Q: Please tell me if thallium TMT is negative for how many years can one not worry about heart problem.

A:Exercise Thallium Scan is an investigation which is more accurate than a plain exercise test (TMT) in determining the presence of any severe blockages in the heart arteries. It is performed like an exercise test, but during exercise a radioactive material called Thallium is given by injection and a special gamma camera scans the heart. It is an out patient non invasive investigation.