Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon 97239-3098, USA.
J Am Soc Echocardiogr. 2013 Mar;26(3):290-6. doi: 10.1016/j.echo.2012.12.008. Epub 2013 Jan 11.
Syndrome X in women is thought to be caused by coronary microvascular dysfunction, the exact site of which is unknown. The aim of this study was to characterize the microvascular site of dysfunction in these patients using myocardial contrast echocardiography.
Women with exertional angina, positive test results on stress imaging, but no coronary artery disease (the study group, n = 18) and age-matched control women also with no coronary artery disease (n = 17) were enrolled. Myocardial contrast echocardiography was performed at rest and during dipyridamole-induced hyperemia. Mean microbubble velocity (β) and myocardial blood volume (A) were measured, and myocardial blood flow (A · β) was computed. In addition, plasma concentrations of eicosanoids, female sex hormones, and C-reactive protein were measured.
Rest β and myocardial blood flow (A · β) were higher in the study compared with the control women (1.61 ± 0.68 vs. 0.74 ± 0.44, P = .0001, and 157 ± 121 vs. 54 ± 54, P = 0.0001, respectively) despite similar heart rates and systolic blood pressures. After the administration of dipyridamole, whereas the changes in A and A · β were not significantly different between the two groups, β reserve (the ratio of stress β to rest β) was markedly lower in the study group (1.48 ± 0.62 vs. 2.78 ± 0.94, P = .0001). Blood hematocrit, eicosanoids, female sex hormones, glucose, and C-reactive protein were not different between the two groups.
Coronary autoregulation is abnormal in patients with syndrome X (higher resting β and myocardial blood flow and lower β reserve), which suggests that the coronary resistance vessels are the site of microvascular abnormality.
女性综合征 X 被认为是由冠状动脉微血管功能障碍引起的，但其确切部位尚不清楚。本研究旨在使用心肌对比超声心动图来描述这些患者的微血管功能障碍部位。
纳入了 18 例有运动性心绞痛、应激成像阳性结果但无冠状动脉疾病的女性患者（研究组）和 17 例年龄匹配且无冠状动脉疾病的女性对照者（对照组）。在静息状态和双嘧达莫诱导的充血状态下进行心肌对比超声心动图检查。测量平均微泡速度（β）和心肌血容量（A），并计算心肌血流量（A·β）。此外，还测量了血浆中前列腺素、女性性激素和 C 反应蛋白的浓度。
与对照组相比，研究组静息状态下β和心肌血流量（A·β）更高（1.61±0.68 比 0.74±0.44，P=0.0001；157±121 比 54±54，P=0.0001），尽管心率和收缩压相似。双嘧达莫给药后，两组的 A 和 A·β变化无显著差异，但研究组的β储备（应激β与静息β的比值）明显较低（1.48±0.62 比 2.78±0.94，P=0.0001）。两组间的血液红细胞压积、前列腺素、女性性激素、血糖和 C 反应蛋白无差异。
综合征 X 患者的冠状动脉自动调节异常（静息β和心肌血流量较高，β储备较低），这表明冠状动脉阻力血管是微血管异常的部位。
