AI Article Synopsis

  • Researchers studied heart rate patterns in unrestrained cats after a high dose of cocaine (10 mg/kg) via IV.
  • Cocaine caused an initial increase in heart rate (tachycardia) and decreased heart rate variability, which persisted even after heart rates returned to baseline during recovery.
  • Advanced analysis showed cocaine increased the correlation between consecutive heartbeats, leading to a pattern where heart rate accelerations were quickly followed by decelerations, indicating a restriction of heart rate fluctuations.

Article Abstract

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.

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http://dx.doi.org/10.1097/00005344-199203000-00024DOI Listing

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