Paroxysmal tachycardia - Causes, symptoms and treatment. MF.

Causes of paroxysm
Symptoms and Diagnosis
Treatment
Lifestyle, complications, prognosis

Due to the fact that the heart is affected by various factors in the human body, it can react to the slightest deviations in the functioning of internal organs by violations of its functions. This especially applies to the conductivity and contractility function. So, for example, the correct rhythm of contractions of the cardiac muscle( myocardium) depends on the balanced influence of the autonomic nervous system, on the level of the adrenaline hormones( adrenaline) and the thyroid gland in the blood and on the condition of the heart muscle itself. Therefore, in conditions and diseases that alter the internal constancy of the organism or cause damage to the myocardium, heart rhythm disturbances may develop. These are changes in heart rate and / or electrical impulse in the atria and ventricles. One of these disorders is tachycardia - rapid heart rate. But if some types of tachycardia develop as a reaction to stress, muscle load, fever, and in principle are not dangerous to health, other types of tachycardia can indicate serious diseases and even carry a threat to human life. The latter include paroxysmal tachycardia.

Paroxysm - an attack of cardiac arrhythmia, lasting from a few seconds to hours, less often to several days, which suddenly occurs and suddenly ends. Paroxysmal is not only tachycardia, but atrial fibrillation. Paroxysmal tachycardia is a type of heart rhythm disturbance, characterized by the onset of attacks of rapid heart rate with a heart rate of 140 to 250 per minute with a regular sinus rhythm.

Rhythm disturbances in the form of paroxysms develop due to the fact that on the path of the electrical signal through the heart there are obstacles, or, conversely, additional ways of carrying out the pulse( bundles of Kent, James).This leads to the fact that parts of the muscle begin to contract over the obstacle, since the impulse returns to them repeatedly back, and an ectopic focus of excitation( located in the wrong place) is formed. In addition, areas of the myocardium that receive a pulse from additional beams are stimulated more often than necessary. The result is a frequent contraction of the ventricles of the heart with a lack of time for sufficient relaxation of the heart muscle, and as a consequence, a violation of the discharge of blood into the aorta. From this internal organs suffer, and, first of all, the brain. This is the danger of paroxysmal tachycardia.

The figure shows schematically the circulation of the pulse in the myocardium of the atria and ventricles.

The following types of paroxysmal tachycardia are distinguished depending on the site of the conduction system of the heart, where the "breakdown" occurred:

1. Supraventricular( supraventricular) tachycardia
- atrial tachycardia - occurs when the ectopic focus is located in the atria of
- atrioventricular - when positioned in the atrial-ventricular connection
2. Ventricular tachycardia - when localized in the ventricular tissue of the heart
- unstable - recorded on an ECG of less than 30 seconds
-- for 30 seconds or more

Flowing paroxysmal tachycardia isolated acute, recurrent and constantly continuously recurrent form.

The most dangerous is ventricular tachycardia, since it most often leads to cardiac arrest. Recurrent and recurrent forms are also dangerous because, often occurring, lead to the wear of the heart muscle and to the rapid development of heart failure.

Causes of paroxysmal tachycardia

Even though supraventricular tachycardia does not always indicate organic heart disease, it is still not a norm option together with ventricular tachycardia. That is, in any case, you need to look for the cause that caused these rhythm disturbances.
Nadzheludochkovaya tachycardia most often develops not directly from the damage to the heart tissue, but as a result of a violation of neurohumoral effects or the toxic effects of certain substances on the heart.

The following diseases can serve as its causes:

- availability of additional paths for holding the pulse. This is an innate feature, and can manifest at any age. Particularly important are the bundle of Kent( between the atrium and the ventricle) and the James bundle( connecting the sinoatrial and atrioventricular nodes).In the presence of additional beams, there is, as it were, a "dumping" of the electrical signal earlier than it should be in the norm. As a result, premature ventricular excitation occurs, but in most cases this signal returns back, circulating between the primary and additional bundles. This will lead to supraventricular tachycardia. In general, this condition is called ventricular pre-excitation syndrome. There are two syndromes - Wolff - Parkinson - White and Clerk - Levi - Christesco( syndrome of shortened PQ).Thus, these two syndromes can lead to the development of the supraventricular tachycardia
- , the toxic effect of cardiac glycosides ( strophanthin, digoxin, korglikon) during their overdose, as well as the arrhythmogenic effect of some antiarrhythmic drugs( propafenone, quinidine)
- , neurogenic (neurosis, neurasthenia), persistent stresses
- Alcohol, drug use
- excess cardiotropic hormones in the body - with hyperthyroidism(hyperthyroidism) increases the level of triiodothyronine in the blood, with adrenal and adrenaline( adrenaline and norepinephrine)
- tumors of other organs ( gastric ulcer, gastritis, cholecystitis, renal and hepatic insufficiency)

The ventricular tachycardia in most cases develops in thethe result of organic damage to the heart. Causes of ventricular tachycardia:
- the most common cause is coronary heart disease, especially myocardial infarction with the formation of postinfarction cardiosclerosis( scar replacement of muscle tissue)
- myocarditis, also having cardiosclerosis
- cardiomyopathy and myocardial dystrophy - metabolic disturbances in cardiac cellsmuscle and development of structural changes in it
- congenital heart diseases
- Brugada syndrome - clinical electrocardiographic syndrome, caused by a genemutation of proteins responsible for the transfer of sodium into and out of the myocardium cell, as a result of which contractility and impulse on the heart cells are impaired. The syndrome is dangerous by the sudden development of life-threatening rhythm disturbances and sudden cardiac death.

The factors that trigger the occurrence of paroxysm include:
- emotional stress or considerable physical stress
- alcohol intake
- cigarette smoking
- hypertensive crisis
- taking a regular dose of the medicine( cardiac glycoside or antiarrhythmics)

Symptoms of paroxysmal tachycardia

Between paroxysms of tachycardiathe patient can feel satisfactory. In the case of a chronic disease, the patient complains, depending on the nature of the disease. For example, when hyperthyroidism is concerned about trembling in the limbs, expressed weight loss, irritability, hair loss, heart defects and chronic heart failure - shortness of breath, fatigue, dizziness, heart pain, problems with the gastrointestinal tract - abdominal pain, nausea, heartburnetc.

Paroxysm of tachycardia is accompanied by a sensation of a push in the heart area and the consequent subjective palpitation. The patient literally feels that the heart beats very often. In addition, general weakness, choking, chest pain, dizziness, speech and vision impairment, loss of sensation and movements in the hands or feet may occur. A weak ventricular tachycardia can not manifest itself in any way. Persistent ventricular tachycardia can be accompanied by loss of consciousness and lead to the development of ventricular fibrillation, which is manifested by a picture of clinical death - lack of consciousness, pulse, independent breathing, pupillary response to light.

Diagnosis of paroxysmal tachycardia

The diagnosis of paroxysmal tachycardia, as a rule, does not cause difficulties and is confirmed by ECG during an attack. ECG - signs:
- paroxysmal atrial tachycardia - rhythm sinus, correct, with a heart rate of 140 - 250 per minute. The tooth P( shows the pulse from the sinoatrial node at the atrium) before each ventricular complex, but its amplitude is reduced, it can be deformed, negative or biphasic( part of the tooth is positive, part is negative).QRS is not enlarged and not deformed.
- paroxysm of tachycardia from the atrio-ventricular node - the P wave is negative, located after QRS, or it is not present at all. The QRS complex is normal.

Paroxysm of supraventricular tachycardia

- paroxysm of ventricular tachycardia - atrioventricular dissociation develops - the atria and ventricles contract separately, each in its rhythm( ventricles contract at a frequency of 140 - 220 per minute).There is a tooth P, but it is difficult to identify it. The QRS complex is extended( more than 0.12 sec), deformed.

Paroxysm of ventricular tachycardia

In addition to the standard ECG,
- daily monitoring of ECG,
- heart ultrasound,
- transesophageal electrophysiological examination( with supraventricular tachycardia),
- physical exercise samples( treadmill, bicycle ergometry),
- MRIheart,
- coronary angiography.

The plan of examination is appointed by a doctor in a polyclinic or in a hospital.

Treatment of paroxysmal tachycardia

Therapy of paroxysmal tachycardia is aimed at preventing the development of an attack and treating the underlying disease during the inter-attack period, as well as on arresting the attack of the heart palpitations. Prevention of frequent occurrence of attacks of ventricular tachycardia with the help of a constant intake of medications is aimed at preventing complications and sudden cardiac death.

Asymptomatic form of supraventricular tachycardia of continuous admission of cardiac drugs does not require. With frequent paroxysms that cause subjective discomfort and hemodynamic disorders, in addition to treating diseases of the digestive, nervous and endocrine systems, alcoholism, drug addiction and other diseases leading to the development of supraventricular tachycardia, the patient is assigned beta - adrenoblockers( carvedilol, bisoprolol), calcium channel antagonists( verapamil), antiarrhythmics( aymalin, allapinin, cordarone, etc.).

Ventricular tachycardia is more dangerous for health and life, especially as it is caused more often by serious heart diseases. Therefore, the patient, even with a single paroxysm in life, should be carefully examined in the cardiology or arrhythmology department, and should take beta-blockers and / or antiarrhythmics for a while after the attack.

First emergency aid for the management of paroxysm of tachycardia:

1. In the pre-hospital stage:
- lay the patient
- measure blood pressure and pulse on the wrist
- call an ambulance on the phone "03"
- use vagal tests - ask the patient to take a deep breathand stiffen, click on the closed eyeballs, cough. Samples can be effective only with supraventricular tachycardia.
- with the development of clinical death - resuscitative measures( indirect cardiac massage and artificial respiration according to the 15: 2 scheme - 15 strokes on the sternum through two injections of air into the patient's lungs)

2. Emergency medical team:
- with paroxysmal supraventricular tachycardia -after registration of the ECG intravenously struino adenosine triphosphate( ATP), digoxin, novocainamide + mezatone at initially low blood pressure, with ineffectiveness and the development of clinical death - electropulse therapy( withomoschyu defibrillator).
Hospitalization in a hospital is indicated with a severe general condition of the patient, a high risk of complications, pain in the heart, dyspnea, pulmonary edema. In case of stable condition, the patient may be left under the supervision of a district doctor.
- with paroxysmal ventricular tachycardia - after ECG recording - electropulse therapy, in the absence of restoration of sinus rhythm - intravenously stream lidocaine, novocaineamide + mezaton, cordarone, in the absence of effect - electropulse therapy. Hospitalization in the hospital is mandatory.

3. In hospital , intravenous infusions of antiarrhythmics( lidocaine, cordarone, novocainamide), complete examination are performed. The question of the need for cardiosurgical treatment is being addressed.

Cardiosurgical treatment is indicated in cases of frequent attacks of ventricular tachycardia, high risk of death and consists in the implantation of an artificial pacemaker( cardioverter-defibrillator).For supraventricular tachycardia, the indication for surgery is the long existence of a disease with frequent seizures, leading to heart failure, which is difficult to treat medically. The operation consists in radiofrequency ablation - "cauterizing" additional beams with a radio pulse by inserting electrodes into the heart cavity through the vessels.

Lifestyle

In order to exclude the provoking factors of the development of paroxysmal tachycardia, you need to stop drinking alcohol, coffee in large quantities, and reduce the number of cigarettes smoked. Significant physical stress and stress are also recommended to reduce. For the health of the heart and blood vessels, it is important to eat correctly and rationally, eliminate fatty foods, fried foods, consume vegetables, fruits, natural juices, sour-milk products, cereals and cereals, and consume confectionery.

To prevent the development of cardiovascular disease, in particular, atherosclerosis and coronary heart disease, it is necessary to struggle with excess weight, get rid of bad habits, monitor blood pressure and control blood cholesterol level, taking lipid-lowering medications prescribed by a doctor if necessary.

Patients with attacks of ventricular tachycardia and a high risk of death should, on a regular basis, perhaps even for life, take prescribed medications, especially beta-blockers, antiarrhythmics and antiaggregants( aspirin, tromboass, aspicor, etc.).

Complications of paroxysmal tachycardia

The most formidable complication of paroxysm of ventricular tachycardia is ventricular fibrillation and death. In addition, acute heart failure, pulmonary edema, myocardial infarction may develop. Do not exclude thromboembolic complications - thromboembolism of the pulmonary artery, ischemic stroke, acute thrombosis of the renal arteries, arteries of the lower limbs, etc. Prevention of complications is the regular intake of drugs and the timely determination of indications for the implantation of a pacemaker. Complications of paroxysmal supraventricular tachycardia are extremely rare.

Forecast of

The prognosis for supraventricular tachycardia in the absence of organic damage to the heart is favorable, especially if the original cause was eliminated( adjusted dosage of cardiac glycosides, normalized level of hormones in the body, etc.) For ventricular tachycardia, the forecast is less favorable, especially if tachycardia is coronarynature, that is, it was due to ischemia or myocardial infarction. The mortality in the case of development of ventricular tachycardia against the background of acute infarction is high and is 36% in the first month, and 55% in the first year. Nevertheless, with a regular intake of drugs or after implantation of a pacemaker, the forecast is relatively favorable.

Doctor therapist Sazykina O.Yu.