Spargias K S, Lindsay S J, Kawar G I, Greenwood D C, Cowan J C, Ball S G, Hall A S
Institute for Cardiovascular Research, University of Leeds, Leeds, U.K.
Eur Heart J. 1999 Aug;20(16):1158-65. doi: 10.1053/euhj.1998.1445.
QT interval dispersion is a marker of inhomogeneous ventricular repolarization, and therefore has the potential to predict re-entry arrhythmias. Following acute myocardial infarction, increased QT dispersion has been associated with a higher risk of ventricular arrhythmias. However, whether or not QT dispersion predicts prognosis post-acute myocardial infarction is not clear. We addressed this issue by analysing the AIREX study registry.
AIREX was a follow-up study of 603 post-acute myocardial infarction patients who exhibited clinical signs of heart failure and were randomly allocated to ramipril or placebo. An interpretable 12-lead ECG obtained between day 0 and day 9 after the index infarction (median time 2 days) was available in 501 patients. We examined whether QT dispersion was a predictor of all-cause mortality in the AIREX study registry (mean follow-up 6 years).
QT dispersion measurements were significantly increased in patients who subsequently died (QT dispersion: 92.0 +/- 38.5 ms vs 82.7 +/- 34.3 ins. P=0.005; rate corrected QT dispersion: 105.7 +/- 42.7 ms vs 93.1 +/- 35.9 ms, P<0.001). Univariate analysis showed that QT dispersion as a predictor of all-cause mortality risk (QT dispersion: hazard ratio per l0 ms 1.05, [95% CI 1.02 to 1.09]. P= 0.004; rate corrected QT dispersion: 1-07 [1.03 to 1.10], P<0.001): an increase of 10 ms added a 5-7%, relative risk of death. QT dispersion remained an independent predictor of all-cause mortality risk on multivariate analysis (QT dispersion: 1.05 [1.01 to 1.09], P=0.027; rate corrected QT dispersion: 1.05 [1.01 to 1.09]. P=0.022).
QT dispersion. measured from Li routine 12-lead ECG following acute myocardial infarction complicated by heart failure provides independent information regarding the probability of long-term survival. However. the low sensitivity of this electrocardiographic marker limits its usefulness for risk stratification if used in isolation.
QT间期离散度是心室复极不均一性的一个指标，因此有预测折返性心律失常的潜力。急性心肌梗死后，QT离散度增加与室性心律失常风险较高相关。然而，QT离散度是否能预测急性心肌梗死后的预后尚不清楚。我们通过分析AIREX研究登记数据来解决这个问题。
AIREX是一项对603例有心力衰竭临床体征的急性心肌梗死后患者进行的随访研究，这些患者被随机分配至雷米普利或安慰剂组。501例患者有在首次梗死（中位时间2天）后0至9天之间获得的可解读的12导联心电图。我们在AIREX研究登记数据中（平均随访6年）检查QT离散度是否是全因死亡率的预测指标。
随后死亡的患者QT离散度测量值显著增加（QT离散度：92.0±38.5毫秒对82.7±34.3毫秒，P=0.005；心率校正QT离散度：105.7±42.7毫秒对93.1±35.9毫秒，P<0.001）。单因素分析显示QT离散度是全因死亡风险的预测指标（QT离散度：每10毫秒的风险比为1.05，[95%可信区间1.02至1.09]，P=0.004；心率校正QT离散度：1.07[1.03至1.10]，P<0.001）：增加10毫秒使死亡相对风险增加5 - 7%。在多因素分析中，QT离散度仍然是全因死亡风险的独立预测指标（QT离散度：1.05[1.01至1.09]，P=0.027；心率校正QT离散度：1.05[1.01至1.09]，P=0.022）。
急性心肌梗死合并心力衰竭后，从常规12导联心电图测量的QT离散度提供了关于长期生存概率的独立信息。然而，该心电图指标的低敏感性限制了其单独用于风险分层的实用性。
