Guzman Juan Camilo, Garcia Ronald Gerardo, Dillenburg Rejane, Sieger Federico Silva, Lopez-Jaramillo Patricio, Morillo Carlos A
Autonomic Physiology Laboratory, Research Institute, Fundacion Cardiovascular de Colombia, Bucaramanga, Santander, Colombia, Ontario, Canada.
Europace. 2006 Apr;8(4):306-11. doi: 10.1093/europace/euj053. Epub 2006 Feb 3.
To determine whether central serotoninergic system activity is impaired by orthostatic challenge in patients with neurocardiogenic syncope (NCS).
Thirty-five [mean age: 24 (SD): 6 years] patients with a clinical history of NCS and positive head-up tilt test and 35 age-matched healthy volunteers (CON = 25+/-5 years) with negative response were studied. Overnight dexamethasone suppression test (DST) (1.5 mg given at 11 p.m.) was performed to assess the sensitivity of the hypothalamic-pituitary-adrenal axis by measuring next day cortisol (microg/dL) at 8 a.m. and 4 p.m. Cardiac autonomic function, cortisol, and prolactin (ng/dL) were also determined at baseline supine (BAS) and after 5, 10, and 15 min of orthostatic stress (OS) at 60 degrees . No significant differences were observed in cortisol plasma levels after the DST: CON = 0.6+/-0.6 microg/dL vs. NCS = 0.6+/-0.5; P = 0.7. Cardiac autonomic function, cortisol, and prolactin responses were similar in both study groups (CON vs. NCS; P > 0.05) during BAS: cortisol = 8.6+/-4 vs.8.7+/-4 microg/dL and prolactin = 16.8+/-9 vs. 16.8+/-9 ng/dL; OS-5: cortisol = 8.7+/-5 vs. 8.5+/-4 microg/dL and prolactin = 16.9+/-9 vs. 15.8+/-9 ng/dL; OS-10: cortisol = 8.5+/-5 vs. 8.1+/-3 microg/dL; prolactin = 16.2+/-9 vs. 15.8+/-9 ng/dL, and OS-15: cortisol = 9.0+/-5 vs. 8.4+/-4 microg/dL; prolactin = 17.1+/-9 vs. 15.5+/-9 ng/dL.
Central serotoninergic response during orthostatic challenge was not impaired in patients with recurrent NCS. These findings suggest that the activation of the hypothalamic-pituitary-adrenal axis is not altered in patients with recurrent NCS.
确定神经心源性晕厥（NCS）患者在直立位刺激下中枢5-羟色胺能系统活性是否受损。
研究了35例[平均年龄：24（标准差）：6岁]有NCS临床病史且直立倾斜试验阳性的患者，以及35例年龄匹配、反应阴性的健康志愿者（对照组=25±5岁）。进行过夜地塞米松抑制试验（DST）（晚上11点给予1.5毫克），通过测量次日上午8点和下午4点的皮质醇（微克/分升）来评估下丘脑-垂体-肾上腺轴的敏感性。还在基线仰卧位（BAS）以及60度直立应激（OS）5、10和15分钟后测定心脏自主神经功能、皮质醇和催乳素（纳克/分升）。DST后血浆皮质醇水平无显著差异：对照组=0.6±0.6微克/分升，NCS组=0.6±0.5微克/分升；P=0.7。在BAS期间，两个研究组（对照组与NCS组；P>0.05）的心脏自主神经功能、皮质醇和催乳素反应相似：皮质醇=8.6±4与8.7±4微克/分升，催乳素=16.8±9与16.8±9纳克/分升；OS-5时：皮质醇=8.7±5与8.5±4微克/分升，催乳素=16.9±9与15.8±9纳克/分升；OS-10时：皮质醇=8.5±5与8.1±3微克/分升；催乳素=16.2±9与15.8±9纳克/分升，以及OS-15时：皮质醇=9.0±5与8.4±4微克/分升；催乳素=17.1±9与15.5±9纳克/分升。
复发性NCS患者在直立位刺激期间中枢5-羟色胺能反应未受损。这些发现表明，复发性NCS患者下丘脑-垂体-肾上腺轴的激活未改变。
