Long-term outcome of fulminant myocarditis as compared with acute (nonfulminant) myocarditis

Nonpharmacologic treatment of acute heart failure

Acute heart failure is unusual in the pediatric population, but in many situations it justifies aggressive therapy. For example, children with lymphocytic myocarditis have an overall survival rate of nearly 90%, with complete myocardial recovery for the majority. Pharmacologic agents traditionally have been the mainstay of medical therapy for acute heart failure, but, in recent years, there has been increasing interest in using measures that reduce the myocardial workload. This article highlights nonpharmacologic approaches to the management of severe heart failure in the critically ill child. It also concentrates on physiologic approaches that address the balance between oxygen demand and delivery; the manipulation of cardiopulmonary interactions to optimize ventricular function; and the use of mechanical circulatory support as a method of achieving ultimate myocardial rest.

The outcome of idiopathic dilated cardiomyopathy and myocarditis in children from the west of Scotland

We analysed retrospectively all infants and children with idiopathic dilated cardiomyopathy (IDC) and myocarditis at the Regional Cardiac Centre of the Royal Hospital for Sick Children, Glasgow, during 1980-1997. Among the 39 patients with IDC, 25 (64%) were infants aged < 1 year, eight (20.5%) had wheezing as the presenting symptom, and only six (15%) had a significant cardiac murmur. Thirty-eight of thirty-nine patients diagnosed in life were followed-up for 1 day to 15 years (median 3 years). Twelve of the thirty-nine (31%) died, six deaths were within a week of presentation and the rest within a year. The survival at 1 year and at 12 years was 0.69 (95% CI 0.54 to 0.84). Fourteen patients had histologically proven myocarditis, and all 9/14 (64%) detected at post-mortem and one of the five diagnosed in life died. Patients with myocarditis exhibited an actuarial survival of 0.29 (95% CI 0.04 to 0.53) at 1 year and at 9 years, significantly lower than IDC patients (log rank 9.8, P < 0.01). There was no difference in the outcome for patients with positive or negative Coxsackie titres or who presented in the 1980s and in the 1990s. No risk factor that independently influenced the outcome or survival could be identified in either group. Thus our study from a relatively well-defined population of the west of Scotland showed that a significant proportion of children with IDC and myocarditis died in the first week of illness and that patients with myocarditis had shorter survival.

Myocarditis in patients with clinical presentation of myocardial infarction and normal coronary angiograms

OBJECTIVES

The aim of this study was to assess the diagnosis of myocarditis in patients presenting with acute myocardial infarction (MI) and normal coronary angiograms.

BACKGROUND

Most often in these patients, the etiologic diagnosis remains unclear once they are found to have normal coronary arteries. The diagnosis of myocarditis mimicking MI is clinically relevant, because numerous arguments suggest a relation between myocarditis and dilated cardiomyopathy. Myocardial indium-111 (111In)-antimyosin antibody (AMA)/rest thallium-201 (201Tl) imaging allows noninvasive detection of myocarditis.

METHODS

Forty-five patients admitted to three intensive care units for suspicion of acute MI, with normal coronary angiograms, were investigated. Indium-111-AMA planar images and then a dual-isotope rest AMA/201Tl tomographic study were performed. Six-month echocardiographic follow-up was obtained in 80% of the patients with initial left ventricular (LV) wall motion abnormalities.

RESULTS

In eight patients, AMA and 201Tl scintigraphy were negative. In two patients, a matched 201Tl defect and focal AMA uptake suggested acute MI (due to prolonged vasospasm or spontaneously reperfused coronary occlusion). In 17 patients, diffuse AMA uptake over the whole LV suggested diffuse myocarditis. In 18 patients, focal AMA uptake with a normal 201Tl scan suggested diffuse but heterogeneous, or focal myocarditis. Complete functional recovery was observed in 81% of the patients with a pattern of myocarditis.

CONCLUSIONS

Among 45 patients presenting with acute MI and normal coronary angiograms, 38% had diffuse myocarditis and 40% had a scintigraphic pattern of heterogeneous or focal myocarditis. Short-term follow-up showed complete LV functional recovery in 81% of these patients.

Mechanical circulatory support for patients with acute-fulminant myocarditis

This report provides a review of mechanical circulatory support for patients in cardiogenic shock secondary to acute/fulminant myocarditis. Experience and outcomes with extracorporeal membrane oxygenation, left ventricular assist device support (ABIOMED, Thoratec, Thermo Cardiosystems, Novacor), and biventricular ventricular assist device support (ABIOMED, Thoratec) are described. Patients in cardiogenic shock secondary to acute myocarditis in its fulminant presentation can recover, surprisingly with normal cardiac function. An aggressive approach to the use of mechanical support is strongly justified. Survival, either by bridge to transplant or recovery, should approach 70%. Transplantation can often be avoided.

Etiology, evaluation, and management of acute myocarditis

The evaluation and management of acute myocarditis remain two of the most difficult challenges that general internists and cardiologists face today. Although the majority of cases are subclinical and self-limited, the true prevalence of myocarditis in the general population is unknown. In its most severe form, patients with myocarditis may present with rapidly progressive heart failure, cardiogenic shock, or complex arrhythmia. Indeed, acute myocarditis should be in the differential diagnosis of acute heart failure, particularly in young and previously healthy individuals.

Predictors of disease course in patients with acute myocarditis

BACKGROUND

Clinical manifestations of acute myocarditis, with distinct onset, vary from asymptomatic to fatal. The predictors of the course of the disease in patients with acute myocarditis at initial presentation have not yet been established. In this study, we examined the predictive values of various parameters in the disease course of patients with myocarditis.

METHODS AND RESULTS

Twenty-one consecutive patients who had been diagnosed as having acute myocarditis by histological examinations were analyzed. The patients with myocarditis were divided into the survival group (n=13) and the fatal group (n=8). We examined the parameters of the clinical state, hemodynamic variables, required therapies, biochemical laboratory data, and cytokines. The control groups were composed of 23 patients with old myocardial infarction and 20 healthy volunteers. The fatal group had lower blood pressure and higher pulmonary capillary wedge pressure compared with those values in the survival group. Mechanical ventilation support was more frequently required in the fatal group. Serum levels of soluble Fas (sFas) and soluble Fas ligand (sFasL) were significantly higher in the myocarditis group than in the 2 control groups. Furthermore, levels were significantly higher in the fatal group than in the survival group for sFas (13.93+/-4.77 versus 3.77+/-0.52 ng/mL, respectively; P:<0.001) and sFasL (611.4+/-127.7 versus 269.5+/-37.3 pg/mL, respectively; P:<0.05). Other clinical states, hemodynamic variables, required therapies, and biochemical laboratory parameters were not different between the 2 groups.

CONCLUSIONS

Elevation of sFas and sFasL levels at initial presentation appear to be a good serological marker to predict the prognosis of acute myocarditis.

Myocarditis

Myocarditis and its sequela, dilated cardiomyopathy (DCM), cause substantial morbidity and mortality, especially in children and young adults. Physicians should include myocarditis in the differential diagnosis of all patients who have new symptoms of heart failure, arrhythmia, or chest pain syndromes of unclear cause, and should strongly consider performing endomyocardial biopsy (EMB) to establish the diagnosis. It may be necessary to perform multiple or serial biopsies to increase sensitivity. Patients with myocarditis and symptomatic heart failure, chest pain, or arrhythmias need hospitalization for evaluation and treatment. Patients with symptomatic left ventricular dysfunction should be treated with conventional heart failure therapy, including angiotensin-converting enzyme (ACE) inhibitors, digitalis, diuretics, and beta-blockers. Patients with arrhythmias or syncope may require electrophysiologic evaluation. In addition to conventional therapy, physicians should consider a course of immunosuppressive therapy in selected patients. The clinical course, response to therapy, and left ventricular function need close monitoring. Patients with myocarditis and rapidly progressive heart failure or cardiogenic shock should be referred early to an advanced heart failure center for implantation of a ventricular assist device and consideration for cardiac transplantation.

Host gene regulation during coxsackievirus B3 infection in mice: assessment by microarrays

Host genetic responses that characterize enteroviral myocarditis have not yet been determined. The injurious and inflammatory process in heart muscle may reflect host responses of benefit to the virus and ultimately result in congestive heart failure and dilated cardiomyopathy. On the other hand, host responses within the myocardium may secure the host against acute or protracted damage. To investigate the nature of modified gene expression in comparison with normal tissue, mRNA species were assessed in myocardium using cDNA microarray technology at days 3, 9, and 30 after infection. Of 7000 clones initially screened, 169 known genes had a level of expression significantly different at 1 or more postinfection time points as compared with baseline. The known regulated genes were sorted according to their functional groups and normalized expression patterns and, subsequently, interpreted in the context of viremic, inflammatory, and healing phases of the myocarditic process.

Echocardiographic findings in fulminant and acute myocarditis

OBJECTIVES

We sought to use echocardiography to assess the presentation and potential for recovery of left ventricular (LV) function of patients with fulminant myocarditis compared with those with acute myocarditis.

BACKGROUND

The clinical course of patients with myocarditis remains poorly defined. We have previously proposed a classification that provides prognostic information in myocarditis patients. Fulminant myocarditis causes a distinct onset of illness and severe hemodynamic compromise, whereas acute myocarditis has an indistinct presentation, less severe hemodynamic compromise and a greater likelihood of progression to dilated cardiomyopathy.

METHODS

Echocardiography was performed at presentation and at six months to test the hypothesis that fulminant (n = 11) or acute (n = 43) myocarditis could be distinguished morphologically.

RESULTS

Patients with both fulminant (fractional shortening 19 +/- 4%) and acute myocarditis (17 +/- 7%) had LV systolic dysfunction. Patients with fulminant myocarditis had near normal LV diastolic dimensions (5.3 +/- 0.9 cm) but increased septal thickness (1.2 +/- 0.2 cm) at presentation, while those with acute myocarditis had increased diastolic dimensions (6.1 +/- 0.8 cm, p < 0.01 vs. fulminant) but normal septal thickness (1.0 +/- 0.1 cm, p = 0.01 vs. fulminant). At six months, patients with fulminant myocarditis had dramatic improvement in fractional shortening (30 +/- 8%) compared with no improvement in patients with acute myocarditis (19 +/- 7%, p < 0.01 for interaction between time and type of myocarditis).

CONCLUSIONS

Fulminant myocarditis is distinguishable from acute myocarditis by echocardiography. Patients with fulminant myocarditis exhibit a substantial improvement in ventricular function at six months compared with those with acute myocarditis. Echocardiography has value in classifying patients with myocarditis and may provide prognostic information.