Yoshiga Chie, Dawson Ellen Adele, Volianitis Stefanos, Warberg Jørgen, Secher Niels H
Department of Anaesthesia, The Copenhagen Muscle Research Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
Faculty of Science, School of Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK.
Exp Physiol. 2019 Mar;104(3):379-384. doi: 10.1113/EP087522.
What is the central question of this study? Is cardiac output during exercise dependent on central venous pressure? What is the main finding and its importance? The increase in cardiac output during both rowing and running is related to preload to the heart, as indicated by plasma atrial natriuretic peptide, but unrelated to central venous pressure. The results indicate that in upright humans, central venous pressure reflects the gravitational influence on central venous blood rather than preload to the heart.
We evaluated the increase in cardiac output (CO) during exercise in relationship to central venous pressure (CVP) and plasma arterial natriuretic peptide (ANP) as expressions of preload to the heart. Seven healthy subjects (four men; mean ± SD: age 26 ± 3 years, height 181± 8 cm and weight 76 ± 11 kg;) rested in sitting and standing positions (in randomized order) and then rowed and ran at submaximal workloads. The CVP was recorded, CO (Modelflow) calculated and arterial plasma ANP determined by radioimmunoassay. While sitting, (mean ± SD) CO was 6.2 ± 1.6 l min , plasma ANP 70 ± 10 pg ml and CVP 1.8 ± 1.1 mmHg, and when standing decreased to 5.9 ± 1.0 l min , 63 ± 10 pg ml and -3.8 ± 1.2 mmHg, respectively (P < 0.05). Ergometer rowing elicited an increase in CO to 22.5 ± 5.5 l min as plasma ANP increased to 156 ± 11 pg ml and CVP to 3.8 ± 0.9 mmHg (P < 0.05). Likewise, CO increased to 23.5 ± 6.0 l min during running, albeit with a smaller (P < 0.05) increase in plasma ANP, but with little change in CVP (-0.9 ± 0.4 mmHg). The increase in CO in response to exercise is related to preload to the heart, as indicated by plasma ANP, but unrelated to CVP. The results indicate that in upright humans, CVP reflects the gravitational influence on central venous blood rather than preload to the heart.
本研究的核心问题是什么？运动期间的心输出量是否依赖于中心静脉压？主要发现及其重要性是什么？划船和跑步期间的心输出量增加与心脏的前负荷有关，这由血浆心钠素表明，但与中心静脉压无关。结果表明，在直立的人体中，中心静脉压反映的是重力对中心静脉血的影响，而非心脏的前负荷。
我们评估了运动期间心输出量（CO）的增加与中心静脉压（CVP）以及作为心脏前负荷指标的血浆动脉心钠素（ANP）之间的关系。七名健康受试者（四名男性；平均±标准差：年龄26±3岁，身高181±8厘米，体重76±11千克）以随机顺序分别处于坐姿和站姿休息，然后在次最大负荷下进行划船和跑步。记录CVP，计算CO（采用Modelflow）并通过放射免疫分析法测定动脉血浆ANP。坐姿时，（平均±标准差）CO为6.2±1.6升/分钟，血浆ANP为70±10皮克/毫升，CVP为1.8±1.1毫米汞柱；站立时，CO降至5.9±1.0升/分钟，血浆ANP为63±10皮克/毫升，CVP为 -3.8±1.2毫米汞柱（P<0.05）。测力计划船使CO增加至22.5±5.5升/分钟，此时血浆ANP增加至156±11皮克/毫升，CVP增加至3.8±0.9毫米汞柱（P<0.05）。同样，跑步期间CO增加至23.5±6.0升/分钟，尽管血浆ANP的增加幅度较小（P<0.05），但CVP变化不大（-0.9±0.4毫米汞柱）。运动时CO的增加与心脏的前负荷有关，这由血浆ANP表明，但与CVP无关。结果表明，在直立的人体中，CVP反映的是重力对中心静脉血的影响，而非心脏的前负荷。
