A person can certainly undergo stress thallium within 20 days of heart attack if he doesn't have any gross heart failure, which can only be detected and certified by the treating cardiologist. Similarly following an angiography, one can undergo a stress thallium test within 2-3 days if there is no swelling or haematoma at the site of the angiography. Stress thallium is essentially a diagnostic test and it does not treat or cure the blockages and therefore 100% blocked RCA can not be treated with stress thallium. However, the same can be treated either with an angioplasty or a bypass surgery depending on the type of blockage and the length that the blockage has been in existence. For a 100% blockage, I don't think there is any medical remedy available as on date.