Comparison of smartphone‐based and standard base‐apex electrocardiography in healthy dairy cows

Abstract

Background There is good diagnostic accuracy of smartphone‐based ECG in the evaluation of heart rate (HR), heart rhythm, and ECG values for humans, horses, dogs, and cats. Objectives Assess feasibility and reliability of a smartphone ECG device to evaluate HR expressed as beats per minute and ECG values in cows. Animals Fifty‐five healthy Holstein Friesian cows. Methods Prospective observational study. A standard base‐apex ECG was acquired for 60 seconds in each cow. A smartphone ECG tracing was recorded simultaneously using a single‐lead bipolar ECG recorder. All ECGs were reviewed by 1 blinded investigator. The following ECG variables were assessed: HR, P wave duration, PR interval, QRS complex and QT interval (milliseconds), P wave, and QRS complex polarity. Agreement between standard and smartphone ECG was evaluated by Cohen's k test and the Bland‐Altman test. Results Smartphone ECG tracings were interpretable in 89% of the recordings. Minimal differences of no clinical relevance were found between standard and smartphone ECG tracings regarding HR and duration of ECG waves and interval. Good agreement found in the evaluation of QRS complex polarity (85%) but not for P wave polarity (k = 0.006). Artifacts were rare but of significantly higher frequency in smartphone ECG compared to standard ECG tracings (22% versus 0%; P = .005). Conclusions and Clinical Importance Good quality single‐lead ECG tracings can be recorded by smartphone device in healthy cows. Smartphone tracings are reliable for evaluation of HR and selective ECG variables. Smartphone ECG can represent an additional tool for ECG screening in cows.

Comparison of Standard Electrocardiography and Smartphone-Based Electrocardiography Recorded at Two Different Anatomic Locations in Healthy Meat and Dairy Breed Does

“…Studies of horses and dogs have found perfect heart rate agreement with smart-phone based ECGs (4,6,13), and while the BA heart rate agreement in the does of this study was not perfect, it was close enough that differences may be clinically insignificant (113.5 ± 10.6 vs. 115 ± 10.9 bpm). In cattle smartphone ECGs were found to be reliable indicators of heart rate and some ECG parameters (7), and this appears to be in agreement with the findings of the does in the study.…”

“…Heart rate was measured manually from printed ECGs for both standard and smartphone ECGs (BA and ST); heart rate as automatically calculated via the smartphone app was also recorded. Complex measurements (amplitudes and durations of all waveforms and intervals) and assessment of cardiac rhythm were performed on standard and smartphone BA ECGs as previously reported (7,8). Additionally, all ECGs were quality scored based on the presence or absence of baseline undulation and tremor artifacts using a three point scoring system (lowest possible = 0; highest possible = 3) previously described for veterinary use (8,9).…”

“…Standard base-apex ECG protocol was performed as described for cattle by Bonelli et al (7). Does were manually restrained while standing via holding of a neck collar.…”

“…Does were manually restrained while standing via holding of a neck collar. Standard ECGs were collected via a commercial ECG recorder (MAC-1200 ECG System, Marquette Hellige GmbH, Germany) using standard base-apex placement of the negative lead on the lower 1/3 of the left jugular furrow, the positive lead at the left 5th intercostal space caudal to the olecranon, and the third lead at the region of the point of the left shoulder as previously described for dairy cows (7). Smartphone ECG monitoring occurred simultaneously with the smartphone monitor (AliveCor Veterinary Heart Monitor, AliveCor, San Francisco, California) placed sequentially at two different locations, in random order: on the left chest wall ventral to the positive lead (base-apex placement, BA), or on the ventral midline centered on the xiphoid region (sternal placement, ST).…”

“…The pairing of smartphone technology with a wireless enabled ECG recorder has resulted in the ability to record ECG tracings with less cumbersome equipment than has traditionally been utilized for veterinary species. These devices have demonstrated efficacy for cats ( 3 ), dogs ( 4 ), horses ( 5 , 6 ), dairy cattle ( 7 ), and water buffalo calves ( 8 ), but currently no studies describe the use of this new technology for goats.…”