TC-99M SESTAMIBI CARDIAC SPECT IMAGING DURING CORONARY-ARTERY OCCLUSION IN HUMANS - COMPARISON WITH DIPYRIDAMOLE STRESS STUDIES

PURPOSE: To compare the magnitude of change in regional myocardial per fusion during dipyridamole stress with that during coronary occlusion. MATERIALS AND METHODS: The authors prospectively studied 14 men with more than 50% diameter stenosis in at least one major coronary artery. Same-day rest and dipyridamole technetium-99m sestamibi single photon emission computed tomography (SPECT) was performed 24 hours before co ronary angioplasty. During angioplasty, while the vessel was occluded, 15 mCi (555 MBq) of tracer was injected, and SPECT studies were obtai ned 60 minutes later. Extent of regional perfusion abnormalities was e stimated. RESULTS: Regional perfusion defect was greater during stress and occlusion than during rest (20%, P =.001 and 14%, P =.009, respec tively). SPECT defect during coronary occlusion was similar to that ob tained during pharmacologic stress with dipyridamole (53% vs 47%, P =. 02). CONCLUSION: Tc-99m sestamibi SPECT with dipyridamole stress is a good predictor of the extent of perfusion abnormalities that occur dur ing coronary occlusion and may facilitate estimation of the total myoc ardium in jeopardy from a stenotic lesion.