Low cardiac output as physiological phenomenon in hibernating, free-ranging Scandinavian brown bears ( Ursus arctos ) : an observational study
Background: Despite 5-7 months of physical inactivity during hibernation, brown bears (Ursus arctos) are able to cope with physiological conditions that would be detrimental to humans. During hibernation, the tissue metabolic demands fall to 25% of the active state. Our objective was to assess cardi...
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fthsinnlandet:oai:brage.inn.no:11250/276712 2024-03-03T08:49:17+00:00 Low cardiac output as physiological phenomenon in hibernating, free-ranging Scandinavian brown bears ( Ursus arctos ) : an observational study Jørgensen, Peter Godsk Arnemo, Jon Martin Swenson, Jon E. Jensen, Jan S. Galatius, Søren Frøbert, Ole 2014 application/pdf http://hdl.handle.net/11250/276712 https://doi.org/10.1186/1476-7120-12-36 eng eng Cardiovascular Ultrasound Jørgensen et al. (2014). Low cardiac output as physiological phenomenon in hibernating, free-ranging Scandinavian brown bears ( Ursus arctos ) : an observational study. Cardiovascular Ultrasound 2014, 12 :36 http://www.cardiovascularultrasound.com/content/12/1/36 http://hdl.handle.net/11250/276712 https://doi.org/10.1186/1476-7120-12-36 12 Cardiovascular Ultrasound 36 Animal model cardiovascular disease Acute cardiac care Thrombosis Echocardiography Journal article Peer reviewed 2014 fthsinnlandet https://doi.org/10.1186/1476-7120-12-36 2024-02-02T12:42:07Z Background: Despite 5-7 months of physical inactivity during hibernation, brown bears (Ursus arctos) are able to cope with physiological conditions that would be detrimental to humans. During hibernation, the tissue metabolic demands fall to 25% of the active state. Our objective was to assess cardiac function associated with metabolic depression in the hibernating vs. active states in free-ranging Scandinavian brown bears. Methods: We performed echocardiography on seven free-ranging brown bears in Dalarna, Sweden, anesthetized with medetomidine-zolazepam-tiletamine-ketamin e during winter hibernation in February 2013 and with medetomidine-zolazepam-tiletamine during active state in June 2013. We measured cardiac output noninvasively using estimates of hemodynamics obtained by pulsed wave Doppler echocardiography and 2D imaging. Comparisons were made using paired T-tests. Results: During hibernation, all hemodynamic indices were significantly decreased (hibernating vs. active state): mean heart rate was 26.0 (standard deviation (SD): 5.6) beats per min vs. 75.0 (SD: 17.1) per min (P = 0.002), mean stroke volume 32.3 (SD: 5.2) ml vs. 47.1 (SD: 7.9) ml (P = 0.008), mean cardiac output 0.86 (SD: 0.31) l/min vs. 3.54 (SD: 1.04) l/min (P = 0.003), and mean cardiac index 0.63 (SD: 0.21) l/min/kg vs. 2.45 (SD: 0.52) l/min/ m 2 (P < 0.001). Spontaneous echo contrast was present in all cardiac chambers in all seven bears during hibernation, despite the absence of atrial arrhythmias and valvular disease. Conclusion: Free-ranging brown bears demonstrate hemodynamics comparable to humans during active state, whereas during hibernation, we documented extremely low-flow hemodynamics. Understanding these physiological changes in bears may help to gain insight into the mechanisms of cardiogenic shock and heart failure in humans Article in Journal/Newspaper Ursus arctos Høgskolen i Innlandet: Brage INN Cardiovascular Ultrasound 12 1 |
institution |
Open Polar |
collection |
Høgskolen i Innlandet: Brage INN |
op_collection_id |
fthsinnlandet |
language |
English |
topic |
Animal model cardiovascular disease Acute cardiac care Thrombosis Echocardiography |
spellingShingle |
Animal model cardiovascular disease Acute cardiac care Thrombosis Echocardiography Jørgensen, Peter Godsk Arnemo, Jon Martin Swenson, Jon E. Jensen, Jan S. Galatius, Søren Frøbert, Ole Low cardiac output as physiological phenomenon in hibernating, free-ranging Scandinavian brown bears ( Ursus arctos ) : an observational study |
topic_facet |
Animal model cardiovascular disease Acute cardiac care Thrombosis Echocardiography |
description |
Background: Despite 5-7 months of physical inactivity during hibernation, brown bears (Ursus arctos) are able to cope with physiological conditions that would be detrimental to humans. During hibernation, the tissue metabolic demands fall to 25% of the active state. Our objective was to assess cardiac function associated with metabolic depression in the hibernating vs. active states in free-ranging Scandinavian brown bears. Methods: We performed echocardiography on seven free-ranging brown bears in Dalarna, Sweden, anesthetized with medetomidine-zolazepam-tiletamine-ketamin e during winter hibernation in February 2013 and with medetomidine-zolazepam-tiletamine during active state in June 2013. We measured cardiac output noninvasively using estimates of hemodynamics obtained by pulsed wave Doppler echocardiography and 2D imaging. Comparisons were made using paired T-tests. Results: During hibernation, all hemodynamic indices were significantly decreased (hibernating vs. active state): mean heart rate was 26.0 (standard deviation (SD): 5.6) beats per min vs. 75.0 (SD: 17.1) per min (P = 0.002), mean stroke volume 32.3 (SD: 5.2) ml vs. 47.1 (SD: 7.9) ml (P = 0.008), mean cardiac output 0.86 (SD: 0.31) l/min vs. 3.54 (SD: 1.04) l/min (P = 0.003), and mean cardiac index 0.63 (SD: 0.21) l/min/kg vs. 2.45 (SD: 0.52) l/min/ m 2 (P < 0.001). Spontaneous echo contrast was present in all cardiac chambers in all seven bears during hibernation, despite the absence of atrial arrhythmias and valvular disease. Conclusion: Free-ranging brown bears demonstrate hemodynamics comparable to humans during active state, whereas during hibernation, we documented extremely low-flow hemodynamics. Understanding these physiological changes in bears may help to gain insight into the mechanisms of cardiogenic shock and heart failure in humans |
format |
Article in Journal/Newspaper |
author |
Jørgensen, Peter Godsk Arnemo, Jon Martin Swenson, Jon E. Jensen, Jan S. Galatius, Søren Frøbert, Ole |
author_facet |
Jørgensen, Peter Godsk Arnemo, Jon Martin Swenson, Jon E. Jensen, Jan S. Galatius, Søren Frøbert, Ole |
author_sort |
Jørgensen, Peter Godsk |
title |
Low cardiac output as physiological phenomenon in hibernating, free-ranging Scandinavian brown bears ( Ursus arctos ) : an observational study |
title_short |
Low cardiac output as physiological phenomenon in hibernating, free-ranging Scandinavian brown bears ( Ursus arctos ) : an observational study |
title_full |
Low cardiac output as physiological phenomenon in hibernating, free-ranging Scandinavian brown bears ( Ursus arctos ) : an observational study |
title_fullStr |
Low cardiac output as physiological phenomenon in hibernating, free-ranging Scandinavian brown bears ( Ursus arctos ) : an observational study |
title_full_unstemmed |
Low cardiac output as physiological phenomenon in hibernating, free-ranging Scandinavian brown bears ( Ursus arctos ) : an observational study |
title_sort |
low cardiac output as physiological phenomenon in hibernating, free-ranging scandinavian brown bears ( ursus arctos ) : an observational study |
publisher |
Cardiovascular Ultrasound |
publishDate |
2014 |
url |
http://hdl.handle.net/11250/276712 https://doi.org/10.1186/1476-7120-12-36 |
genre |
Ursus arctos |
genre_facet |
Ursus arctos |
op_source |
12 Cardiovascular Ultrasound 36 |
op_relation |
Jørgensen et al. (2014). Low cardiac output as physiological phenomenon in hibernating, free-ranging Scandinavian brown bears ( Ursus arctos ) : an observational study. Cardiovascular Ultrasound 2014, 12 :36 http://www.cardiovascularultrasound.com/content/12/1/36 http://hdl.handle.net/11250/276712 https://doi.org/10.1186/1476-7120-12-36 |
op_doi |
https://doi.org/10.1186/1476-7120-12-36 |
container_title |
Cardiovascular Ultrasound |
container_volume |
12 |
container_issue |
1 |
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1792506483237191680 |