Tomassoni G, Pisanó E, Gardner L, Krucoff M W, Natale A
Division of Cardiology, Duke University, Veterans Administration Medical Center, Durham, North Carolina, USA.
J Electrocardiol. 1998;30 Suppl:187-90. doi: 10.1016/s0022-0736(98)80073-3.
The ability of QT interval dispersion to predict the occurrence of ventricular fibrillation (VF) after acute myocardial infarction treated with thrombolytic therapy is controversial. Continuous 12-lead electrocardiographic (ECG) monitoring for 48 hours or longer provides an opportunity to detect transient changes of QT dispersion and correlate such changes with the clinical outcome. In 543 consecutive patients enrolled in the TAMI-9 and GUSTO I studies, serial changes of the QT dispersion were analyzed in an attempt to predict the occurrence of VF with a system that monitored continuously the 12-lead ECG and stored it at least every 20 minutes. Measurements of QT dispersion were made at a median time of 2.37 hours after the onset of chest pain and at 24- and 48-hour intervals. A total of 43 patients experienced VF during the acute phase of myocardial infarction; of these patients, 33 (77%) had anterior infarcts. However, despite the higher preponderance of anterior myocardial infarcts in the VF group, patients with anterior infarcts did not have longer QT dispersion than those with other infarct locations. Similarly, no significant differences in the QT dispersion were observed at any time between the group with VF and that without. Women had increased QT dispersion in the initial and 24-hour ECG as compared with men (P = .005). However, this normalized at the 48-hour measurements. Despite this difference, there was no higher incidence of VF in female patients. In conclusion, the data suggest that QT dispersion alone is not sufficient to explain the occurrence of VF in the acute phase of myocardial infarction after thrombolytic therapy.
溶栓治疗的急性心肌梗死后QT间期离散度预测室颤（VF）发生的能力存在争议。连续48小时或更长时间的12导联心电图（ECG）监测为检测QT离散度的短暂变化并将此类变化与临床结局相关联提供了机会。在参加TAMI - 9和GUSTO I研究的543例连续患者中，分析了QT离散度的系列变化，试图通过一个连续监测12导联ECG并至少每20分钟存储一次的系统来预测VF的发生。在胸痛发作后的中位时间2.37小时以及24小时和48小时间隔时进行QT离散度测量。共有43例患者在心肌梗死急性期发生VF；在这些患者中，33例（77%）为前壁梗死。然而，尽管VF组中前壁心肌梗死更为常见，但前壁梗死患者的QT离散度并不比其他梗死部位的患者长。同样，VF组和无VF组之间在任何时间均未观察到QT离散度的显著差异。与男性相比，女性在初始和24小时ECG时的QT离散度增加（P = 0.005）。然而，在48小时测量时这一差异恢复正常。尽管存在这一差异，但女性患者中VF的发生率并未更高。总之，数据表明，仅QT离散度不足以解释溶栓治疗后急性心肌梗死急性期VF的发生。
