Features of paroxysmal supraventricular( supraventricular) tachycardia

A sharp increase in the heart rate while maintaining the rhythm is called paroxysmal tachycardia. It can be ventricular or supraventricular.

If the focus of pathological impulses is in the sinoatrial, atrioventricular node or atrial tissues, then paroxysmal supraventricular( supraventricular) tachycardia( PNT) is diagnosed.

Contents

  • 1 Prevalence and development process
  • 3 Prevalence and development process
  • 3 Classification and signs on the ECG
  • 4 Causes, risk factors
  • 5 Symptoms
  • 6 Diagnosis
  • 7 Emergency care
  • 8 Treatment and rehabilitation
  • 9 Possible consequences, complications and prognosis
  • 10 Preventive measures

Characteristics of the disease


Supraventricular formdisease occurs when the impulse occurs at the level of the atrial tissues. The frequency of cardiac contractions increases to 140-250 per min .

Such a tachycardia develops according to 2 scenarios:

  • A normal pulse source stops controlling the cardiac contractions of
    .They arise under the influence of abnormal foci, which are above the level of the ventricles of the heart.
  • The pulse circulates around the circle .Because of this, the increased heart rate remains. This condition is called "repeated inspiration" excitation. It develops if bypasses of the excitation pulse appear.

Paroxysmal supraventricular tachycardia are the potential life-threatening states of the .But the prognosis at their occurrence is more favorable, than at development of intensive ventricular reductions. They rarely testify to left ventricular dysfunction and organic heart disease.

Seizures last from several hours to several days, can be stopped without treatment. Persistent paroxysmal tachycardia occur rarely.

Prevalence and development process of

In women, the supraventricular form is diagnosed 2 times more often than in men .People who have crossed the 65-year threshold, the probability of its development is 5 times higher. But it is not found very often: its prevalence does not exceed 0.23%.

Atrial form of tachycardia occurs in 15-20%, and atrial-ventricular - in 80-85%.Attacks develop at any time.

Many are diagnosed with this disease even in their childhood .But it can also develop as a complication after cardiac diseases. Paroxysmal supraventricular rhythm disturbance is considered an intermediate link between fatal and benign problems with a heart rhythm.

Paroxysms of attacks come and end suddenly .The rest of the time, patients do not complain about the rhythm, it's normal, the frequency fluctuations of the contractions are not significant.

At the time of attack, the frequency of atrial contractions becomes more than 100, sometimes it reaches 250 bpm. The ventricles contract at the same rate or less with AB blockade.

Classification and signs on the ECG

Depending on the type of arrhythmia, the mechanism of the seizure differs.

  • The sinoatrial tachycardia appears due to the recirculation of the pulse through the sinus node and the right atrium myocardium. On the ECG in this condition, the tooth of P. is preserved. It is he who is responsible for the contraction of the atria. The frequency of contractions reaches 220 bpm.
  • Atrial arrhythmia appears with an increase in activity of the pathological focus, which has its own automation device.

    The shape of the P wave on the ECG is modified: it becomes negative or biphasic. With this form, the attack can develop gradually. The heart contracts at a rate of 150-250 bpm.

  • Paroxysmal AV-node tachycardia appears when there are 2 parallel pathways in the atrium and ventricular junction. Their functional characteristics are different.

    The fast and slow path form a ring, because of this the exciting pulse begins to circulate in a circle. The excitation of the atria and ventricles occurs simultaneously, therefore on the ECG the tooth P is absent.

Causes, risk factors

Doctors distinguish physiological and pathological tachycardias .In the first case, the rapidity of the rhythm is a reaction to physical stress or stress. The pathological state develops because of the failure of the mechanism of pulse formation in the physiological source.

Doctors distinguish cardiac and non-cardiac causes of disease. These include:

  • congenital heart disease in children and adolescents;
  • heart disease in adulthood;
  • toxic myocardial damage by drugs;
  • increase in the tone of the sympathetic department of the nervous system;
  • appearance of abnormal ways in which the nerve impulse goes to the heart;
  • reflex nerve irritation, which develops due to the reflection of impulses from damaged organs;
  • dystrophic changes in myocardial tissue: after a heart attack, cardiosclerosis, infectious lesions;
  • metabolic problems that have developed against the background of disruptions in the thyroid gland, adrenal glands or the development of diabetes mellitus;
  • intoxication when taking alcohol, drugs or chemicals.

In some cases, the cause can not be established. To the risk factors for the development of the disease include:

  • hereditary predisposition;
  • pregnancy period( the burden on all organs increases);
  • use of diuretics.

In childhood and adolescence, tachycardia appears against the background:

  • electrolyte disturbances;
  • psycho-emotional or physical overstrain;
  • exposure to adverse conditions: with increased body temperature, lack of fresh air in the room.

Symptoms of

Patients who have encountered PNT, describe their condition differently. In some cases, the attacks are virtually asymptomatic. In others, the condition deteriorates noticeably.

It has been observed that older people do not always notice a faster pace. And the young complain about the clear manifestations of this disease.

Paroxysmal supraventricular tachycardia manifests itself as follows:

  • acceleration of heartbeat in the chest;
  • appearance of shallow breathing;
  • palpable pulsation of blood vessels;
  • dizziness;
  • tremor of the hands;
  • darkening in eyes;
  • hemiparesis: the defeat of the limbs on the one hand;
  • speech disorders;
  • increased sweating;
  • increased number of urination;
  • fainting.

Symptoms appear suddenly and disappear unexpectedly.

Diagnosing

If you have attacks of a sharp heart beat, you should consult a cardiologist. An accurate diagnosis is established after a special examination. For the detection of supraventricular paroxysms use:

  • physical examination;
  • carrying out ultrasound, MRI, MSCT of the heart: they are made to exclude organic pathology with suspicion of paroxysmal tachycardia;
  • instrumental examination: ECG, ECG under load, Holter and electrophysiological intracardiac examination.

A characteristic feature of the disease is the rigidity of the rhythm. It does not depend on the load and the frequency of breathing. Therefore, it is important to carry out an auscultatory examination as part of the diagnosis.

It is important to determine the type of tachycardia : supraventricular or ventricular. The second state is more dangerous.

If it is not possible to pinpoint the diagnosis of PNT, the disease is regarded as a ventricular tachycardia and treated accordingly.

Also patients with PST should be examined to exclude such syndromes:

  • weakness of the sinus node;
  • overexcitation of ventricles.
Therapy is selected depending on the type of tachycardia. A specific type of disease is established based on the results of the ECG.

Emergency Care

There are several methods for reducing the occurrence of an attack by a patient. The patient is recommended:

  • to throw back his head;
  • immerse the face in cold water for 10-35 seconds, its temperature should be about 2 ° C;
  • put an ice collar around your neck;
  • press on the eyeballs;
  • strain the abdominal press and hold your breath for 20 seconds.

Vagal techniques are used to arrest an attack of supraventricular paroxysmal tachycardia:

  • a sharp exhalation through the closed nose and mouth( Valsalva test);
  • Carrying out massage of carotid arteries( with care make people who have atherosclerosis or impaired cerebral blood flow);
  • provoking cough, in which the diaphragm erupts.

Treatment and rehabilitation

After the examination and determination of the nature of the disease, the doctor determines whether the patient needs a special antiarrhythmic treatment of .

To prevent attacks, prescribe drugs that restore the heart rate. But long-term use of some antiarrhythmic drugs negatively affects the life expectancy. Therefore should be selected by the cardiologist .

Means that are intended for relief of attacks are also chosen by the doctor taking into account the patient's medical history. Some advise the to perform the breathing exercises, which slow the rhythm.

In hospital, an attack is stopped by intravenous antiarrhythmic drugs. Also use electropulse therapy.

If there is evidence against paroxysmal supraventricular tachycardia , use the operation. It is necessary: ​​

  • in case of frequent attacks, which the patient does not tolerate;
  • at preservation of displays of disease on a background of reception of antiarrhythmics;
  • to people with occupations in which loss of consciousness is life-threatening;
  • in situations where prolonged drug therapy is undesirable( at a young age).

Surgeons conduct radiofrequency ablation of the pathological pulse source. More details about such operations are described in this video:

Therapy is directed not only to the elimination of arrhythmia, but also to the changing the quality of life of the patient .Rehabilitation will be impossible if you do not follow the doctor's recommendations. Nutrition and lifestyle are important for the treatment of arrhythmia.

Possible consequences, complications and prognosis

Short-term unexpressed seizures do not cause serious discomfort, so their severity underestimates many .PNT can cause a patient's disability or lead to sudden arrhythmic death.

The prognosis depends on:

  • such as paroxysmal supraventricular tachycardia;
  • concomitant diseases, which provoked its appearance;
  • the duration of seizures and the presence of complications;
  • myocardial conditions.

In the long course of PNT , some develop heart failure , which worsens myocardial ability to contract.

Ventricular fibrillation is a serious complication of tachycardia. This chaotic contraction of individual fibers of the myocardium, which without emergency resuscitation leads to death.

Also attacks affect cardiac output intensity. As they decrease coronary circulation worsens .This leads to a decrease in the blood supply to the heart and can lead to the development of angina and myocardial infarction.

Preventive measures


It is impossible to prevent the development of seizures .Even regular intake of antiarrhythmic drugs does not guarantee that PNT will not appear. And get rid of arrhythmia allows surgical intervention.

Doctors claim that should be treated with a major disease that provokes arrhythmia .Also it is necessary: ​​

  • to exclude alcohol and drugs;
  • to revise the diet: the menu should not be excessively salty foods, fried and fatty foods, smoked products;
  • monitor the concentration of glucose in the blood.
Daily exercise can train the heart muscle and reduce the likelihood of an attack.

If you have signs of tachycardia, you need to undergo a full examination of .If the doctor diagnoses a paroxysmal supraventricular tachycardia, you will have to constantly monitor your condition. It is necessary to identify the underlying disease and direct all efforts to fight it. This will prevent the occurrence of complications.