Changes in heart rate, heart rate variability, and atrioventricular block during withholding of food in thoroughbreds

Hajime Ohmura, Pedro L. Boscan, Adrian M. Solano, Scott D Stanley, James H Jones

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Objective-To determine whether withholding of food affects autonomic nervous system balance by analysis of heart rate (HR), HR variability (HRV), and frequency of second-degree atrioventricular block in horses. Animals-5 healthy Thoroughbreds. Procedures-For two 24-hour periods in a crossover study, food was withheld from horses or horses were maintained on their regular feeding schedule (control conditions) in their stalls and Holter monitor ECG recordings were obtained. The ECGs were analyzed by use of fast-Fourier transformation, and power spectrum densities were calculated for low-frequency (0.01 to 0.07 Hz) and high-frequency (0.07 to 0.6 Hz) variations in HR. Serum cortisol and plasma ACTH, norepinephrine, and glucose concentrations were measured at predetermined time points. Results-Withholding of food resulted in significantly lower HR and more frequent second- degree atrioventricular block (the frequency of which was inversely related to the HR), compared with findings for control conditions. Circadian rhythms were similar during foodwithholding and control conditions; peak HR was detected from 7:00 pm to 8:00 pm, and the lowest HR was detected in the early morning. During food-withholding conditions, the lowfrequency and high-frequency components of HRV were significantly higher, and the lowfrequency- to-high-frequency ratio was lower than during control conditions. Serum cortisol concentration was higher and plasma glucose concentration was lower at 6:00 pm in horses when food was withheld, compared with findings during control conditions. Conclusions and Clinical Relevance-Indices of HRV seemed to be sensitive to changes in autonomic nervous activity and may be useful as clinical indices of the neuroendocrine response to stressors in horses.

Original languageEnglish (US)
Pages (from-to)508-514
Number of pages7
JournalAmerican Journal of Veterinary Research
Volume73
Issue number4
DOIs
StatePublished - Apr 2012

Fingerprint

Atrioventricular Block
heart rate
Heart Rate
Horses
Food
horses
cortisol
Hydrocortisone
Electrocardiography
autonomic nervous system
Glucose
glucose
Autonomic Nervous System
corticotropin
Circadian Rhythm
norepinephrine
Serum
Adrenocorticotropic Hormone
circadian rhythm
Cross-Over Studies

ASJC Scopus subject areas

  • veterinary(all)

Cite this

Changes in heart rate, heart rate variability, and atrioventricular block during withholding of food in thoroughbreds. / Ohmura, Hajime; Boscan, Pedro L.; Solano, Adrian M.; Stanley, Scott D; Jones, James H.

In: American Journal of Veterinary Research, Vol. 73, No. 4, 04.2012, p. 508-514.

Research output: Contribution to journalArticle

@article{23ad37c4d9b647d69a05740b1c99c4b9,
title = "Changes in heart rate, heart rate variability, and atrioventricular block during withholding of food in thoroughbreds",
abstract = "Objective-To determine whether withholding of food affects autonomic nervous system balance by analysis of heart rate (HR), HR variability (HRV), and frequency of second-degree atrioventricular block in horses. Animals-5 healthy Thoroughbreds. Procedures-For two 24-hour periods in a crossover study, food was withheld from horses or horses were maintained on their regular feeding schedule (control conditions) in their stalls and Holter monitor ECG recordings were obtained. The ECGs were analyzed by use of fast-Fourier transformation, and power spectrum densities were calculated for low-frequency (0.01 to 0.07 Hz) and high-frequency (0.07 to 0.6 Hz) variations in HR. Serum cortisol and plasma ACTH, norepinephrine, and glucose concentrations were measured at predetermined time points. Results-Withholding of food resulted in significantly lower HR and more frequent second- degree atrioventricular block (the frequency of which was inversely related to the HR), compared with findings for control conditions. Circadian rhythms were similar during foodwithholding and control conditions; peak HR was detected from 7:00 pm to 8:00 pm, and the lowest HR was detected in the early morning. During food-withholding conditions, the lowfrequency and high-frequency components of HRV were significantly higher, and the lowfrequency- to-high-frequency ratio was lower than during control conditions. Serum cortisol concentration was higher and plasma glucose concentration was lower at 6:00 pm in horses when food was withheld, compared with findings during control conditions. Conclusions and Clinical Relevance-Indices of HRV seemed to be sensitive to changes in autonomic nervous activity and may be useful as clinical indices of the neuroendocrine response to stressors in horses.",
author = "Hajime Ohmura and Boscan, {Pedro L.} and Solano, {Adrian M.} and Stanley, {Scott D} and Jones, {James H}",
year = "2012",
month = "4",
doi = "10.2460/ajvr.73.4.508",
language = "English (US)",
volume = "73",
pages = "508--514",
journal = "American Journal of Veterinary Research",
issn = "0002-9645",
publisher = "American Veterinary Medical Association",
number = "4",

}

TY - JOUR

T1 - Changes in heart rate, heart rate variability, and atrioventricular block during withholding of food in thoroughbreds

AU - Ohmura, Hajime

AU - Boscan, Pedro L.

AU - Solano, Adrian M.

AU - Stanley, Scott D

AU - Jones, James H

PY - 2012/4

Y1 - 2012/4

N2 - Objective-To determine whether withholding of food affects autonomic nervous system balance by analysis of heart rate (HR), HR variability (HRV), and frequency of second-degree atrioventricular block in horses. Animals-5 healthy Thoroughbreds. Procedures-For two 24-hour periods in a crossover study, food was withheld from horses or horses were maintained on their regular feeding schedule (control conditions) in their stalls and Holter monitor ECG recordings were obtained. The ECGs were analyzed by use of fast-Fourier transformation, and power spectrum densities were calculated for low-frequency (0.01 to 0.07 Hz) and high-frequency (0.07 to 0.6 Hz) variations in HR. Serum cortisol and plasma ACTH, norepinephrine, and glucose concentrations were measured at predetermined time points. Results-Withholding of food resulted in significantly lower HR and more frequent second- degree atrioventricular block (the frequency of which was inversely related to the HR), compared with findings for control conditions. Circadian rhythms were similar during foodwithholding and control conditions; peak HR was detected from 7:00 pm to 8:00 pm, and the lowest HR was detected in the early morning. During food-withholding conditions, the lowfrequency and high-frequency components of HRV were significantly higher, and the lowfrequency- to-high-frequency ratio was lower than during control conditions. Serum cortisol concentration was higher and plasma glucose concentration was lower at 6:00 pm in horses when food was withheld, compared with findings during control conditions. Conclusions and Clinical Relevance-Indices of HRV seemed to be sensitive to changes in autonomic nervous activity and may be useful as clinical indices of the neuroendocrine response to stressors in horses.

AB - Objective-To determine whether withholding of food affects autonomic nervous system balance by analysis of heart rate (HR), HR variability (HRV), and frequency of second-degree atrioventricular block in horses. Animals-5 healthy Thoroughbreds. Procedures-For two 24-hour periods in a crossover study, food was withheld from horses or horses were maintained on their regular feeding schedule (control conditions) in their stalls and Holter monitor ECG recordings were obtained. The ECGs were analyzed by use of fast-Fourier transformation, and power spectrum densities were calculated for low-frequency (0.01 to 0.07 Hz) and high-frequency (0.07 to 0.6 Hz) variations in HR. Serum cortisol and plasma ACTH, norepinephrine, and glucose concentrations were measured at predetermined time points. Results-Withholding of food resulted in significantly lower HR and more frequent second- degree atrioventricular block (the frequency of which was inversely related to the HR), compared with findings for control conditions. Circadian rhythms were similar during foodwithholding and control conditions; peak HR was detected from 7:00 pm to 8:00 pm, and the lowest HR was detected in the early morning. During food-withholding conditions, the lowfrequency and high-frequency components of HRV were significantly higher, and the lowfrequency- to-high-frequency ratio was lower than during control conditions. Serum cortisol concentration was higher and plasma glucose concentration was lower at 6:00 pm in horses when food was withheld, compared with findings during control conditions. Conclusions and Clinical Relevance-Indices of HRV seemed to be sensitive to changes in autonomic nervous activity and may be useful as clinical indices of the neuroendocrine response to stressors in horses.

UR - http://www.scopus.com/inward/record.url?scp=84859148142&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84859148142&partnerID=8YFLogxK

U2 - 10.2460/ajvr.73.4.508

DO - 10.2460/ajvr.73.4.508

M3 - Article

VL - 73

SP - 508

EP - 514

JO - American Journal of Veterinary Research

JF - American Journal of Veterinary Research

SN - 0002-9645

IS - 4

ER -