Mean systolic ejection rate after aortocoronary bypass graft surgery

In 62 patients with coronary artery disease who underwent aortocoronary bypass graft surgery, we measured the mean systolic ejection rate invasively at rest and during upright exercise before and several months after operation. After bypass surgery, mean systolic ejection rate did not show any change at either supine or sitting rest and at submaximal exercise levels of walking on a treadmill. At maximal exercise, only patients with complete revascularization showed a significant increase in heart rate from 105 to 147 (+40%) and mean systolic ejection rate from 339 ml/sec to 404 ml/sec (+19%, P less than 0.001). Patients with incomplete revascularization did not show a substantial change in these variables. Beta-blocker withdrawal did not affect the result significantly.