Heart rate variability in horses with acute gastrointestinal disease requiring exploratory laparotomy.

The research article discusses the effect of acute gastrointestinal diseases on heart rate variability (HRV) in horses that undergo exploratory laparotomy. It suggests that horses with ischemic gastrointestinal disease exhibit reduced HRV, which is also associated with higher mortality rates.

Research Objective

• The study was designed to explore HRV in horses enduring acute gastrointestinal disease and consequently requiring exploratory laparotomy.
• The researchers hypothesized that horses suffering from ischemic gastrointestinal disease would demonstrate reduced HRV compared to horses with nonischemic lesions.
• Another hypothesis suggested a potential correlation between reduced HRV and higher mortality rates among the examined horses.

Research Methodology

• The research was a prospective, clinical, observational study and was carried out at the University Veterinary Teaching Hospital.
• The study involved a total of 67 horses; 57 presented acute colic conditions and 10 were engaged for elective surgical procedures.
• The research process involved recording the admission heart rate, and then placing continuous telemetry within 2 hours of recovery from general anesthesia, which was then monitored and recorded for 48 to 52 hours postoperatively.
• The electrocardiograms data was later manually inspected, and R-to-R intervals were deduced and uploaded onto the HRV software for analysis.
• The research applied the time domain and frequency spectral analysis at various times postoperatively. The statistical study was done using a two-way ANOVA for repeated measures and logistic regression analysis.

Key Findings

• Horses identified with an ischemic gastrointestinal lesion at the time of surgery demonstrated significantly higher postoperative heart rates and reduced time domain-derived measures of HRV compared to those with nonischemic gastrointestinal lesions or control horses.
• Surviving horses had significantly lower postoperative heart rates, higher time domain, and lower low-frequency spectral measures of HRV compared to nonsurvivors.
• The multivariable logistic regression model had a receiver operating characteristic area under the curve (AUC) of 0.95 and showed a significant improvement in predicting mortality compared to admission HR evaluation alone.

Conclusion

• The research concludes that there is a strong association between reduced HRV and ischemic gastrointestinal disease and mortality in horses.
• HRV analysis has been proposed as a noninvasive technique providing diagnostic and prognostic information relevant to the management of postoperative horses with severe gastrointestinal disease.