Sinus tachycardia is a change in cardiac activity, characterized by increased heart rate (heart rate) to approximately 100 – 130 beats per minute. Increase of these indicators is typically associated with adaptive response of sinus node to exercise, stress, pain, fever, joy, intoxication, etc.
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In other words, the tachycardia appears when you decrease vagal tone and increase in sympathoadrenal activity. This condition occurs more often in people with a healthy heart when the autonomic nervous system because of their normal functioning is able sufficiently to affect cardiac function. Physiological sinus tachycardia may also occur with Atropine sulfate or with a deep breath.
Sinus tachycardia may be pathological. In chronic heart failure in the right chambers of the heart is an increase in pressure. This leads to the activation of the nervous system and reflex increase in heart rate (Bainbridge reflex). In this case, tachycardia is not adaptive in relation to the whole body and can worsen the underlying disease.
Causes of sinus tachycardia
All of the factors that increases the frequency of contraction of the heart, divided into intracardiac (heart) and noncardiac (extracardiac).
Intracardiac factors causing the increase in heart rate:
- acute and chronic forms of heart failure;
- severe angina;
- malformations of the heart;
- myo-, endo – and pericarditis;
- various cardiomyopathies.
In persons suffering from diseases of the cardiovascular system, one of the first symptoms of dysfunction of the left ventricle and the occurrence of heart failure is sinus tachycardia.
To extracardial causes of tachycardia include various emotional stress or physical exertion. An important role is played by hereditary predisposition. Often, sinus tachycardia is a symptom of dysfunction of the individual elements of the brain (tumor) or the autonomic nervous system. This includes NDC (neuro-circulatory dystonia), some psychoses, etc.
Fairly common causes a functional increase in heart rate is the increased release of adrenaline in the blood. This can occur when:
- a sharp fall in blood pressure;
- the attacks of pain.
Normal sinus tachycardia also appears with fever on the background of any infectious diseases (SARS, influenza, pneumonia). The average increase in temperature of one degree Celsius is an increase in heart rate of 10-15 beats per minute. In children the figure below.
Certain toxins and medications have a direct or reflex influence on the sinus node, causing tachycardia. These include:
- Norepinephrine and Epinephrine;
- diuretics (Furosemide, gidrokhlorisiazit);
- Aminophylline and Atropine;
- some drugs that lower pressure (arterial);
- glucocorticoids (adrenal hormones) and thyroid hormones;
- strong tea, nicotine, coffee and alcohol.
Known cases in which the sinus node is excessively or do not respond to the above substances. This is probably due to primary lesions of the source of the rhythm. This response of sinus node in medicine is called inadequate.
Symptoms unlike other abnormalities and diseases of the heart, sinus tachycardia is the most “mild” symptoms. In most cases, the increase in heart rate not felt by man. Rarely patients may complain of fatigue and feeling of General discomfort.
For a true sinus tachycardia is characterized by increased heart rate at rest or at night. It should be borne in mind that during sleep, the frequency of contractions in the norm is reduced for physiological reasons.
More serious manifestations of the disease are discomfort in the heart region, a feeling reinforced and palpitations. Sometimes these symptoms are accompanied by dizziness or syncope (fainting) state.
Another complaint of patients suffering from sinus tachycardia, is a pain behind the breastbone. Often these feelings interfere with breathing, a feeling of fear. Significantly reduced exercise tolerance.
Usually with sinus tachycardia bouts of palpitations stop yourself. However, similarly, they appear again. The occurrence of this condition is not dangerous for the body with a healthy heart. Only in the case of existing pathologies of the cardiovascular system cases of tachycardia can cause harm to humans.
Sinus tachycardia in a child
Sinus tachycardia in children Increase heart rate in children is quite common. An elevated heart rate is observed in normal emotional and physical tension. At an early age it is manifested to a greater extent. Newborn, the heart rate more than 160 beats per minute billed with a diagnosis of sinus tachycardia. The condition is found almost half of the children. The main reasons are:
- the increase in the level of glucose in the blood;
- the attacks of pain;
- the increase in temperature.
To the first year of life in the absence of any disease sinus tachycardia go away on their own without any medical treatment.
Suspect in children pathology of the sinus node, in that case, if the heart rate is in the range of 100 – 160 beats per minute for five minutes or more. It is important to consider all the triggering factors and the presence of cardiac and cerebral symptoms (shortness of breath, fainting, dizziness and pain in the heart area).
The older children often sinus tachycardia is a manifestation of physical or emotional overloads, certain endocrine diseases, or anemia. In this case, it is crucial to determine the cause and prevent the tachycardia, because the state data may subsequently lead to hypertensive form of dystonia. With the progression of the disease may develop heart failure or other cardiac pathology.
Upon detection of bouts of palpitations in children and adolescents need dynamic observation. However, one should consider the fact that the cause of the sinus tachycardia may not be fully developed cardiovascular system.
Despite the various reasons for such a heart, if you experience bouts of palpitations, you need to release the neck of the child from the clothes and provide fresh air (if it happened in the room).
Sinus tachycardia in pregnancy
Measuring heart rate during pregnancy During pregnancy sinus tachycardia does not apply to threatening conditions for the fetus and mother, so many do not pay attention to it. But be aware that for 9 months these often worsen some chronic diseases and symptoms were exacerbated by even minor deviations by health.
The appearance of sinus tachycardia in pregnancy due to various factors. Among them special importance is the total restructuring of the body for the period of carrying a child. Thus, the change of the hormonal background of the organism, increases the load on the nervous system, increases the intensity of work of all internal organs. In addition, because of the increasing size of the fetus and the uterus are compressed and changing their position in the abdominal and thoracic cavity.
True sinus tachycardia a pregnant woman, the doctor may enter only once will exclude all possible causes of this condition. These include frequent vomiting, loss of blood or dehydration… it is Important to note at what period appears increase in heart rate. In the beginning of pregnancy is a more dangerous symptom than such, appears closer to the birth. In the last months tachycardia usually occurs due to the fact that the diaphragm is pressing the heart and it changes its position in the chest. For this reason, even when the heart rate to 120 beats per minute in the last three months of gestation, the treatment for adjusting the heart function is not assigned.
Diagnosis and ECG changes
Diagnosis sinus tachycardia is not a big deal. It is conducted in two stages:
- The definition of heart rate by probing the pulse on the arteries.
- Recording and interpretation of ECG.
Sinus tachycardia ECG on Trying to determine sinus tachycardia on the electrocardiogram it is important to understand that this type of restructuring of the heart is not paroxysmal pathology, so all the teeth on the ECG will not change its shape. The P wave will be positive in standard I, II, and aVF leads, and also in V2-V6 of the pectoral. In aVR and V1 it can be negative.
The next symptom of sinus tachycardia is a shortening of the interval R-R. thus we can detect a reduction in the distance between the ventricular QRS-complexes. In addition, unlike atrial fibrillation, the data intervals in the entire ECG are almost equal (because of the normal respiratory arrhythmia is occurring, the distance can vary by 10%).
In severe sinus tachycardia atrial P wave may overlap with the ST segment or T repolarization prong of the previous complex. Another difference from paroxysmal tachycardia is gradually growing and decreasing heart rate change.
Treatment of sinus tachycardia
The basis of therapy of this tachycardia is directed at elimination of the reason causing this condition. In many cases, to achieve normal heart rate by normalization of the mode activity and avoid stressful situations. With no effect or with more severe disease assigned to anti-anxiety medications. In addition, the need to minimize the consumption of coffee, strong tea, nicotine and alcohol.
If the cause of the disease was other pathology, then treatment assignment is possible only after a comprehensive examination. If sinus tachycardia neurogenic Genesis neurologist may prescribe antipsychotic drugs or tranquilizers.
Reflexive sinus tachycardia is a compensatory reaction to the decrease in blood pressure or changes in the level of thyroid hormones. With increasing heart rate for this reason, the disease is sure to cure depending on the cause of it. Otherwise there may be complications in the form of a fall in blood pressure and cardiovascular disease.
If the cause of tachycardia was hyperthyroidism, the basis of the treatment is simultaneous treatment with thyreostatics drugs with beta-blockers. In case of contraindications to the last or hypersensitive to their substitute to drugs from the group of calcium antagonists.
If existing heart failure, worsening of sinus tachycardia, appropriate receiving cardiac glycosides in combination with the same beta-blockers.
Selection of the dosage of all drugs should be done strictly individually. The target criterion is the decrease in the heart rate to 60 – 70 beats per minute. In the case of dystonia is allowed to maintain the heart rate to 90 beats per minute. Note should be taken and the patient’s subjective sensations in the change of the heart.
Inadequate form of tachycardia requires more extensive treatment, as it usually is no effect from all the medication. In this case, a radio-frequency cauterization of the area of the heart, which is responsible for sinus tachycardia. If this treatment option proved ineffective, it shows the implantation of a permanent pacemaker, who will perform the role of an artificial pacemaker.
The prognosis of the disease
The outcome of sinus tachycardia generally favorable. However, in the case of tachycardia due to heart failure or impairment of left ventricular function to predict the outcome quite difficult. This is due to the fact that the emerging rise in the heart rate response of the heart and blood vessels on changes the amount of ejected blood into the blood stream.
In addition to a healthy lifestyle an important point in the prevention of sinus tachycardia is early diagnosis and adherence to recommendations for treatment of any disease (not just cardiovascular).
Thus, we can conclude that sinus tachycardia as an independent pathology, is not a dangerous disease. More often it is a compensatory reaction to changes in the human body.