摘要
目的 研究血管迷走性晕厥(VS)患者发生晕厥时压力反射敏感性(BRS)的变化及其与神经内分泌因素的关系,以探讨BRS的变化在VS发生中的作用。方法42例不明原因晕厥患者,其中基础倾斜试验(HUT)阳性病人22例,阴性20例及20例健康人(HUT呈阴性反应),进行HUT。在HUT前、HUT结束或阳性反应时,抽取肘静脉血分别测定血浆内皮素(ET)、一氧化氮(NO)、去甲肾上腺素(NE)水平,并用新福林法测定(BRS)。结果①HUT(＋)组在晕厥发生时BRS较基础状态明显减弱。在倾斜试验结束时,HUT(＋)组,血浆ET,NO水平较基础水平明显升高,血浆NE水平较基础水平亦有升高趋势。②倾斜结束时,HUT(＋)组血浆ET,NO变化与BRS呈负相关。血浆NE浓度变化与BRS无相关。结论VS患者在发生晕厥时BRS减弱;血浆ET,NO水平异常与BRS减弱可能共同参与了VS的发生机制。
Abstract: Objective To study the changes ofbaroreflex sensitivity (BRS) during head-up tilt test(HUT) in patients with vasovagal syncope (VS), and toexamine the relationship between baroreflex sensitivity andneurohormonal factors. Furtherly, to investigate the ef-fects of the changes of BBS on VS. Method Forty-twopatients with unexplained syncope (Among the 42 pa-tients, there are 22 patients with positive HUT and 20 pa-tients with negative HUT respectively) and 20 healthy vol-unteers (with negative HUT) underwent passive head-uptilt testing, Antecubital vein blood samples were takenbefore and after HUT, or at syncope. The fasting plasmaendothelin, Serum nitric oxide (NO) . Serum NE wasmeasured. Use the changes in systolic blood pressure afteran intravenous bolus injection of phenylephrine as inde-pendent variable, and the prolongation of R-R interval asdependent variable. The regression analysis was made be-tween these two variables, and the slope of the regressiveline would be the BBS. Results (1)During the syncope,the BBS significantly reduced in HUT ( + ) group thanbaseline. At the end of tilt, the level of plasma ET,serum NO in patients with positive HUT significantly in-creased compared with baseline or normal controls, andthe plasma concentration of NE also had the trend of in-crease.(2)By multiple regression analysis, the plasmaET, NO at the end of HUT in patients with positive HUTwere found to be negatively related with BBS, but therewas no relationship between BBS and NE. Conclusions During the syncope occured, the BBS in patients withVS decreased siginificantly compared with normal con-trols. The abnormal plasma ET, NO concentration mightcontribute to the mechanism of VS.
出处
《岭南心血管病杂志》
2001年第6期426-428,共3页
South China Journal of Cardiovascular Diseases
