Hatch J P, Borcherding S
Department of Psychiatry, University of Texas Health Science Center, San Antonio.
Biofeedback Self Regul. 1991 Mar;16(1):37-43. doi: 10.1007/BF01000444.
Three-dimensional vectorcardiography was used to characterize changes in the T-wave vector loop during exposure to cold pressor stress. Data were collected from 8 subjects during baseline, cold pressor, and recovery periods. Maximum vector length, polar angle of the longest vector, azimuth angle of the longest vector, sum of all vectors, polar angle of the vector sum, azimuth angle of the vector sum, surface area of the loop, and maximum distance between adjacent vectors were computed from the T-wave vector loop. The amplitude of the one-dimensional T-wave (TWA) was also computed. Interbeat interval and TWA decreased during hand immersion and increased during recovery. Of the vectorcardiographic measures, only maximum vector length and vector sum showed statistically significant change; both decreased during the task and returned to baseline during recovery. TWA accounted for 46% of the task related variance compared to 53% and 47% respectively, for vector sum and maximum vector length. Changes in TWA probably reflect a true change in cardiac electrical potential rather than a change in T-wave vector loop shape or orientation.
采用三维向量心电图来描述冷加压应激期间T波向量环的变化。在基线期、冷加压期和恢复期收集了8名受试者的数据。从T波向量环计算最大向量长度、最长向量的极角、最长向量的方位角、所有向量之和、向量和的极角、向量和的方位角、环的表面积以及相邻向量之间的最大距离。还计算了一维T波（TWA）的振幅。手部浸入期间心跳间期和TWA降低，恢复期增加。在向量心电图测量中，只有最大向量长度和向量和显示出统计学上的显著变化；两者在任务期间均降低，并在恢复期恢复到基线水平。与向量和及最大向量长度分别占任务相关方差的53%和47%相比，TWA占任务相关方差的46%。TWA的变化可能反映了心脏电位的真实变化，而非T波向量环形状或方向的变化。
