Frequency of arrhythmias detected in 9440 feline electrocardiograms by breed, age, and sex

The purpose of this study was to describe the frequency of arrhythmias detected in unsedated feline patients from general practice settings. A total 10,638 feline electrocardiograms (ECGs) were retrospectively collected of which 9440 met the inclusion criteria. Recordings were evaluated by a board-certified cardiologist. If an arrhythmia was present in the ECG tracing, the cardiologist categorized the arrhythmia using pre-established keywords. At least one arrhythmia was observed in 249 cases (2.64%, 95% confidence interval (CI): 2.34–2.98, 249/9440), with the most common arrhythmia encountered being ventricular premature complexes (1.63%, 95% CI: 1.39%–1.91%, 154/9440). Ragdoll cats had the highest odds of arrhythmia (odds ratio (OR): 3.17, 95% CI: 1.43–6.17, P=0.036). Both geriatric (Age: 13+ years, OR: 1.70, 95% CI: 1.24–2.34, P=0.013) and senior (Age: 10–13 years, OR: 1.68, 95% CI: 1.19–2.37, P=0.003) cats had higher odds of having an arrhythmia than adult cats. The odds of male cats having an arrhythmia were slightly higher than female (OR: 1.36, 95% CI: 1.06–1.76, P=0.018). Of the 9440 ECGs included in this study, at least one arrhythmia was detected in 249 distinct cases. Arrhythmias were more common in older cats, male cats and the Ragdoll cat breed. While it is important to note that the presence of an arrhythmia alone does not always indicate the presence of heart disease, further research on the association between breed cardiac health is needed.