Yamagishi H, Toda I, Akioka K, Hirata K, Yoshiyama M, Teragaki M, Takeuchi K, Yoshikawa J, Ochi H
First Department of Internal Medicine, Osaka City University Medical School, Osaka, Japan.
Jpn Circ J. 2000 Aug;64(8):572-8. doi: 10.1253/jcj.64.572.
In chronic Q-wave myocardial infarction, QT dispersion is closely correlated with infarct size, but this correlation has not been evaluated for acute myocardial infarction (AMI). The effects of abnormal fatty acid metabolism on QT dispersion were examined in 123 patients with AMI who underwent resting iodine-123-15-iodophenyl 3-methyl pentadecanoic acid (BMIPP)/thallium-201(201Tl) myocardial single photon emission computed tomography (SPECT) and electrocardiographic analysis in the subacute phase. The relationship between BMIPP and 201Tl was defined as match when the total defect score for BMIPP was equal to or smaller than that for 201Tl, and as mismatch when the total defect score for BMIPP was larger than that for 201Tl. Twenty-six patients (21%) demonstrated BMIPP-201Tl match and 97 (79%) demonstrated mismatch. Infarct size was closely correlated with QT dispersion (r=0.67, p<0.001) in patients with BMIPP-201Tl match, but weakly correlated (r=0.30, p<0.005) in patients with BMIPP-201Tl mismatch. For small infarctions, QT dispersion was significantly larger in patients with BMIPP-201Tl mismatch than in those with BMIPP-201Tl match (62+/-24 ms vs 41+/-18 ms, p=0.03), but did not differ between the 2 groups for large infarctions. This study shows that QT dispersion is influenced by infarct size and by the presence of metabolically ischemic but viable myocardium in patients with AMI.
在慢性Q波心肌梗死中，QT离散度与梗死面积密切相关，但急性心肌梗死（AMI）中尚未评估这种相关性。在123例亚急性期接受静息碘-123-15-碘苯基3-甲基十五烷酸（BMIPP）/铊-201（201Tl）心肌单光子发射计算机断层扫描（SPECT）和心电图分析的AMI患者中，研究了异常脂肪酸代谢对QT离散度的影响。当BMIPP的总缺损评分等于或小于201Tl的总缺损评分时，BMIPP与201Tl的关系定义为匹配；当BMIPP的总缺损评分大于201Tl的总缺损评分时，定义为不匹配。26例患者（21%）表现为BMIPP-201Tl匹配，97例（79%）表现为不匹配。在BMIPP-201Tl匹配的患者中，梗死面积与QT离散度密切相关（r=0.67，p<0.001），而在BMIPP-201Tl不匹配的患者中相关性较弱（r=0.30，p<0.005）。对于小面积梗死，BMIPP-201Tl不匹配的患者QT离散度显著大于BMIPP-201Tl匹配的患者（62±24 ms对41±18 ms，p=0.03），但大面积梗死时两组之间无差异。本研究表明，AMI患者的QT离散度受梗死面积以及代谢性缺血但存活心肌的存在情况影响。
