Contrada R J, Dimsdale J, Levy L, Weiss T
Department of Psychology, Rutgers-The State University, New Brunswick, New Jersey 08903.
Psychophysiology. 1991 Jul;28(4):458-62. doi: 10.1111/j.1469-8986.1991.tb00731.x.
This report examines the hypothesis that electrocardiographic T-wave amplitude is sensitive to graded increases in beta-sympathetic stimulation of the heart. Beta-adrenergic activity was manipulated pharmacologically in 9 healthy men by bolus infusion of isoproterenol in each of six doses: 0.1, 0.25, 0.5, 1.0, 2.0, and 4.0 micrograms. Results indicated that elevations in heart rate above placebo values increased as a linear function of isoproterenol dose. In contrast, the dose-response curve for T-wave amplitude was best described by a quadratic function: an initial reduction in T-wave amplitude at low levels of isoproterenol infusion was followed by a significant reversal of this effect at higher doses. Comparison of the heart rate and T-wave amplitude data points to limitations in the use of the latter as an index of beta-adrenergic activity. One of several possible explanations for the T-wave results would entail a mechanism that preserves ventricular function at high levels of beta-sympathetic stimulation.
本报告检验了心电图T波振幅对心脏β-交感神经刺激分级增加敏感这一假说。通过静脉推注六种剂量（0.1、0.25、0.5、1.0、2.0和4.0微克）的异丙肾上腺素，对9名健康男性的β-肾上腺素能活性进行了药理学调控。结果表明，心率高于安慰剂值的升高幅度随异丙肾上腺素剂量呈线性增加。相比之下，T波振幅的剂量反应曲线最好用二次函数来描述：在低剂量异丙肾上腺素输注时，T波振幅最初降低，随后在较高剂量时这种效应出现显著逆转。心率和T波振幅数据的比较表明，将T波振幅用作β-肾上腺素能活性指标存在局限性。T波结果的几种可能解释之一涉及一种在高水平β-交感神经刺激下维持心室功能的机制。
