[Global and regional left ventricular myocardial function following aorto-coronary multiple (5-, 6-, 7-) bypass. Non-invasive determination with technetium 99m-pertechnetate scintigraphy].

In 19 patients (mean age 55.3 years) with severe, diffuse coronary artery disease and stable angina pectoris, coronary artery bypass surgery was performed with an average of 5.36 anastomoses per patient. At 15.5 +/- 8 months postoperatively, radionuclide ventriculograms were obtained in the RAO projection (first-pass-technique) at rest and during maximal exercise by means of a multicrystal camera. To assess the effects of revascularization on the myocardial function, analysis was performed for global ejection fraction (GEF) as well as three regional ejection fraction (GEF) as well as three regional ejection fractions (REF) corresponding to the vascular beds of the three major coronary arteries. During exercise global ejection fraction increased in 13 patients (68.4%) an average of 9.5%-points from 51.5 to 61.0%, in one patient (5.2%) remained unchanged and in five patients (26.3%) decreased an average of 9.6% %-points from 62.6 to 53.0% (all changes p less than 0.05). The classification of the various myocardial regions was based on the preoperative coronary angiogram as well as intraoperative in-situ findings according to the status of the coronary vessels, the extent of revascularization and the presence of remote myocardial infarctions. Regions of group I had a significantly higher fraction of complete revascularizations, that is 79.9%. 61.1% of group-II-territories were incompletely revascularized. The weighted balance of the three regions supplied by the left anterior descending artery, the circumflex and the right coronary artery explains the postoperative response of the global ejection fraction to exercise.(ABSTRACT TRUNCATED AT 250 WORDS)