The Annals of Thoracic Surgery, Vol 39, 340-345, Copyright © 1985 by The Society of Thoracic Surgeons
Improvement in resting ventricular performance following coronary bypass surgery
CI Tchervenkov, JF Symes, AD Sniderman, R Lisbona, VA Derbekyan, RJ Novick, JE Wynands, AR Dobell and JE Morin
To assess the changes in resting left ventricular (LV) function following
coronary bypass surgery, technetium 99m-labeled multiple equilibrated blood
pool gated scans were performed in 53 consecutive patients at rest, before
operation, and at 24 hours and 1 week after operation. Left ventricular
ejection fraction (LVEF) and end-diastolic volume (EDV) were measured. The
LVEF increased significantly from a preoperative value of 49 +/- 2% to 56
+/- 2% at 24 hours after operation (p less than 0.05) and 56 +/- 2% at 1
week following operation (p less than 0.05 compared with the preoperative
value). The EDV also exhibited significant changes, decreasing from a
preoperative value of 148 +/- 8 ml to 91 +/- 11 ml at 24 hours (p less than
0.001) and 114 +/- 9 ml at 1 week (p less than 0.01 compared with the
preoperative value). When the patients were divided into two groups
according to the preoperative LVEF (Group 1, LVEF of greater than or equal
to 50%; Group 2, LVEF of less than 50%), the observed changes were similar.
This study demonstrates significant improvement in resting LV function 24
hours following coronary bypass surgery. This improvement persists at 1
week and is not related to the degree of preoperative impairment. We
conclude that the combination of successful revascularization and optimal
myocardial protection can result in significant improvement of LV function
at rest.