This study concerns ( a ) the antiarrhythmic properties of arnodiaquin and primaquine in comparison with those of quinidine and ( b ) the ionic fluxes caused by acetylcholine and the depression of these fluxes by the antiarrhythmic drugs used. Under ( a ) it was found that both amodiaquin and primaquine are as effective as quinidine in halting atrial fibrillation induced by the injection of acetylcholine after pretreatment with neostigmine. Under ( b ) no ion fluxes were demonstrated after the injection of acetylcholine under the conditions of the experiment.
UINIDINE is an established drug in the treat-Q. ment of cardiac disorders. It is the dextroisotner of quinine arid is the most active of the cinchona alkaloids in antiarrhythmic activity (1). Quiniditie has been reported ljy Lewis (2) t o have the following effects on heart muscle: i t depresses excitability, slows conduction, slows the rate, increases the refractory period, and causes a decrease in vagal tone. It has no effect on 1.he contractility of the heart in normal
A search of the literature revealed two synthetic atititnalarials that had been studied only a very little for their antiarrhythmic activity.