Brown R A, McCormick K A, Vaitkevicius P V, Fleg J L
Laboratory of Behavioral Sciences, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224.
Chest. 1991 Sep;100(3):738-43. doi: 10.1378/chest.100.3.738.
To evaluate the effect of postural shifts on continuous-wave Doppler indices of left ventricular performance in normal man, we recorded Doppler signals suprasternally in 69 healthy volunteers, ranging in age from 20 to 86 years, in the supine position and 2 min after assumption of sitting and standing postures. All indices decreased progressively with increasing orthostasis: peak acceleration (PKA): 15.6 +/- 4.5 m/s2 to 14.0 +/- 4.0 m/s2 to 13.6 +/- 4.6 m/s2; peak velocity (PKV): 0.64 +/- 0.18 m/s to 0.58 +/- 0.17 m/s to 0.56 +/- 0.17 m/s; stroke distance (SD): 11.4 +/- 3.7 cm to 9.8 +/- 3.4 cm to 8.0 +/- 2.8 cm; SD x heart rate (VIH): 717 +/- 272 cm to 655 +/- 268 cm to 572 +/- 217 cm, from supine to sitting to standing, respectively (p less than 0.001). In contrast heart rate increased modestly from 62.4 +/- 10.0 bpm supine, to 66.9 +/- 12.4 bpm sitting, to 71.3 +/- 9.9 bpm standing (p less than .001). Similar postural changes in Doppler variables were seen in all three age groups (20 to 44 years; 45 to 64 years; and 65 to 86 years). Thus, orthostasis in normal subjects is accompanied by a reduction in all continuous-wave Doppler indices of left ventricular performance, regardless of age.
为评估体位改变对正常男性左心室功能连续波多普勒指标的影响，我们对69名年龄在20至86岁的健康志愿者进行了胸骨上多普勒信号记录，记录体位分别为仰卧位、坐位及站立位，坐位及站立位均在仰卧位2分钟后进行。随着直立位程度增加，所有指标均逐渐下降：峰值加速度（PKA）：从仰卧位时的15.6±4.5m/s²降至坐位时的14.0±4.0m/s²，再降至站立位时的13.6±4.6m/s²；峰值速度（PKV）：从仰卧位时的0.64±0.18m/s降至坐位时的0.58±0.17m/s，再降至站立位时的0.56±0.17m/s；搏出距离（SD）：从仰卧位时的11.4±3.7cm降至坐位时的9.8±3.4cm，再降至站立位时的8.0±2.8cm；SD×心率（VIH）：从仰卧位时的717±272cm降至坐位时的655±268cm，再降至站立位时的572±217cm，p均小于0.001。相比之下，心率仅略有增加，从仰卧位时的62.4±10.0次/分钟升至坐位时的66.9±12.4次/分钟，再升至站立位时的71.3±9.9次/分钟（p小于0.001）。在所有三个年龄组（20至44岁、45至64岁、65至86岁）中均观察到类似的多普勒变量体位变化。因此，无论年龄大小，正常受试者直立位时左心室功能的所有连续波多普勒指标均会降低。
