Kasprowicz A L, Manuck S B, Malkoff S B, Krantz D S
Department of Psychology, University of Pittsburgh, PA 15260.
Psychophysiology. 1990 Nov;27(6):605-19. doi: 10.1111/j.1469-8986.1990.tb03181.x.
This study evaluates the reproducibility of individual differences in behaviorally evoked cardiovascular reactivity among 39 young adult males. Presented also are initial data describing idiosyncratic patterns of hemodynamic adjustment that may underlie pressor responses to laboratory stressors. Subjects were administered three experimental stressors (mental arithmetic, mirror tracing, and bicycle exercise) on two occasions, four weeks apart. Heart rate, blood pressure, and impedance-derived measurements of cardiac pre-ejection period, stroke index, cardiac index, and total peripheral resistance were obtained during baseline and task periods at each session. To index task-induced "reactivity," residualized (baseline-adjusted) change scores were calculated for all variables; percentage change from baseline was also calculated for impedance-derived hemodynamic measurements. Test-retest (inter-session) correlations were significant for nearly all baseline, task, and change-score measurements. The few exceptions included diastolic blood pressure changes during mirror tracing and bicycle exercise and changes in stroke index and peripheral resistance during mental arithmetic. Although virtually all baseline and task correlations exceeded .60, reactivity indices yielded consistently lower retest correlations (significant r's = .35-.78; median r = .49). In subsequent analyses, subsets of individuals were identified whose reactions to mental arithmetic at the first laboratory session reflected changes in either cardiac output (CI reactors, n = 9) or total peripheral resistance (TPR reactors, n = 6), or a combination of cardiac and vascular influences (Mixed reactors, n = 8). This typology of hemodynamic response: (a) was corroborated by corresponding group differences in heart rate, pre-ejection period, and stroke index; (b) was reproducible on retesting; and (c) showed some generalization to the mirror tracing task, though not to bicycle exercise.
本研究评估了39名年轻成年男性在行为诱发的心血管反应中个体差异的可重复性。文中还给出了初步数据，描述了可能是对实验室应激源压力反应基础的血流动力学调整的特殊模式。受试者在相隔四周的两个时间段接受了三种实验应激源（心算、镜像追踪和自行车运动）。在每次实验的基线期和任务期获取心率、血压以及通过阻抗得出的心脏射血前期、每搏指数、心脏指数和总外周阻力的测量值。为了衡量任务诱发的“反应性”，计算了所有变量的残差（基线调整后）变化分数；还计算了阻抗衍生的血流动力学测量值相对于基线的百分比变化。几乎所有基线、任务和变化分数测量的重测（不同时间段之间）相关性都很显著。少数例外包括镜像追踪和自行车运动期间的舒张压变化以及心算期间的每搏指数和外周阻力变化。尽管几乎所有基线和任务相关性都超过了0.60，但反应性指数的重测相关性始终较低（显著r值 = 0.35 - 0.78；中位数r = 0.49）。在后续分析中，确定了一些个体亚组，他们在第一次实验室实验中心算的反应反映了心输出量（CI反应者，n = 9）或总外周阻力（TPR反应者，n = 6）的变化，或者是心脏和血管影响的组合（混合反应者，n = 8）。这种血流动力学反应类型：(a) 通过心率、射血前期和每搏指数的相应组间差异得到了证实；(b) 在重新测试时具有可重复性；(c) 对镜像追踪任务有一定的普遍性，但对自行车运动则不然。
