In diseases caused by viruses, problems in the upper respiratory tract are most common, this situation is called flu. In addition, viruses affect many organ systems, some viruses can affect organs such as the liver, and this is called hepatitis. Some viruses are known to cause heart problems, although not very often. These problems often progress with less obvious symptoms and do not cause any permanent heart problems. However, the disease called myocarditis may have a very severe course in some patients and may cause heart failure in the long term.
What is myocarditis?
Myocarditis is a rare inflammatory heart muscle disease, accounting for approximately 25% of heart muscle diseases. It is characterized by disruption of cardiac muscle cells. It is an important disease in terms of causing long-term problems in the heart muscle. We do not know its true frequency, as it progresses with very mild symptoms in many patients and the rate of complete recovery is high.
What causes myocarditis?
The most common cause of myocarditis is viral infections. Among virus infections, “cocsackie” and adenovirus are the most common agents. Apart from these viruses, it is known that all known viruses can cause myocarditis. It can develop due to various drugs, toxic substances and other system diseases.
How does myocarditis occur?
Viruses enter the heart muscle cells, multiply there and cause damage to the cells. In this period, if the rate of dysfunctional heart cells is too high in some patients, sudden heart failure may develop. During this formation, the pericardium is also frequently affected. This condition is called myopericarditis.
In a group of patients, antibodies are formed by the immune system against the unusual proteins that leak into the circulation from the heart muscle cells affected by the viruses, and these antibodies damage the heart muscle cells. As a result, the structure of the heart muscle deteriorates and a picture of insufficiency in the heart muscle, which we call cardiomyopathy, develops.
What are the symptoms of myocarditis?
Clinical manifestations are very diverse. It can range from mild weakness to shock. General signs of deterioration of the general condition are observed in young infants, such as feeding problems, paleness and vomiting. In older children, the most common symptom is chest pain unrelated to exertion. This symptom develops mostly due to the effect of the heart membrane. It lasts for a few hours, in some patients the complaints may continue for up to 24 hours. Pain is often in the form of pressure. Findings such as spreading to the arm and sweating are often absent. Pain does not change with breathing.
Other findings include rhythm problems. Ventricular arrhythmias are the most common rhythm problems. Ventricular premature beats are common, while ventricular tachycardia is rare. In rapidly progressing cases, signs of heart failure may progress very rapidly.
How is it diagnosed?
There is often a history of viral infection within a few weeks in the history. In some patients, a clear history of viral infection may not be detected.
Examination findings of many patients are often normal. An increase in heart rate may occur. This finding is frequently observed in subclinical cases. Irregularity in heart rhythm can be noticed by listening. In severe cases, there may be signs of heart failure.
What is seen in the laboratory?
Changes due to edema in the heart muscle in the EKG; conduction disorders and premature beats can be observed. Echocardiographic examination does not detect any significant finding in most patients. Findings due to mild valve insufficiency and fluid accumulation in the pericardium may be observed. In severe cases, decreased left ventricular contractions and severe valve insufficiency may be observed. Deterioration of heart wall movements can be detected by advanced echocardiographic methods.
In laboratory examinations, troponin and creatine kinase myocardial band, which indicates damage to the heart muscle, may be observed, as well as elevated liver function tests. There are no definite limits in this regard. In patients presenting with chest pain, the diagnosis can be made by performing troponin and other blood tests. Myocarditis should be suspected in patients presenting with chest pain and high troponin levels. Isolation of viruses is very difficult and can be done in some specialized centers.
Cardiac magnetic resonance imaging is a very useful method in the diagnosis of myocarditis. In the early period, edema in the heart muscle is prominent. In many patients, often no abnormality can be detected. This method is very successful in showing the increase in connective tissue that develops in the heart muscle in the late period in patients with myocarditis.
In suspected cases, pathological examination and virus studies can be performed by performing a biopsy from the heart muscle. This diagnostic method should be used if there is severe heart muscle involvement.
How should myocarditis be treated?
Patients with cardiac muscle involvement or pericardial fluid accumulation should be taken seriously. Commonly used drugs for treatment are non-steroidal anti-inflammatory drugs. These drugs are used for 4-6 weeks depending on the severity of the disease. In some patients, intravenous immunoglobulin (IVIG) can be given, but its efficacy is controversial. In addition, more complicated treatments such as cortisone, azathioprine, cyclosporin A, interferon alfa and OKT3 can be used when necessary. Among them, immunoglobulin and cortisone are the most preferred treatment methods.
If there is heart failure or fluid accumulation in the pericardium in the early period, rest at home is recommended. Patients diagnosed with myocarditis should avoid heavy exercise. Exercise restriction can be removed when patients with abnormality detected by echocardiography or MRI reach normal values.
Treatment of heart failure and arrhythmias in patients with myocarditis remains important. Medications should be used in the treatment of heart failure. Interventional methods can be life-saving in patients for whom adequate effect cannot be achieved. Patients who develop severe heart failure in the early period can get rid of this situation with appropriate treatment.
Do patients with myocarditis have a long-term heart problem?
2/3 of patients with myocarditis recover completely. Approximately 10% of patients develop serious heart problems that require continued treatment. Other patients have non-serious heart problems. Myocarditis is more severe in newborn babies and is more likely to leave a permanent heart problem.
In the long term, problems with rhythm may develop due to the increase in connective tissue in the heart muscle. Patients with this condition should be checked at regular intervals.
