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Hemodynamic adjustments during breath-holding in trained divers.
- Source :
- European Journal of Applied Physiology; Oct2013, Vol. 113 Issue 10, p2523-2529, 7p, 2 Charts, 1 Graph
- Publication Year :
- 2013
-
Abstract
- Purpose: Voluntary breath-holding (BH) elicits several hemodynamic changes, but little is known about maximal static immersed-body BH. We hypothesized that the diving reflex would be strengthened with body immersion and would spare more oxygen than maximal dry static BH, resulting in a longer BH duration. Methods: Eleven trained breath-hold divers (BHDs) performed a maximal dry-body BH and a maximal immersed-body BH. Cardiac output (CO), stroke volume (SV), heart rate (HR), left ventricular end-diastolic volume (LVEDV), contractility index (CTI), and ventricular ejection time (VET) were continuously recorded by bio-impedancemetry (PhysioFlow PF-05). Arterial oxygen saturation (SaO) was assessed with a finger probe oximeter. Results: In both conditions, BHDs presented a bi-phasic kinetic for CO and a tri-phasic kinetic for SV and HR. In the first phase of immersed-body BH and dry-body BH, results (mean ± SD) expressed as percentage changes from starting values showed decreased CO (55.9 ± 10.4 vs. 39.3 ± 16.8 %, respectively; p < 0.01 between conditions), due to drops in both SV (24.9 ± 16.2 vs. 9.0 ± 8.5 %, respectively; p < 0.05 between conditions) and HR (39.7 ± 16.7 vs. 33.6 ± 17.0 %, respectively; p < 0.01 between conditions). The second phase was marked by an overall stabilization of hemodynamic variables. In the third one, CO kept stabilizing due to increased SV (17.0 ± 20.2 vs. 10.9 ± 13.8 %, respectively; p < 0.05 between conditions) associated with a second HR drop (14.0 ± 10.0 vs. 12.7 ± 8.9 %, respectively; p < 0.01 between conditions). Conclusion: This study highlights similar time-course patterns for cardiodynamic variables during dry-body and immersed-body BH, although the phenomenon was more pronounced in the latter condition. [ABSTRACT FROM AUTHOR]
- Subjects :
- BREATH holding
HEMODYNAMICS
OXYGEN in the body
HEART beat
OXIMETERS
Subjects
Details
- Language :
- English
- ISSN :
- 14396319
- Volume :
- 113
- Issue :
- 10
- Database :
- Complementary Index
- Journal :
- European Journal of Applied Physiology
- Publication Type :
- Academic Journal
- Accession number :
- 90245843
- Full Text :
- https://doi.org/10.1007/s00421-013-2690-z