Changes of Intracoronary Electrocardiogram by Repeated Occlusion: Repefusion During Percutaneous Transluminal Coronary Angioplasty / 대한내과학회지

ABSTRACT

OBJECTIVE: Brief epidodes of ischemia have been shown to make the heart more resistant to subsequent ischemia in animal studies(known as ischemic preconditioning, IP). This phenomenon was tested in patients undergoing percutaneous transluminal coronary angioplasty(PTCA). METHODS: Thirteen patients who had significant epicardial coronary stenosis without myocardial infarction, ventricular hypertrophy or conduction defect, received two to four 2-min balloon inflations separated by 5 min of reperfusion. Surface electrocardiogram(S-ECG) and intracoronary electrocardiogram (IC-ECG) from an angioplasty guide wire were recorded before and after balloon inflation. RESULTS: The changes of ST segment were observed in 13 out of 15 lesions on IC-ECG and 7 on S-ECG. The maximal ST changes on IC-ECG and S-ECG were 20.2+/-13.7mm and 1.21.5mm respectively(p<0.01). The time to beginning of ST segment change after balloon inflation were 10.1+/-12.6 seconds and 63.3+/-14.2 seconds on IC-ECG and S-ECG, respectively(p<0.01). The maximal changes of ST segment on IC-ECG during the second inflation were significantly lower than that during the first(20.2+/-13.7 vs 16.312.3mm, p<0.05). However, changes of R wave, T wave and QT interval were not significantly different between two inflations. The recovery time to baseling ECG after initiation of reperfusion were 50.2+/-41.7 seconds and 38.5+/-29.6 seconds for the first inflation and the second, respectively(P<0.05). CONCLUSION: These results suggest that IC-ECG is more sensitive and reliable than S-ECG in detection of myocardial ischemia and that IP may occur during PTCA since ST segment shift is decreased and is normalized earlier at the second balloon inflation compared with the first.