Ahmad H R, Akhtar S, Khan M A, Khan K S, Qureshi A A, Romana H, Hughes P F
Department of Physiology, Aga Khan University Medical Centre, Karachi, Pakistan.
Eur J Obstet Gynecol Reprod Biol. 1996 May;66(1):31-7. doi: 10.1016/0301-2115(96)02387-1.
We determined the dynamic and steady state responses of heart rate (HR) to orthostatic stress (standing up) in normotensive and hypertensive pregnant women. Using a continuous recording with servo-photosphygmography, HR response to change in posture from left lateral recumbent position to standing was analysed. The subjects were divided into five groups comprising: Groups I, II and III: normotensive pregnant women in each of the three trimesters of pregnancy (total n = 77); Group IV: women with gestational proteinuric hypertension (GPH) in the third trimester (n = 16); Group V: age-matched non-pregnant normotensive controls (n = 15). The HR reacted with a typical overshoot response to this orthostatic change with HR rising to a peak and then settling to a new but higher steady state. Change in steady state HR from lying to standing (delta HR), rate of rise of HR in response to standing (i.e. the acceleration slope (HRon)), and rate of fall of HR after reaching the peak (i.e. deceleration slope (HRoff)) were evaluated from standing heart rate time curves. HRon in response to standing showed a downward trend with gestation (ANOVA, P < 0.05) in normotensive gravida. The deceleration slope (HRoff) showed a distinct gestational age-related decrease from first to third trimester in normotensive women (ANOVA, P < 0.01). The most striking observation was that the slope of HRoff for the GPH group was significantly steeper than that of normotensive women of comparable gestational age (unpaired t-test P < 0.01) and approximated to that of the non-pregnant group. The difference in HR response between normotensive women and those with GPH in the third trimester suggests it may have potential as a new marker for pre-eclampsia.
我们测定了血压正常和高血压孕妇心率（HR）对直立位应激（站立）的动态和稳态反应。使用伺服光电容积描记法进行连续记录，分析了从左侧卧位到站立姿势改变时的心率反应。受试者分为五组，包括：第一组、第二组和第三组：妊娠三个阶段的血压正常孕妇（共77例）；第四组：妊娠晚期妊娠蛋白尿性高血压（GPH）妇女（16例）；第五组：年龄匹配的血压正常非妊娠对照组（15例）。心率对这种直立位变化表现出典型的过冲反应，心率先上升至峰值，然后稳定在一个新的但更高的稳态。从站立心率时间曲线评估从卧位到站立时稳态心率的变化（δHR）、站立时心率上升速率（即加速斜率（HRon））以及达到峰值后心率下降速率（即减速斜率（HRoff））。在血压正常的孕妇中，站立时的HRon随孕周呈下降趋势（方差分析，P<0.05）。血压正常的女性从妊娠第一阶段到第三阶段，减速斜率（HRoff）与孕周明显相关，呈下降趋势（方差分析，P<0.01）。最显著的观察结果是，GPH组的HRoff斜率明显比孕周相当的血压正常女性更陡（非配对t检验，P<0.01），且接近非妊娠组。妊娠晚期血压正常女性和GPH女性之间心率反应的差异表明，它可能有潜力作为子痫前期的一个新标志物。
