Antiarrhythmic agent

Antiarrhythmic agent (antiarrhythmic funds) - substances that influence anxiety and conductivity of the heart muscle, and thereby normalizing heart rate. To the complications include quinidine, and procainamide.
Quinidine and procainamide reduce anxiety attack, slow the passage of impulses on conduction system of the heart, in large doses can interfere and force of heart, and quinidine more than novokainamid. Use both of these tools with atrial fibrillation, paroxysmal tachycardia, arrythmia. Contraindications to the use - see Procainamide, Quinidine.
As a means of complications is also used potassium chloride, aymalin, propranolol (inderal), atropine, ephedrine, izadrin and adrenaline. Potassium chloride is the most effective in arrhythmias associated with intoxication cardiac of glikozidam. Alkaloid rauwolfia aymalin (see Tissue) and propranolol (see Adrenolytic funds) are used when PVC and paroxysmal tachycardia.
Holinoliticescoe (atropine) and adrenomimeticescoe (ephedrine, izadrin, adrenaline) the means used to treat arrhythmiasassociated with violations conductivity attack,- pearlkolodny, atrioventricular blockade. The mechanism of action of these groups of substances associated with improved conductivity infarction. Separate antiarrhythmic agent - see the article by name drugs.

Antiarrhythmic agent - drugs, the normalizing of disturbed cardiac rhythm. Antiarrhythmic agent sizable number of medicinal substances, diverse on chemical structure and possessing along with antiarrhythmic activity other pharmacological properties.
In accordance with the characteristics of pathogenesis of heart arrhythmias in which they are applied, antiarrhythmic agent can be divided into two groups: 1) used for the prevention and treatment of ectopic arrhythmias due to a violation of the process of impulseresponse (arrythmia, paroxizmalnaya tachycardia, atrial fibrillation); 2) intended for therapy of rhythm disorders, caused mainly by the dysfunction of the conductivity. A. S. reduce pathological anxiety attack, suppress heterotopic impulsoobrazovanie, slowing the conduction of impulses through the conduction system of the heart and either restore the activities of the sinus node as the main driver rhythm or without eliminating arrhythmia, slowing the frequency of the contractions of the ventricles, which also has a positive effect on hemodynamics. This group A. C. includes quinine (see), it programasi isomer - quinidine, derived novocaine - novocaine-amide, one of rauwolfia alkaloids - aymalin. To some extent this group A. S. may also include heart glycosides, salts of potassium and magnesium, some protivogistaminne means neurologiske funds and other Quinidine (see) is effective in all kinds of cumulative departments, including at the counter form of atrial fibrillation. The therapeutic effect is manifested only with optimal concentration in the blood, which is achieved frequent meals drug under special schemes. Quinidine relatively toxic, and therefore quite often there are cases of intolerance and idiosyncrasy. Novokainamid (see) more effective with ventricular fibrillation than in supraventricular. He has less severe toxic effects than quinidine. Aymalin, particularly effective in atrial and ventricular arrythmia and paroxysmal tachycardia, favorably with quinidine and procainamide hydrochloride less pronounced negative effect on airway diseases.
In the modern view, these antiarrhythmic agent change the exchange of electrolytes in the myocardium, reducing the permeability of cell membranes to intracellular and extracellular potassium sodium; changes transmembrane move cations affect bioelectric activity of myocardial cells and their ability to impulsoobrazovanie, extend refractory period of the heart muscle and reduce her anxiety. Antiarrhythmic effects of quinidine and procainamide hydrochloride to a certain extent also depends on their ability to inhibit the synthesis of acetylcholine, which plays an important role in the implementation of the functions of mechanical heart.
Heart glycosides (see) used in certain disorders of the heart rhythm, mainly for cupping paroxysmal tachycardia, elimination arrythmia and translation tachysystolic form of atrial fibrillation in predicitions. The antiarrhythmic mechanism of action of cardiac glycosides due to their inotropic effect, normalizing effect on metabolic processes in myocardium, as well as the impact on non cardiac innervation, resulting oppressed automaticity of sinus node and atrioventricular conduction. Note, however, that heart glycosides, changing electrolyte metabolism of myocardium, increase its excitability, shorten refractory phase, which in combination with depression conductivity can cause arrhythmia.
For the treatment of certain cumulative departments, especially arising from the use of cardiac glycosides, in recent times with success: use salts of potassium, magnesium sulfate and disodium salt ethylenediaminetetraacetic acid (EDTA). Antiarrhythmic effect of these substances due to the normalization of electrolyte balance of the myocardium. Disodium salt EDTA - active complexone - ties in serum ionized calcium, which is sinergistom cardiac glycosides. Recently there were messages antiarrhythmic action of a number of drugs from different pharmacological groups. So, rhythm disorders, characterized by the ectopic impulses have been effective some neurologiske tools - derivatives fenotiazina (see Hloratsizin), antidepressants (imipramine), analgesic agents (morphine), anticonvulsants (phenytoin), protivogistaminne means (antazolin), as well as some enzymes (e.g. kokarboksilaza). To resolve ventricular tachycardia occurring on the face of myocardial infarction and accompanied by a fall in blood pressure, apply some sympathomimetic amines (detoxamin, metaraminol, mezaton).
Another group of antiarrhythmic drugs are drugs used to treat arrhythmias due to a violation of atrioventricular conduction (partial, complete heart block, the syndrome Adams - Stokes - blinking). In these cases, using mainly the substances possessing simpatomimeticescoy activity (see Adrenaline, Ephedrine, Izadrin), sometimes anticholinergic agents (atropine). Sympathomimetic substances improve conductivity, and if block reinforce impulsoobrazovanie ventricular centers automatic. Izadrin, unlike epinephrine and ephedrine, increases anxiety attack without causing hypertensive effect. This group A. S. should include sodium lactate, improves conductivity in the result of the direct action of sodium ion and the emergence of alkalosis, and ACTH and corticosteroid hormones.
Working on different links of metabolism in the myocardium and providing sometimes opposite impact on non cardiac innervation and directly on the heart, A. S. can not only eliminate adults, but also contribute to their appearance. This must especially be taken into account when parenteral (intravenous) the use of quinidine, procainamide hydrochloride, cardiac glycosides and sympathomimetic amines.