Tachycardia is called rapid heartbeat, having any origin. It occurs if the heart rate becomes higher than 100 beats per minute.
In this case, the rhythm can remain correct, that is, the duration of the intervals between contractions of the heart is constant. A condition in which an attack of tachycardia begins suddenly and ends just as suddenly is called paroxysmal tachycardia.
It should be noted that there is no clear boundary between the absence of tachycardia and its presence. For example, the American Association of Cardiologists diagnoses tachycardia after exceeding the heart rate of 100 beats / min. Thus, it can be considered that a heartbeat within 90-100 beats is a borderline condition, which suggests a high risk of heart problems in the future.
The mechanism of development of tachycardia
The work of the heart is regulated by the plexus located in the right atrium, which is called the sinus node. It sets the rhythm and frequency of contractions due to the generation of nerve impulses, which through the conducting system spreads to the muscles (myocardium) of the heart and causes their contraction.
An increase in the number of pulses in the sinus node or other parts of the conduction system, respectively, causes an increase in the heart rate — tachycardia.
Why does heart tachycardia occur, what is it and how to treat it? It should be understood that tachycardia is a symptom, not a disease. Its causes lie in a number of other diseases, including:
- disorders of the autonomic nervous system;
- congenital anomalies of the heart, for example, extra chords in it;
- endocrine disorders (hyperthyroidism);
- hemodynamic disorders;
- various arrhythmias, etc.
Tachycardia can manifest itself as a normal reaction to emotional and heavy physical exertion, at an elevated temperature, due to drinking alcohol, from smoking.
Tachycardia is divided into 2 forms: physiological and pathological. The first may appear in a healthy person during normal heart function as a reaction to external factors, the second occurs in the presence of certain diseases.
Pathological tachycardia is harmful to the body:
- Firstly, in this case, an attack of tachycardia is dangerous, which is an intensive work of the heart: the ventricles do not have time to fill with blood, which leads to a decrease in blood pressure and the outflow of blood from the organs.
- Secondly, increased heart rate leads to a deterioration in the blood supply. The heart requires more oxygen, because it works more, and the deterioration of the blood supply conditions leads to the risk of developing ischemic disease and, as a result, to “earn” a heart attack.
Pathological tachycardia is classified according to certain signs (localization and causes) and can be represented as follows:
- Paroxysmal, having a different origin, therefore in it allocate forms: supraventricular or supraventricular, which happens 2 types (atrial and atrioventricular) and ventricular or ventricular.
- Sinus with an increase in heart rate over a certain indicator compared with the age norm (for adults -> 90 beats per minute), in which the impulse comes from the sinus node, which is a pacemaker.
Symptoms of tachycardia
When tachycardia develops, the main symptoms are frequent palpitations, a feeling of weakness, a feeling of dizziness, a feeling of lack of air, a feeling of approaching loss of consciousness.
In the absence of cardiac lesions, symptoms of sinus tachycardia are not pronounced and may not be subjectively felt for a long time. A slight increase in the heart rate to 100 beats / min is usually detected randomly when measuring blood pressure.
The initial symptoms are usually not paid attention and resort to medical care, when the attacks have a frequency of 130-150 beats / min, which is almost twice the normal heart rate.
Before determining how to treat tachycardia, it is necessary to undergo an examination and determine the causes of its occurrence.
Common tests for diagnosis are:
- Electrophysiological study. The method is aimed at studying the electrical properties of the myocardium, identifying the mechanism, and determining the localization of foci of tachyarrhythmia.
- An electrocardiogram (ECG) is a method for recording electrical impulses of the heart. Thanks to the ECG, the doctor finds out the frequency and rhythm of heart contractions, as well as reveals changes characteristic of various heart diseases. ECG allows you to specify the diagnosis of sinus (supraventricular) or ventricular tachycardia. If necessary, you will be offered bicycle ergometry - registration of the work of the heart during physical exertion (work on the exercise bike).
- Evaluation of the sensitivity of the baroreflex (the study of vegetative regulation).
- Magnetic resonance imaging (study of the foci of fibrous and adipose tissue in the heart).
- X-ray examination of the heart (using contrast).
- Complete blood count allows you to specify the number of red blood cells, hemoglobin and other blood cells, which can detect diseases such as anemia, leukemia, etc.
Taking into account the results of all tests, and taking into account the existing symptoms of tachycardia, appropriate treatment is prescribed.
In addition to conduction disturbances, heart rhythm tachycardia can produce such complications as:
- cardiac asthma
- cerebral thromboembolism,
- arrhythmic shock,
- pulmonary edema,
- pulmonary embolism,
- acute circulatory failure of the brain.
Ventricular tachycardia in combination with acute myocardial infarction can cause death.
In the case of tachycardia, treatment depends on the causes of development and its specific type. In a number of situations, no treatment is required - just calm down, relax, change lifestyle, etc. The main directions of treatment of tachycardia is to prevent its attacks in the future, minimizing the complications caused and bringing the heart rate to a normal state.
If we talk about the medical method of eliminating heart palpitations, these are mainly sedative drugs. In the first 10-15 minutes, if the heart rate is not restored at rest, you can take such drugs as volokardin, Corvalol, valerian tincture. Also reduce the pulse will help glycine tablet, which must be put under the tongue.
In addition to sedative drugs, antiarrhythmic drugs can also be used. This is a fairly extensive group of medicines with a different mechanism of action on the body. Prescribes such medications only the attending physician based on all the data on your health. Antiarrhythmic drugs are, for example, flecainide, adenosine, propranolol, verapamil and other drugs.
In some cases, when drug treatment does not give the effect, doctors resort to surgical intervention. For example, with serious hormonal disorders, when there is a need to remove a part of the gland that produces an excess of hormones. Also, the operation is indicated for gross heart defects and other heart diseases, when the only way out is surgery.
Sinus tachycardia in patients with heart disease is most often a manifestation of heart failure or left ventricular dysfunction. In these cases, the prognosis can be quite serious, since sinus tachycardia is a reflection of the response of the cardiovascular system to the reduction of the ejection fraction and the breakdown of intracardiac hemodynamics.
In the case of physiological sinus tachycardia, even with pronounced subjective manifestations, the prognosis, as a rule, is satisfactory.
Under the prevention of sinus tachycardia refers to the early diagnosis and timely treatment of pathology, as well as the elimination of non-cardiac factors for the development of arrhythmias. Serious consequences of tachycardia can be avoided with strict adherence to recommendations for maintaining a healthy lifestyle.