group (p < 0.001). In addition, the levels of serum adhesion molecules were significantly higher in the patients with severe carditis than in the patients with mild to moderate carditis (p < 0.001). Among the severe carditis group, the level of serum adhesion molecules was significantly higher among the patients with heart failure than among the patients without heart failure (p < 0.001). Furthermore, the pretreatment serum levels of ICAM-1 and VCAM-1 were significantly higher among the patients with residual valve lesion (p = 0.002) than among those without the lesion (p < 0.001). The cutoff values were obtained for the prediction of residual valvular lesion (ICAM-1, >1,032.3 μg/ml; VCAM-1, >3,662.3 μg/ml; E-selectin, >104.8 μg/ml). Finally, by combining the three adhesion molecules in a single prediction model, the highest area under the curve (AUC) ± standard error (SE) was obtained (0.869 ± 0.052), and the positive likelihood ratio for having a residual valvular lesion was increased (17.33). Levels of serum adhesion molecules could predict residual valvular lesions in RHD patients. The authors recommend that the serum level of adhesion molecules be measured in all cases of ARF carditis.

[Analysis of distribution and pathological characteristics of 9 fatal trichinosis cases in Yunnan]

OBJECTIVE

To explore forensic pathology features of the fatal trichinosis cases and to summarize the population distribution characteristics of trichinosis in Yunnan.

METHODS

Nine recent fatal trichinosis cases were collected from the Forensic Science Identification Center of Kunming Forensic Hospital. Pathological and epidemiological characteristics of trichinosis were analyzed.

RESULTS

The nine cases were all died in heart failure due to myocarditis. Among them, 1 case was complicated by encephalitis and 3 cases were complicated by pneumonia. The population mainly involved Bai and Dai nationalities. The geographic distribution was concentrated in Dali, Dehong, Lincang, Xishuangbanna, etc. The cases commonly appeared in winter and spring.

CONCLUSION

The cause of trichinosis is closely due to the habit of eating raw pork. It can be diagnosis through the pathological changes of the muscle system in the death cases.

Prevalence of acute kidney injury and prognostic significance in patients with acute myocarditis

Objective

Myocarditis is an inflammation of the myocardium. The condition is commonly associated with rapid disease progression and often results in profound shock. Impaired renal function is the result of impairment in end-organ perfusion and is highly prevalent among critically ill patients. The aim of this study was to evaluate the incidence of acute kidney injury (AKI) and identify the relationship between AKI and the prognosis of patients with acute myocarditis.

Design, Measurements and Main Results

This retrospective study reviewed the medical records of 101 patients suffering from acute myocarditis between 1996 and 2011. Sixty of these patients (59%) developed AKI within 48 hours of being hospitalized. AKI defined as AKIN stage 3 (p = 0.007) and SOFA score (p = 0.03) were identified as predictors of in-hospital mortality in multivariate analysis. The conditional effect plot of the estimated risk against SOFA score upon admission categorized according to the AKIN stages showed that the risk of in-hospital mortality was highest among patients in AKIN stage 3 with a high SOFA score.

Conclusions

Among patients with acute myocarditis, AKI defined as AKIN stage 3 and elevated SOFA score were associated with unfavorable outcomes. AKIN classification is a simple, reproducible, and easily applied evaluation tool capable of providing objective information related to the clinical prognosis of patients with acute myocarditis.

Demographics, trends, and outcomes in pediatric acute myocarditis in the United States, 2006 to 2011

BACKGROUND

There is a lack of clear diagnostic and management guidelines for acute myocarditis in the pediatric population. We used a multi-institutional database to characterize demographics, practice variability, and outcomes in this population.

METHODS AND RESULTS

Patients with acute myocarditis (n=514) were identified from April 2006 to March 2011 using the Pediatric Health Information System database, and regional variations in management and outcomes were analyzed. Ninety-seven patients (18.9%) received extracorporeal membrane oxygenation, 22 (4.3%) received ventricular assist device, 21 (4.1%) received heart transplantation, and 37 (7.2%) died. Of the 104 patients who received extracorporeal membrane oxygenation or ventricular assist device, 17 (16.3%) had heart transplantation, 25 (24%) died, and 62 (59.6%) showed recovery of myocardial function. There was a decrease in the use of endomyocardial biopsy (P=0.03) and an increase in the use of magnetic resonance imaging (P<0.01) over the study period. Although the use of medications and procedures varied between different regions, the occurrence of death or heart transplantation showed no significant regional associations. The use of extracorporeal membrane oxygenation (odds ratio, 5.8; 95% confidence interval, 2.9-11.4; P<0.01), ventricular assist device (odds ratio, 8.2; 95% confidence interval, 2.7-24.9; P<0.01), and vasoactive medications (odds ratio, 5.7; 95% confidence interval, 1.2-26.1; P=0.03) was independently associated with death/transplantation.

CONCLUSIONS

There is significant temporal and regional variation in the diagnostic modalities and management used for pediatric myocarditis, which continues to have high morbidity and mortality. Extracorporeal membrane oxygenation, ventricular assist device, and vasoactive medications are independently associated with increased mortality/transplantation.

Cardiogenic shock due to left ventricular outflow obstruction and complete atrioventricular block in a patient with hypertrophic cardiomyopathy with acute myocarditis

A 67-year-old woman was referred to our hospital with a sudden syncopal attack. She suffered from cardiogenic shock due to left ventricular (LV) outflow stenosis with simultaneous complete atrioventricular (AV) block. An endomyocardial biopsy of the left ventricle demonstrated myocardial disarray and myocardial fibrous and edematous tissue with infiltration of mononuclear cells. Cardiac magnetic resonance imaging (cMRI) detected a damaged septal area that was likely associated with the conduction disturbance. The diagnosis was hypertrophic cardiomyopathy accompanied by acute myocarditis. Although the LV outflow stenosis was transient, the complete AV block was persistent, thus requiring permanent pacemaker implantation.

[Inflammatory-destructive biomarkers of atherosclerotic plaques instability. Study of arterial wall and blood]

Concentrations of tumor necrosis factor, interleukin 1- and its receptor antagonist, IL-6, IL-8, IL-18, IL-2, ligand of CD40 receptor (CD40L), high sensitive C-reactive protein (hsCRP), monocyte chemotactic protein -1, endothelial monocyte activating protein II, adhesive molecules (sICAM-1 and sVCAM-1), matrix metalloproteinase (MMP-3, MMP-7, MMP-9), tissue inhibitor of metalloproteinase (TIMP-1) and endothelin-1 were studied in blood and in coronary artery intima/media of men with coronary atherosclerosis without acute coronary syndrome. Blood levels of hsCRP, IL-8, IL-6 and CD40L were higher, while blood levels of sVCAM and TIMP-1 were lower in men with prevalence of unstable atherosclerotic plaques compared to men with prevalence of stable atherosclerotic plaques in coronary arteries. Blood levels of hsCRP, IL-6 and IL-8 correlated with characteristics of coronary artery atherosclerotic plaques instability. Correlation between hsCRP blood level and hsCRP concentration in coronary artery intima/media material was also revealed.

Comparative evaluation of left and right ventricular endomyocardial biopsy: differences in complication rate and diagnostic performance

BACKGROUND

Endomyocardial biopsy (EMB) represents the gold standard for diagnosing myocarditis and nonischemic cardiomyopathies. This study focuses on the risk of complications and the respective diagnostic performance of left ventricular (LV), right ventricular (RV), or biventricular EMB in patients with suspected myocarditis and/or cardiomyopathy of unknown origin.

METHODS AND RESULTS

In this 2-center study, 755 patients with clinically suspected myocarditis (n=481) and/or cardiomyopathy of nonischemic origin including those with infiltrative or connective tissue disease (n=274) underwent either selective LV-EMB (n=265; 35.1%), selective RV-EMB (n=133; 17.6%), or biventricular EMB (n=357; 47.3%) after coronary angiography and exclusion of significant coronary artery disease. Cardiovascular magnetic resonance, including late gadolinium enhancement, imaging was performed in 540 patients (71.5%). The major complication rate for LV-EMB was 0.64% and for RV-EMB, 0.82%. Considering postprocedural pericardial effusion that occurred after biventricular EMB, the minor complication rate for LV-EMB varied between 0.64% to 2.89% and for RV-EMB, between 2.24% and 5.10%. Diagnostic EMB results were achieved significantly more often in those patients who underwent biventricular EMBs (79.3%) compared to those who underwent either selective LV-EMB or selective RV-EMB (67.3%; P<0.001). In patients with biventricular EMB, myocarditis was diagnosed in LV-EMB samples in 18.7% and in RV-EMB samples in 7.9% (P=0.002) , and it was diagnosed in both ventricles in 73.4%. There were no differences in the number of positive LV-EMB, RV-EMB, or LV- and RV-EMB findings when related to the site of cardiovascular magnetic resonance-based late gadolinium enhancement.

CONCLUSIONS

Both LV-EMB and RV-EMB are safe procedures if performed by experienced interventionalists. The diagnostic yield of EMB may be optimized when samples from both ventricles are available. Preferential biopsy in regions showing late gadolinium enhancement on cardiovascular magnetic resonance does not increase the number of positive diagnoses of myocarditis.

Influenza-related viral myocarditis

Seasonal influenza outbreak is responsible for significant morbidity and mortality around the world. The disease can be severe, leading to rapid worsening of breathing and culminating in death. The pulmonary manifestations are prominent and may mask the involvement of other organs, such as the heart. This paper will discuss the incidence, clinical manifestations, and management of viral myocarditis in a modest attempt to heighten awareness of acute viral myocarditis for early recognition and prompt management during seasonal episodes of influenza infection.

Use of a percutaneous left ventricular assist device for high-risk cardiac interventions and cardiogenic shock

OBJECTIVE

We sought to describe the use of the TandemHeart percutaneous left ventricular assist device (PVAD) in a group of high-risk patients undergoing complex cardiovascular procedures.

BACKGROUND

There is a substantial risk of acute decompensation and death in patients with cardiogenic shock or a reduced cardiac reserve undergoing high-risk cardiovascular interventions. The TandemHeart PVAD provides near-total hemodynamic support in this setting.

METHODS

Thirty-seven high-risk patients underwent placement of the TandemHeart PVAD during 38 separate procedures between April 2007 and April 2009. PVAD insertion was considered emergent if a patient was not expected to survive more than 6 hours without PVAD support. Technical success was defined as successful initiation of the PVAD and completion of the intended interventional procedure.

RESULTS

All 37 patients were in cardiogenic shock or undergoing complex coronary and valvular interventions with a high probability of hemodynamic collapse. The mean (+/- standard deviation) patient age was 73 +/- 14 years; 97% were in either NYHA class III-IV heart failure or cardiogenic shock; and the mean EuroSCORE was 11 +/- 3.4. Indications for ventricular assist device placement included critical aortic stenosis (n = 8), severe left main coronary stenosis (n = 18), severe multivessel coronary stenosis (n = 19) and severe cardiomyopathy (n = 23). Four patients were being managed for fulminant myocarditis, ventricular free-wall rupture, flail mitral valve or severe paravalvular leak. Despite their critical status and frequent (82%) need for post-procedure blood transfusion, this complex and high-risk patient population tolerated PVAD-supported intervention well and technical success was achieved in all patients. Seventy-one percent of patients survived to hospital discharge with improved functional status. Most deaths occurred in patients not expected to survive due to their moribund status and multiorgan failure.

CONCLUSION

This experience demonstrates the utility and effectiveness of TandemHeart PVAD support in patients with advanced disease, critical clinical status and limited therapeutic options.

[Myocarditis and cardiomyopathy: underestimated complications resulting from clozapine therapy]

BACKGROUND

Treatment with clozapine can affect the heart, leading to serious complications such as myocarditis and cardiomyopathy. When in their early stages both illnesses are difficult to diagnose; this can have serious consequences. Recent analyses of clozapine data suggest that particularly myocarditis is possibly more common than has been assumed hitherto.

AIM

To determine the frequency of these complications and to find out what diagnostic tests are available and whether it is necessary or possible to adjust current guidelines on these complications.

METHOD

The relevant literature was consulted via PubMed, Embase Psychiatry and Psycinfo on the basis of the keywords 'clozapine' and 'myocarditis', 'cardiomyopathy' and 'heart failure'.

RESULTS

Studies showed that the incidence of myocarditis varied from 0.015 to 1.3%. Cardiomyopathy was the subject of fewer studies, one study reported an incidence of 0.022%. More than 50% of the cases of myocarditis developed during the first few weeks of treatment, the average time being about 15 days. For an early diagnosis it is important to monitor the patient's symptoms carefully, especially during the first four weeks following the start of medication. Monitoring should include laboratory tests and electrocardiography. Echocardiography and MRI can be useful additions to the diagnostic process.

CONCLUSIONS

Early diagnosis of myocarditis is important because it is a serious condition. Timely recognition of subclinical myocarditis could possibly prevent later complications such as cardiomyopathy. Clinical guidelines are proposed on the basis of the literature.

Routine performance of endomyocardial biopsy decreases the incidence of orthotopic heart transplant for myocarditis

BACKGROUND

In critically ill children presenting with dilated cardiomyopathy (DCM), the presence of myocarditis predicts an improved chance of myocardial recovery. Noninvasive differentiation of myocarditis from other causes of DCM is difficult. However, sensitivity of endomyocardial biopsy has been questioned.

METHODS

We reviewed clinical, echocardiographic, catheterization, and pathology data from all children admitted to the intensive care unit with DCM undergoing orthotopic heart transplantation since the inception of our transplant program in 1987 and all patients with definitively diagnosed myocarditis presenting since 1996.

RESULTS

Thirty-six patients with DCM underwent orthotopic heart transplantation. Cellular infiltrate was present in 3 of 36 (8.3%) explanted specimens. Pre-transplant biopsy was performed in 81%. No explanted heart demonstrated infiltrates after a negative biopsy. One biopsy was positive with negative explant histology after transplant 6 months later. No patient with biopsy-proven myocarditis died while listed for transplantation. Eleven additional patients with myocarditis did not undergo transplant. Ten have survived and experienced complete (n = 9) or near complete (n = 1) recovery of myocardial function. One patient died shortly after presentation from fulminant myocarditis. The 10 transplant-free survivors could not be easily distinguished from our transplant cohort by clinical features at presentation.

CONCLUSION

The incidence of cellular infiltrate in explanted hearts was significantly lower than that previously reported. Potentially, our aggressive myocarditis diagnostic protocol was useful in therapeutic stratification as a cohort of myocarditis patients avoided transplant and experienced complete recovery of myocardial function despite being difficult to distinguish clinically from our DCM transplant cohort at presentation.

Kawasaki disease - an Indian perspective

Kawasaki disease (KD) was first reported from Japan in 1967 by a young pediatrician, Tomisaku Kawasaki, while working at the Red Cross Hospital in Tokyo. Soon therafter, Marian Melish independently reported children with a similar clinical profile from Hawaii in the United States. KD has now been reported from all parts of the world, including several centers in India. Based on the epidemiology and clinical features, an infectious etiology has been suspected for long but no definitive causative agent has been implicated so far. Like many other vasculitides, the diagnosis of this condition is based on the recognition of a temporal sequence of clinical features, none of which is pathognomonic in isolation. KD is believed to be the commonest vasculitic disorder of children. Incidence rates as high as 60-150 per 100,000 children below 5 years of age have been reported from several countries. In India (as also perhaps in many other developing countries), however, majority of children with KD continue to remain undiagnosed probably because of the lack of awareness amongst pediatricians. The clinical features of KD can be confused with other common conditions like scarlet fever and the Stevens Johnson syndrome, if the clinician is not careful. Development of coronary artery abnormalities (CAA) is the hallmark of KD and accounts for most of the morbidity and mortality associated with the disease. Prompt recognition of the disease and early initiation of treatment with intravenous immunoglobulin (IVIG) results in significant reduction in the occurrence of CAA. It is, therefore, imperative for the pediatrician to diagnose and treat KD expeditiously. KD should be considered in the differential diagnosis of all febrile illnesses in young children where the fever persists for more than 5-7 days.

Influenza A1 myocarditis in conscripts

The incidence of viral myocarditis was studied prospectively at the Central Military Hospital 1 in Finland in connection with an A1 virus influenza epidemic in Jan. 1978. Of 104 conscripts taken consecutively to hospital because of a sudden respiratory infection, 41 had serologically confirmed influenza A, 37 were serologically negative, while in 26 it was not possible to carry out complete virological analyses. Six of the serologically confirmed influenza patients had acute myocarditis on the basis of serial electrocardiographic ST segment and/or T wave changes, unresponsive to beta-blockade. The incidence of the influenza A myocarditis was thus 9% of the 67 verified and suspected cases of influenza taken together. Multidirectional echocardiography revealed regional myocardial dysfunction in all the influenza patients with myocarditis; the MB-CK isoenzyme was elevated in 3 of them. The ECG changes found in connection with influenza thus commonly indicate the presence of myocardial involvement, usually a mild one.

Field and laboratory evidence that Bungowannah virus, a recently recognised pestivirus, is the causative agent of the porcine myocarditis syndrome (PMC)

In 2003 an outbreak of sudden deaths occurred in 2-3-week-old piglets on a piggery in New South Wales, Australia. There was a marked increase in the birth of stillborn piglets and preweaning losses associated with a multifocal non-suppurative myocarditis with myonecrosis. The aim of this study was to review existing data and to undertake further investigations of specimens from naturally infected pigs to provide evidence to support the hypothesis that Bungowannah virus, a recently recognised pestivirus, causes the porcine myocarditis syndrome (PMC). Sera collected from gilts and sows from affected and unaffected units were tested for Bungowannah virus antibody by a peroxidase-linked assay and Bungowannah virus RNA by qRT-PCR in selected cases. Stillborn piglets from affected and an unaffected unit were also tested for Bungowannah virus antibody and RNA. Body fluid IgG levels and the incidence of myocardial lesions in these stillborn piglets are summarised. Tissue sections from stillborn piglets with myocarditis/myonecrosis were examined for Bungowannah virus RNA by in situ hybridisation. A clear temporal association between the occurrence of PMC on a unit or module and exposure to Bungowannah virus was identified by serological tests in both breeding aged animals and stillborn pigs. In addition, at the individual animal level on affected units, Bungowannah virus RNA was detected in stillborn piglets in large amounts by qRT-PCR and in association with myocardial lesions by in situ hybridisation. The examination of field material from cases of PMC by serology, qRT-PCR and in situ hybridisation provides strong indirect evidence that Bungowannah virus is the causative agent for PMC.