Gugova F K, Lapin V V
Patol Fiziol Eksp Ter. 2002 Apr-Jun(2):20-2.
We investigated 21 healthy volunteers (10 males and 11 females, mean age 23 +/- 4 years). All the subjects have undergone two 20 min head-up tilt tests using tilt table "TRI W.G. inc." (USA): the first with footplate support and the second with bicycle saddle. Thoracic electrical impedance was measured using impedance cardiography according to Kubicek et al. The protocols included an initial period of 20 min of supine rest while baseline thoracic impedance, blood pressure and heart rate were recorded and then followed by a tilt to 65 degrees. Changes of impedance were measured at min 1, 2, 3, 5, 7, 10, 15, 20 after the procedure. Women had higher values of thoracic impedance both at rest and during the tilt test than men. The value of impedance of the chest negatively correlated with the body mass index. We suppose that an increase of impedance more than 15% may be related with pathological venous pooling. Thoracic impedance may be used to monitor changes of thoracic fluid volumes with posture and possibly to assess orthostatic regulation. The contribution of leg muscles in orthostatic regulation does not reflect values of thoracic impedance.
我们对21名健康志愿者（10名男性和11名女性，平均年龄23±4岁）进行了研究。所有受试者均使用美国“TRI W.G. inc.”公司的倾斜台进行了两次20分钟的头高位倾斜试验：第一次试验时踏板有支撑，第二次试验时使用自行车座。根据库比切克等人的方法，采用阻抗心动图测量胸段电阻抗。试验方案包括仰卧休息20分钟的初始阶段，期间记录基线胸段电阻抗、血压和心率，然后倾斜至65度。在试验过程后的第1、2、3、5、7、10、15、20分钟测量电阻抗变化。在静息状态和倾斜试验期间，女性的胸段电阻抗值均高于男性。胸部电阻抗值与体重指数呈负相关。我们推测，电阻抗增加超过15%可能与病理性静脉淤血有关。胸段电阻抗可用于监测胸段液体容量随体位的变化，并可能用于评估直立调节功能。腿部肌肉在直立调节中的作用并不反映胸段电阻抗值。
