title: Simultaneous measurement of atrial and ventricular pacemaker activity.
abstract: The isolated perfused rat heart with surgically-induced heart block was used to determine the effect of drugs on the activity of the atrial and ventricular pacemaker simultaneously. Complete atrio-ventricular dissociation was produced by tying a ligature around the Bundle of His under direct vision. Pacemaker rates remained stable for at least 2 hours. Perfusion of the hearts with quinidine produced a decrease in the rate of both the atrial and ventricular pacemaker. The ventricular pacemaker was more susceptible to the depressant action of quinidine than the atrial pacemaker.
mesh_terms: D000818:Animals; D016275:Atrial Function; D004305:Dose-Response Relationship, Drug; D004562:Electrocardiography; D006327:Heart Block; D006329:Heart Conduction System; D006339:Heart Rate / Q000187:drug effects; D066298:In Vitro Techniques; D008026:Ligation; D008297:Male; D010138:Pacemaker, Artificial; D011802:Quinidine / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D013997:Time Factors; D016276:Ventricular Function
chemical_list: D011802:Quinidine