AJP - Heart and Circulatory Physiology, Vol 239, Issue 3 427-H431, Copyright © 1980 by American Physiological Society
Effect of pentobarbital anesthesia on vulnerability to ventricular fibrillation
A. K. Dawson, A. S. Leon and H. L. Taylor
Ventricular fibrillation threshold (VFT), frequently determined in dogs
during pentobarbital sodium anesthesia, usually is replaced by a single
repetitive extrasystole threshold (SRET) or a multiple repetitive
extrasystole threshold (MRET) determination in conscious animals and in the
human being. In the present study SRET, MRET, and VFT were determined
initially in 39 pentobarbital sodium-anesthetized dogs. One week later
these three thresholds were redetermined during anesthesia in 13 of the 39
dogs (control group). In the remaining 26 dogs (experimental group),
thresholds were redetermined while the dogs were conscious. Significant
changes in threshold values occurred only in the experimental group for VFT
(P < 0.001) and MRET (P < 0.02). The square of the linear correlation
coefficient showed conscious state MRET to be a good predictor of conscious
state VFT (R2 = 0.90). Conscious state SRET and anesthetized state VFT
showed less predictiveness for the conscious VFT (R2 = 0.72 and 0.51,
respectively). These data indicate that MRET may be preferable to SRET as
an index of VFT. The SRET, MRET, and VFT determined during pentobarbital
anesthesia may not accurately reflect the value of these parameters in the
conscious animal.
