Evaluating the accuracy of a six-lead smartphone-based electrocardiographic device compared with standard electrocardiography in brachymorphic dogs

BackgroundNo previous study has evaluated the accuracy of a six-lead smartphone-based electrocardiographic (s-ECG) device in dogs. MethodsThis was a prospective multicentre study. Patients referred for cardiologic consultation were selected. In each patient, a 30-second electrocardiogram was simultaneously acquired with a novel six-lead s-ECG and a standard six-lead ECG machine (st-ECG). A board-certified cardiologist evaluated each recording. Nineteen ECG variables, including heart rate and rhythm, as well as quantitative and qualitative features of waves, segments and intervals, were analysed. Agreement between s-ECG and st-ECG was evaluated using Cohen's kappa coefficient and the Bland-Altman test. ResultsSeventy-five dogs were enrolled, and 140 ECG tracings were analysed. There was perfect agreement between the two methodologies for heart rate and rhythm classification, both in dogs with sinus rhythm and those with pathological rhythms. Although some disagreement was found when comparing measurements of quantitative variables obtained with the s-ECG and the st-ECG, none of the differences was of clinical relevance. LimitationsThe sample size was limited, and the interobserver variability was not analysed. ConclusionThe six-lead s-ECG studied herein is comparable to the st-ECG for heart rate and rhythm assessment, and seems clinically acceptable for the interpretation of waves, segments and intervals in dogs.