Effects of volatile anesthetics on intracardiac impulse conduction

1993 Fiscal Year Final Research Report Summary

• Project/Area Number: 03670737
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: 麻酔学
• Research Institution: Kinki University
• Principal Investigator: SUEKANE Keita Kinki University, School of Medicine, professor, 医学部, 教授 (80088533)
• Co-Investigator(Kenkyū-buntansha): KUMODE Osamu Kinki University, School of Medicine, lecture, 医学部, 講師 (90225235)
• Project Period (FY): 1991 – 1993
• Keywords: sevoflurane / halothane / action potential / ion channel / sinoatrial node

Research Abstract

The effects of sevoflurane and halothane on the electrophysiologic properties of the isolated spontaneously beating sinoatrial (SA) node in the guinea pig were examined. The piece of right atria containing the SA node was perfused with Krebs' solution and gassed with 5%CO_2 in O_2. During administraiton of the test solutions that were equilibrated with 1%, 2%, 3% or 4% sevoflurane or with 1% or 2% halothane, respectively, the following changes were observed. Introduction of these anesthetics (sevoflurane and halothane) for fifteen minutes produced a significant decrease in the sinus rate, decreases in the slope of phase 0 and phase 4, and a increase in the action potential duration. At higher concentrations, 3% or 4% for sevoflurane and 2% for halothane, these anesthetics significantly decreased the action potential amplitude and its overshoot. There was no change in the threshold potential or maximum diastolic potential. It is concluded that the decrease in the slope of phase 4 and the increase in the action potential duration by both sevoflurane and halothane lowered the sinus rate of the sinoatrial node in the guinea pig.