Treatment of Myocarditis
In order to treat myocarditis, the underlying cause must first be treated (etiotropic therapy). Otherwise, there will be a relapse in the disease. Only after this issue has been addressed can the doctors concentrate on treating myocarditis.
The treatment of myocarditis is generally aimed at treating heart failure, improving cardiac hemodynamics, and providing supportive therapy in order to increase the quality and prolong the patient’s life. The treatment of myocarditis, for the most part, is the same, regardless of the underlying cause.
Etiotropic therapy
Treatment that can focus on the underlying cause can yield the most results. For example, in cases of myocarditis caused by bacterial infection, antibiotics should be used. However, since many bacteria cause an autoimmune reaction, antibacterial therapy is not enough to combat this disease.
Despite the fact that the main focus of treatment is reducing the inflammation, NSAIDs have proven to be ineffective and even detrimental to the treatment of the patient with myocarditis. Animal studies have shown that using NSAIDs during acute and subacute phases of myocarditis greatly increases inflammation (two-three fold), caused myocytes necrosis, and increased mortality. This effect is attributed to the fact that NSAIDs decreased viral clearance and increased cytotoxic response. Moreover, NSAIDs come in conflict with ACE inhibitors which are often used for chronic heart failure caused by myocarditis.
Similarly, immunosuppression therapy (use of prednisolone and other immunosuppressants) has been proven to be fruitless, except in treatment of giant cell myocarditis and cardiac sarcoidosis. Three large-scale clinical trials have shown no significant benefits for using immunosuppression therapy.
Antiviral treatment using intravenous immunoglobulin (IVIG) has been shown to work no better than placebo, except in one study conducted on children with acute myocarditis done by Drucker and colleagues.
Supportive care
- First of all, physical activity should be avoided as much as possible. Returning to normal physical activity should be done only after 6 months after the treatment of myocarditis is over. Moreover, patients with stable heart failure are even recommended to have physical exercise.
- Treatment of myocarditis (especially in severe cases) begins by establishing cardiac and hemodynamic monitoring.
- Supplemental oxygen is also a necessary step, as it lowers the hypoxia of the body’s tissues caused by the heart failure.
- Finally, fluid management is essential for the recovery of the patient. Heart failure often leads to retention of the fluids within the body, leading to elevated blood pressure and excessive strain on the heart’s muscle.
Drug therapy
Drugs used for treating myocarditis include the following:
- Vasodilators
- Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers – these drugs allow lowering the blood pressure by decreasing the tension of blood vessels. These drugs can also reduce cardiac remodeling which leads to dilated cardiomyopathy. Besides, ACE inhibitors and ARBs significantly reduce inflammation, fibrinosis and necrosis caused by viral myocarditis.
- Diuretics – work by expelling the excess water within the body effectively lowering the blood pressure. However, it should be noted that loop diuretics shouldn’t be used for a long period of time, since they can cause levels of potassium to drop, which in turn leads to arrhythmia and bradycardia, worsening the patient’s condition.
- Beta-blockers – should be used with great caution since most of them slow down the heart rhythm, which can greatly worsen the condition of the patient with heart failure. These drugs improve ventricular function and increase survival. The type of beta-blocker also makes a difference on the outcome of the disease. For example, experimental data shows that carvedilol has a cardioprotective effect, since it suppresses the inflammatory cytokines and has antioxidant properties. Metoprolol and propranolol on the other hand do not exhibit similar effects.
- Aldosterone antagonists – are recommended for treating patients with systolic heart failure. Moreover, one of the members of this family of drugs – eplerenone has an anti-inflammatory effect, which has shown to suppress fibrosis and myocardial remodeling.
Surgical therapy
Myocarditis can often lead to a number of complications including heart failure and arrhythmias. Sometimes these conditions cannot be treated using drug therapy and the doctors have to resort to surgery:
- In cases when patients with acute myocarditis have atrioventricular block II or III, a temporary pacemaker should be implanted. If AV block III is persistent, though it happens rarely, a permanent pacemaker should be installed. This device is also installed in patients with bradycardia or congestive heart failure.
- Implantable cardiac defibrillator. Patients who are at risk of having sudden ventricular fibrillation as a result of damage to the electrical conduction system of the heart by myocarditis. This device is able to detect cardiac arrhythmia and send an electrical impulse to restore the normal rhythm of the heart.
- Percutaneous circulatory support – percutaneous ventricular assist devices allow for effective ventricular unloading, while maintaining a good blood flow throughout the rest of the body. For example, an intra-aortic balloon pump counterpulsation can substantially decrease the strain the heart experiences while improving the blood flow in the coronary arteries and throughout the rest of the body.
- Installing a ventricular assist device – an artificial circulatory device that can be used to replace the function of a heart. Some of these devices are meant for short-term use (for example, recovering from heart surgery or heart attack). In other cases a long-term device is installed, which can be used for years, and sometimes for the whole life of the patient (patients suffering from severe congestive heart failure).
- Extracorporeal membrane oxygenation. This technique can provide the patient with respiratory and cardiac support when their heart or lungs can no longer function. This is a temporary solution as it is a very complicated procedure and leads to a large number of complications.
- Heart transplantation. In many cases myocarditis can quickly lead to severe heart failure which cannot be treated using drugs. In such cases cardiac transplantation is in order. This can be done either by using a donor’s heart or an artificially-made heart. The downside of using donor organs is that the person has to use immunosuppressive drugs for the rest of their lives in order to prevent the organ from being rejected by the body. Artificial hearts, on the other hand, and not yet up to par with the real ones, however, technologies improve with each passing year, bringing a fully functional artificial heart closer and closer to reality.
Prognosis for myocarditis varies greatly from person to person. As mentioned above, sometimes myocarditis can pass unnoticed. In other cases it can quickly lead to severe heart failure resulting in death unless the heart is replaced. People with myocarditis are also at risk for sudden arrhythmias, which can prove to be fatal. These arrhythmias can be prevented by implanting a defibrillator which will restart the heart in case.
