Cardiac arrhythmia prevalence and risk factors in 24-h electrocardiograms of sedentary horses.
Authors: Maas Lauren T, Louie Elizabeth Williams, Finno Carrie J, Donnelly Callum G, Stern Joshua A, Hill Ashley E, Morgan Jessica M
Journal: Equine veterinary journal
Summary
# Editorial Summary Cardiac arrhythmias are frequently detected during routine electrocardiography in horses, yet their clinical significance remains poorly understood—a gap this recent study addressed by examining 94 clinically healthy, sedentary university-owned horses with 24-hour ambulatory ECG and echocardiography recordings alongside standardised risk factor assessment. The researchers found remarkably high arrhythmia prevalence: supraventricular premature complexes in 86.2% of the population and ventricular premature complexes in 24.5%, though only 38.3% met the threshold for clinical concern (>1 supraventricular complex per hour or any ventricular complexes). Increased heart girth emerged as a significant independent risk factor for arrhythmia detection (odds ratio 1.06 per unit increase), with age retained as a confounding variable in the final model. For equine practitioners, these findings suggest that whilst sporadic arrhythmias during rest are near-universal in horses and may not indicate pathology, measurement of heart girth could help stratify those warranting closer cardiovascular monitoring or further investigation; notably, the high prevalence in sedentary animals with no overt disease history supports the need for cautious interpretation of isolated arrhythmias during resting recordings rather than assuming clinical significance. The authors acknowledge limitations in their body condition score range and small stallion numbers, emphasising that further research should explore whether detected arrhythmias predict future disease or performance issues.
Read the full abstract on PubMed
Practical Takeaways
- •Cardiac arrhythmias are extremely common in apparently healthy horses at rest; their presence alone does not indicate clinical disease requiring treatment
- •Monitor body condition and heart girth in sedentary horses, as increased heart girth may indicate elevated arrhythmia risk
- •Consider 24-h ECG screening in horses with increased heart girth or when arrhythmias are suspected, but understand that frequent arrhythmias in resting horses are often benign
Key Findings
- •92.6% of clinically healthy sedentary horses experienced at least one arrhythmia during 24-h ambulatory ECG recording
- •Supraventricular premature complexes were detected in 86.2% of horses and ventricular complexes in 24.5%
- •38.3% of horses met criteria for being affected by arrhythmias (>1 SVPC/h or any VPC)
- •Increased heart girth score was significantly associated with arrhythmia detection (OR 1.06, p=0.05)