急性心肌梗死恢复期患者平板运动试验Q-T间期离散度的价值研究

目的 探讨急性心肌梗死恢复期患者运动试验后Q-T间期离散度（Q-Td）的变化.方法 观察51例急性心肌梗死恢复期患者（观察组）平板运动试验的Q-Td的变化,并观察运动后出现严重室性心律失常、胸痛、血压下降与Q-Td变化的关系.结果 患者峰心率时Q-Td（64.3±20.5ms）较运动前（51.2±23.5ms）增大,差异有显著统计学意义（P＜0.01）.运动中出现严重室性心律失常或明显胸痛、血压下降者15例（A亚组）与36例未出现者（B亚组）比较,运动前Q-Td差异无统计学意义（59.1±17.5ms和16.3±19.2ms,P ＞0.05）,峰心率时A亚组Q-Td（76.8±15.5ms）较B亚组（60.1±16.1ms）延长,差异有显著统计学意义（P＜0.01）.两亚组Q-Td多壁梗死均比单壁梗死延长,A亚组多壁梗死比B亚组延长,差异均有统计学意义（P ＜0.05）.结论 急性心肌梗死患者运动后Q-Td进一步增大,出现严重室性心律失常的危险性增大.平板运动试验可作为筛选急性心肌梗死高危人群的手段之一.

The Significance of QT Dispersion Changes during Treadmill Exercise Test in Convalescent Myocardial Infarction Patients

Objective To assess the significance of QT dispersion （QTd） changes during treadmill exercise test （TET） in convalescent myocardial infarction （MI） patients. Methods QTd changes as well as ventricular arrhythmia, chest pain and blood pressure were evaluated during TET in 51 convalescent MI patients. Results QTd increased significantly at peak heart rate （64.3 ± 20.5ms ） compared to that at baseline （51.2 ± 23.5ms） （P〈0.001）. Serious ventricular arrhythmia, severe angina pectoris or blood pressure reduction occurred in 15 cases （group A） and did not in 36 cases （group B） during exercise. QTd was not significant difference between group A and B at baseline （59.1 ± 17.5 ms vs. 46.3 ± 19.2 ms, P 〉0.05）, but significantly larger in group A than in group B at peak heart rate （76.8 ± 15.5 ms vs. 60.1 ± 16.1ms, P〈0.01）. QTd increased more significantly in patients with multiple sites than a single site of infarction （P〈0.05）. Also, QTd was significantly larger in patients with multiple sites of infarction in group A than in group B （P〈0.05）. Conclusion The risk of serious ventricular arrhythmia may increase along with QTd increase at exercise in acute MI patients. TET may be one of the approaches to identify a high-risk population of acute MI.