Nadzheludochkovaya tachycardia
Nadzheludochkovaya tachycardia - this is one of the types of arrhythmia, the cause of which is a failure in electrical conductivity, regulation of the rate of contraction of the heart. Nadzheludochkovye tachycardia have a more favorable course in comparison with ventricular. Supraventrikulyarnaya form of tachycardia is much less associated with organic damage to the heart and a violation of the functioning of the left ventricle. But still, the supraventricular tachycardia is considered as a condition endangering life, due to some probability of presyncopal or syncope, as well as sudden arrhythmic death.
In the heart of a physically healthy person, each contraction is a consequence of an electrical impulse that is generated by a pacemaker that is in the right atrium. After this, the impulse arrives at the next node from which it is transferred to the ventricles. In the process of the development of supraventricular tachycardia, the pacemaker can not control the contractions due to the formation of pathological ways or an additional node, which leads to a breakdown in the rhythm of the heart. Nadzheludochkovaya tachycardia causes
Nadzheluduchkovaya tachycardia, the signs of which - a very high frequency of contractions of the heart muscle( up to two hundred and fifty times per minute), a sense of fear, has several causes( prerequisites) of development. In adolescence, tachycardia can be functional. Such a tachycardia is caused by a variety of stressful situations, anxiety, strong emotions.
In the occurrence of supraventricular tachycardia, the importance of the state of the human nervous system plays a big role. The impetus for the development of supraventricular tachycardia can be neurasthenia, climacteric changes, neurocirculatory dystonia, concussion. The attack can also happen due to the reflex effects of the kidneys, diaphragm, bile, gastrointestinal tract. Much less often the reflex action on the main organ of the circulatory system is exerted by the spine, lungs and pleura, pancreas and genital organs.
Nadzheludochkovuyu tachycardia can cause certain medicines, especially Novokainamid, Quinidine. Also very dangerous is an overdose of cardiac glycosides, which can cause a severe supraventricular tachycardia, which in half of the reported cases terminates lethal. Paroxysms in this case arise because of a significant change in the level of potassium in the body. There are a number of other reasons, in some cases leading to tachycardia: hypertension, a protracted infectious process, thyrotoxicosis. An attack can occur on the operating table during heart surgery, during therapy with electrical impulses. In some cases, paroxysm can precede fibrillation.
Nadzheludochkovaya tachycardia in children and young people is sometimes a manifestation of a congenital defect in the conductive ways of the heart - the syndrome of Wolff-Parkinson-White. With this pathology, the atria and the ventricles receive additional ways of conducting, located outside the atrioventricular node. Because of this, the excitation of the ventricles is accelerated, which causes supraventricular tachycardia.
Nadzheludochkovaya tachycardia symptoms of
The main symptom of supraventricular tachycardia is a sharp rapid increase in contractions of the heart muscle. During an attack, the heart can contract at a rate of one hundred and fifty-two hundred and fifty times per minute. Often, you can follow the pattern: the higher the heart beat frequency, the more intense and brighter the symptoms appear.
Manifestations of this disease in each individual case have certain distinctive features. They are caused by the presence or absence of organic damage to the myocardium, the location of the pathological pacemaker in the organ, the state of the blood flow, the duration of the attack, and the state of the heart muscle. During supraventricular tachycardia, the patient may experience dizziness. A common symptom of this pathology is pain in the chest or neck, dyspnea may appear. Often supraventricular tachycardia accompanies a feeling of fear, panic and anxiety. The pain symptom can be manifested by a pressing feeling in the chest( constriction).
If the attack is prolonged for a long time, a person may have signs indicating the occurrence of cardiovascular failure. This dangerous condition can be diagnosed by simple and very characteristic signs: the emergence of difficulties in the implementation of inspiration, the development of edema on the hands, legs, face, the appearance of acrocyanosis( fingertips on the hands and feet, and the site of the mouth and nose acquire a pale blue bluish tinge).A prolonged attack of tachycardia can result in a fainting condition. In this state, a person needs the help of doctors.
An indication of the occurrence of supraventricular tachycardia is also reduced blood pressure. Especially often the pressure drops, if the attack lasts a long time. That's why a person with a prolonged attack of tachycardia needs to measure pressure, since his critical fall can seriously threaten human life, cause a collapse.
It is important to know that people with low blood pressure are more likely to develop supraventricular tachycardia. This is due to the fact that with low blood pressure in the arteries, its inflow to the organs decreases, and the body tries to correct it by increasing the contractions of the heart. This is why supraventricular tachycardia is so common in hypotensive patients.
If a person suffers from such a form of tachycardia for a long time and seizures are often repeated, he needs to undergo a test, since without necessary treatment, heart failure and dilated cardiomyopathy may occur.
Nadzheludochkovaya tachycardia ECG
On ECG with supraventricular tachycardia in QRS, there are no deformities. In rare cases, its form can still change due to aberrant conduct. Re-entry in the atrioventricular node is a common cause of the onset of precisely supraventricular tachycardia( six out of ten cases of supraventricular tachycardia occur in this form).There is an opinion that re-entry in the atrioventricular node arises due to the fact that it is longitudinally dissociated into two ways, separated functionally. With an attack of tachycardia, the impulse passes anterograde one of these ways, and retrograde - the second. That is why the atria are excited with the ventricles at the same time, the retrograde P-teeth merge with the QRS and become invisible on the ECG or recorded immediately after the complex.
If the blockade occurred in the most atrioventricular node, re-entry is interrupted. But the block in the fascicle bundle or below it can not affect in any way the overhand tachycardia. Such blockages are very rare, especially in young patients, which is why the appearance of the atrioventricular block with supraventricular tachycardia testifies against re-entry( reciprocal AV node tachycardia).
A rare reason for the appearance of supraventricular tachycardia is re-entry in the sinus node. In this case, the pulse propagates inside the sinus node, therefore, when tachycardia, the P-teeth do not differ in any way from the P-wave sinus rhythm. In the distribution of the impulse, the atrioventricular node does not participate, which is why the size of the PQ interval, the absence or presence of an atrioventricular block, depend solely on the properties of the atrioventricular node.
Every twentieth case of supraventricular tachycardia is caused by re-entry in the atria. The impulse in this case circulates in the atria, with supraventricular tachycardia before the QRS, a tooth P is recorded, which indicates an anterograde spread of the pulse in the atria. In the re-entry circuit, the atrioventricular node is not included. That is why AB blockade does not affect this form of supraventricular tachycardia.
The causes of rare cases of supraventricular tachycardia are foci with increased automatism. The shape of the P wave with tachycardia directly depends on where the ectopic source is located.
Nadzheluduchkovaya tachycardia treatment
If a person has a supraventricular tachycardia, emergency care should be given promptly. A very effective method is the Tchermak-Herring test. Manipulation is performed when the patient is in a horizontal position. It is necessary for thirty seconds to press the thumb on the sleepy knot on the right. It is at the level of the upper border of the thyroid cartilage in the projection of the inner surface of the upper third of the sternocleidomastoid muscle. As soon as the attack has ended, it is necessary to immediately stop pressing on the artery. This trial is contraindicated for people in advanced age with atherosclerosis, in the late stages of hypertension, as well as in case of an overdose of funds based on digitalis.
The above sample can be replaced by the Ashner-Danyini test. It consists in simultaneous, gentle pressure on the eyeballs of the patient. This manipulation is only possible in a supine position. It can not be performed for more than thirty seconds, as soon as the effect appears, the effect is stopped. The Eschner-Danyini test is prohibited if the patient suffers from eye pathologies. To remove an attack of supraventricular tachycardia will help and artificially caused vomiting, wiping with cold water, strong pressure on the upper half of the abdomen. In the event that reflex methods of influence did not yield any result, use medicamentous agents.
Nadzheludochkovuyu tachycardia in our time is quite successfully and effectively treated with verapamil. In order to stop an attack, 0,25% Verapamil is injected into a vein in the amount of two milliliters. After the attack has ended, it is necessary to switch to the tablet form of the remedy. Assign one tablet 2-3 times a day. If Verapamil was ineffective, beta-blockers( Anaprilin, Viskin, Oxprenolol) are used instead. During an attack, Anaprilin is given intravenously( 0.001 g for 60-120 seconds).If after a few minutes there is no result, the same dose is administered. In total it is possible to make five-ten injections of Anaprilin under the control of hemodynamics and ECG.Inside, the drug is prescribed for 1-2 tablets one to three times a day( the dose is selected by the doctor).
Oxprenolol for arresting an attack of supraventricular tachycardia is injected into a vein at a dosage of 0.002 grams. Usually this amount is sufficient and repeated administration is not required. Orally Oxprenolol take two to four tablets per day( 0.04-0.08 grams).Vine is used intravenously in a jet at a dose of 0.0002-0.001 grams, in the form of a dropper in a five percent solution of glucose or per os for three to six tablets per day( 0.015-0.03 grams).
Quite often Novocainamide is used to stop an attack of supraventricular tachycardia. It is injected into a vein or muscle of five to ten milliliters of a 10% drug. You can take and inside for 0.5-1 gram every two hours until the seizure stops. It is important to know that the administration of Novocainamide parenterally can lead to disturbances in hemodynamics, including collapse.
Aimalin is a good therapeutic agent in most cases. This drug is priceless in the treatment of seriously ill patients who can not be given Novocainamide, quinidine, beta-blockers because of their toxicity and a bright antihypertensive effect. Aimalin is injected very slowly( about five minutes) at 0.05 grams in 10-20 milliliters of 5% glucose or sodium chloride. After the attack was successfully stopped, Aimalin is prescribed in the form of tablets( one or two tablets three to four times a day).
If the patient is often disturbed by minor attacks of supraventricular tachycardia, the Pulse-norm will help. During an attack, you need to drink two pills, and then take one dragee every eight to twelve hours.
Rapidly suppresses the supraventricular tachycardia with a drug such as Trifosadenin. This agent is injected into the vein rapidly( one to two seconds).Usually, one to three milliliters of 1% Trifosadenin is taken for one injection. Immediately after the administration of the drug in the body in the same vein, you need to enter ten milliliters of sodium chloride( 0.9%) or a five percent solution of glucose. If there is no effect for one hundred and twenty seconds, you need to give the patient a double dose of this medicine. In the first minutes after the injection, a person may have a headache or a spasm of the bronchi. It is not worth to be afraid of these phenomena, since they are transitory in character and pass very quickly without consequences.
Its effectiveness in the attack of supraventricular tachycardia was shown by Procainamide. This drug is injected into the vein, injecting very slowly. For infusions take a ten percent solution. The introduction of this agent is better done with the use of a special dispenser for medicinal preparations. This is necessary in order to prevent the possible development of hypotension.
With supraventricular tachycardia, Esmolol can be used. This is an ultra-short beta-blocker. First, the patient is given the drug in a loading dosage( up to five hundred micrograms per kilogram) for sixty seconds. In the next four minutes, the drug is administered at a rate of fifty milligrams per kilogram. In most cases, during these five minutes, the effect comes from the administration of the drug, an attack of supraventricular tachycardia passes. If, however, the attack continues and the sick person does not become easier, it is necessary to repeat the introduction of the loading dose of Esmolol.
If there is a situation where it is impossible to be absolutely sure that the arisen tachycardia is exactly nadzheludochkovoy, it is best to introduce Novokainamid or Amiodarone. The method of administration of Novocaineamide has already been described above, Amiodarone is injected into a vein in an amount of three hundred milligrams of struino. Preliminary it must be diluted with twenty milligrams of five percent glucose. Sodium chloride( isotonic) for breeding Novokainamid is prohibited.
After the attack succeeded to stop, a patient with supraventricular tachycardia is prescribed therapy that helps to avoid relapses. These drugs include cardiac glycosides and various antiarrhythmic drugs. Now very popular for outpatient treatment is the combination of Diltiazem with Verapamil.
Each patient with supraventricular tachycardia is unique in its own way, therefore the scheme for treatment at home is selected by the doctor individually. Usually, the doctor chooses from such medicines as Sotalol, Etatsizin, Quinidine, Propafenone, Azimilide, Allapinin and some other drugs. Sometimes a doctor prescribes monotherapy, and in some cases it is necessary to combine several drugs.
The prognosis for life for people with supraventricular tachycardia is quite favorable, tachycardia does not affect the life expectancy of a person and even on quality if the patient complies with the recommendations of his doctor.
