目的 探讨不明原因胸闷痛儿童静息期卧位与立位心电图T波及ST段振幅变化的临床意义。方法 选取以不明原因胸闷痛(静息期)为主诉的6~14岁儿童122例行直立倾斜试验(HUTT),分HUTT阳性组(n=61)和HUTT阴性组(n=61)。测量卧位与立位12导联心电图的心率及Ⅱ、Ⅲ、aVF、V₅导联T波和ST段振幅。结果 (1)HUTT阴性组:立位较卧位心率增快(P<0.05),Ⅱ、Ⅲ、aVF、V₅导联T波振幅降低(P<0.05);Ⅱ、aVF、V₅导联ST段振幅增加(P<0.05)。(2)HUTT阳性组:立位较卧位心率增加(P<0.05),Ⅱ、Ⅲ、aVF、V₅导联T波振幅降低(P<0.05);V₅导联ST段振幅增加(P<0.05)。(3)T波振幅及ST段振幅变化:立位与卧位心电图Ⅱ、Ⅲ、aVF、V₅导联T波及ST段振幅在HUTT阳性组、HUTT阴性组之间差异无统计学意义(P>0.05)。(4)卧位与立位心电图T波和ST段振幅差比较:HUTT阳性组卧位与立位心电图Ⅱ、Ⅲ、aVF、V₅导联T波振幅差及心率差较HUTT阴性组增加(P<0.05)。结论 不明原因胸闷痛静息期儿童HUTT阳性组卧位与立位心电图T波振幅差及心率差较HUTT阴性组增加,表明卧位与立位心电图T波振幅变化对提示自主神经功能紊乱具有临床价值。

Objective To investigate the clinical significance of changes in T wave and ST segment amplitudes on electrocardiogram (ECG) from supine to standing position in children with unexplained chest tightness or pain in resting stage. Methods A total of 122 6-14-year-old children with a chief complaint of unexplained chest tightness or pain (resting stage) underwent head-up tilt test (HUTT). According to HUTT results, these children were divided into HUTT-positive (n=61) and HUTT-negative groups (n=61). They underwent 12-lead ECG in the supine and standing positions, and heart rate and T wave and ST segment amplitudes in II, III, aVF and V₅ leads were measured. Results In the HUTT-negative group, heart rates were significantly higher in the standing position than in the supine position (P<0.05), T wave amplitudes in II, III, aVF, and V₅ leads were significantly lower in the standing position than in the supine position (P<0.05), and ST segment amplitudes in II, aVF and V₅ leads were significantly higher in the standing position than in the supine position (P<0.05). In the HUTT-positive group, heart rates were significantly higher in the standing position than in the supine position (P<0.05), T wave amplitudes in II, III, aVF and V₅ leads were significantly lower in the standing position than in the supine position (P<0.05), and ST segment amplitude in V₅ lead was significantly higher in the standing position than in the supine position (P<0.05). There were no significant differences between the two groups with respect to ST segment amplitude and T wave amplitude in II, III and aVF leads of the supine or standing position (P>0.05). Compared with the HUTT-negative group, the HUTT-positive group had significantly greater T wave amplitude differences in II, III, aVF and V₅ leads, and heart rate difference from supine to standing position (P<0.05). Conclusions Among the children with unexplained chest tightness or pain in resting stage, T wave amplitude differences in II, III, aVF and V₅ leads and heart rate difference from supine to standing position are greater in the HUTT-positive group than in the HUTT-negative group. This suggests that the changes in T wave amplitude on ECG from supine to standing position can indicate autonomic nervous system dysfunction.