Nitroglycerin resting Tl-201 myocardial perfusion imaging will be performed between 2-5 days after myocardial infarction. Subjects will have a peripheral intravenous line placed and will be injected with 2.5-3.5mCi of Tl-201. The Tl-201 given will be a slightly lower dosage than the standard clinical protocol of Yale New Haven Hospital nuclear cardiology lab because of improved reconstruction algorithms with CT will allow lower doses of radioactive isotopes. Resting myocardial perfusion images will be acquired 5 minutes post-injection on a multislice helical SPECT/CT (GE Infinia Hawkeye) followed by a CT scan. A redistribution image will be performed 4 hours after thallium administration. Each SPECT scan will take approximately 25 minutes. Perfusion defect size will be quantified using the Yale C-Q method previously described [2].