DISORDERS OF CARDIAC RHYTHM IN PATIENTS WITH PRE-EXCITATION SYNDROME OF VENTRICLES AND THEIR PHARMACOLOGICAL CORRECTION

Abstract

The aim of the research was to analyze the possibility of using different antiarrhythmic agents in patients with pre-excitation syndrome and disorders of cardiac rhythm. Most typical disorders of cardiac rhythm in patients with pre-excitation syndrome are orthodromic reciprocating supraventricular tachycardia, antidromic supraventricular tachycardia, atrial fibrillation and atrial fibrillation. During attack of tachycardia in patients with syndrome of pre-excitation, different clinical symptoms can be observed. They can range from mild palpitation to syncope. This tachycardia can be even reason of sudden cardiac death. Main its mechanism is macroreentrant circuit involving the AV-node, the additional pathway, the atria, the ventricles. To arrest the attacks of atrioventricular reciprocating tachycardia in patients with WPW syndrome and with narrow complexes QRS, calcium channel blocker verapamil has efficacy in 95% of patients. However, for treatment this arrhythmia with wide complexes QRS verapamil is contraindicated. Besides, it should be taken in account that treatment with this type of cardiac arrhythmia cardiac glycosides is also forbidden. Verapamil and cardiac glycosides are contraindicated for termination of arrhythmia in patients with WPW syndrome and such disorders of cardiac rhythm as atrial fibrillation (flutter). For therapy of atrial fibrillation (flutter) in patients with WPW syndrome antiarrhythmic agents of agents of І A subclass (quinidine, procainamide, disopyramide, propafenone) and ІІІ class (amiodarone, sotalol) can be useful. For interruption of paroxysmal tachycardia in patients with pre-excitation syndrome antiarrhythmical preparations of plant origin (gilurytmal and allapinin) have high efficacy. Termination of paroxysmal tachycardia in patients with premature excitation of ventricles can be achieved after administration of antiarrhythmic agents of ІС subclass, in particular after using of propafenone and encainide. However, treatment with the help of these agents quite often leads to appearance of arrhythmogenic action. In pre-excitation syndrome and cardiac arrhythmias, it is impossible to use drugs, which cause the acceleration of conductivity of nerve impulses in additional pathways (cardiac glycosides, β-blocker agents, for example propranolol). In patients with paroxysmal atrioventricular reciprocating (circular) tachycardia digitalis and calcium channel blockers should be avoided. Such agents as digoxin and verapamil in this arrhythmia can turn out to be dangerous in WPW syndrome, since they raise the conductivity through additional conductive pathways.