Myocarditis is an inflammatory disease of the heart muscle (myocardium), and while it is very rare (only around 1000 people in the USA develop it each year), it is quite serious. It attacks men and women of all ages and results from various causes. While most cases are produced by a virus, it can be brought on by toxins, drugs, and hypersensitive immune reactions.

Most cases of myocarditis in the U.S. originate from a virus, and the disease may remain undiagnosed by doctors because its lacks early symptoms. Or it may suddenly strike people as an acute, catastrophic illness which needs immediate treatment. Although this inflammation or degeneration of the heart may be fatal, it often goes undetected. It may also disguise itself as various types of heart disease.

While myocarditis has many causes, the main one is viral. Myocarditis usually results from the Coxsackie B virus, and may also result from measles, influenza, chicken ox, hepatitis virus, or the adenovirus in children. Additional causes of myocarditis include:

Additional causes of myocarditis include:

– Bacterial infections, such as tetanus, gonorrhea, or tuberculosis
– Parasite infections, such as Chagas' disease (which is caused by an insect-borne protozoan most commonly seen in Central and South America)
– Rheumatic fever
– Heart surgery
– Radiation therapy for cancer that is localized in the chest, such as breast or lung cancer
– Particular medications.

Myocarditis may start as fatigue, shortness of breath, fever and aching joints, all traits of a flu-like illness. But myocarditis may strike suddenly, in the form of heart failure, or sudden cardiac death without any previous symptoms. If inflammation of the heart muscle leads to congestive heart failure, symptoms such as swollen ankles and feet, distended neck veins, a rapid heartbeat, and difficulty breathing while reclining may all appear.

For sudden severe myocarditis, patients may have the following symptoms:

– Rhythm disturbances of the heart
– Rapid heartbeat (Ventricular tachycardia)
– Left or right ventricular enlargement
– Shortness of breath (Dyspnea)
– Pulmonary edema (the accumulation of fluid in the lungs due to left-sided heart failure)
– Swollen legs.

Diagnosis

The symptoms may help a doctor diagnosis the problem. An ECG test may show some abnormality. Other tests may be tried to find the cause of the inflammation. For example, blood tests, a scan of the heart (echocardiogram), or others.

While myocarditis is serious, no medical treatment is necessary if it results from a general viral infection. The only steps to recovery are rest and avoidance of physical activity. Rest becomes more important to recovery if the case is severe myocarditis with signs of dilated cardiomyopathy (disease of the heart muscles). Then medical treatment for congestive heart failure may include the following medications: angiotensin converting enzyme (ACE) inhibitors, diuretics to reduce fluid retention, digitalis to stimulate a stronger heartbeat, and low-dose beta-blockers.

When myocarditis is caused by bacteria, antibiotics are used to fight the infection. If severe rhythm disturbances are involved, cardiac assist devices, an "artificial heart," or heart transplantation may be the only option for total recovery.

For the more uncommon causes, or if complications develop, a range of treatments may be needed. For example:

– Oxygen.
– Medication to treat heart failure or arrhythmias.
– pacemaker if certain arrhythmias develop.
– Antibiotics if the cause of the myocarditis is a bacterial infection.
– Steroid medication if the cause is giant-cell myocarditis.
– Stopping consumation of alcohol if alcohol is the cause.

For most cases of viral myocarditis, the illness goes away on its own, and there are no complications. Symptoms may last only a few days or weeks. However, more serious viral infections can cause severe or persistent inflammation and complications.

Complications may with the more uncommon causes of myocarditis. Sometimes the inflammation clears but the heart is permanently damaged, leaving some heart failure which may require long-term medication.

In some cases, the inflammation and heart damage is so severe that the only option is a heart transplant. Some cases of 'sudden death' are due to severe myocarditis, which develops quickly.

Although myocarditis is an unpredictable disease, the following measures may help prevent its onset. Individuals should:

– Take extra care to stay clear of infections, and treat infections appropriately.
– Restrict alcohol consumption to no more than one or two drinks a day.
– Maintain current vaccinations against diphtheria, tetanus, measles, rubella, and polio.
– Avoid anything that may cause the abnormal heart to work too hard, including salt and intense exercise.