The electrocardiogram of anaesthetized southern sea lion (Otaria flavescens) females

Abstract

This study was the first ECG description for this species, and provides valuable information for cardiac monitoring during anaesthesia.

Echocardiographic Left Ventricular Structure and Function in Healthy, Non-Sedated Southern Sea Lions (Otaria flavescens)

“…Based on our results, potential heart abnormalities could be preliminarily evaluated enabling a cardiac disease diagnosis. In this sense, a previous left atrial enlargement suggested by an ECG with a notched p wave of unusually high amplitude and a deviated positive electrical axis found in one free-ranging SSL female (Dassis et al, 2016) could be confirmed by echocardiography. With regards to the animals in our study, the lack of previous values for this species prevents the accurate identification of heart abnormalities or pathologies.…”

“…Although its life history, ecology, and physiology have been broadly studied, there are just a few studies of its cardiovascular anatomy and physiology. The electrocardiogram (ECG) of anaesthetized SSLs has been recently characterized (Dassis et al, 2016), but it did not include any evaluation of heart disease. The objective of this study was to test transthoracic echocardiography as a method to characterize heart morphology and function in SSLs for health evaluation that can lead to improved veterinary care and animal welfare (Brando, 2010;Poser et al, 2011).…”

Comparative electrocardiogram in two anesthetized pinnipeds, the South American fur seal (Arctocephalus australis) and the Southern sea lion (Otaria byronia), with analysis of ECG parameters allometry

“…However, because of methodological challenges, our understanding of the cardiac conduction system and performance in marine mammals is still fragmentary. Electrocardiographic recordings in Pinnipedia are limited to a few species of seals (Andrews et al, 1997; DeKleer, 1975; Falabella et al, 1999; Murdaugh et al, 1961; Van Citters et al, 1965), sea lions (Dassis et al, 2016, 2019; Ponganis et al, 1997; Storlund et al, 2021), and the walrus Odobenus rosmarus (Storlund et al, 2021). However, there has been no comparative study of the ECG among Pinnipedia, leaving the question of how conserved the cardiac conduction system within this clade is.…”

“…Among these relations, the one‐quarter law (with a β scaling coefficient close to 0.25), is the most recently accepted for describing cardiac rates and ECG time parameters (Günther & Morgado, 1997; Meijler & Meijler, 2011; Noujaim et al, 2004), and assumes that the heart behaves as a set of “fractal‐like” networks that minimize propagation time across the conducting system while ensuring an hemodynamically optimal atrioventricular activation sequence (Günther & Morgado, 1997; Meijler & Meijler, 2011; Noujaim et al, 2004). Previous studies of the conduction system allometry in the case of marine mammals are mostly focused on the HR (Castellini & Zenteno Savin, 1997; Mortola, 2015) or one ECG duration parameter such as the PR interval (PRi, duration of atrial depolarization and propagation of the impulse through the atrioventricular node; Dassis et al, 2016, 2019). Only one recent study has reported allometric equations for the conduction system through ECG recording in marine mammals, including Pinnipedia (Storlund et al, 2021).…”

Measurement of the QT Interval: Lessons from Thirty-Two Animal Species for the Correction of the QT Interval by Heart Rate

“…amount of their life in water such as whales [9], dolphins [10,11], sea lions [12] and seals [13]. They include wild animals such as brown bears from either a sanctuary or caught in the wild [14,15], lions and tigers [16,17].…”