RT Journal Article SR Electronic T1 A METHOD FOR THE EVALUATION OF DEPRESSANTS OF SUBATRIAL RHYTHMIC FUNCTION IN THE HEART OF THE INTACT ANIMAL JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 36 OP 41 VO 129 IS 1 A1 Jay Roberts A1 Ralph Baer YR 1960 UL http://jpet.aspetjournals.org/content/129/1/36.abstract AB A method is described for the study of depressant action of drugs on the rhythmic function of the A-V node and ventricle in the intact animal. The method involves the phenomena of "escape" of subatrial ectopic beats when the sinus is sufficiently slowed by vagal stimulation and the alltagonism between stimulant and depressant drugs on rhythmic function. The depressant action of a series of quinidine doses on subatrial rhythmicity was revealed by the increment in the epinephrine or isoproterenol test dose required to induce cetopic beats after quinidine administration. It is expected that this method should prove useful for the study and comparison of drugs with stimulant and depressant actions on A-V nodal or ventricular rhythmicity, actions of a magnitude otherwise undetectable in the normally heating heart of the intact animal.