Actions of halothane and isoflurane on Purkinje fibers in the infarcted canine heart: conduction, regional refractoriness, and reentry. Anesth Analg 1993 Apr;76(4):718-25
Date
04/01/1993Pubmed ID
8466007Scopus ID
2-s2.0-0027465579 (requires institutional sign-in at Scopus site) 7 CitationsAbstract
The actions of halothane (HAL) and isoflurane (ISO) on conduction and regional refractoriness were studied in infarcted canine hearts to compare their effects on reentry in vitro. In two anesthetic groups of 8 hearts, high and low dose effects were assessed using action potentials recorded from Purkinje fibers located in the nonischemic and ischemic regions. An extrastimulus technique was used to determine the relationship between delay of conduction of premature impulses into the more refractory ischemic region and induction of reentrant responses. At high doses (HAL 0.60 mM and ISO 0.64 mM, approximately 2.3 minimum alveolar anesthetic concentration [MAC]) both anesthetics decreased (P < or = 0.05) the effective refractory period for direct intracellular stimulation of nonischemic fibers (local ERP, initial control: 294 +/- 8 ms); the decrease with HAL (-29 +/- 6 ms) was smaller (P < or = 0.05) than with ISO (-50 +/- 7 ms). HAL and ISO also decreased (P < or = 0.05) the coupling interval of the earliest premature impulse which conducted into the infarct (system effective refractory period [SERP], control: 301 +/- 7 ms) by -31 +/- 11 and -44 +/- 8 ms, respectively. In contrast, the functional refractory period (FRP) in the ischemic region (control:354 +/- 4 ms) was increased by HAL (26 +/- 8 ms; P < or = 0.05) but decreased by ISO (-14 +/- 4 ms, P < or = 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Author List
Turner LA, Polic S, Hoffmann RG, Kampine JP, Bosnjak ZJMESH terms used to index this publication - Major topics in bold
AnimalsDisease Models, Animal
Dogs
Electric Stimulation
Electrophysiology
Halothane
Heart Conduction System
Isoflurane
Myocardial Infarction
Myocardial Ischemia
Purkinje Fibers
Tachycardia, Sinoatrial Nodal Reentry