COMPARISON OF A SMARTPHONE-BASED ELECTROCARDIOGRAM DEVICE WITH A STANDARD SIX-LEAD ELECTROCARDIOGRAM IN THE ATLANTIC BOTTLENOSE DOLPHIN (TURSIOPS TRUNCATUS)

Abstract

A bipolar, single-lead electrocardiogram (ECG) device is capable of recording ECGs with an integrated smartphone application. To determine the utility of this device, phone-based ECGs (pECG) were compared with standard six-lead ECGs (sECG) in four female Atlantic bottlenose dolphins ( Tursiops truncatus) at the National Aquarium. Study animals were trained to haul out onto a dry deck in ventral recumbency and allow simultaneous 30-sec ECG acquisition using the two devices. The pECG device was held against the thoracic wall caudal to the left axilla. The sECGs were recorded in the frontal plane. Instantaneous heart rates were obtained from identical QRS complexes on both ECGs. Three boarded cardiologists independently evaluated the rhythm and the polarity of the QRS depolarization for each recording and the results were compared. The mean heart rate was 80 beats/min (range 62-92 beats/min) and 80 beats/min (range 60-92 beats/min) for the pECG and sECGs, respectively. All four dolphins displayed sinus respiratory arrhythmia, and one animal had occasional atrial premature contractions. Rhythm diagnosis and QRS polarity were identical for the pECG and sECG. Dolphin vocalizations created artifacts on the pECG that were not present on the sECG, so pECGs had to be acquired without vocalization. The pECG appears to be an accurate and useful method to monitor the heart rate in Atlantic bottlenose dolphins. This system is inexpensive and portable, making it valuable for health examinations, transport monitoring, and stranding responses.

Using Respiratory Sinus Arrhythmia to Estimate Inspired Tidal Volume in the Bottlenose Dolphin (Tursiops truncatus)

“…One alternative proxy could be to use the changes in f H associated with each breath, the Respiratory Sinus Arrhythmia (RSA) (de Burgh Daly, 1986). While RSA is universally present in a number of air-breathing vertebrates such as the toad, horse, dog, seal, and dolphin (Scholander, 1940; Hayano et al, 1996; Cooper et al, 2003; Noren et al, 2004; Harms et al, 2013; Zena et al, 2017; McDonald et al, 2018; Yaw et al, 2018; Piccione et al, 2019), and even in air-breathing fish (Grossman and Taylor, 2007), its physiological significance is debated (Hayano et al, 1996; Yasuma and Hayano, 2004). It has been suggested that RSA improves gas exchange by enhancing the ventilation-perfusion matching and reduces cardiac work (Yasuma and Hayano, 2004; Ben-Tal et al, 2012, 2014).…”

Cardiac assessments of bottlenose dolphins (Tursiops truncatus) in the Northern Gulf of Mexico following exposure to Deepwater Horizon oil

“…In horses, similar isolated arrhythmias are seen commonly due to high vagal tone and are not necessarily indicative of cardiac pathology, especially if they are infrequent, isolated, and disappear with exercise [43,[71][72][73][74][75]. In dolphins, isolated premature complexes have been reported in dolphins at rest [25], as well as during dives, and are thought to be related to the interplay of sympathetic and parasympathetic tone [26], as in horses. In the authors' experience, isolated premature complexes or isolated instances of atrioventricular block are seen fairly commonly in managed dolphins both in and out of water, and are of little clinical significance, though true prevalence studies have yet to be performed.…”

“…There were no baseline cardiac data on the BB dolphin population prior to the DWH spill, and there is a paucity of information about dolphin cardiac health in general. Recent studies have laid the foundation for cardiac assessment techniques in cetaceans, including electrocardiography (ECG) in managed and free-ranging cetaceans [24][25][26][27][28][29] and echocardiography in dolphins managed under human care [30][31][32][33]. In this study, techniques for advanced cardiac assessment were refined with managed care dolphins, then applied to free-ranging dolphins in BB and dolphins outside of the oil spill footprint in SB.…”

Standardization of Dolphin Cardiac Auscultation and Characterization of Heart Murmurs in Managed and Free-Ranging Bottlenose Dolphins (Tursiops truncatus)

“…In recent years, initial steps have been taken to develop antemortem diagnostic cardiac tools in an effort to better understand dolphin cardiology. ECG techniques were first described in dolphins in 1970 (40), and comprehensive findings in putatively healthy dolphins were described by Harms et al (41), with additional reports in managed and free-ranging dolphins and other cetaceans in the last two decades (42)(43)(44)(45)(46). Continued research and investigation have laid the foundation for echocardiographic assessment in managed dolphin populations.…”