目的　探讨单纯主动脉瓣狭窄(AS)学龄期儿童的时域法T波电交替(TWA)特点。方法　入选15例单纯AS学龄期儿童以及60例年龄、性别相匹配的正常对照儿童，以平板运动仪进行TWA检测，采用时域法微伏级TWA(MTWA)分析，比较单纯AS组与对照组持续MTWA发生率，以及不同TWA表现单纯AS儿童运动试验心肌缺血的发生率。结果　与对照组相比，AS学龄期儿童的持续MTWA发生率明显增高，差异有统计学意义(P<0.01)；发生持续MTWA的AS学龄期儿童运动过程中心肌缺血的发生率高于无持续MTWA者，差异有统计学意义(P<0.05)。结论　AS学龄期儿童存在持续TWA的电生理基础，同时持续TWA与运动负荷心肌缺血密切相关，持续TWA可作为临床评价AS学龄期儿童心功能的重要心电生理指标。

Objective　To explore the characteristics of T wave alternans (TWA) in aortic stenosis (AS) in school-aged children. Methods TWA was analyzed in 15 AS patients and 60 age-matched normal children using Microvolt T-Wave Alternans and the incidence of sustained TWA was compared between two groups. Myocardial ischemia during treadmill test was studied in sustained TWA and non-sustained TWA in AS patients. Results Compared with normal children, the incidence of sustained TWA was significantly increased in AS group (P<0.01). In AS school-aged patients, the incidence of myocardial ischemia is higher in sustained TWA than in non-sustained TWA during treadmill test (P<0.05). Conclusions AS school-aged children have electrophysiologic basis for sunstained TWA. TWA is closely related to myocardial ischemia during treadmill test. Sustained TWA could be used as an important electrophysiologic index to assess the cardiac function in children with AS.