Matsuoka S, Akita H, Takahashi Y, Nishioka A, Kuroda Y
Department of Pediatrics, University of Tokushima, School of Medicine, Japan.
Acta Paediatr Jpn. 1993 Feb;35(1):27-31. doi: 10.1111/j.1442-200x.1993.tb03000.x.
The present study examined chronotropic dysfunction and the role of vagotony in congenital long QT syndrome, sinus node function and the effects of parasympathetic blockade. Six patients with congenital long QT syndrome were studied. The four males and two females, aged 1-15 years, had episodes of syncope and malignant ventricular arrhythmias. Congenital long QT syndrome was defined as a corrected QT interval greater than 0.45 s, T wave alternans and the age at diagnosis. The sinus heart rate measured from a 24 h electrocardiograph was abnormally low (< 50 min) in three patients (1, 4 and 5 years old) and did not increase sufficiently with the administration of atropine in five of the six patients with congenital long QT syndrome. From intracardiac electrophysiological studies, the corrected sinus node recovery time was prolonged in three patients and the total sinoatrial conduction time was prolonged in two patients. In most patients who had an abnormally long sinoatrial conduction time and corrected sinus node recovery time, these values returned to normal following atropine administration. In one patient, the corrected sinus node recovery time was prolonged paradoxically by atropine. Sinus node dysfunction in congenital long QT syndrome was affected by vagotony associated with a right sympathetic nerve system abnormality.
本研究探讨了变时性功能障碍以及迷走神经张力在先天性长QT综合征、窦房结功能和副交感神经阻滞效应中的作用。对6例先天性长QT综合征患者进行了研究。这4名男性和2名女性，年龄在1至15岁之间，有晕厥和恶性室性心律失常发作。先天性长QT综合征定义为校正QT间期大于0.45秒、T波交替以及诊断时的年龄。从24小时心电图测得的窦性心率在3例患者（1岁、4岁和5岁）中异常低（<50次/分钟），并且在6例先天性长QT综合征患者中的5例中，给予阿托品后心率没有充分增加。通过心内电生理研究，3例患者的校正窦房结恢复时间延长，2例患者的总窦房传导时间延长。在大多数窦房传导时间异常延长和校正窦房结恢复时间延长的患者中，给予阿托品后这些值恢复正常。在1例患者中，阿托品反而使校正窦房结恢复时间延长。先天性长QT综合征中的窦房结功能障碍受与右交感神经系统异常相关的迷走神经张力影响。
