Respiratory sinus arrhythmia and submersion bradycardia in bottlenose dolphins (Tursiops truncatus).
J Exp Biol
; 224(Pt 1)2021 01 07.
Article
en En
| MEDLINE
| ID: mdl-33257432
ABSTRACT
Among the many factors that influence the cardiovascular adjustments of marine mammals is the act of respiration at the surface, which facilitates rapid gas exchange and tissue re-perfusion between dives. We measured heart rate (fH) in six adult male bottlenose dolphins (Tursiops truncatus) spontaneously breathing at the surface to quantify the relationship between respiration and fH, and compared this with fH during submerged breath-holds. We found that dolphins exhibit a pronounced respiratory sinus arrhythmia (RSA) during surface breathing, resulting in a rapid increase in fH after a breath followed by a gradual decrease over the following 15-20â
s to a steady fH that is maintained until the following breath. RSA resulted in a maximum instantaneous fH (ifH) of 87.4±13.6â
beatsâ
min-1 and a minimum ifH of 56.8±14.8â
beatsâ
min-1, and the degree of RSA was positively correlated with the inter-breath interval (IBI). The minimum ifH during 2â
min submerged breath-holds where dolphins exhibited submersion bradycardia (36.4±9.0â
beatsâ
min-1) was lower than the minimum ifH observed during an average IBI; however, during IBIs longer than 30â
s, the minimum ifH (38.7±10.6â
beatsâ
min-1) was not significantly different from that during 2â
min breath-holds. These results demonstrate that the fH patterns observed during submerged breath-holds are similar to those resulting from RSA during an extended IBI. Here, we highlight the importance of RSA in influencing fH variability and emphasize the need to understand its relationship to submersion bradycardia.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Delfín Mular
/
Arritmia Sinusal Respiratoria
Límite:
Animals
Idioma:
En
Revista:
J Exp Biol
Año:
2021
Tipo del documento:
Article
País de afiliación:
Estados Unidos