dipyridamole stress and rest gated 99mtc-sestamibi myocardial perfusion spect: left ventricular function indices and myocardial perfusion findings

introduction: we investigated the difference in left ventricular ejection fraction (lvef) and end-systolic volume(esv) measured by gated myocardial perfusion spect (gspect) in the post-dipyridamole stress and rest periods, and compared the results with the perfusion patterns found in the conventional non-gated tomograms. methods: 297 consecutive patients were studied with post-stress and rest 99mtc-sestamibi gspect using a two-day protocol. stress images were obtained 90 min after dipyridamole infusion and radiotracer injection. all acquisitions were analyzed visually, semi-quantitatively and quantitatively using qgs software. results: patients were divided into 4 groups according to the perfusion patterns: group-1 = no perfusion defects (n= 129, 43.4%); group-2 = reversible perfusion defects (n = 85, 28.6%); group-3=fixed defects (n =52, 17.5%); group 4 = partially reversible perfusion defects (n =31, 10.4%). differences between post-stress lvef (sef) and rest lvef (ref) (def=sef-ref) were +3.39, -6.45, -1.61, and -0.70 for groups 1, 2, 3 and 4 respectively. post-stress stunning (>5% decrease in lvef) was present in 49 patients (16.5%). sef was significantly more than ref in patients with summed difference score (sds)