Bradycardia: causes, symptoms, treatment
Bradycardia is a condition in which the heart beats at a slower rate than normal, that is, the heart rate (heart rate), or heart rate, is less than 60 beats per minute. Normally, in a healthy person, heart rate is from 60 to 100 beats per minute.
Bradycardia is not an independent disease, but a symptom that indicates abnormalities in the heart. It can be the result of heart diseases or pathologies of other organs and systems.
But bradycardia can also be physiological, that is, it is a variant of the norm. As a rule, physiological bradycardia is characteristic of athletes or people engaged in heavy physical labor.
What causes bradycardia?
Pathological bradycardia is caused by the fact that the conductivity of the electrical impulse to the heart muscles is disturbed. It is the electrical impulse produced by the sinus node, the so-called pacemaker, that causes the muscles to contract, and the heart to beat, providing blood circulation in the body. This process occurs automatically and continuously. When it is broken, the heart begins to beat slower and bradycardia occurs. If the violation occurs during the formation of an impulse in the sinus node, they speak of sinus bradycardia, but if the impulse is generated normally, but then a failure occurs during it, they speak of heart block.
How is bradycardia manifested?
Bradycardia (both sinus and heart block) is manifested by the following symptoms:
discomfort in the heart;
feeling of lack of air, shortness of breath;
dizziness and fainting;
short-term loss of vision;
These symptoms may appear to a greater or lesser extent, and they may be present all or only some of them. Often, manifestations of bradycardia are mistaken for signs of fatigue or age. Bradycardia is diagnosed by heart rate (less than 60 beats per minute) and ECG changes.
Depending on the severity, three degrees of bradycardia are distinguished:
light – heart rate of 50-60 beats per minute;
moderate – 40-50 beats per minute;
pronounced – less than 40 beats per minute.
With mild to moderate bradycardia, symptoms are usually absent, as blood circulation is not impaired. But with severe bradycardia, circulatory disorders occur, which causes the above symptoms. With a heart rate of 30 to 40 beats per minute, a person feels weak, he gets tired quickly, has difficulty concentrating, there is palpitations, dizziness and shortness of breath, pallor of the skin, and vision may be impaired. With a pulse of less than 30 beats per minute, fainting or convulsions are possible. Fainting with severe bradycardia is called Morgagni – Adams – Stokes syndrome. In this case, the blood supply to the brain is disturbed, and the patient needs urgent medical care.
What are the causes of bradycardia?
Pathological bradycardia can be caused by heart diseases (cardiac causes) and diseases of other organs and systems (extracardial causes).
Cardiac causes include: coronary heart disease, myocardial infarction, chronic heart failure, cardiomyopathy, myocarditis, endocarditis, heart defects, age-related changes in the heart. Bradycardia can also cause tumors and brain injuries, meningitis, high intracranial pressure, hypothyroidism, cerebral edema, flu, hepatitis, gastric and duodenal ulcer, some tumors, etc.
Bradycardia may occur when taking certain medications (pharmacological bradycardia): beta-blockers, cardiac glycosides, antiarrhythmic drugs, etc. In this case, bradycardia disappears after taking the drug.
Pathological bradycardia can occur in acute or chronic form. Acute bradycardia occurs suddenly, in conditions that injure the heart – heart attack, poisoning. Chronic bradycardia lasts for years, accompanying severe illnesses that occur for a long time.
What is the danger of bradycardia?
If there are no symptoms of bradycardia, then it does not pose any danger to health, and even more so to life. Nevertheless, its presence may indicate that some pathological process takes place in the body. Therefore, if bradycardia is detected, it is necessary to conduct an examination and, if necessary, to treat the disease with which bradycardia is associated.
Fainting is dangerous with bradycardia, as it can lead to cardiac arrest.
How is bradycardia treated?
If bradycardia is not accompanied by symptoms, then it does not need to be treated. In the event of low blood pressure, heart failure, arrhythmias, fainting, treatment is carried out, which depends on the causes of bradycardia. In case of heart disease, the installation of a pacemaker is indicated. If bradycardia was the result of another, non-cardiac pathology, you should start with the treatment of the underlying disease. In addition, medications that increase heart rate are also used.