McKenzie D C, Goodman L S, Nath C, Davidson B, Matheson G O, Parkhouse W S, Hochachka P W, Allen P S, Stanley C, Ammann W
Department of Sport Science, Allan McGavin Sports Medicine Centre, University of British Columbia, Vancouver, Canada.
J Appl Physiol (1985). 1991 Jun;70(6):2650-5. doi: 10.1152/jappl.1991.70.6.2650.
Six male Quechua Indians (34.0 +/- 1.1 yr, 159.5 +/- 2.1 cm, 60.5 +/- 1.6 kg), life-long residents of La Raya, Peru (4,350-m altitude with an average barometric pressure of 460 Torr), were studied using noninvasive methods to determine the structural and functional changes in the cardiovascular system in response to a 6-wk deacclimation period at sea level. Cardiac output, stroke volume, and left ventricular ejection fractions were determined using radionuclide angiographic techniques at rest and during exercise on a cycle ergometer at 40, 60, and 90% of a previously determined maximal O2 consumption. Subjects at rest were subjected to two-dimensional and M-mode echocardiograms and a standard 12-lead electrocardiogram. Hemoglobin and hematocrit were measured on arrival at sea level by use of a Coulter Stacker S+ analyzer. After a 6-wk deacclimation period, all variables were remeasured using the identical methodology. Hemoglobin values decreased significantly over the deacclimation period (15.7 +/- 1.1 to 13.5 +/- 1.2 g/dl; P less than 0.01). The results indicate that the removal of these high-altitude-adapted natives from 4,300 m to sea level for 6 wk results in only minor changes to the cardiac structure and function as measured by these noninvasive techniques.
六名男性克丘亚印第安人（年龄34.0±1.1岁，身高159.5±2.1厘米，体重60.5±1.6千克），他们是秘鲁拉亚的终身居民（海拔4350米，平均气压460托），采用非侵入性方法进行研究，以确定在海平面进行6周去适应期后心血管系统的结构和功能变化。使用放射性核素血管造影技术，在静息状态以及在自行车测力计上以先前确定的最大耗氧量的40%、60%和90%进行运动时，测定心输出量、每搏输出量和左心室射血分数。对静息状态下的受试者进行二维和M型超声心动图检查以及标准12导联心电图检查。到达海平面时，使用库尔特S+分析仪测量血红蛋白和血细胞比容。经过6周的去适应期后，使用相同方法重新测量所有变量。在去适应期内，血红蛋白值显著下降（从15.7±1.1降至13.5±1.2克/分升；P<0.01）。结果表明，将这些适应高海拔的当地人从4300米转移到海平面6周，通过这些非侵入性技术测量，心脏结构和功能仅发生轻微变化。
