Takase B, Tujimoto T, Kitamura K, Hamabe A, Uehata A, Kazusige I, Satomura K, Ohsuzu F, Kurita A
National Defense Medical College, Internal Medicine-1, Tokorozawa, Saitama, Japan.
Clin Cardiol. 2001 Feb;24(2):127-31. doi: 10.1002/clc.4960240206.
Prolonged QT dispersion (QTd) is shortened by successful percutaneous transluminal coronary angioplasty (PTCA) in patients with ischemic heart disease. Particularly, QTd plays an important role in the prognostication in patients with prior myocardial infarction (MI). However, whether the effect of PTCA on QTd differs in patients with and without prior MI is not clear, and this study sought to clarify this question.
In 41 consecutive patients with ischemic heart disease, we measured QTd from a routine 12-lead electrocardiogram taken at 72 h before and after successful PTCA. Patients were divided into two groups based on the presence or absence of prior MI: Group 1 consisted of 24 patients with angina (61 +/- 11 years old) without prior MI and Group 2 was comprised of 17 patients (69 +/- 10 years old) with prior MI. QTd was calculated as the difference between the maximum and minimum QT and QT corrected for heart rate (QTc), using Bazett's formula for calculating QTcd. All measurements were obtained manually and blindly.
In Group 1, 15 of 24 patients (63%) demonstrated multivessel disease and 16 of 24 (67%) patients had high QTd > 60 ms. Percutaneous transluminal coronary angioplasty decreased QTd and QTcd in Group 1 (QTd, from 83 +/- 35 to 57 +/- 19 ms, p < 0.05 ; QTcd, from 89 +/- 37 to 63 +/- 33 ms, p < 0.05), whereas no changes were observed in Group 2 (QTd, from 73 +/- 25 to 69 +/- 22 ms, NS; QTcd, from 80 +/- 30 to 79 +/- 28 ms, NS). QTd is more sensitive to decrease by successful PTCA in patients with angina than in patients with prior MI.
The effect of successful PTCA on inhomogeneity of ventricular repolarization reflected by QTd in patients with prior MI is different from that in patients without prior MI.
在缺血性心脏病患者中，成功的经皮腔内冠状动脉成形术（PTCA）可缩短QT离散度（QTd）。特别是，QTd在既往有心肌梗死（MI）的患者的预后评估中起重要作用。然而，PTCA对QTd的影响在有和没有既往MI的患者中是否不同尚不清楚，本研究旨在阐明这个问题。
在41例连续的缺血性心脏病患者中，我们在成功的PTCA前后72小时从常规12导联心电图测量QTd。根据是否有既往MI将患者分为两组：第1组由24例无既往MI的心绞痛患者（61±11岁）组成，第2组由17例有既往MI的患者（69±10岁）组成。QTd计算为最大和最小QT之间的差值以及使用Bazett公式校正心率后的QT（QTc）来计算QTcd。所有测量均手动且盲法获得。
在第1组中，24例患者中有15例（63%）表现为多支血管病变，24例患者中有16例（67%）QTd>60ms。经皮腔内冠状动脉成形术降低了第1组的QTd和QTcd（QTd，从83±35降至57±19ms，p<0.05；QTcd，从89±37降至63±33ms，p<0.05），而第2组未观察到变化（QTd，从73±25降至69±22ms，无统计学意义；QTcd，从80±30降至79±28ms，无统计学意义）。与有既往MI的患者相比，成功的PTCA使心绞痛患者的QTd更易降低。
成功的PTCA对既往有MI的患者中由QTd反映的心室复极不均一性的影响与无既往MI的患者不同。
