title: Comparison of the effects of halothane, isoflurane, and sevoflurane on atrioventricular conduction times in pentobarbital-anesthetized dogs.
abstract: It is not known how sevoflurane affects the cardiac conduction system. We compared the effects of halothane, isoflurance, and sevoflurane on specialized atrioventricular (AV) conduction times in eight pentobarbital-anesthetized dogs. AV conduction times with three inhaled anesthetics at end-tidal concentrations of 1 and 2 minimum alveolar anesthetic concentration (MAC), were measured by His-bundle electrocardiography during both sinus rhythm and right atrial pacing at a slightly higher rate than sinus one. Heart rate and arterial pressure were simultaneously recorded. Halothane prolonged AV nodal conduction time during sinus rhythm (A-H interval) at 2 MAC compared with the control value, whereas isoflurane and sevoflurane did not alter the A-H interval, His-Purkinje conduction time (H-V interval), and ventricular conduction time (H-S interval) during sinus rhythm at 1 and 2 MAC. All three inhaled anesthetics did not change AV conduction times during right atrial pacing. No significant difference in AV conduction times was observed between isoflurane and sevoflurane. Heart rate during sinus rhythm remained unchanged despite a decrease in arterial pressure with three inhaled anesthetics. The property of sevoflurane and isoflurane which does not affect the cardiac conduction system may be important in the stability of the cardiac rhythm during anesthesia with these drugs.
authors.affiliation: Department of Anesthesiology, Jichi Medical School, Tochigi, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Nakaigawa
authors.forename: S
authors.initials: S
authors.lastname: Akazawa
authors.forename: R
authors.initials: R
authors.lastname: Shimizu
authors.forename: R
authors.initials: R
authors.lastname: Ishii
authors.forename: R
authors.initials: R
authors.lastname: Yamato
mesh_terms: D000771:Anesthesia, Intravenous; D018685:Anesthetics, Inhalation / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001283:Atrioventricular Node / Q000187:drug effects*; D001794:Blood Pressure / Q000187:drug effects; D002036:Bundle of His / Q000187:drug effects; D002304:Cardiac Pacing, Artificial; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004562:Electrocardiography / Q000187:drug effects*; D004987:Ethers / Q000008:administration & dosage / Q000494:pharmacology*; D006221:Halothane / Q000008:administration & dosage / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects; D007530:Isoflurane / Q000008:administration & dosage / Q000494:pharmacology*; D008738:Methyl Ethers; D010424:Pentobarbital / Q000008:administration & dosage*; D011690:Purkinje Fibers / Q000187:drug effects; D000077149:Sevoflurane; D013997:Time Factors
chemical_list: D018685:Anesthetics, Inhalation; D004987:Ethers; D008738:Methyl Ethers; D000077149:Sevoflurane; D007530:Isoflurane; D010424:Pentobarbital; D006221:Halothane