Department of Neuroradiology, Centro Hospitalar Universitário de São João, E.P.E., Porto, Portugal.
Department of Neurology, Centro Hospitalar Universitário de São João, E.P.E., Porto, Portugal.
Exp Physiol. 2023 Jan;108(1):103-110. doi: 10.1113/EP090502. Epub 2022 Nov 20.
What is the central question of this study? How are dynamic cerebral autoregulation and brain vasoreactivity influenced by severe aortic stenosis and its surgical treatment? What are the main findings and their importance? Dynamic cerebral autoregulation is preserved in the long term in patients with severe aortic stenosis and does not change after surgical aortic valve replacement. However, carbon dioxide vasoreactivity is impaired in these patients.
Surgical aortic valve replacement (SAVR) alters the natural course of severe aortic stenosis (AS). In this study, we aimed to determine the effects of the disease on dynamic cerebral autoregulation and vasoreactivity (VR) and to assess their changes after SAVR. We recruited 23 patients diagnosed with severe AS eligible for SAVR and 15 healthy matched controls. AS patients had lower mean VR to CO (P = 0.005) than controls, but dynamic cerebral autoregulation was preserved. Cerebral haemodynamics showed no significant change after SAVR. Patients with smaller baseline aortic valve areas presented with smaller low frequency phase changes after surgery (P = 0.016). Severe AS does not seem to impact dynamic cerebral autoregulation but does reduce VR to CO . SAVR does not alter cerebral autoregulation nor vasoreactivity.
这项研究的核心问题是什么?严重主动脉瓣狭窄及其手术治疗如何影响动态脑自动调节和脑血管反应性?主要发现及其重要性是什么?严重主动脉瓣狭窄患者的长期动态脑自动调节得以保留,且在主动脉瓣置换手术后不会改变。然而,这些患者的二氧化碳血管反应性受损。
主动脉瓣置换手术(SAVR)改变了严重主动脉瓣狭窄(AS)的自然病程。在这项研究中,我们旨在确定疾病对动态脑自动调节和血管反应性(VR)的影响,并评估其在 SAVR 后的变化。我们招募了 23 名符合 SAVR 条件的严重 AS 患者和 15 名匹配的健康对照者。与对照组相比,AS 患者的 CO 平均 VR 较低(P = 0.005),但动态脑自动调节得以保留。SAVR 后,脑血流动力学没有明显变化。基线主动脉瓣面积较小的患者术后低频相位变化较小(P = 0.016)。严重 AS 似乎不会影响动态脑自动调节,但会降低 CO 的 VR。SAVR 不会改变脑自动调节或血管反应性。