Atrial and His-Purkinje conduction times during isoflurane anaesthesia in humans.
The effect of isoflurane 2.0 MAC on human atrioventricular conduction time was studied. A non-invasive recording system for the detection of His-Purkinje potentials based on signal averaging techniques was used. Recordings were made in 15 patients before and after induction with isoflurane. We were able to measure atrial (P-H) and His-Purkinje (HPS) conduction times in 11 patients. Mean (+/- SEM) P-H conduction time decreased from 101.8 +/- 5.3 to 89.3 +/- 3.3 ms (P less than 0.01). HPS conduction times did not change significantly. Heart rate increased significantly from 86.7 +/- 4.2 to 94.9 +/- 4.7 beats min-1 (P less than 0.05). Systolic blood pressure decreased from 117.3 +/- 4.6 to 94.1 +/- 4.7 mmHg (P less than 0.05). It is concluded that the effects of isoflurane on supraventricular conduction time in humans depend on interactions of several different mechanisms.
Department of Anaesthesiology, Free University Hospital Amsterdam, The Netherlands.
G J
GJ
Scheffer
N T
NT
Van Schagen
R
R
Jonges
H H
HH
Ros
A
A
Peper
J J
JJ
De Lange
D000293:Adolescent; D000328:Adult; D000703:Analog-Digital Conversion; D000769:Anesthesia, Inhalation; D001283:Atrioventricular Node / Q000187:drug effects*; D001794:Blood Pressure / Q000187:drug effects; D002036:Bundle of His / Q000187:drug effects*; D002648:Child; D004562:Electrocardiography / Q000187:drug effects / Q000379:methods; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007530:Isoflurane / Q000494:pharmacology*; D008875:Middle Aged; D009431:Neural Conduction / Q000187:drug effects*; D011690:Purkinje Fibers / Q000187:drug effects*; D013997:Time Factors
D007530:Isoflurane