Perioperative myocardial infarction diagnosed by technetium 99m stannous pyrophosphate myocardial scintigrams

Two groups of patients have been studied using 99mTc stannous pyrophosphate myocardial imaging prior to and 3-5 days after myocardial revascularization. The first group consisted of 48 patients undergoing revascularization, including 26 with unstable angina and seven with concomitant valve replacement. There were 3 deaths (6%), and the incidence of perioperative infarction by electrocardiogram (ECG) and enzyme analysis was 6/48 (12%), while 15 of 48 (31%) had positive myocardial scintigrams. The second group of 29 patients included one nonischemic death (3%) that was excluded. The operative technique was changed (optical magnification used, silastic tapes avoided, venting avoided, while aortic cross clamping was used frequently). In this latter group two of 29 (7%) had ECG evidence of infarction while four of 28 (14%) had positive scintigrams, compared to the pervious incidence of 31%. The imaging technique is simple, reliable, and probably more sensitive in the postoperative setting than ECG and enzyme analysis. It appears useful in evaluating the influence of changes in operative technique on myocardial preservation.