van Veen Teelkien R, Panerai Ronney B, Haeri Sina, Singh Jasbir, Adusumalli Jasvant A, Zeeman Gerda G, Belfort Michael A
Department of Obstetrics and Gynecology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands; Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, TX.
Department of Cardiovascular Sciences, University of Leicester, Leicester, England, UK.
Am J Obstet Gynecol. 2015 Apr;212(4):513.e1-7. doi: 10.1016/j.ajog.2014.11.003. Epub 2014 Nov 7.
Cerebrovascular complications that are associated with hypertensive disorders of pregnancy (preeclampsia, chronic hypertension [CHTN], and gestational hypertension [GHTN]) are believed to be associated with impaired cerebral autoregulation, which is a physiologic process that maintains blood flow at an appropriate level despite changes in blood pressure. The nature of autoregulation dysfunction in these conditions is unclear. We therefore evaluated autoregulation in 30 patients with preeclampsia, 30 patients with CHTN, and 20 patients with GHTN and compared them with a control group of 30 normal pregnant women.
The autoregulatory index (ARI) was calculated with the use of simultaneously recorded cerebral blood flow velocity in the middle cerebral artery (transcranial Doppler ultrasound), blood pressure (noninvasive arterial volume clamping), and end-tidal carbon dioxide during a 7-minute period of rest. ARI values of 0 and 9 indicate absent and perfect autoregulation, respectively. We use analysis of variance with Bonferroni test vs a control group. Data are presented as mean ± standard deviation.
ARI was significantly reduced in preeclampsia (ARI, 5.5 ± 1.6; P = .002) and CHTN (ARI, 5.6 ± 1.7; P = .004), but not in GHTN (ARI, 6.7 ± 0.8; P = 1.0) when compared with control subjects (ARI, 6.7 ± 0.8). ARI was more decreased in patients with CHTN who subsequently experienced preeclampsia than in those who did not (ARI, 3.9 ± 1.9 vs 6.1 ± 1.2; P = .001). This was not true for women with GHTN or control subjects who later experienced preeclampsia.
Pregnant women with CHTN or preeclampsia (even after exclusion of superimposed preeclampsia) have impaired autoregulation when compared with women with GHTN or normal pregnancy. Whether the decreased ARI in patients with CHTN who later experience preeclampsia is due to preexistent differences or early affected cerebral circulation remains to be determined.
与妊娠高血压疾病（子痫前期、慢性高血压[CHTN]和妊娠期高血压[GHTN]）相关的脑血管并发症被认为与脑自动调节功能受损有关，脑自动调节是一种生理过程，可在血压变化时将血流维持在适当水平。这些情况下自动调节功能障碍的性质尚不清楚。因此，我们评估了30例子痫前期患者、30例CHTN患者和20例GHTN患者的自动调节功能，并将其与30例正常孕妇的对照组进行比较。
在7分钟的休息期间，通过同时记录大脑中动脉的脑血流速度（经颅多普勒超声）、血压（无创动脉容积钳夹）和呼气末二氧化碳来计算自动调节指数（ARI）。ARI值为0和9分别表示自动调节缺失和完美。我们使用方差分析和Bonferroni检验与对照组进行比较。数据以平均值±标准差表示。
与对照组（ARI，6.7±0.8）相比，子痫前期（ARI，5.5±1.6；P = 0.002）和CHTN（ARI，5.6±1.7；P = 0.004）患者的ARI显著降低，但GHTN患者（ARI，6.7±0.8；P = 1.0）未降低。随后发生子痫前期的CHTN患者的ARI比未发生子痫前期的患者降低得更多（ARI，3.9±1.9对6.1±1.2；P = 0.001）。对于GHTN患者或后来发生子痫前期的对照组女性，情况并非如此。
与GHTN患者或正常妊娠女性相比，CHTN或子痫前期（即使排除叠加子痫前期）的孕妇存在自动调节功能受损。后来发生子痫前期的CHTN患者的ARI降低是由于先前存在的差异还是早期脑循环受影响仍有待确定。
