Comparative study of the action of local anesthetics on AV conductivity of dog heart in situ.
Effects of local anesthetics (procaine, lidocaine, prilocaine, mepivacaine and bupivacaine) on AV conductivity were studied using a direct perfusion technique of the canine AV node artery in situ. The agents induced dose-dependent depression of AV conductivity in doses between 100 microgram and 3 mg. The depression was assumed to have resulted from their direct action on the AV node, since it was not affected by prior administration of atropine or tetrodotoxin into the AV node artery. The order of potency to suppress AV nodal conductivity evaluated from ED50 for causing first to third degrees of AV block was bupivacaine greater than mepivacaine = prilocaine = lidocaine greater than procaine with a relative potency ratio of 5 : 2--2.5 : 1.
D000109:Acetylcholine / Q000494:pharmacology; D000779:Anesthetics, Local / Q000494:pharmacology*; D000818:Animals; D001283:Atrioventricular Node / Q000187:drug effects*; D001285:Atropine / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D004285:Dogs; D004347:Drug Interactions; D004569:Electroencephalography; D006329:Heart Conduction System / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D009431:Neural Conduction / Q000187:drug effects*
D000779:Anesthetics, Local; D001285:Atropine; D000109:Acetylcholine