Myocarditis is an inflammation of the heart muscle from any cause.
What is going on in the body?
Inflammation can change the heart in many ways. It can make it weaker and affect the way it functions. Inflammation can cause certain areas of the heart muscle to die. Sometimes only a small area is affected, but serious cases may involve the entire heart.
What are the causes and risks of the condition?
There are many causes of this condition, including:
- infections, usually viral, but occasionally of bacterial, fungal, or rickettsial origin
- autoimmune disorders, such as rheumatoid arthritis, which occur when a person's immune system attacks his or her own body
- radiation therapy, which may be given to treat cancer in the chest
- exposure to chemicals or drugs, such as cocaine or a medication used to treat cancer, called doxorubicin
- Drugs, such as certain chemotherapeutic agents, antibiotics, anticonvulsants, and diuretics
Other causes are possible, and sometimes the cause is unknown.
What can be done to prevent the condition?
Often nothing can prevent this condition. Avoiding exposure to drugs known to cause this condition, such as cocaine, may prevent some cases.
How is the condition diagnosed?
A healthcare provider may suspect this condition after taking a person's health history and doing a physical exam. The provider may order a variety of tests, including:
- ECG (a heart tracing)
- chest x-ray
- echocardiogram, an imaging test that uses ultrasound waves to look at blood flow and pressures within the heart
- blood cultures to check for infection in the blood
- blood tests to look for heart muscle damage (troponim I)
- biopsy of the heart muscle, which involves taking a small piece of heart muscle for testing in the lab
Long Term Effects
What are the long-term effects of the condition?
Often this condition is silent, causing few or no symptoms, and goes away on its own. Most people recover completely. Rarely, a person may develop permanent congestive heart failure, arrhythmias, and damage to the heart muscle, known as cardiomyopathy.
What are the risks to others?
There are no risks to others.
What are the treatments for the condition?
If an infection can be identified, antibiotics are sometimes helpful. If a biopsy of the heart muscle shows active inflammation, corticosteroids or other anti-inflammatory medications maybe useful.
A variety of medications can be used to treat the complications of this condition, such as congestive heart failure and arrhythmias. In severe cases, a person may need a heart transplant to survive.
What are the side effects of the treatments?
All medications have possible side effects. For instance, diuretics may cause allergic reactions, dehydration, and salt imbalances. Medications used to treat irregular heartbeats may cause other irregular heartbeats, stomach upset, or allergic reactions. A heart transplant is high risk surgery that can result in infections, bleeding, or death. However, for some persons, it is the only option for survival beyond a few days to weeks.
What happens after treatment for the condition?
Most people fully recover from this condition. For some, however, heart function may get worse over time. The end result may be permanent heart muscle damage, such as dilated cardiomyopathy. In this condition, the heart muscle becomes thin and flabby, and is unable to pump blood effectively. Someone with this condition will need ongoing treatment and in extreme cases, a heart transplant.
How is the condition monitored?
Routine visits to a healthcare provider for monitoring of the heart's function are needed.
Merck Manual, 1999
Harrison's Principles of Internal Medicine, 1991
Current Medical Diagnosis and Treatment, 1996