Tachycardia. Causes and Treatment
The state when the number of heartbeatsmeasured from 90 or more beats per minute, is called tachycardia. The increase in heart rate as a result of fear, excitement or additional physical activity is a normal physiological phenomenon. But there is still such a thing as pathological tachycardia. The reasons for which this condition is considered harmful, are as follows:
- the work of the heart becomes ineffective, sinceblood supply of various organs and tissues of the body decreases because of lowering of arterial pressure due to incomplete filling of the ventricles with blood;
- because of the risk of developing a heart attack or coronary heart disease due to poor blood supply to the heart and lack of oxygen, while increasing the load on it.
This phenomenon is not considered a disease: It is known that with various diseases there is a symptom such as tachycardia. The causes that are often repeated are characterized by different forms of arrhythmia, disorders of autonomic (otherwise, vegetative) nervous system, hemodynamic disorders. They are explained by the structure and principle of the heart, which consists of four chambers: the two upper chambers (atria) and the two lower chambers (ventricles). The rhythm of the heart is usually controlled by a sinus node that is in the right atrium (more precisely, in its side wall), which is a natural pacemaker. The sinus node produces electrical impulses, usually starting with each heart beat. From the sinus node, electrical impulses pass through the atria, cause contractions in the muscles of the atria and the supply of blood to the ventricles. When electrical impulses reach the muscles of the ventricles, they contract, resulting in blood flowing into the artery and entering the lungs and other organs and tissues of the body.
The sinus node is excited at a frequency that dependsfrom the sympathetic (part of the autonomic nervous system, the nerve nodes of which are located remotely from the innervated organs) and parasympathetic (part of the autonomic nervous system that works with the sympathetic nervous system) stimulation. If sympathetic or parasympathetic innervation is violated, as well as sinus node proper pathology, a sinus (or ventricular) tachycardia occurs. Its causes lie in the malfunctioning of the sinus node itself or in internal problems.
There are also external problems, for example, failures inwork of the autonomic nervous system. As a result of disturbances in the sympathetic nervous system (increased stimulation), palpitation appears, that is, there is tachycardia. The reasons for the rapid heartbeat of healthy people are due to the use of caffeine. Failures in the endocrine system may be accompanied by an increase in the production of adrenaline and lead to tachycardia. For external reasons, hemodynamic response can be attributed when, with a decrease in blood pressure (due to blood loss, sudden changes in body position or dehydration of the body), due to the feedback mechanism, the frequency of heart beats increases.
You can list the main causes of tachycardia.
- Damage to the heart muscle due to heart disease.
- Congenital anomalies of electrical impulses, as well as diseases and congenital anomalies of the heart itself.
- High pressure.
- Abuse of alcohol, fever, smoking, drinking too many caffeinated drinks.
Side effect of drugs.
- Abuse of recreational drugs, such as cocaine.
- Imbalance of electrolytes, minerals required to conduct electrical impulses.
- Hyperfunction of the thyroid gland (hyperthyroidism). In some cases, the exact cause of tachycardia can not be determined, it is called ideopathic.
How to cure tachycardia? Methods of treatment depend on the cause, age and state of health of the patient, as well as some other factors. The task is to slow down the accelerated heart rate, prevent subsequent episodes of tachycardia and reduce the risk of complications. It is often enough to prescribe treatment for hyperthyroidism. In other cases, when the cause is not found, the doctor will have to try other methods. To restore normal heartbeat, antiarrhythmic injections (flecainide or propafenone) are administered. Exposure to the heart by electric current (cardioversion affects the heart to electrical impulses and restores a normal rhythm) can be used for emergency care when other methods of treatment do not work. Implantation defibrillator-cardioverter, which controls the heartbeat and provides an electric current to restore the correct heart rate.