Balasubramanian V, Hoon R S
Am Heart J. 1976 Jan;91(1):43-9. doi: 10.1016/s0002-8703(76)80433-4.
Twenty normal subjects and 32 patients with ischemic heart disease (IHD) were subjected to submaximal treadmill exercise. The mean transthoracic electrical impedance (TEI) was measured with a tetrapolar lead system and the changes were correlated to the extent of ST depression observed on an on-line digital computer. Six subjects of pre-excitation syndrome with "false" ST depression were also studied. The normal subjects did not show a significant change of TEI during exercise. The patients with IHD showed a steady and significant decrease in TEI, correlating with the extent of ST depression. Recovery was slow after the cessation of exercise. The subjects with false ST changes showed no decrease of TEI. The changes were more profound in subjects who developed anginal pain during the test. These findings are attributed to an increase in the thoracic blood volume and pulmonary extravascular water due to transient left ventricular dysfunction in angina.
20名正常受试者和32名缺血性心脏病（IHD）患者进行了次极量平板运动。使用四极导联系统测量平均经胸电阻抗（TEI），并将这些变化与在线数字计算机上观察到的ST段压低程度相关联。还研究了6名伴有“假性”ST段压低的预激综合征患者。正常受试者在运动期间TEI未显示出显著变化。IHD患者的TEI呈稳定且显著下降，与ST段压低程度相关。运动停止后恢复缓慢。有假性ST段改变的受试者TEI未下降。在测试期间发生心绞痛的受试者中，这些变化更为明显。这些发现归因于心绞痛时短暂性左心室功能障碍导致胸腔血容量和肺血管外水量增加。
