Topcu Burcu, Akalin Figen
Faculty of Medicine, Department of Pediatrics, Marmara University, Kadiköy/Istanbul, Turkey.
Cardiol Young. 2010 Apr;20(2):165-72. doi: 10.1017/S1047951109991211. Epub 2010 Mar 22.
Neurocardiogenic syncope is a common disorder, which is considered as a benign condition. However, sudden loss of conscience and muscle tone causes anxiety among the family members due to its similarity to sudden death. Autonomic nervous system dysregulation is thought to be responsible in the aetiology. Heart rate variability is used for assessment of autonomic nervous system.We evaluated 24 children between 6 and 18 years (mean plus or minus standard deviation is equal to 12.5 plus or minus 3.28, with neurocardiogenic syncope and 10 healthy controls, mean plus or minus standard deviation is equal to 12.48 plus or minus 3.27) by using 24 hour Holter monitorisation and head-up tilt test. Heart rate variability analysis was performed using the Holter recordings obtained both during head-up tilt test and throughout the day.Our results revealed that, there is no significant difference between the study and the control groups in terms of the mean heart rate and all indices of the heart rate variability (p > 0.05). However, during the first 5 minutes of the head-up tilt test, standard deviation of all RR intervals and root mean square of successive differences were significantly lower in the syncope group compared with the control group, 42.17 plus or minus 12.56 versus 60.10 plus or minus 33.10 and 21.26 plus or minus 8.87 versus 36.80 plus or minus 31.03; p-values 0.02 and 0.03, respectively.In conclusion; autonomic functions in children with neurocardiogenic syncope are similar to healthy children. However, sympathetic hyperactivation occurs during the early phase of orthostatic stress in children with neurocardiogenic syncope comparing to healthy controls. Parasympathetic innervation is not sufficient in compensation of this sympathetic hyperactivation. Management strategy in neurocardiogenic syncope should be based on these pathophysiologic mechanisms.
神经心源性晕厥是一种常见疾病，被认为是一种良性病症。然而，由于其与猝死相似，意识和肌张力的突然丧失会引起家庭成员的焦虑。自主神经系统失调被认为是病因。心率变异性用于评估自主神经系统。我们使用24小时动态心电图监测和直立倾斜试验对24名6至18岁的儿童（平均加减标准差等于12.5加减3.28，患有神经心源性晕厥）和10名健康对照者（平均加减标准差等于12.48加减3.27）进行了评估。使用在直立倾斜试验期间和全天获得的动态心电图记录进行心率变异性分析。我们的结果显示，研究组和对照组在平均心率和心率变异性的所有指标方面没有显著差异（p>0.05）。然而，在直立倾斜试验的前5分钟，晕厥组所有RR间期的标准差和连续差值的均方根显著低于对照组，分别为42.17加减12.56与60.10加减33.10以及21.26加减8.87与36.80加减31.03；p值分别为0.02和0.03。总之，神经心源性晕厥儿童的自主功能与健康儿童相似。然而，与健康对照相比，神经心源性晕厥儿童在直立应激早期会出现交感神经过度激活。副交感神经支配不足以补偿这种交感神经过度激活。神经心源性晕厥的管理策略应基于这些病理生理机制。
