Retrospective study of allometric relationship between heart rate, electrocardiographic parameters and bodyweight in dogs

Abstract

Retrospective study of allometric relationship between heart rate, electrocardiographic parameters and bodyweight in dogs[Estudo retrospectivo da relação alométrica entre frequência cardíaca, parâmetros eletrocardiográficos e peso corporal em cães] ABSTRACTThe allometric relationship between bodyweight (BW) and heart rate (HR) has been described as inversely proportional in domestic species, but that has been refuted. The relationship between HR and electrocardiographic variables is described in literature. However, studies about the variation and influence of factors on the hemodynamic and electrocardiographic parameters in dogs are not abundant.As the metabolic rate is defined as the production and dissipation of heat by the body surface area (BSA) in m², it is essential to define that relationship. A retrospective study was conducted to analyze the correlation between HR, ECG parameters and BW in dogs. One thousand electrocardiographic tracings were analyzed in addition to the ECG parameters and clinical data such as gender, age and bodyweight. The determination of BSA was performed as follows: BSA (m 2 ) = (10.1 x bodyweight 0.67 ) X 10 -4 . When the unified groups were analyzed, there was a negative but weak correlation (r= -0.14, P< 0.0001) between bodyweight and HR. There were differences between weight groups regarding electrocardiographic variables. There is no allometric relationship between BW and HR in dogs. Weight was associated with changes in ECG variables.

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

“…As an alternative discussion, and despite the wide acceptance of HR allometry scaling, there is still some controversy and recent studies have put back into debate its application in some species like the dog, in which cardiac control seemed to be more regulated by behavior (Cruz Aleixo et al, 2017, 2019), or within breeds of the same species such as the horse (Schwarzwald et al, 2012). In the particular case of aquatic mammals, one previous study has positively determined HR allometry in a wide BM range from 27 species (Mortola, 2015).…”