Marongiu E, Crisafulli A, Ghiani G, Olla S, Roberto S, Pinna M, Pusceddu M, Palazzolo G, Sanna I, Concu A, Tocco F
Medical Sciences, University of Cagliari, Cagliari, Italy.
Science Applied to Biological Systems, University of Cagliari, Cagliari, Italy.
Int J Sports Med. 2015 Apr;36(4):297-301. doi: 10.1055/s-0034-1389969. Epub 2014 Nov 27.
Cardiac output has never been assessed during free-diving diving in the sea. Knowledge of human diving response in this setting is therefore scarce. 3 immersions were performed by 7 divers: at depths of 10 m, 20 m and 30 m. Each test consisted of 3 apnea phases: descent, static and ascent. An impedance cardiograph provided data on stroke volume, heart rate and cardiac output. Mean blood pressure, arterial O2 saturation and blood lactate values were also collected. Starting from a resting value of 4.5±1.6 L∙min(-1), cardiac output at 10 m showed an increase up to 7.1±2.2 L∙min(-1) (p<0.01) during the descent, while conditions during the static and ascent phases remained unchanged. At 20 m cardiac output values were 7.3±2.4 L∙min(-1) and 6.7(±1).2 L∙min(-1) during ascent and descent, respectively (p<0.01), and 4.3±0.9 L∙min(-1) during static phase. At 30 m cardiac output values were 6.5±1.8 L∙min(-1) and 7.5±2 L∙min(-1) during descent and ascent, respectively (p<0.01), and 4.7±2.1 L∙min(-1) during static phase. Arterial O2 saturation decreased with increasing dive depth, reaching 91.1±3.4% (p<0.001 vs. rest) upon emergence from a depth of 30 m. Blood lactate values increased to 4.1±1.2 mmol∙L(-1) at the end of the 30 m dive (p<0.001 vs. rest). Results seem to suggest that simultaneous activation of exercise and diving response could lead to an absence of cardiac output reduction aimed at an oxygen-conserving effect.
在自由潜水入海过程中，心输出量从未被评估过。因此，关于人类在这种情况下的潜水反应的知识很匮乏。7名潜水员进行了3次潜水：深度分别为10米、20米和30米。每次测试包括3个屏气阶段：下潜、静止和上升。阻抗心动图提供了关于每搏输出量、心率和心输出量的数据。还收集了平均血压、动脉血氧饱和度和血乳酸值。从静息值4.5±1.6升·分钟-1开始，在10米深度时，心输出量在下潜过程中增加至7.1±2.2升·分钟-1（p<0.01），而在静止和上升阶段情况保持不变。在20米深度时，上升和下潜阶段的心输出量分别为7.3±2.4升·分钟-1和6.7（±1）.2升·分钟-1（p<0.01），静止阶段为4.3±0.9升·分钟-1。在30米深度时，下潜和上升阶段的心输出量分别为6.5±1.8升·分钟-1和7.5±2升·分钟-1（p<0.01），静止阶段为4.7±2.1升·分钟-1。动脉血氧饱和度随潜水深度增加而降低，从30米深度浮出水面时降至91.1±3.4%（与静息相比，p<0.001）。在30米潜水结束时，血乳酸值升至4.1±1.2毫摩尔·升-1（与静息相比，p<0.001）。结果似乎表明，运动和潜水反应的同时激活可能导致旨在节约氧气的效应的心输出量减少缺失。
