Variations in heart rate and rhythm of harbor seal pups during rehabilitation

Sonja Fonfara*, Domingo Casamian-Sorrosal, Janne Sundermeyer, Tanja Rosenberger

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

5 Citations (Scopus)


Heart rate and rhythm is regulated by the autonomic nervous system, which matures during the first months of life. Little is known about heart rate and rhythm development and potential arrhythmias in seal pups during rehabilitation in seal centers. Using an iPhone ECG device, 1 min ECGs were obtained from harbor seal pups admitted to a seal rehabilitation facility. ECGs were taken from 55 seals after admission, 53 seals after 14 d, and 52 seals prior to release. From 24 seal pups additional ECGs were taken daily for the first week of rehabilitation. At admission sinus rhythm with a median heart rate of 148 complexes per minute was detected, prior to release sinus bradycardia or sinus arrhythmia with a median heart rate of 104 complexes minute was present. P wave morphology was highly variable and single supra- and ventricular premature complexes were recorded in individual animals. The first 14 d were characterized by highly variable heart rates and rhythms, including episodes of sinus tachycardia and 2nd degree atrioventricular blocks. The reduction in heart rates and development of a regular heart rhythm during rehabilitation suggest adaptation to the unfamiliar environment, resolution of disease, and/or maturation of the autonomic nervous system.

Original languageEnglish
Pages (from-to)998-1013
Number of pages16
JournalMarine Mammal Science
Issue number3
Early online date22 Dec 2014
Publication statusPublished - 1 Jul 2015


  • ECG
  • Arrhythmia
  • Atrioventricular block
  • Autonomic nervous system
  • Harbor seal
  • Heart rhythm
  • Tachycardia


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