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Object and Methods : Thirty-four patients (mean age : 58.1±8.3 years, M : F=21 : 13) with angina in the absence of previous myocardial infarction, who underwent percutaneous coronary intervention (stenting and/ or balloon PTCA, n=25) or coronary arterial bypass grafting (CABG, n=9) were evaluated to assess the relationships between the degree of improvement in myocardial dipyridamole TI-201 SPECT and the degree of decrease in QTc dispersion after coronary revascularization. QTc dispersions were measured manually using digitizer by a single observer from ECGs printed at 25 mm/sec, 1 day-before, immediately, 1 day, and 1 month after the revascularization procedure. Myocardial TI-201 SPECTs were performed before and 1 month after the revascularization and ischemic indices were measured in all cases. Results : Mean QTc dispersion was 51.4±17. 0 msec before revascularization, 42.6± 15.1 msec immediately after, 45.6± 19.3 msec 1 day after and 37.4± 11. 6 msec 1 month after revascularization. The decrease of QTc dispersion immediate (p=0.001) and 1 month (p <0.001) after revascularization, were statistically significant. Mean T1-201 SPECT ischemic index measured before the revascularization (7.8±5.9) was significantly higher (p<0.001) than the one measured 1 month after the revascularization (1.5±2.8). But, in A ischemic index (ischemic index before revascularizationischemic index 1 month afer revascularization), there was no significant difference between the patients with decrease in QTc dispersion after revascularization(6.2±6.3, n=27) and the patients without decrease in QTc dispersion (6.6±5.2, n=7). There was no statistically significant correlation between A QTc (QTc dispersion before revascularization - QTc dispersion 1 month afer revascularization) and A ischemic index in total subjects. Conclusion : QTc dispersions decrease after successful coronary revascularizations in patients with angina, but considering the relationships between the changes of QTc dispersions and ischemic indices in myocardial dipyridamole TI-201 SPECT, the degree of decrease in QTc dispersion after coronary revascularization does not have the relationships with the quantitative degree of improvement in myocardial ischemia. (Korean Circulation J 2000; 30 (8) : 998-1003)
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