[Critical study of the stress electrocardiogram after aortocoronary bypass, based on 95 coronary angiographic...

This paper studies the correlations between the stress electrocardiogram and the angiographic findings after aorto-coronary bypass grafts. 95 correlations were established in 75 patients (coronary angiography and stress tests were performed on two occasions after the operation in 20 patients). 32 patients had a past history of myocardial infarction. The stress test was positive when the ST depression was equal to or greater than 1 mm, over more than 80 milliseconds. Four groups could be defined on the basis of the angiography: patient graft(s) with no residual stenosis; old or new coronary lesions; occlusion of one or more grafts; malfunction of the graft(s). The stress test and the coronary angiography were separated by a mean delay of 4.6 days. The stress test was positive in 43 cases, due to the residual postoperative stenoses in 63% of cases, due to occlusion of the graft(s) in 25% of cases and due to malfunction of the graft(s) in 9% of cases. In 3% of cases, the signs of ischaemia were due to an old infarct. The stress test was negative in 52 cases. This negative result corresponded to the 66% of cases with complete revascularisation of the coronary system; in 34% of cases, there were persistent angiographic abnormalities, consisting of uncorrectable coronary stenoses in half of the cases. When the coronary revascularisation was complete, the stress test was negative in every case. Residual coronary lesions were associated with a positive stress test in 66% of cases and with a negative test in 34% of cases.(ABSTRACT TRUNCATED AT 250 WORDS)