Myocarditis is the inflammation of the heart muscle. It presents with varied mild to severe symptoms including dyspnea, chest pain, syncope, palpitations, fatigue, arrhythmias, heart congestion, cardiogenic shock and sudden death. Long term complications of myocarditis include dilated cardiomyopathy and chronic heart failure. It usually affects young adults ranging from 20-51 years of age and autopsy studies have shown about 12% death cases in patients less than 40 years.
Both, infectious and non-infectious causes have been implicated in the disease process; however, some idiopathic cases are also noted. Viral infection (adenovirus, enterovirus) is the most common cause in North America and Western Europe. Other infectious causes include bacteria (chlamydia, haemophilus, legionella), protozoa (entamoeba, leishmania), spirocheta (borrelia, leptospira), fungi (actinomyces, aspergillus, candida), helminthics (ascaris, schistosoma), and rickettsia (Coxiella burnetii, R. rickettsii). Non-infectious causes include autoimmune diseases (IBD, systemic lupus erythematosus, giant cell myocarditis), systemic diseases (Churg-Strauss syndrome, celiac disease, sarcoidosis, collagen disease), drugs (anthracyclines, amphetamines, cocaine), venoms hypersensitivity reactions (bee, wasp, spider, snakes), drugs hypersensitivity reactions (NSAIDs, azithromycin, benzodiazepines), radiation therapy, heart stroke, hypothermia and transplant rejection.(1)
How To Cope With Myocarditis?
The management of myocarditis presenting as dilated cardiomyopathy is standard heart failure therapy. These include angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, beta-blockers (bisoprolol, carvedilol, and metoprolol) and diuretics as recommended by AHA/ACCF and ESC guidelines for heart failure management.
The use of non-steroidal anti-inflammatory drugs is contraindicated in myocarditis as they are known to increase inflammation and are associated with higher mortality rates. It is also important to use digoxin in low doses and with caution as it is associated with increased mortality when used in high doses in murine models of viral myocarditis.
Antiviral therapy (ribavirin, interferon) is found effective in preventing the onset of cardiomyopathy and reducing the severity and mortality of the disease. However, in established cases of myocarditis, ribavirin does not have much role, though interferon is effective in eliminating viral genome and improving left ventricular function.(1)
Intravenous immunoglobulin has antiviral as well as immunomodulating effects that point towards its effectiveness in acute viral myocarditis. Although, it has shown to improve left ventricular function in pediatric patients, it has no effect in adult population.
The role of immunosuppressive therapy is still controversial in the management of myocarditis. Where some randomized controlled trials in patients with acute myocarditis and idiopathic dilated cardiomyopathy have found the effectiveness of prednisone, azathioprine and cyclosporin of little value, some studies have found corticosteroids and cyclosporin effective in the treatment of giant cell myocarditis. A recent trial of Therapy in Inflammatory Dilated Cardiomyopathy showed effectiveness of prednisone and azathioprine in the improvement of left ventricular ejection fraction. Therefore, immunosuppressive therapy can be considered in chronic virus negative dilated cardiomyopathy in cases where optimal medical therapy is proved ineffective.(2)
Arrhythmias are treated with select medications and temporary or permanent pacemakers. Although, arrhythmias resolve after few weeks, symptomatic or persistent ventricular tachycardia requires treatment with antiarrhythmics or implantable cardioverter-defibrillator or cardiac transplantation.(1)
Patients with cardiogenic shock may benefit from mechanical circulatory support. It is especially beneficial for adult or pediatric patients with fulminant myocarditis in shock, in whom short term recovery is expected. However, for acute myocarditis patients, who do not benefit from optimal medical therapy, ventricular assist device is more effective.
Rest is paramount to cope with myocarditis and is important for complete recovery from the disease. Therefore, it is very important to avoid physical exertion and vigorous physical exercises for at least 6 months or longer after the onset of symptoms. Recovery is based on the normalization of left ventricular function, after which the exercises can be resumed. This is based on the fact that myocarditis is associated with increased mortality with aerobic exercise and that acute myocarditis has resulted in sudden death of young athletes. It is also pertinent to stay away from alcohol and cardiotoxic drugs that have the potential to worsen the disease state.(1)
- Is Myocarditis Contagious?
- Can Myocarditis Kill You?
- Life Expectancy For Myocarditis
- What Is The Prognosis For Myocarditis & How Can I Recover Fast?
- Is Troponin Elevated In Myocarditis?
- What Is The Difference Between Myocarditis And Pericarditis?
- How Do You Get Myocarditis & How Do You Know If You Have It?