儿童长QT综合征及其尖端扭转型室性心动过速的预防、管理与紧急处理

Prevention, management and emergency treatment of children with long QT interval syndrome and its advanced Torsades de Pointes

长QT综合征（Long QT interval syndrome，LQTS）是以心电图上QT间期延长和室性心律失常为特征的一种离子通道病。该病的发生与钾通道蛋白、钠通道蛋白、钙通道相关因子和膜适配蛋白的基因突变密切相关，现已证实了13种导致LQTS的突变基因。其临床特征主要表现为心电图QT间期异常延长、巨幅T波交替等，以及因此发生的尖端扭转型室性心动过速（Torsades de Pointes）、晕厥甚至猝死。心律失常事件的发生和基因型密切相关。LQTS1通常在运动和情绪激动时发生心律失常，而LQTS2则在安静时或突然出现声音时发生。儿童LQTS合并尖端扭转型室性心动过速发作时可导致循环灌注迅速恶化，具有生命危险，需要紧急处理。尖端扭转型室性心动过速发作的紧急处理包括静推硫酸镁、直流电击转复心律失常、纠正电解质等内环境紊乱、去除导致QT延长的药物。LQTS治疗的长效管理包括生活方式干预、口服β受体阻滞剂、植入心律转复除颤仪、左心交感神经切除以及靶向药物等。

Long QT interval syndrome （LQTS） is an ion channelopathy disease which holds the characteristics of the prolongation of QT interval on electrocardiogram （ECG） and ventricular arrhythmia （VT）. The occurrence of this disease is associated with mutations among potassium channel protein,sodium channel protein, calcium channel related factor, and membrane adaptation protein. Now, there were 13 genes that their mutation results in LQTS. The clinical feature is mainly manifested on the abnormal prolongation of QT interval,the giant T wave altemans on the ECG and the syncope or cardiac sudden death resulted from torsades de pointes （TdP） ventficular tachycardia. Arrhythmic events are closely related with the gene type involved. On LQTS1 ,the arrhythmia was normally triggered by sports and emotional excitement,and LQTS2 was by loud noises. The emergency treatment is required when the TdP occurred, because it will result in rapid deterioration of circulatory perfusion and sudden death. The emergency treatment includes intravenous administration of magnesium sulfate, synchronized or nonsynchronized DC shock for cardioversion, correcting internal environmental disturbance such as hypokalemia, and terminating the use of certain drugs which could cause the prolongation of QT interval. The long term management of LQTS includes lifestyle intervention, oral administration of β-blockers, implantation of implantable cardioverter defibrillator （ ICD）, left cardiac sympathetic denervation and certain target drugs.