[Heart rate fluctuations in the horse at rest: (1) Investigation of heart rate changes by spectrum analysis].

The research article discusses a study on heart rate variability in horses at rest, exploring their emotionality by analyzing the autonomic control’s influence. The method applied here, called spectral analysis, compares the normal heart rate fluctuations with those after the horses received atropine and atropine+adrenaline injections.

Methodology

• The researchers used spectral analysis to analyze the heart rate fluctuations in horses. This method allowed them to study the variations in the frequency domain.
• Heartbeat intervals were recorded for an hour, and a series of 1,024 heartbeats was extracted for the power spectrum of density computation.
• The power spectrum density was calculated using the Fourier Transform of the autocorrelation function of the series. The autocorrelation function measures how much a signal resembles itself, and the Fourier Transform decomposes a function or signal into its constituent frequencies.

Results and Comparison

• Spectral analysis was applied to the heart rate recordings to display its sensitivity.
• The normal heartbeat fluctuations at rest were compared to heart rate fluctuations after atropine and atropine+adrenaline injections.
• The study’s findings indicate that the normal power spectrum featured various low frequency components (< 0.1 cycle/beat).
• An injection of atropine reduced heart rate variability.
• Conversely, an injection of atropine combined with adrenaline increased the power of low-frequency fluctuations.

Implication

• The research findings demonstrate how analyzing heart rate fluctuations can offer insights into a horse’s emotional state. This provides valuable knowledge for equine health professionals and trainers, who can apply this understanding to optimize the welfare and performance of horses.