Heart rate dynamics after acute cocaine administration.
We examined heart rate (HR) patterns after a bolus intravenous (i.v.) administration of a high (10 mg/kg) dose of cocaine in unrestrained cats. Mean R-R intervals, SD, and other measures of variability were assessed in three periods: waking baseline, early postcocaine administration, and later recovery periods. Cocaine resulted in initial tachycardia and reduced HR variability. This reduction in variability was independent of changes in the average rate: during the recovery period, HR returned to baseline values, but the reduced variability persisted. Nonlinear methods of assessment yielded additional results: Cocaine introduces a high correlation between one beat and the next and a tendency for cardiac accelerations to be followed immediately by decelerations and vice versa. The overall effect of the drug is to restrict deviation from a fixed rate.
Garfinkel
A
A
Brain Research Institute, UCLA School of Medicine 90024-1761.
Raetz
S L
SL
Harper
R M
RM
D000818:Animals; D002415:Cats; D003042:Cocaine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006339:Heart Rate / Q000187:drug effects* / Q000502:physiology; D008297:Male
D003042:Cocaine