RESUMO
Electrocardiography is the method used to monitor the electrical impulses in the heart. These diagnostics are increasingly making use of smartphone-based technologies. The objective of this research was to determine whether the Alivecor KardiaMobile (ECGAKM) smartphone-modulated electrocardiographic device, a novel ECG device, can be used to obtain reliable electrocardiogram (ECG) readings in horses. The device was initially tested in 36 Nooitgedacht pony mares to determine the best site of application, method of skin preparation, and ECGAKM device orientation for reliable ECG tracings. Once the most reliable site for ECG acquisition was determined, the device was then applied, in this manner, to 31 Nooitgedacht pony mares and compared with a standard telemetric ECG system (ECGTV). The ECGAKM device was best applied in the fourth intercostal space on the left hemithorax in a vertical orientation and with the skin dampened with 70% ethanol. Mean values determined for RR and QT intervals between the ECGAKMS and ECGTV were not significantly different, however, mean values for the duration of the QRS complexes were significantly different for the two devices. There is acceptable agreement between the ECGTV and ECGAKM devices with regards to the measurement of the PQ; RR and QT intervals but not the QRS duration. The automatically calculated heart rate is not an accurate measure of true heart rate. The Alivecor KardiaMobile (ECGAKM) device can be considered as a simplified screening ECG device in situations where the more standardised system is either unavailable or impractical, but has some limitations.
RESUMO
An endogenous adrenocorticotropic hormone (ACTH) concentration above the reference interval (RI) is commonly used as means for diagnosing equine pituitary pars intermedia dysfunction (PPID). Basal ACTH concentrations are highly dependent on photoperiod and RIs should be month- and location-specific. To date, no ACTH RIs have been specifically established for South Africa. This study aimed to determine geographically and seasonally relevant RIs for equine ACTH in the Gauteng province of South Africa. A longitudinal prospective study was conducted over twelve months to determine ACTH RIs for a representative population of healthy South African horses in the Gauteng province. Eighty clinically healthy horses under 12 years of age were recruited for monthly venous blood sample collection, from July 2019 to June 2020. ACTH was measured using a chemiluminescent assay. RIs were constructed for each month of the year. This South African population showed similar temporal changes in ACTH concentrations to those previously observed in other locations. Upper reference limits were at their lowest in early summer (21.4 pg/ml, 90% CI 20.8-21.7) with a pronounced increase in autumn (60.6 pg/ml, 90% CI 53.1-62.7), and tapered off in winter (22.3 pg/ml, 90% CI 19.9-23.2). The month-specific ACTH RIs generated in this study will improve the accuracy of diagnosis and monitoring of PPID in the local equine population. These results highlighted the previously recommended need for seasonal and location-specific RIs.
