Approach Considerations
Medical therapy for congestive heart failure (CHF) is fairly standard. [1] The general principles of therapy for CHF are applicable to patients with myocarditis. These principles include the manipulation of preload, afterload, and contractility. Therefore, fluid restriction and diuretics, inotropic support to optimize contractility with continuous intravenous (IV) inotropic agents, and IV vasodilator agents, are all important potential interventions for CHF caused by myocarditis of a nonviral origin.
Additional general maneuvers to reduce the workload of the heart, thereby improving symptoms of CHF, include the following:
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Inotropes via continuous drip
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Afterload reducing agents
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Diuretics
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Digitalis
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Beta-blockers
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Mechanical ventilation
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Arrhythmia therapy
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Anticoagulation
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Metabolic demand reduction
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Bed rest
Treatment of the specific causes of the myocarditis (ie, bacterial sepsis, rickettsial disease) is necessary. However, it is still not entirely clear if the use of immunosuppressive therapy for myocarditis is indicated. [1, 2]
Some rationale for immunosuppressive therapy for myocarditis has been put forth, because the pathophysiology of myocarditis appears to involve the immune system's reaction against the myocardium. Adult studies have failed to clearly determine the role of immunosuppressive therapy. Some preliminary data suggest that certain combinations of immunosuppressive agents may be beneficial in patients with acute myocarditis. [19]
Guidelines recommendations
The Heart Failure Society of America does not recommend routine use of immunosuppressive therapies for patients with myocarditis. [1] The European Society of Cardiology guidelines have the following recommendations regarding immunosuppressive therapies for myocarditis [9] :
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Only initiate immunosuppression after active infection has been ruled out on endomyocardial biopsy by polymerase chain reaction.
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Consider immunosuppression in proven autoimmune (eg, infection-negative) forms of myocarditis, without immunosuppression contraindications (eg, giant cell myocarditis, cardiac sarcoidosis, myocarditis associated with known extracardiac autoimmune disease).
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Steroid therapy is indicated in cardiac sarcoidosis in the presence of ventricular dysfunction and/or arrhythmia and in some forms of infection-negative eosinophilic or toxic myocarditis with heart failure and/or arrhythmia.
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On an individual patient basis, immunosuppression may be considered in infection-negative lymphocytic myocarditis refractory to standard therapy in patients with no contraindications to immunosuppression.
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Follow-up endomyocardial biopsy may be required to guide the intensity and the length of immunosuppression.
Surgical therapy
Surgical care for patient with myocarditis is primarily recommended if medical treatment fails and if the patient is symptomatic.
Some children with fulminant myocarditis develop progressive and fatal course and these patients should be supported by extracorporeal membrane oxygenation (ECMO) or ventricular assist devices (VAD) acutely. [7] Because complete recovery is possible in a high percentage of these patients, active consideration for mechanical circulatory support (ECMO or VAD) should be given to treat these children.
Surgical treatment may include cardiac transplantation for patients that develop a chronic, symptomatic dilated cardiomyopathy.
Pediatric ventricular assist devices (VADs) have been used as bridges to children with end-stage heart failure, including those resulting from myocarditis. [20]
Another surgical procedure that may be used is left ventricular volume reduction (Battista operation).
Inpatient care
Need for, and length of, inpatient care varies with severity of the illness. Prolonged supportive therapy may be required until the patient can resume spontaneous ventilation and be adequately maintained on oral anticongestive therapy.
Patient follow-up
Patients require close outpatient follow-up care with clinical assessment, electrocardiography, and echocardiography, [9] especially if significant residual CHF is present. Some patients may continue to have symptoms of moderate to severe CHF that may require eventual cardiac transplantation. However, some patients do completely recover and have normal cardiac function and may only need occasional follow-up evaluation.
Diet and Activity
Advise patients with chronic, moderate to severe heart failure that a "no-added-salt" diet is probably beneficial. Otherwise, ensure adequate calories and nutrition for growth.
During the acute phase of myocarditis, most clinicians agree that bed rest should be recommended (eg, ≥6 months [17] ) until the inflammation has resolved based on cardiac magnetic resonance imaging findings or endomyocardial biopsy results, as well as once cardiac function has normalized. [17]
Several animal studies have suggested that exercise during the acute viremia can potentiate the disease. However, after recovery and during the healing and/or chronic phases of myocarditis, activity as tolerated is believed to be acceptable.
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Pediatric nonviral myocarditis. This image is reveals myocarditis with scarring at autopsy. It is a short-axis gross photograph from an 8-year-old child who had clinical myocarditis, showing scarring of both ventricles, more prominent in the left. The fibrosis depicts a random distribution with epicardial, myocardial, and pericardial involvement.
