Evaluation of a smartphone-based electrocardiogram device accuracy in field and in hospital conditions in horses

Preliminary study on heart response and locomotor parameters in Donkeys (Equus asinus) during exercise using fitness tracker (Equimetre)

The welfare of donkeys remains a compelling subject for researchers, with limited literature available on the response of the donkey cardiovascular system during strenuous exercise. The study aimed to address two primary objectives. Firstly, to assess the reliability of wearable devices in detecting heart rate (HR) and ECG readings. Secondly, to determine HR, locomotor and cardiac troponin 1 (cTnI) levels in donkeys during exercise. A total of seven donkeys were outfitted with two systems for ECG measurements, namely Equimetre and the Standard base apex, to enable a comparison between the two. Additionally, fifteen apparently healthy donkeys equipped with Equimetre were divided into two groups: the race group (R), consisting of donkeys trained for racing, and the non-race group (NR), comprising donkeys used for regular riding. The results indicated a level of agreement between the two devices in intervals R-R (P =  < 0.0001), S-T (P = 0.0002), Q-T(P = 0.0003), P-R (P = 0.0037), segment P-R (P = 0.0023) and HR (P =  < 0.0001) at rest. This suggested that Equimetre can provide a level of accepted ECG reading in donkey. No significant difference in heart response and locomotor parameters between donkey groups, although this finding needs further studies to verify it and to understand the dynamics of donkey. This study demonstrates the feasibility of Equimetre in detection HR and present initial data of heart response and locomotor in donkeys during exercise.

Evaluation of a smartphone electrocardiograph in healthy foals and comparison to standard base-apex electrocardiography

Smartphone-based technology for ECG recording has recently spread as a complementary tool for electrocardiographic screening and monitoring in adult horses and in other animal species. The present study aimed to assess the feasibility and accuracy of a smartphone-based ECG in healthy foals. This was a prospective observational study (authorization n. 45,865/2016) including 22 foals aged less than 21 days. A reference standard base-apex ECG (rECG) was acquired, and a smartphone ECG (sECG) was recorded immediately after by using a smartphone-based single lead electrocardiograph. All ECG tracings were evaluated in a blind fashion by a single board-certified cardiologist, who judged whether the tracings were acceptable for interpretation and performed ECG measurements and diagnosis. The Spearman correlation coefficient, the Cohen's k test and the Bland-Altman test were used to assess the agreement between sECG and rECG. All sECG tracings were acceptable for interpretation. All foals showed sinus rhythm on both rRCG and sECG tracings, with perfect agreement in heart rate classification (κ = 0.87; p < 0.001). No clinically relevant differences were found in the assessment of waves and intervals duration. Concerning P wave and QRS complex polarity, the percentage of agreement between rECG and sECG was 78% and 83%, respectively. About ECG tracing quality, rECG and sECG showed a substantial agreement (κ = 0.624; p < 0.001). In conclusion, the smartphone-based ECG device tested in the present study recorded good quality single-lead ECG tracings in foals, reliable for heart rate and ECG measurements, but different polarity of P waves and QRS complexes was found in some foals in comparison to rECG.

Evaluation of a digital stethoscope for electrocardiographic recording in donkeys: Preliminary results

The digital stethoscope (DS) is a cost-effective single-lead digital stethoscope that allows simultaneous electrocardiographic (ECG) and phonocardiographic recordings on a smartphone. Despite its application in small animals and horses, there are currently no studies on its use in donkeys. The aim of this study was to evaluate the use of a new smartphone-based DS device in recording ECG tracings in donkeys. Standard base-apex lead ECG (sECG) and single-lead DS ECG (dECG) were simultaneously recorded for at least 30 s. Both sECG and dECG tracings were analysed by the same operator, recording heart rate, ECG waves and intervals, and the presence and duration of artefacts. Thirty-seven donkeys were included. The dECG tracings were interpretable in all the animals (100 %). The results showed perfect agreement between the sECG and dECG data for the classification of heart rhythm and P-wave polarity. Strong agreement was found in the evaluation of heart rate calculated manually and automatically by the smartphone app, QRS complex polarity, T wave polarity, and duration of the PR interval. However, no agreement was found in the evaluation of P wave duration, QRS complex duration and amplitude, and T wave duration and amplitude. In conclusion, although this is only a preliminary study, the DS was a valid, practical, and easy to use electrocardiographic tool for recording good-quality ECG tracings to assess the ECGs of donkeys in the field.

Smartphone-based six-lead ECG: A new device for electrocardiographic recording in dogs

Smartphone-based technology for electrocardiographic recording is now part of the new concept of mobile health in both human and veterinary medicine. Although smartphone-based ECG for electrocardiographic screening in dogs is reliable, one-lead ECG devices have mainly been evaluated. This prospective study assessed the feasibility and the diagnostic reliability of a new smartphone-based six-lead electrocardiograph (smECG) in dogs, in comparison to a standard six-lead electrocardiograph (stECG). All ECG tracings were blindly reviewed by an expert operator, who judged whether tracings were acceptable for interpretation, performed the electrocardiographic measurements, and assigned a diagnosis. The agreement in the electrocardiographic interpretation and diagnosis between smECG and stECG was assessed using the Bland-Altman test and Cohen's k test. The study included 108 client-owned dogs. The tracings obtained by the smECG were interpretable in 100 % of cases. No clinically relevant differences between smECG and stECG were found in the assessment of heart rate, interval duration, and QRS mean electrical axis. The smECG tended to underestimate the amplitude of the P and R waves. Perfect agreement was found in the detection of sinus rhythm, atrial fibrillation, ventricular arrhythmias, atrioventricular blocks, and bundle branch blocks. Our study suggests that the tested smartphone-based six-lead ECG is a clinically reliable device for the assessment of heart rate and heart rhythm in dogs, and thus could be used in a clinical setting in dogs and for telemedicine.

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

BACKGROUND

No previous study has evaluated the accuracy of a six-lead smartphone-based electrocardiographic (s-ECG) device in dogs.

METHODS

This 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.

RESULTS

Seventy-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.

LIMITATIONS

The sample size was limited, and the interobserver variability was not analysed.

CONCLUSION

The 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.

The position of ground electrode affects electrocardiographic parameters in horses

Background and Aim:

Improper attachment of the grounding lead is one of the artifacts and causes difficulty in interpretation of ECG. This study aimed to examine the effects of the position of a ground electrode on electrocardiographic (ECG) parameters in horses.

Materials and Methods:

Sixteen Arabian horses without any cardiac problems were included in this study. The animals were divided into two groups, the base-apex lead method 1 (BA1 method) and the base-apex lead method 2 (BA2 method) with the reposition of the ground limb electrode to the xiphoid. ECG recordings (paper speed=25 mm/s and calibration=10 mm/mV) were performed to obtain six limb leads (leads I, II, III, aVR, aVL, and aVF). The amplitude and duration of P waves and QRS complexes, PR interval, QT interval, and T duration were analyzed. T wave morphology was observed. Heart rate was evaluated by using R-R interval in each recording.

Results:

Heart rate, P duration and amplitude, PR interval and T duration, and QRS duration and amplitude were not significantly different between the BA1 and the BA2 method, except that the BA2 method had a significantly higher QT interval than did the BA1 method (p<0.05). A higher significance of the percentage of coefficient of variation was seen on the P wave amplitude and the ORS amplitude in the BA1 method when compared to BA2 method (p<0.05).

Conclusion:

These data indicated that base-apex lead method with reposition of the ground limb electrode to the xiphoid can decrease variation of ECG configuration and might be useful for routine ECG evaluation and monitoring in horses. The limitation of this study was the evaluation of cardiac morphology and function by echocardiography to exclude cardiac problems. In further, the studies should examine the effect of breed, age, body weight, and sex on electrocardiography parameters in horses.

Application of an electrocardiography device (iECG) for heart rhythm analysis after exercise in Thoroughbred horses

AliveCor is a smartphone electrocardiography device (iECG) providing automated heart rate (HR) and rhythm determination. Atrial fibrillation (AF) in horses often is paroxysmal and rapid ECG acquisition is needed for diagnostic confirmation. iECGs were collected post-race from 15 horses with AF and 64 horses in sinus rhythm (SR). Results of manual assessment were compared to 3 commercial algorithms for HR and rhythm. Agreement between manually derived HR (HR_M ) and HR derived by the AliveECG Vet (HR_VET ) and Kardia version-1 (K_V1 HR) and Kardia advanced (K_ADV HR) algorithms was quantified by the Bland-Altman limits of agreement test. Agreement between manual rhythm classification and K_V1 and K_ADV algorithms for AF and SR was calculated by the Kappa statistical coefficient. The agreement (bias, 95% limits), between HR_M and HR_VET was 7.1 BPM (-29 to 43) in AF and -4.2 BPM (-38 to 30) in SR, between HR_M and K_V1 HR, was -0.3 BPM (-31 to 30) in AF and 0.2 BPM (-3 to 4) in SR, and between HR_M and K_ADV HR was 7.0 BPM (-29 to 43) in AF and 0.2 BPM (-3.9 to 4.2) in SR. Agreement between manual rhythm classification and K_V1 was 0.36 (0.13-0.59), and K_ADV was 0.84 (0.68-0.99). Sensitivity and specificity for identification of AF and SR of the K_V1 algorithm were 60, 100% and 83, 100%, respectively, and of K_ADV was 87, 100% and 93, 100% respectively. The Kardia algorithms improved precision for HR determination in SR but not AF. The advanced algorithm accurately distinguished between AF and SR. The iECG is suitable for recording episodes of AF following exercise.

Evaluation of Cardiac Arrhythmias before, during, and after Treadmill Exercise Testing in Poorly Performing Standardbred Racehorses

The incidence of significant arrhythmias in sport horses and knowledge about their exact influence on athletic performance need to be clarified. The aims of the present study are to report the prevalence of cardiac arrhythmias during maximal treadmill exercise in poorly performing Standardbreds, and to investigate the possible relationship of demographic, cardiac and performance indices on premature complexes (PCs). Electrocardiographic Holter recordings before, during and after treadmill exercise testing of 158 poorly performing Standardbreds were analyzed retrospectively. Fifty horses did not have any type of arrhythmia. One hundred and eight horses had at least one type of arrhythmia, such as sinus arrhythmia (8.2%), sinoatrial block (3.2%), second-degree atrioventricular block (33.5%), supraventricular PCs (7.6%), and ventricular PCs (48.1%). A multiple regression analysis showed weak evidence that the occurrence of premature complexes decreases as the minimum heart rate increases, and a tendency for these arrhythmias to increase with increasing age and maximum lactate concentration. Our results suggest that PCs are frequent in poorly performing Standardbred racehorses, but further studies are necessary to clarify their role and clinical significance.

Evaluation of a new portable 1-lead digital cardiac monitor (eKuore) compared with standard base-apex electrocardiography in healthy horses

Recently, the use of smartphone ECG devices has been reported in humans and animals. Nevertheless, as the electrodes of these devices are inseparable, they can create only a precordial reading in veterinary species. Thus, although the smartphone ECG devices are considered valuable as a screening tool for the detection of some common arrhythmias, they are not always a reliable method for the measurement of the duration of the electrical deflections. The objectives of this study were to evaluate the feasibility of a novel smartphone ECG device, to report the readings obtained recorded simultaneously with a reference ECG system, and to compare the heart rate and duration of cardiac deflections obtained with the two methods. A total of 28 healthy mares of different breeds and age were included in this study and ECG recordings were obtained simultaneously with a reference ECG telemetry system with surface electrodes attached to the skin with alligator clips using a standard base-apex system and a smartphone ECG device with electrodes positioned alternatively with a standard and a modified base apex derivation. All the recordings obtained were considered acceptable for interpretation. An excellent agreement was found between the two methods for the evaluation of heart rate and polarity of cardiac deflections. No differences regarding number, duration and percentage of artifacts were found. This technology could become a valid diagnostic tool in the cardiological assessment of horses, in particular on the field.