Data From: Cardiac arrhythmia prevalence and risk factors in 24-h electrocardiograms of sedentary horses

Background: Cardiac arrhythmias are common in horses, but their clinical
relevance remains controversial. Objectives: To describe prevalence and
identify risk factors for arrhythmias that may warrant additional
screening in a sedentary mixed-breed population of horses. Study Design:
Prospective cross-sectional. Methods: Ninety-four clinically healthy,
university-owned, sedentary horses underwent 24-h ambulatory
electrocardiograms and echocardiograms. Potential risk factors were
recorded for all horses. Affected individuals were defined as those with
>1 supraventricular premature complex/h or with any ventricular
premature complexes for risk factor analysis. Forward stepwise logistic
regression was used to identify factors associated with the presence of
arrhythmia. The p value <0.15 was considered significant in
univariable screening and p ≤ 0.05 was considered significant overall.
Results: During recording, 92.6% (87/94) of horses experienced an
arrhythmia. Supraventricular premature complexes were present in 86.2%
(81/94) of the horses, and ventricular complexes were present in 24.5%
(23/94) of the horses. Of the sample, 38.3% (36/94) were considered
affected by arrhythmias. Increased heart girth score was associated with
detection of arrhythmias (OR 1.06, 95% CI 1–1.12, p = 0.05), and age was
retained in the final model as a confounder. Main Limitations: The study
sample included a limited range of body condition scores and number of
stallions for risk factor analysis. Conclusion: Arrhythmias occurred with
high frequency in this group of horses despite no known history or
clinical signs of cardiovascular disease. Increased heart Q2 girth is a
potential risk factor for arrhythmia in the horse.