ABSTRACT
This study was carried out on 20 mongrel dogs anesthetized by halothane [1-1.5% in O2 4 L/min.], to find the role of disopyramide on the epinephrine induced arrhythmias on these dogs. They were divided into two equal groups, a therapeutic group [10 dogs], they received disopyramide [2-3 mg/kg] to treat the developed dysrrhythmias induced by epinephrine [130 mug/min.] and a prophylactic group [10 dogs]; they received disopyramide [2.9 mg/kg] in advance to against the development of epinephrine [130 mug/min.] induced dysrrhythmias. The therapeutic administration of disopyramide succeeded to decrease significantly the epinephrine induced tachycardia [P <0.05] and to revert the developed dysrrhythmias [ventricular premature beats] with cure rate 90%, the 10% failure being a case of ventricular fibrillation. The prophylactic administration of disopyramide maintained the rhythm sinus in presence of epinephrine challenge with a prophylactic success of 10%, but it did not guard against the increase in heart rate induced by epinephrine [P <0.001]. It was recommended from the present study to use disopyramide in the anaesthetic field whenever there is a risk of dysrhythmia develops due to epinephrine-halothane interaction