T Wunderlich1,2, N Frey3, W Kähler1, M Lutz3, P Radermacher4, S Klapa1, I Koch1, F Tillmans1, J Witte1, A Koch1. 1. Christian-Albrechts-Universität Kiel, Institut für Experimentelle Medizin, Sektion Maritime Medizin, c/o Schifffahrtmedizinisches Institut der Marine, Kronshagen. 2. Bundeswehrkrankenhaus Ulm, Abteilung Anüsthesiologie und Intensivmedizin, Oberer Eselsberg 40, Ulm. 3. Universitätsklinikum Schleswig-Holstein, Klinik für Kardiologie und Angiologie, Kiel. 4. Universitätsklinikum Ulm, Institut für Anästhesiologische Pathophysiologie und Verfahrensentwicklung, Ulm.
Abstract
OBJECTIVE: Hyperoxia is known to influence cardiovascular and endothelial function, but it is unknown if there are differences between younger and older persons. The aim of this study was to monitor changes in myocardial diastolic function and flow-mediated dilatation (FMD) in younger and elderly volunteers, before and after exposure to relevant hyperbaric hyperoxia. METHODS: 51 male patients were separated into two groups for this study. Volunteers in Group 1 (n=28, mean age 26 ±6, "juniors") and Group 2 (n=23, mean age 53 ±9, "seniors") received standard HBO₂ protocol (240kPa oxygen). Directly before and after hyperoxic exposure in a hyperbaric chamber we took blood samples (BNP, hs-troponin-t), assessed the FMD and echocardiographic parameters with focus on diastolic function. RESULTS: After hyperoxia we observed a high significant decrease in heart rate and systolic/diastolic FMD. Diastolic function varied in both groups: E/A ratio showed a statistically significant increase in Group 1 and remained unchanged in Group 2. E/e' ratio showed a slight but significant increase in Group 1, whereas e'/a' ratio increased in both groups. Deceleration time increased significantly in all volunteers. Isovolumetric relaxation time remained unchanged and ejection fraction showed a decrease only in Group 2. There were no changes in levels of BNP and hs-troponin-t in either group. CONCLUSION: Hyperoxia seems to influence endothelial function differently in juniors and seniors: FMD decreases more in seniors, possibly attributable to pre-existing reduced vascular compliance. Hyperoxia-induced bradycardia induced a more pronounced improvement in diastolic function in juniors. The ability of Group 1 to cope with hyperoxia-induced effects did not work in the same manner as with Group 2.
OBJECTIVE:Hyperoxia is known to influence cardiovascular and endothelial function, but it is unknown if there are differences between younger and older persons. The aim of this study was to monitor changes in myocardial diastolic function and flow-mediated dilatation (FMD) in younger and elderly volunteers, before and after exposure to relevant hyperbaric hyperoxia. METHODS: 51 male patients were separated into two groups for this study. Volunteers in Group 1 (n=28, mean age 26 ±6, "juniors") and Group 2 (n=23, mean age 53 ±9, "seniors") received standard HBO₂ protocol (240kPa oxygen). Directly before and after hyperoxic exposure in a hyperbaric chamber we took blood samples (BNP, hs-troponin-t), assessed the FMD and echocardiographic parameters with focus on diastolic function. RESULTS: After hyperoxia we observed a high significant decrease in heart rate and systolic/diastolic FMD. Diastolic function varied in both groups: E/A ratio showed a statistically significant increase in Group 1 and remained unchanged in Group 2. E/e' ratio showed a slight but significant increase in Group 1, whereas e'/a' ratio increased in both groups. Deceleration time increased significantly in all volunteers. Isovolumetric relaxation time remained unchanged and ejection fraction showed a decrease only in Group 2. There were no changes in levels of BNP and hs-troponin-t in either group. CONCLUSION:Hyperoxia seems to influence endothelial function differently in juniors and seniors: FMD decreases more in seniors, possibly attributable to pre-existing reduced vascular compliance. Hyperoxia-induced bradycardia induced a more pronounced improvement in diastolic function in juniors. The ability of Group 1 to cope with hyperoxia-induced effects did not work in the same manner as with Group 2.
Authors: Elizabeth G Damato; Seth J Fillioe; Seunghee P Margevicius; Ryan S Mayes; Jonathan E Somogyi; Ian S Vannix; Alireza Abdollahifar; Anthony M Turner; Lidia S Ilcus; Michael J Decker Journal: Front Physiol Date: 2022-04-28 Impact factor: 4.755
Authors: Ivana Šegrt Ribičić; Maja Valić; Joško Božić; Ante Obad; Duška Glavaš; Igor Glavičić; Zoran Valić Journal: Croat Med J Date: 2019-06-13 Impact factor: 1.351