口服依那普利治疗神经心原性晕厥

Effects of oral enalapril on neurally mediated syncope

目的观察依那普利治疗神经心原性晕厥的疗效及探讨其作用机制。方法对４８例倾斜试验重复性良好的阳性神经心原性晕厥患者分别口服安慰剂及依那普利１周后复查倾斜试验，并利用荧光法测量倾斜试验检查前后血中儿茶酚胺的浓度。结果安慰剂组２４例神经心原性晕厥患者仅８例倾斜试验检查转阴，阴转率为３３．３％；依那普利组２４例，除３例因干咳副作用退出试验外，余２１例神经心原性晕厥均转阴（Ｐ＜０．０００１）。平均随访１３．４±２．１个月，安慰剂组２４例中有１３例发生神经心原性晕厥，发生率为５４．２％，而依那普利组无１例再发。儿茶酚胺测定发现神经心原性晕厥发作前血浆儿茶酚胺浓度异常增高，安慰剂干预对血浆儿茶酚胺浓度无明显影响，依那普利干预则有效地抑制儿茶酚胺的分泌。

Objective To investigate the effects of oral enalapril on neurally mediated syncope (NMS) and to study its mechanism. Methods 48 patients with unexplained syncope and positive response to head up tilt table test were examined again with the test after administering enalapril or placebo for one week. High speed ion exchange column chromatography was used to determined the plasma catecholamine concentrations. Results During the repeat tilt table test, response was negative in 8 of 24 cases (33.3%) after administration of placebo, none of 24 cases was positive after enalapril treatment, except three cases discontinuing enalapril because of dry cough. Enalapril or placebo was administered orally for an average of 13.4±2.1 months, 13 of 24 paitents had recurrence of syncope in placebo treated group, but none of patients in enalapril treated group had presyncope or syncope. Plasma catecholamine concentration before administration of enalapril or placebo was significantly elevated during tilt as compared with supine position. Enalapril significantly inhibited the catecholamine release from the sympathetic nerve ending, but placebo did not. Conclusion Administering angiotensin converting enzyme inhibitor orally may be effective for neurally mediated syncope.