Sinus tachycardia types of diagnosis and causes

Paroxysmal tachycardia is a type of arrhythmia characterized by heart attacks (paroxysms) with a heart rate of 140 to 220 or more per minute, arising under the influence of ectopic pulses that lead to the replacement of the normal sinus rhythm. Paroxysms of tachycardia have a sudden onset and end, of varying durations and, as a rule, maintained a regular rhythm. Ectopic impulses can be generated in the atria, atrioventricular junction, or ventricles.

Paroxysmal tachycardia is etiologically and pathogenetically similar to extrasystole, and several extrasystoles following in a row are regarded as a short paroxysm of tachycardia. With paroxysmal tachycardia, the heart does not work economically, blood circulation is ineffective, therefore tachycardia paroxysms that develop against the background of cardiopathology lead to circulatory failure. Paroxysmal tachycardia in various forms is detected in 20-30% of patients with prolonged ECG monitoring.

Main characteristics

Sinus tachycardia is called a form of arrhythmia, what does this mean? This type of tachycardia is caused by a disorder:

  • pulse generation by the sinus node, which controls the heart rate;
  • conduction of impulses from the sinus node to the ventricles.

The sinus node is the part of the heart in which the sinus rhythm forms. There a wave of excitement arises, which spreads to the heart and contributes to its synchronous work.

In adults, a heart rate of 100 beats per minute is considered the limit. For children, this indicator is calculated by age, and the deviation is considered to be an excess of heart rate by 10% from the age norm.

With sinus tachycardia, the heart rate is 95–130 beats per minute (without physical exertion), 150–160 – with a load. In athletes, this figure can reach 180-240 strokes.

Distinguish between functional and pathological (or prolonged) forms.

Classification of paroxysmal tachycardia

At the place of localization of pathological impulses, atrial, atrioventricular (atrioventricular) and ventricular forms of paroxysmal tachycardia are distinguished. Atrial and atrioventricular paroxysmal tachycardia are combined into a supraventricular (supraventricular) form.

By the nature of the course, acute (paroxysmal), constantly recurring (chronic) and continuously recurring forms of paroxysmal tachycardia are found. The course of a continuously recurring form can last for years, causing arrhythmogenic dilated cardiomyopathy and circulatory failure. According to the development mechanism, reciprocal (associated with the re-entry mechanism in the sinus node), ectopic (or focal), multifocal (or multi-focal) forms of supraventricular paroxysmal tachycardia are distinguished.

The basis for the development of paroxysmal tachycardia in most cases is the re-entry of the pulse and the circular circulation of excitation (reciprocal re-entry mechanism). Less commonly, tachycardia paroxysm develops as a result of the presence of an ectopic focus of abnormal automatism or a focus of post-depolarization trigger activity. Regardless of the mechanism of occurrence of paroxysmal tachycardia, the development of extrasystole is always preceded.

Development mechanism

Sinus tachycardia develops according to one of the scenarios:

  • Activation of the symptomatic system, which is part of the nervous system. The substance norepinephrine from nerve fibers activates the sinus node.
  • Decreased activity of the parasympathetic system. Its substance acetylcholine inhibits the generation of pulses, which leads to a decrease in heart rate. When the activity of the parasympathetic system decreases, the role of the sympathetic system increases, as a result of which the heart rate increases.
  • Direct influence of influencing factors on the sinoatrial node during normal functioning of the sympathetic and parasympathetic nervous system. Active substances act on cells that generate impulse and excite them.

Causes of Tachycardia

Symptom often occurs in young people. The reason for this is the immaturity of the nervous system. The body needs a balance of the sympathetic and parasympathetic nervous system. But at a young age, the balance is poorly maintained, so there are advantages, which causes an attack (cardioneurosis).

Various factors contribute to the development of sinus tachycardia. The physiological form is a reaction to the load, stressful situation, high temperature. As for pathological CT, extracardial and intracardial groups of factors are distinguished.

Extracardial factors include:

  • Neurogenic – develops in individuals (more often in young women) with an unstable nervous system, with a tendency to neurosis, depression, etc., due to the high sensitivity of the heart receptors to stress hormones.
  • Toxic – caused by toxic substances – alcohol, tobacco, as well as internal factors (thyrotoxicosis, adrenal gland tumor – pheochromocytoma, more often manifested in women), chronic infections (tuberculosis, tonsillitis).
  • Medicinal – occurs due to activity or overdose. So hormones, drugs for the treatment of lung ailments, hypertension, antidepressants affect the body.
  • Hypoxic – this is how the body reacts to oxygen deficiency. In turn, the cause of hypoxia is respiratory diseases and blood pathologies, in which the delivery of gas to organs and systems is disrupted (anemia, leukemia, chronic blood loss, etc.).

Intracardial factors are caused by heart disease. Often (but not always) the development of sinus tachycardia in people with heart disease indicates heart failure or impaired left ventricular function, since then there is a decrease in ejection fraction or a clinically significant deterioration of hemodynamics within the heart.

It should be understood that tachycardia is not a disease, but a syndrome, that is, a symptom of a manifestation of a primary disease. Usually, ventricular tachycardia occurs as a result of severe dystrophic changes in the heart muscle, and paroxysmal supraventricular – with the excitation of the sympathetic nervous system.

– Various diseases of the endocrine system, which lead to increased secretion of adrenaline, such as pheochromocytoma. Also, the cause of tachycardia can be hypothalamic syndrome.

– Disorders of the autonomic nervous system caused by excitation of the sympathetic nervous system. The effect on the sympathetic cardiac nerve fibers can be either direct or indirect, when acting on the adrenal glands, which in turn leads to the release of adrenaline into the bloodstream and, as a result, the heart rate increases. It should be noted that this kind of tachycardia can occur in subjectively healthy people, for example, after a cup of strong coffee, unrest, and so on.

– Various arrhythmias associated with impaired conduction of the impulse to the ventricles from the sinus node or in violation of the pulse generation itself directly in the sinus node. Moreover, if a violation of generation arises as a result of the pathological function of the sinus node, then such a rhythm disturbance is called sinus tachycardia.

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– Hemodynamic disturbances when the opposite effect occurs, associated with blood pressure in the vessels. For example, lowering blood pressure causes tachycardia. Other hemodynamic causes may be associated with a decrease in the volume of circulating blood due to dehydration or bleeding.

– Ventricular idiopathic tachycardia occurs most often in young people with a chronic form of ischemic heart disease.

– Myocardial infarction causes a specific tachycardia, which occurs in the acute course of a heart attack suddenly for several seconds and also suddenly disappears on its own.

– WPW – syndrome (ventricular pre-excitation syndrome).

– Intoxication with cardiac glycosides.

Also, tachycardia can occur with: prolapse of the mitral valve, myocarditis, congenital and acquired heart defects, cardiomyopathy, congenital syndrome of prolongation of the QT interval, as a complication in the treatment of quinidine, adrenaline, isadrine or psychotropic drugs, as well as open heart surgery.

According to etiological factors, paroxysmal tachycardia is similar to extrasystole, with the supraventricular form usually caused by increased activation of the sympathetic nervous system, and ventricular – by inflammatory, necrotic, dystrophic, or sclerotic lesions of the heart muscle.

With the ventricular form of paroxysmal tachycardia, the focus of ectopic excitation is located in the ventricular parts of the conducting system – the bundle of His, its legs, and also Purkinje fibers. The development of ventricular tachycardia is more often observed in elderly men with coronary heart disease, myocardial infarction, myocarditis, hypertension, heart defects.

An important prerequisite for the development of paroxysmal tachycardia is the presence of additional pathways for conducting an impulse in the myocardium of a congenital nature (the Kent bundle between the ventricles and atria, bypassing the atrioventricular node; Maheim fibers between the ventricles and the atrioventricular node) or resulting from myocardial damage (myocarditis, cardiac infarction). Additional ways of conducting an impulse cause a pathological circulation of excitation along the myocardium.

In some cases, the so-called longitudinal dissociation develops in the atrioventricular node, leading to the uncoordinated functioning of the fibers of the atrioventricular connection. In the event of longitudinal dissociation, part of the fibers of the conducting system functions without deviations, the other, on the contrary, conducts excitation in the opposite (retrograde) direction and serves as the basis for the circular circulation of pulses from the atria to the ventricles and then back through the retrograde fibers to the atria.

In childhood and adolescence, idiopathic (essential) paroxysmal tachycardia is sometimes found, the cause of which cannot be reliably established. The basis of neurogenic forms of paroxysmal tachycardia is the influence of psychoemotional factors and increased sympathoadrenal activity on the development of ectopic paroxysms.

Symptoms of paroxysmal tachycardia

Paroxysm of tachycardia always has a sudden distinct beginning and the same end, while its duration can vary from several days to several seconds.

The patient feels the onset of paroxysm as a push in the region of the heart, turning into an increased heartbeat. The heart rate during paroxysm reaches 140-220 or more per minute while maintaining the correct rhythm. An attack of paroxysmal tachycardia may be accompanied by dizziness, a noise in the head, a feeling of constriction of the heart. Transient focal neurological symptoms – aphasia, hemiparesis, are less common. The course of paroxysm of supraventricular tachycardia can occur with symptoms of autonomic dysfunction: sweating, nausea, flatulence, mild subfebrile condition. At the end of the attack, polyuria is noted for several hours with the release of a large amount of light urine of low density (1,001-1,003).

The protracted course of tachycardia paroxysm can cause a drop in blood pressure, the development of weakness and fainting. Tolerance to paroxysmal tachycardia is worse in patients with cardiopathology. Ventricular tachycardia usually develops against a background of heart disease and has a more serious prognosis.

During an attack of sinus tachycardia, the patient may experience the following symptoms:

  • “Fluttering” of the heart, rapid heart rate;
  • dyspnea;
  • heaviness, “tightness” in the chest (occurs in the absence of load);
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  • compressive chest pain (no longer than 5 minutes) – with coronary heart disease;
  • general weakness, decreased performance, intolerance to physical activity (with a pathological form).

Functional CT usually does not require medical intervention, passes after the elimination of the provoking factor. However, such manifestations as chest pain, loss of consciousness are a reason for urgent medical attention.

With paroxysmal tachycardia, seizures are usually pronounced. They begin suddenly and also suddenly pass. The patient feels a rapid heartbeat, dizziness, fear, and sometimes fainting and even collapse occurs. Sometimes the patient describes the condition with one phrase: “heart in the heels” or “heart in the throat”.

With a constant frequent heartbeat, the patient complains of general weakness, dizziness, lightheadedness, lack of air, rapid fatigue and intolerance to physical exertion. Diagnosis of tachycardia

Diagnosis of the tachycardia syndrome itself is not so complicated. It should be noted immediately that with paroxysmal tachycardia, the increase in heart rate is almost always very strong from 250 and above heart rate per minute. In chronic tachycardia, it usually ranges from one hundred to one hundred and thirty times per minute.

Almost always, tachycardia is determined using an ECG or exercise ECG. With a paroxysmal form, Holter monitoring is prescribed (daily ECG monitoring).

The usual auscultation of the heart also allows in most cases to determine tachycardia. Moreover, if the rhythm of the gallop is heard, then this indicates in most cases that the cause of tachycardia is heart failure, and if dyspnea is still present in the symptoms, then this is almost 100% confirmation of heart failure.

Additional studies are also prescribed depending on the disease that caused the appearance of tachycardia.

The main treatment for tachycardia is the elimination of the root cause, that is, the disease that led to the development of heart palpitations. If tachycardia is neurogenic, then at the time of the attack, a mild sedative is prescribed, for example, corvalol or valocordin 40-60 drops at a time.

With any form of tachycardia, physiotherapy exercises (LFK), a balanced diet (diet), and a necessarily healthy lifestyle and rejection of bad habits are prescribed.

Also, drugs that reduce heart rate, such as isoptin, anaprilin, isotrapine, etc. are prescribed. In any case, the treatment of tachycardia should be prescribed only by a doctor after a thorough examination and identification of the root cause.

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Complications of paroxysmal tachycardia

With the ventricular form of paroxysmal tachycardia with a rhythm frequency of more than 180 beats. ventricular fibrillation may develop per minute. Prolonged paroxysm can lead to serious complications: acute heart failure (cardiogenic shock and pulmonary edema). A decrease in cardiac output during tachycardia paroxysm causes a decrease in coronary blood supply and cardiac muscle ischemia (angina pectoris or myocardial infarction). The course of paroxysmal tachycardia leads to the progression of chronic heart failure.

Diagnosis of paroxysmal tachycardia

Paroxysmal tachycardia can be diagnosed by the typicality of an attack with a sudden onset and end, as well as data from a study of heart rate. Supraventricular and ventricular forms of tachycardia differ in the degree of increased rhythm. With the ventricular form of tachycardia, heart rate usually does not exceed 180 beats. per minute, and samples with excitation of the vagus nerve give negative results, while with supraventricular tachycardia, heart rate reaches 220-250 beats. per minute, and paroxysm is stopped by vagal maneuver.

When registering an ECG during an attack, characteristic changes in the shape and polarity of the P wave, as well as its location relative to the ventricular complex QRS, are determined, allowing to distinguish the form of paroxysmal tachycardia. For the atrial form, the location of the P wave (positive or negative) in front of the QRS complex is typical. In case of paroxysm coming from the atrioventricular junction, a negative P wave located behind the QRS complex or merging with it is registered. The ventricular form is characterized by deformation and expansion of the QRS complex, resembling ventricular extrasystoles; a regular, unchanged R wave can be recorded.

If the paroxysm of tachycardia cannot be fixed during electrocardiography, resort to daily monitoring of the ECG, recording short episodes of paroxysmal tachycardia (from 3 to 5 ventricular complexes), not subjectively felt by patients. In some cases, with paroxysmal tachycardia, an endocardial electrocardiogram is recorded by intracardiac injection of electrodes. To exclude organic pathology, ultrasound of the heart, MRI or MSCT of the heart is performed.

A complete picture of the severity of the condition is obtained after the examination. Diagnostic measures include:

  • analysis of the anamnesis – the patient is asked to describe the sensations, possible cause-effect relationships, the presence of chronic diseases, living conditions, bad habits, etc .;
  • physical examination – examine the skin, examine the condition of the hair, nails;
  • auscultation – the respiratory rate, wheezing and noise in the heart are determined, which allows to identify the cause of the pathology;
  • general blood test – shows anemia, white blood cell count (increases with a chronic disease);
  • biochemical blood test – gives an idea of ​​the level of cholesterol (low and high density), glucose, potassium, creatine, urea, eliminates diabetes, kidney disease, changes in the chemical composition of blood;
  • urinalysis (general) – excludes diseases of the urinary tract;
  • hormonal analysis – to determine the level of hormones produced by the thyroid gland;
  • echocardiography (echocardiography) – detects structural changes.

The main and most informative study is electrocardiography, or ECG, as well as Holter electrocardiogram (recording is carried out continuously 24–72 hours, at rest and under stress).

The patient is prescribed advice from a psychotherapist, otolaryngologist, and other specialists.

How and how to treat

The main goal of treatment is to eliminate the cause of the attacks, since sinus angina is a symptom of other ailments. Therapy is selected and prescribed by a cardiologist.

This event block includes:

  • refusal of addictions – the use of alcohol, drugs, smoking;
  • diet correction – patients are recommended to eat foods rich in fiber and refuse fatty, hot, spicy dishes, reduce the amount of coffee, tea;
  • compliance with sleep and rest.

If during the examination it was revealed that the infection became the cause of tachycardia, then the treatment is sent to eliminate it. The patient is prescribed debridement for diseases of the oral cavity, removal of a diseased tooth or inflamed tonsils, antibiotic therapy.

With a lack of iron and anemia, the administration of drugs with this element is indicated, with bleeding – the introduction of solutions in order to restore the volume of blood mass.

The lack of oxygen due to bronchopulmonary diseases is eliminated by the introduction of gas through a catheter into the nasal passages.

Medications to eliminate tachycardia itself are prescribed when the patient does not tolerate a rapid heartbeat. With sinus tachycardia, the following drugs are used:

  • beta-blockers – block receptors that respond to stress hormones adrenaline and norepinephrine;
  • if-channel inhibitors – control the degree of excitation in the sinus node, heart rate;
  • sedatives based on medicinal plants – motherwort, valerian root, hawthorn.
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Recovery

The patient may be shown spa treatment in Kislovodsk and other health resorts if intracardiac factors have become the cause. In other cases, rehabilitation measures depend on the underlying disease.

It is recommended to observe the following rules:

  • eliminate intense emotional stress – at home and at work;
  • sleep 8 hours a day;
  • eat right, abandoning spicy and oily;
  • every day to eat vegetables, herbs, fish (especially sea);
  • abandon addictions;
  • do gymnastics (at least 30 minutes daily);
  • control body weight.

Controversial Techniques

Doctors argue about whether cardiac glycosides can be taken with sinus tachycardia. In particular, this relates to digoxin. According to the Russian method, a combination of beta-blockers and digoxin, sometimes with calcium antagonists, achieve clear control over heart rate.

The range of drugs for the treatment of tachycardia is limited, since this can have a side effect with long-term therapy. If drug therapy is not possible, resort to electrical stimulation of the myocardium.

In old age, sinus tachycardia is treated surgically, while pacemakers are installed, which eliminates the blockade of the atrioventricular node.

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Treatment of paroxysmal tachycardia

The question of treatment tactics for patients with paroxysmal tachycardia is solved taking into account the form of arrhythmia (atrial, atrioventricular, ventricular), its etiology, frequency and duration of attacks, the presence or absence of complications during paroxysms (cardiac or cardiovascular failure).

Most cases of ventricular paroxysmal tachycardia require emergency hospitalization. The exception is idiopathic options with a benign course and the ability to quickly stop by introducing a certain antiarrhythmic drug. With paroxysm of supraventricular tachycardia, patients are hospitalized in the cardiology department in the event of the development of acute cardiac or cardiovascular failure.

The occurrence of an attack of paroxysmal tachycardia requires emergency measures in place, and with primary paroxysm or concomitant cardiac pathology, a simultaneous call to the emergency cardiology service is necessary.

To stop paroxysm, tachycardia resort to vagal maneuvers – techniques that have a mechanical effect on the vagus nerve. Vagus maneuvers include straining; Valsalva test (attempt of vigorous exhalation with closed nasal slit and oral cavity); Ashner test (uniform and moderate pressure on the upper inner corner of the eyeball); Chermak-Goering test (pressure on the region of one or both carotid sinuses in the region of the carotid artery); an attempt to cause a gag reflex by irritating the root of the tongue; rubbing with cold water, etc. With the help of vagal maneuvers, it is possible to stop only attacks of supraventricular paroxysms of tachycardia, but not in all cases. Therefore, the main type of help with the developed paroxysmal tachycardia is the introduction of antiarrhythmic drugs.

As an emergency aid, intravenous administration of universal antiarrhythmics effective for all forms of paroxysms is shown: novocainamide, propranoloa (obzidan), aymaline (hiluritmal), quinidine, rhythmodan (disopyramide, rhythmilek), ethmosin, isoptin, cordarone. With prolonged paroxysms of tachycardia that are not stopped by drugs, they resort to electro-pulse therapy.

In the future, patients with paroxysmal tachycardia are subject to outpatient monitoring by a cardiologist who determines the volume and schedule of antiarrhythmic therapy. The appointment of anti-relapse antiarrhythmic treatment of tachycardia is determined by the frequency and tolerance of seizures. Conducting continuous anti-relapse therapy is indicated for patients with tachycardia paroxysms that occur 2 or more times a month and require medical attention to stop them; with rarer, but protracted paroxysms, complicated by the development of acute left ventricular or cardiovascular failure. In patients with frequent, short attacks of supraventricular tachycardia, stopping on their own or with the help of vagal maneuvers, indications for anti-relapse therapy are doubtful.

Long-term anti-relapse therapy of paroxysmal tachycardia is carried out with antiarrhythmic drugs (quinidine bisulfate, disopyramide, morazizin, etatsizin, amiodarone, verapamil, etc.), as well as cardiac glycosides (digoxin, lanatoside). The selection of the drug and dosage is carried out under electrocardiographic control and the patient’s well-being.

The use of β-blockers for the treatment of paroxysmal tachycardia reduces the likelihood of the transition of the ventricular form to ventricular fibrillation. The most effective use of β-blockers in conjunction with antiarrhythmic drugs, which allows to reduce the dose of each of the drugs without compromising the effectiveness of the therapy. Prevention of relapse of supraventricular tachycardia paroxysms, reducing the frequency, duration and severity of their course is achieved by constant oral administration of cardiac glycosides.

Surgical treatment is resorted to with a particularly severe course of paroxysmal tachycardia and the ineffectiveness of anti-relapse therapy. As a surgical aid for tachycardia paroxysms, destruction (mechanical, electrical, laser, chemical, cryogenic) of additional pathways for conducting an impulse or ectopic foci of automatism, radiofrequency ablation (RFA of the heart), implantation of pacemakers with programmed paired and “exciting” electrical stimulation modes or implantation are used defibrillators.

Prognosis for paroxysmal tachycardia

The prognostic criteria for paroxysmal tachycardia are its form, etiology, duration of seizures, the presence or absence of complications, the state of myocardial contractility (since with severe damage to the heart muscle there is a high risk of developing acute cardiovascular or heart failure, ventricular fibrillation).

The most favorable over the course of the essential supraventricular form of paroxysmal tachycardia: most patients do not lose their ability to work for many years, cases of complete spontaneous cure are rarely observed. The course of supraventricular tachycardia due to myocardial diseases is largely determined by the pace of development and the effectiveness of therapy for the underlying disease.

The worst prognosis is observed with the ventricular form of paroxysmal tachycardia that develops against the background of myocardial pathology (acute heart attack, extensive transient ischemia, recurrent myocarditis, primary cardiomyopathies, severe myocardial dystrophy due to heart defects). Myocardial lesions contribute to the transformation of tachycardia paroxysms into ventricular fibrillation.

In the absence of complications, the survival rate of patients with ventricular tachycardia is years or even decades. The lethal outcome in the ventricular form of paroxysmal tachycardia, as a rule, occurs in patients with heart defects, as well as patients who have previously experienced sudden clinical death and resuscitation. The course of paroxysmal tachycardia is improved by constant anti-relapse therapy and surgical rhythm correction.

The prognosis is quite serious if sinus tachycardia is a symptom of heart failure or left ventricular dysfunction. Then the course of the disease is exacerbated.

It is important to remember that sinus tachycardia can be a manifestation of other ailments. But in childhood, during pregnancy and in adolescents, this is often the norm. Then the drugs can do much harm.

Therefore, taking any actions yourself is prohibited. To determine the degree of danger, the advisability of prescribing drugs can only be a specialist after an extensive examination.

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Svetlana Borszavich

General practitioner, cardiologist, with active work in therapy, gastroenterology, cardiology, rheumatology, immunology with allergology.
Fluent in general clinical methods for the diagnosis and treatment of heart disease, as well as electrocardiography, echocardiography, monitoring of cholera on an ECG and daily monitoring of blood pressure.
The treatment complex developed by the author significantly helps with cerebrovascular injuries and metabolic disorders in the brain and vascular diseases: hypertension and complications caused by diabetes.
The author is a member of the European Society of Therapists, a regular participant in scientific conferences and congresses in the field of cardiology and general medicine. She has repeatedly participated in a research program at a private university in Japan in the field of reconstructive medicine.

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