Assessment of circulatory adjustments during underwater apnoea in elite divers by means of a portable device.

Saved in:
Bibliographic Details
Title: Assessment of circulatory adjustments during underwater apnoea in elite divers by means of a portable device.
Authors: Tocco, F., Marongiu, E., Pinna, M., Roberto, S., Pusceddu, M., Angius, L., Migliaccio, G., Milia, R., Concu, A., Crisafulli, A.
Source: Acta Physiologica. Feb2013, Vol. 207 Issue 2, p290-298. 9p. 1 Black and White Photograph, 1 Chart, 4 Graphs.
Subjects: Apnea, Cardiovascular system, Stroke volume (Cardiac output), Bioelectric impedance, Cardiography, Comparative studies
Abstract: Aim Considering that sympathetic activation is induced by exercise, it is reasonable to assume that hemodynamic adjustments to exercise act in opposition to those elicited by the diving response. However, cardiovascular measurements have never been performed during underwater dynamic apnoea ( DA), and this hypothesis remains speculative. Methods Data concerning heart rate ( HR), stroke volume ( SV) and cardiac output ( CO) during static apnoea ( SA) and DA were collected from 12 elite divers by means of an impedance cardiograph adapted to the underwater environment. Mean arterial pressure ( MBP), systemic vascular resistance ( SVR) and arterial oxygen saturation (SaO2) were also assessed. Five trials were performed by the divers: head-out immersion during normal breathing (test A); 3 min of SA immersed at the surface (B) and at 3 m depth (C); DA till exhaustion immersed at the surface (D) and at 3 m depth (E). Results Both B and C conditions led to bradycardia (−17%) compared to A and also induced a decrement in SV (−8%) and in CO (−25%), while MBP was maintained because of an increase in SVR. A significant MBP increment (+11%) was detected only during tests D and E, when a SaO2 drop was also present, whereas HR, SV and CO remained unchanged. Conclusion We concluded that typical diving response was present only during SA, while sympathetic activation was induced by exercise during DA, which partially obscured the effects of the diving response. [ABSTRACT FROM AUTHOR]
Copyright of Acta Physiologica is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Psychology and Behavioral Sciences Collection
Full text is not displayed to guests.
Description
Abstract:Aim Considering that sympathetic activation is induced by exercise, it is reasonable to assume that hemodynamic adjustments to exercise act in opposition to those elicited by the diving response. However, cardiovascular measurements have never been performed during underwater dynamic apnoea ( DA), and this hypothesis remains speculative. Methods Data concerning heart rate ( HR), stroke volume ( SV) and cardiac output ( CO) during static apnoea ( SA) and DA were collected from 12 elite divers by means of an impedance cardiograph adapted to the underwater environment. Mean arterial pressure ( MBP), systemic vascular resistance ( SVR) and arterial oxygen saturation (SaO2) were also assessed. Five trials were performed by the divers: head-out immersion during normal breathing (test A); 3 min of SA immersed at the surface (B) and at 3 m depth (C); DA till exhaustion immersed at the surface (D) and at 3 m depth (E). Results Both B and C conditions led to bradycardia (−17%) compared to A and also induced a decrement in SV (−8%) and in CO (−25%), while MBP was maintained because of an increase in SVR. A significant MBP increment (+11%) was detected only during tests D and E, when a SaO2 drop was also present, whereas HR, SV and CO remained unchanged. Conclusion We concluded that typical diving response was present only during SA, while sympathetic activation was induced by exercise during DA, which partially obscured the effects of the diving response. [ABSTRACT FROM AUTHOR]
ISSN:17481708
DOI:10.1111/apha.12000