Xu W R, Liao Y, Jin H F, Zhang Q Y, Tang C S, Du J B
Department of Pediatrics, Peking University First Hospital, Beijing 100034, China.
Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Beijing 100191, China.
Beijing Da Xue Xue Bao Yi Xue Ban. 2017 Oct 18;49(5):756-759.
Syncope is a common emergency of children and adolescents, which has serious influence on the quality of life. Neurally-mediated syncope, including postural tachycardia syndrome, vasovagal syncope, orthostatic hypotension and orthostatic hypertension, is the main cause of syncope in children and adolescents. The main manifestations of neurally-mediated syncope are diverse, such as dizziness, headache, chest tightness, chest pain, pale complexion, fatigue, pre-syncope and syncope. Although the clinical manifestations are similar, each subtype of syncope has its hemodynamic feature and optimal treatment option. The diagnosis rate of syncope in children has been greatly improved on account of the development of the diagnostic procedures and methods. In recent years, with the promotion of head-up tilt test and drug-provocated head-up tilt test, the hemodynamic classification of neurally-mediated syncope gets continually refined. In recent years, with the effort of clinicians, an appropriate diagnostic protocol for children with syncope has been established. The initial evaluation consists of history taking, physical examination, standing test and standard electrocardiography. After the initial evaluation, some patients could be diagnosed definitely, such as postural tachycardia syndrome, orthostatic hypotension, and situational syncope. Those with a specific entity causing syncope need selective clinical and laboratory investigations. Patients for whom the cause of syncope remained undetermined should undergo head-up tilt test. The precise pathogenesis of neurally-mediated syncope is not entirely clear. In recent years, studies have shown that neurally-mediated syncope may be related to several factors, including hypovolemia, high catecholamine status, abnormal local vascular tension, decreased skeletal muscle pump activity and abnormal neurohumoral factors. Currently based on the possible pathogenesis, the individualized treatment of neurally-mediated syncope has also been studied in-depth. Generally, the management of neurally-mediated syncope includes non-pharmacological and pharmacological interventions. Patient education is the fundamental part above all. In addition to exercise training, the first-line treatments mainly include oral rehydration salts, beta adrenoreceptor blockers, and alpha adrenoreceptor agonists. By analyzing the patient's physiological indexes and biomarkers before treatment, the efficacy of medication could be well predicted. The individualized treatment will become the main direction in the future researches.
晕厥是儿童和青少年常见的急症，对生活质量有严重影响。神经介导性晕厥，包括体位性心动过速综合征、血管迷走性晕厥、直立性低血压和直立性高血压，是儿童和青少年晕厥的主要原因。神经介导性晕厥的主要表现多样，如头晕、头痛、胸闷、胸痛、面色苍白、疲劳、晕厥前状态和晕厥。尽管临床表现相似，但每种晕厥亚型都有其血流动力学特征和最佳治疗方案。由于诊断程序和方法的发展，儿童晕厥的诊断率有了很大提高。近年来，随着头高位倾斜试验和药物激发头高位倾斜试验的推广，神经介导性晕厥的血流动力学分类不断细化。近年来，在临床医生的努力下，已建立了针对晕厥儿童的适当诊断方案。初始评估包括病史采集、体格检查、站立试验和标准心电图检查。经过初始评估，一些患者可明确诊断，如体位性心动过速综合征、直立性低血压和情境性晕厥。那些有特定病因导致晕厥的患者需要进行选择性的临床和实验室检查。晕厥原因仍未确定的患者应进行头高位倾斜试验。神经介导性晕厥的确切发病机制尚不完全清楚。近年来，研究表明神经介导性晕厥可能与多种因素有关，包括血容量不足、高儿茶酚胺状态、局部血管张力异常、骨骼肌泵活动降低和神经体液因素异常。目前基于可能的发病机制，神经介导性晕厥的个体化治疗也得到了深入研究。一般来说，神经介导性晕厥的管理包括非药物和药物干预。患者教育是首要的基本部分。除运动训练外，一线治疗主要包括口服补液盐、β肾上腺素能受体阻滞剂和α肾上腺素能受体激动剂。通过分析治疗前患者的生理指标和生物标志物，可以很好地预测药物疗效。个体化治疗将成为未来研究的主要方向。
