[Dipyridamole-thallium myocardial imaging in patients unable to exercise adequately: comparison with arm and bicycle...

We assessed the usefulness of dipyridamole-thallium myocardial imaging in patients unable to exercise adequately, compared with arm-ergometer and standard (bicycle) ergometer. Fifty-six patients with arteriosclerosis obliterans, aortic aneurysm, aortic dissection and so on, who were revealed normal imaging, were studied. Only one of 13 cases with arm-ergometer and two of 14 with bicycle ergometer reached target heart rate. Lung thallium uptake in the cases with arm-ergometer (37 +/- 9%) is higher than that with dipyridamole (29 +/- 5%). This elevation may be confused with pectoralis muscle uptake. Washout rate is 45 +/- 9% with dipyridamole and 46 +/- 12% with bicycle ergometer, respectively, though there was no significant differences. Myocardial/background counts ratio with dipyridamole (4.6 +/- 0.8%) is significantly higher than that with arm and bicycle ergometer (arm-ergometer; 3.5 +/- 0.7, bicycle ergometer; 4.2 +/- 0.9). Then, myocardial image with dipyridamole have superior quality. We concluded that dipyridamole-thallium myocardial imaging is very useful in the patients who have suboptimal exercise efforts.