Mirvis D M
Am J Cardiol. 1980 Dec 1;46(6):988-96. doi: 10.1016/0002-9149(80)90356-2.
Previously reported clinical studies have suggested an important diagnostic role for exercise-induced QRS changes. To explore the spatial features of such alterations, anterior thoracic isopotential distributions were examined at rest and at 85 percent of maximal heart rate in 30 normal male volunteers. Results demonstrated that exercise caused a reduction in positive forces and an augmentation of negative voltages at most anterior thoracic sites. However, the locations of map extrema were not significantly altered. Difference maps, computed by subtracting time-aligned distributions at rest and during exercise, suggested that exercise generated an electrical field characterized by a central anterior minimum bordered superiorly by positive potentials. The minimum reached a peak magnitude in the middle portion of the QRS pattern, then declined in intensity. Although difference patterns during inscription of the QRS complex were similar to those computed during the P-R and S-T segments, time-intensity curves were discontinuous with marked and abrupt early increases and late decreases in strength in the QRS complex. These results suggest that two commonly considered mechanisms (effects of changes in intracavitary blood mass and of atrial repolarization) cannot be solely responsible for the observed effects.
先前报道的临床研究表明运动诱发的QRS波变化具有重要的诊断作用。为了探究此类改变的空间特征，我们对30名正常男性志愿者在静息状态和最大心率85%时的胸前等电位分布进行了检查。结果表明，运动导致大多数胸前部位的正向力减小，负向电压增大。然而，电位图极值的位置没有明显改变。通过减去静息状态和运动期间时间对齐的分布计算得到的差值图表明，运动产生了一个电场，其特征是前中部有一个最小值，上方为正电位。该最小值在QRS波形态的中部达到峰值，然后强度下降。虽然QRS波群记录期间的差值形态与P-R段和S-T段计算得到的形态相似，但时间-强度曲线是不连续的，QRS波群强度在早期有明显且突然的增加，后期有下降。这些结果表明，两种通常被认为的机制（心腔内血量变化的影响和心房复极化的影响）不能单独解释观察到的效应。
