Early and long-term improvement in left ventricular performance following coronary bypass surgery

Changes in left ventricular performance after coronary artery bypass grafting (CABG) have been variable. Earlier studies based on contrast left ventriculography have shown occasional improvement in left ventricular function in patients with unstable angina or abnormal preoperative ventricular performance, but for the most part repeat cardiac catheterization several months after operation has shown no significant changes in global left ventricular contraction. In the past few years, advances in radiopharmaceutical technology have made the characterization of left ventricular wall motion accurate and highly reproducible. Since prognosis in patients with coronary artery disease and survival after CABG have been related to global ejection fraction (EF), we employed prospectively on analysis of short-term and long-term changes in EF after CABG utilizing multidose hypothermic potassium crystalloid cardioplegia as the method of myocardial protection. Concomitantly, newer techniques in anesthesia and perioperative patient management were employed to minimize myocardial damage in these patients. Postoperative scintigraphic evaluation showed a transient (2-hour) depression in left ventricular function, followed by recovery to preoperative levels at 24 hours and significant improvement in EF at 7 days. From 7 days to 8 months postoperatively, there was no further change in resting EF, but there was another significant exercise-induced increase in EF at the long-term examination. Thus, present advances in the multidisciplinary management of patients with coronary artery disease are associated with improvement in resting and exercise-related EF postoperatively.