Balaji S, Oslizlok P C, Allen M C, McKay C A, Gillette P C
South Carolina Children's Heart Center, Division of Pediatric Cardiology, Medical University of South Carolina, Charleston.
J Am Coll Cardiol. 1994 Mar 1;23(3):779-85. doi: 10.1016/0735-1097(94)90768-4.
The purpose of this study was to review the results of investigation and management of children with syncope and a structurally normal heart.
Syncope is a common clinical problem and has many etiologies. Autonomic testing and, in particular, the tilt/orthostatic test have helped to positively diagnose neurocardiogenic syncope in a high proportion of such patients.
Patient case notes and autonomic test charts were reviewed in 162 children aged 1 to 20 years (mean age 12.8 years) with syncope. The autonomic test consisted of orthostatic maneuver, carotid sinus massage, diving reflex, Valsalva maneuver and dose response to intravenous boluses of isoproterenol and phenylephrine. Serum levels of epinephrine and norepinephrine were drawn during the orthostatic test. After confirmation of neurocardiogenic syncope, treatment was begun with fludrocortisone and salt, and beta-adrenergic blocking agents were used as a second line of therapy when indicated.
The orthostatic test was positive for neurocardiogenic syncope in 100 patients (62%) and negative in 62 (38%). Patients in the former group were older, were more often female and had a diminished response to carotid sinus massage, a higher Valsalva ratio and a higher supine epinephrine level. Both groups showed an increase in epinephrine and norepinephrine levels at 5 min of standing. In the orthostatic positive group at the time of syncope, norepinephrine levels decreased, whereas epinephrine levels increased. Patients in this group were also more sensitive to the vasodilating effect of isoproterenol but not to its chronotropic effects. Eleven patients had cardioinhibitory syncope (asystole > or = 3 s). Of these, three had pacemaker implantation. Fludrocortisone and salt used in 84 patients in the orthostatic positive group produced resolution of symptoms in 55 patients (65%) and improvement in 14 (17%). Ten patients received beta-blockers, with resolution in four and improvement in four.
Patients with orthostatic test-proved neurocardiogenic syncope show evidence of autonomic dysfunction. They also show beta-adrenergic hypersensitivity. Treatment initiated on the basis of the protocol was associated with amelioration of symptoms in the majority of patients.
本研究旨在回顾心脏结构正常的晕厥患儿的检查及处理结果。
晕厥是常见的临床问题，病因众多。自主神经功能检测，尤其是倾斜试验/直立位试验，有助于在很大比例的此类患者中确诊神经心源性晕厥。
回顾了162例年龄在1至20岁（平均年龄12.8岁）的晕厥患儿的病历及自主神经功能检测图表。自主神经功能检测包括直立位动作、颈动脉窦按摩、潜水反射、瓦尔萨尔瓦动作以及对静脉注射异丙肾上腺素和去氧肾上腺素的剂量反应。直立位试验期间检测血清肾上腺素和去甲肾上腺素水平。确诊神经心源性晕厥后，开始使用氟氢可的松和盐治疗，必要时使用β-肾上腺素能阻滞剂作为二线治疗。
100例患者（62%）直立位试验呈神经心源性晕厥阳性，62例（38%）呈阴性。前一组患者年龄较大，女性居多，并对颈动脉窦按摩反应减弱、瓦尔萨尔瓦比值较高且仰卧位肾上腺素水平较高。两组在站立5分钟时肾上腺素和去甲肾上腺素水平均升高。直立位试验阳性组晕厥时去甲肾上腺素水平降低，而肾上腺素水平升高。该组患者对异丙肾上腺素的血管舒张作用更敏感，但对其变时作用不敏感。11例患者发生心脏抑制性晕厥（心脏停搏≥3秒）。其中3例植入了起搏器。直立位试验阳性组的84例患者使用氟氢可的松和盐治疗，55例（65%）症状缓解，14例（17%）症状改善。10例患者接受了β-阻滞剂治疗，4例症状缓解，4例症状改善。
直立位试验证实为神经心源性晕厥的患者存在自主神经功能障碍的证据。他们还表现出β-肾上腺素能超敏反应。按照方案开始的治疗使大多数患者的症状得到改善。
