Stall-side screening potential of a smartphone electrocardiogram recorded over both sides of the thorax in horses.

This research evaluates the potential of a smartphone electrocardiograms (SpECG) taken from both sides of the thorax on horses for detecting arrhythmias, by comparing the results with those obtained from a standard reference ECG (rECG).

Objective and Methodology

• The main objective of the study was to evaluate the effectiveness of SpECG recorded on both sides of the thorax of horses as a feasible arrhythmia screening tool. Moreover, the research was also aimed at comparing the level of agreement between SpECG collected from both sides and rECG, in terms of measuring baseline electrical deflections.
• The method involved 50 horses, which included those admitted to an equine hospital, university-owned horses, and some from an endurance riding facility. These horses were subjected to a prospective observational study as the researchers recorded simultaneous rECG and SpECG tracings from both sides of their thorax. The recording tracings were then analyzed by two experienced observers based on interpretability, duration of baseline electrical deflections, presence and classification of arrhythmias.

Findings and Conclusion

• The results showed that 15 out of 50 horses had spontaneous arrhythmias. There was also excellent agreement observed between the SpECG and rECG devices for the detection of arrhythmias (with a kappa value of 0.91; Significantly significant at P less than .001).
• The study further noticed that fundamental waves (P waves) of diagnostic quality were significantly more present when SpECG was taken from the right side of the thorax (20 compared to 5 instances). In contrast, the QRS and QT intervals — which represent the electric conduction time of the heart — of diagnostic quality were significantly higher when SpECG was recorded from the left side (66 versus 38 and 62 versus 34, respectively).
• However, substantial agreement for the duration of deflections between both devices was only observed for the QRS interval when SpECG was recorded from the left side.
• The paper concludes by emphasizing the importance of obtaining SpECG tracings from both sides of the thorax in horses. It also reinstates that SpECG can be used as a useful arrhythmia-screening tool for diagnosing common arrhythmias in horses, especially when used on-site at a stable.