Why the study?
Does repeated atropine injection alter heart rate variability in Thoroughbred horses?
Does repeated atropine injection alter heart rate variability in Thoroughbred horses?
In Thoroughbred horses, atropine dose-dependently decreases parasympathetic activity, affecting LF power first, then HF power, and finally heart rate, suggesting LF power is a sensitive indicator of parasympathetic tone.
Alerts equine clinicians to early HRV shifts with atropine; leaves open prospective validation before routine adoption.
To investigate the effects of repeated atropine injection on heart rate (HR) variability in resting Thoroughbred horses, two microg/ kg of atropine as parasympathetic nervous blockade was injected intravenously every 6 min to a total of 8 microg/kg after intravenous administration of 0.2 mg/kg of propranolol as sympathetic nervous blockade. We recorded electrocardiograms and obtained the HR, then evaluated variation in HR from the power spectrum in terms of low frequency (LF, 0.01-0.07 Hz) power and high frequency (HF, 0.07-0.6 Hz) power. Administration of atropine decreased parasympathetic nervous activity in a dose-dependent manner, affecting first the LF power, then the HF power and finally HR. These responses may provide valuable information for evaluating autonomic nervous activity in Thoroughbred horses.
No takes yet. Share an insight, caveat, or question.
Ohmura et al. (2001) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: