[Effects of coronary revascularization on infarcted myocardial regions--evaluation on postoperative left ventricular...

In order to determine the effects of coronary revascularization for infarcted regions on postoperative left ventricular function and regional wall motion, we studied first-pass radionuclide angiography at rest and during exercise before and after operation in 18 patients with previous myocardial infarction. Preoperative mean value of left ventricular ejection fraction (LVEF) was significantly decreased during exercise from 56.8 +/- 14.1% to 46.1 +/- 15.5% (p less than 0.01). Postoperatively, there was no change of the values between at rest and during exercise: 53.6 +/- 14.1% versus 51.9 +/- 15.7%. Postoperative mean LVEF during exercise was significantly higher, compared with that of preoperative LVEF (p less than 0.05). Mean regional ejection fraction of infarcted regions was significantly decreased during exercise from 66.0 +/- 15.0% to 56.1 +/- 15.8% (p less than 0.01) before operation. However, there was no significant change in values between at rest and during exercise after operation: 65.4 +/- 13.9% versus 61.8 +/- 14.5%. Mean postoperative regional ejection fraction during exercise was significantly higher, compared with preoperative regional ejection fraction after operation (p less than 0.05). These results might be indicated that regional wall motion of the infarcted regions with ischemia enhanced by exercise preoperatively can be definitely improved by coronary revascularization.