[Effect of ethmozine in patients with paroxysmal atrioventricular nodal tachycardias].

With the aid of the electrophysiological method ethmozine action on patients with paroxysmal atrioventricular nodal tachycardias has been studied. Tachycardia was arrested by ethomozine in 66.6% of patients. With the drug still acting stable tachycardia could not be elicited in 75% of cases. After ethmozine administration in 3 out of 14 patients complete block of impulse retrograde conduction in the atrioventricular node supervened, in the remaining 11 there was a significant increase in the refractory period (a mean of 124.5 ms) and a decrease in the level of Wenckebach's point of the ventriculo-atrial conducting system. The drug had practically no effect on the electrophysiological indices of the atrioventricular node for anterograde conduction. It is concluded that ethmozine is effective for arresting and, possibly, for preventing such disorders in this category of patients. Electrophysiological mechanism of this effect is the block of the echo-impulse of retrograde conduction in the atrioventricular node.