[Myocardial scintigraphy with thallium-201 for evaluation of the patency of aorto-coronary bypasses in multiple vessel disease and multiple bypasses (author's transl)].

The reliability of myocardial scintigraphy with thallium-201 in evaluating the patency of aorto-coronary bypasses was examined. In addition to coronary angiography and ventriculography in 16 patients (42 stenosed vessels, 36 bypasses of which 22 were patent) quantitative myocardial scintigraphy was performed after maximum exercise and at rest, pre- and postoperatively. In general, 12 patients with postoperatively improved angina showed an improvement in their scintigram. The analysis of myocardial areas with a bypass showed a decrease of thallium uptake at rest in 39%, regardless of patency occlusion of the bypass. In 85% of these regions an increased thallium uptake was seen after exercise, again independent of the function of the bypass. The data show that myocardial scintigraphy with thallium-201 cannot be utilized in patients with multiple vessel disease and multiple bypasses to evaluate the patency of a particular bypass, but a general assessment is possible, whether myocardial perfusion has improved.