TY - JOUR

T1 - Cardiovascular regulation - associations between exercise and head up tilt

AU - Koschate, Jessica

AU - Drescher, Uwe

AU - Werner, Andreas

AU - Thieschäfer, Lutz

AU - Hoffmann, Uwe

N1 - Online: 27.03.2019

PY - 2019/8

Y1 - 2019/8

N2 - It was hypothesized that faster cardiorespiratory kinetics during exercise are associated with higher orthostatic tolerance. Cardiorespiratory kinetics of 14 healthy male subjects (30 ± 4 years, 179 ± 8 cm, 79 ± 8 kg) were tested on a cycle ergometer during exercise with changing work rates of 30 and 80 W. Pulmonary oxygen uptake (V O2pulm) was measured breath-by-breath and heart rate (HR), mean arterial blood pressure (MAP), and total peripheral resistance (TPR) were measured beat-to-beat. Muscular oxygen uptake (V O2musc) was estimated from HR and V O2pulm. Kinetic parameters were determined by time-series analysis, using cross-correlation functions (CCFmax(x)) between the parameter and the work rate. Cardiovascular regulations of MAP, HR, and TPR during orthostatic stress were measured beat-to-beat on a tilt seat. Changes between the minima and maxima during the 6° head-down tilt and the 90° head-up tilt positions were calculated for each parameter (Δtilt-up). CCFmax(V O2musc) correlated significantly with ΔTPRtilt-up (r = 0.790, p ≤ 0.001). CCFmax(HR) was significantly correlated with ΔHRtilt-up (r = –0.705, p = 0.002) and the amplitude in HR from 30 to 80 W (rSP = –0.574, p = 0.016). The observed correlations between cardiorespiratory regulation in response to exercise and orthostatic stress during rest might allow for a more differential analysis of the underlying mechanisms of orthostatic intolerance in, for example, patient groups.

AB - It was hypothesized that faster cardiorespiratory kinetics during exercise are associated with higher orthostatic tolerance. Cardiorespiratory kinetics of 14 healthy male subjects (30 ± 4 years, 179 ± 8 cm, 79 ± 8 kg) were tested on a cycle ergometer during exercise with changing work rates of 30 and 80 W. Pulmonary oxygen uptake (V O2pulm) was measured breath-by-breath and heart rate (HR), mean arterial blood pressure (MAP), and total peripheral resistance (TPR) were measured beat-to-beat. Muscular oxygen uptake (V O2musc) was estimated from HR and V O2pulm. Kinetic parameters were determined by time-series analysis, using cross-correlation functions (CCFmax(x)) between the parameter and the work rate. Cardiovascular regulations of MAP, HR, and TPR during orthostatic stress were measured beat-to-beat on a tilt seat. Changes between the minima and maxima during the 6° head-down tilt and the 90° head-up tilt positions were calculated for each parameter (Δtilt-up). CCFmax(V O2musc) correlated significantly with ΔTPRtilt-up (r = 0.790, p ≤ 0.001). CCFmax(HR) was significantly correlated with ΔHRtilt-up (r = –0.705, p = 0.002) and the amplitude in HR from 30 to 80 W (rSP = –0.574, p = 0.016). The observed correlations between cardiorespiratory regulation in response to exercise and orthostatic stress during rest might allow for a more differential analysis of the underlying mechanisms of orthostatic intolerance in, for example, patient groups.

KW - Cardiorespiratory kinetics

KW - Cardiovascular regulation

KW - Exercise

KW - Orthostatic stress

KW - Orthostatic tolerance

KW - Physical fitness

KW - Tilting experiments

UR - https://www.mendeley.com/catalogue/f3654ae3-95f5-3f9a-b5d6-df73c550f61e/

U2 - 10.1139/cjpp-2018-0742

DO - 10.1139/cjpp-2018-0742

M3 - Journal articles

VL - 97

SP - 738

EP - 745

JO - Canadian journal of physiology and pharmacology

JF - Canadian journal of physiology and pharmacology

SN - 0008-4212

IS - 8

ER -