Positive TMT means that you have significant blockage in one of the arteries supplying blood to your heart. And when you were running on the treadmill some part of your heart was not getting enough blood because of which never changes in your ECG This puts you in a very high risk to have a heart attack So you need to get and angiography as soon as possible which will tell us the exact percentage of this blockage in the blood supply If there is 70% or less blockage then the same can be managed on medications. More than 70 to 80% of blockages need intervention like angioplasty