Viral myocarditis
Last reviewed: 23.04.2024
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Viral myocarditis is a pathological condition of viral genesis with myocardial damage (heart muscle). A large number of viruses can cause myocarditis, but you should pay attention to infection with Coxsackie A and B viruses, influenza, hepatitis, herpes and ECHO viruses.
Myocarditis of viral origin is most often observed during the epidemic of influenza. The pathogenesis of the disease is based on the defeat of the myocardium by viruses, the infection of which occurs 2-3 weeks before the development of myocarditis. The nature of the damage is infectious-allergic, which causes the clinic of the disease.
Myocarditis is detected only in a part of all cases, since it sometimes passes without typical manifestations and is masked for respiratory pathology. Viral myocarditis does not require specific treatment, as it can cure itself on its own, however, changes on the ECG and echocardiography persist for several more months.
Causes of viral myocarditis
In most cases, the causes of viral myocarditis are Coxsackie, hepatitis, herpes, rubella, adenovirus, poliomyelitis, influenza and ECHO viruses.
The most frequent causative agent of myocarditis is the Coxsackie virus, which belongs to the group of enteroviruses (RNA-containing). For the destruction of the heart muscle, this virus is characterized by seasonality, in particular summer and autumn.
In addition, Coxsackie is the cause of acute myopericarditis. The virus has a high tropism to the myocardium. Thanks to modern diagnostic methods, it is possible to identify the pathogen in myocardial cells, pericardium and heart valves.
The prevalence of the myocardium caused by Coxsacka reaches 50 percent of all cases of viral heart disease. The disease is observed at any age, but the most likely development of the myocardium in young and middle age.
The causes of viral myocarditis in the form of the Coxsackie virus can provoke pathology after 50 years in people suffering from ischemic injury of blood vessels.
Most often, men suffer from myocarditis and myopericarditis. In women, most cases of the disease occur during pregnancy and feeding. In the case of myocardial development in pregnancy, the probability of infection of the fetus increases, which can lead to stillbirth. As a consequence, myocarditis can be observed in newborns and throughout the first six months of life.
[Symptoms of viral myocarditis
The clinical symptoms of viral myocarditis, caused by the Coxsackie B virus, are characterized by a rise in body temperature, signs of inflammation of the gastric mucosa and intestines, for example, moderate pain in the epigastric region, nausea, vomiting, bowel dysfunction in the form of diarrhea.
When joining the symptoms of myocarditis, there are irregularities in the heart, pain and a sense of lack of air. However, in most cases, pleurodynia (pain syndrome with the movement of the chest, resulting from lesions of the pleura) is attached.
As the progression of the pathology may increase the size of the spleen, lymphadenopathy and orchitis. At the age of 20 years, there is an acute onset and adherence of pleurisy or pericarditis, but that is characteristic of the disease ends quickly and full recovery. At the age of more than 40 years, pathology has a more gradual onset with a predominance of cardiac symptoms (pain, dyspnea, palpitation), which is sometimes taken for angina due to coronary artery disease.
Symptoms of viral myocarditis can also have signs of upper respiratory tract dysfunction, heart failure, pain in the muscles, joints and chest.
If the cause of myocarditis is the influenza virus, which usually occurs during the epidemic, then signs of myocarditis develop within a week or two after infection. Influenza A virus affects the myocardium in 9.7% of all cases, and influenza B - 6.6%.
Symptoms in this case are represented by tachycardia, a violation of the rhythm of the heart, pain, shortness of breath and signs of heart failure. In most cases, the pericardium is affected.
Myocarditis can develop as a result of infection with the polio virus. Due to the fact that pathology is a serious disease, myocarditis can be registered after death. Myocardial infarction is focal with clinical signs of cardiac, vascular and respiratory failure, which are observed against a background of bulbar paralysis.
In addition, there is a possibility of myocarditis in the presence of viral hepatitis. In this case, the symptoms of the defeat of the heart muscle are noted for up to a week to 3 weeks.
Viral myocarditis in children
The acute form of myocardial damage is more common in infants. The most severe course in newborns and young children. Statistics indicate that boys suffer from myocarditis more often than girls.
The main factor in the development of severe myocarditis is considered insufficient immunity, which can be caused by frequent respiratory diseases, concomitant diseases, including chronic, excessive physical and psychoemotional stresses, as well as improper nutrition, day regimen and insufficient sleep.
In addition, viral myocarditis in children can be difficult if there is a genetic predisposition in the form of an inadequate immune response to the virus.
It is accepted to isolate acute myocarditis - up to 1.5 months, subacute - up to 2.5 years and chronic. In addition, babies can tolerate mild, moderate and severe myocarditis.
Symptoms of the defeat of the heart muscle are observed against the background of infection of the body with any virus. At first the general condition of the baby worsens, the hyperthermia grows, the skin turns pale, there is lethargy and reduced motor activity.
In infancy, the baby languidly sucks at the breast or refuses at all. In older age, children complain of pain in the whole body (joints, muscles, abdomen, heart), a feeling of lack of air (shortness of breath) and irregularities in the heart.
If viral myocarditis is detected in children, an objective examination of the doctor reveals an increase in the size of the heart. When listening to the work, the wrong rhythm of the heart is noted (extrasystoles appear - an extraordinary shortening), the pulse is rapid.
In addition, systolic murmur can be heard, which is clearly audible at the tip. It is associated with insufficiency of the mitral valve located between the left atrium and the ventricle of the heart.
With severe myocardial damage, heart failure is observed, which is more common in infancy. In most cases, myocarditis ends in recovery, but in some, persistent rhythm disturbances are possible due to the development of cardiosclerosis.
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Diagnosis of viral myocarditis
In order to correctly diagnose, you need to know all the details of the onset of the disease, and also to find a link with the previous viral pathology.
Diagnosis of viral myocarditis with suspected Coxsackie virus is the presence of a typical gastroenteritis clinic before the appearance of cardiac symptoms, as well as confirmation by laboratory methods of diagnosis.
They consist of the study of paired sera, where it is necessary to detect a fourfold increase in the titer of antibodies in the blood , the detection of the virus or its antigen in feces due to electron microscopy, as well as in other biological fluids.
In addition, immunoelectro-osmophoresis, detection in the blood of Coxsack RNA and in the myocardium using biopsy and the PCR method are widely used.
When ECG study reveals abnormal Q, changes in ST and T on the cardiogram. Quite often there are ventricular extrasystoles and AV conduction abnormalities. It is also worth noting the appearance of persistent diffuse changes in the work of the left ventricle.
Diagnosis of viral myocarditis in influenza is based on ECG research, when on the cardiogram, in addition to periodic changes in T and ST, there is an increase in heart rate, rhythm and conduction disorders with the appearance of AV blockades.
Cardiogram with myocarditis with a pathogen of poliomyelitis is characterized by nonspecific changes - an increase in PR, QT, the appearance of extrasystoles, tachycardia up to atrial fibrillation.
In addition to instrumental methods of diagnosis, a clinical blood test is used to identify the inflammatory process in the body and the heart muscle in particular. General indicators, such as accelerated ESR, increased levels of leukocytes and neutrophils, indicate the presence of an inflammatory focus in the body. The increase in sarcoplasmic enzymes - LDH and KFK - is indicative of myocardial damage.
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Treatment of viral myocarditis
Despite the cause of the defeat of the heart muscle, the treatment of viral myocarditis is more symptomatic. However, in each case, therapy should be selected individually, taking into account the severity of the pathology and the concomitant diseases.
In the presence of the Coxsackie virus, the use of drugs that directly affect the blood coagulation system, such as anticoagulants, should be avoided. Of course, there is a high probability of intracardiac thrombosis, but in this case it is necessary to prevent cardiac tamponade. The cause of it can be the appearance of hemorrhagic exudate in the pericardial cavity.
Treatment of viral myocarditis in type A influenza is based on the use of rimantadine, which should be taken within a week, starting no later than 2 days after the onset of the first symptoms of influenza. There are assumptions that when the virus B is infected, the use of ribavirin is effective, but this has no evidence base.
When poliomyelitis necessarily requires control of the respiratory function. In view of the development of bulbar paralysis in the pathogenesis, the respiratory and vascular center can later be affected, which threatens the patient's life.
Prevention of viral myocarditis
In some cases, the defeat of the cardiac muscle passes without clinical symptoms, but more typical typical cardiac manifestations are observed.
Prevention of viral myocarditis is the timely immunization of the population against such viruses as poliomyelitis, influenza and other pathogens.
However, vaccination does not provide 100% protection against infection. During the epidemic, it is necessary to use individual protective equipment and avoid contact with infected people who have clinical symptoms of the disease.
Nonspecific prophylaxis of viral myocarditis is to increase the body's immune defenses by walking in the fresh air, hardening, playing sports, taking vitamins, eating a balanced diet, and also enough sleep.
In addition, one should not be subjected to stressful situations and control the activity of chronic pathology. Increasing immunity, the body becomes more resistant to viral pathogens, which reduces the risk of developing viral myocarditis.
If infection does occur, it is necessary to start pathogenetic treatment in time in order to avoid prolonged circulation of the pathogen along the bloodstream and defeat of the heart muscle.
Prognosis of viral myocarditis
Most often, myocarditis ends in recovery, but there are cases when persistent changes remain on the cardiogram. The disease lasts for several weeks, but if serious complications develop, such as dilated cardiomyopathy, the risk of death is increased.
The prognosis of viral myocarditis when infected with the Coxsackie virus is very favorable, but it may take several months to restore the normal picture of the cardiogram. In the absence of full-fledged treatment, ECG changes can be persistent, which threatens human life.
In the presence of the influenza B virus, the body observes the development of myocarditis with severe consequences. Among them, it is necessary to focus on hemorrhagic syndrome with hemorrhage in the lung tissue and the development of edema, thromboembolic complications, which may lead to death.
To avoid the occurrence of severe conditions, you should use preventive measures and contact the doctor in a timely manner. As for the defeat of the heart muscle in the presence of viral hepatitis, it must be remembered that there is a high risk of developing congestive heart failure. As a result, a lethal outcome is possible.
Viral myocarditis affects people of all ages, but in the absence of an adequately selected treatment can have serious complications that threaten life. In order to avoid this, it is recommended to consult a doctor in case of an infectious disease and periodically to examine the heart with ECG and Echocardiography, which allows early detection of pathology.