Brief Answer:
Should go for a test called stress thallium.

Detailed Answer:
Hi,
Thanks for asking the query dear.
I am a Cardiologist and would be answering your query.

This means that your heart is supplied by three coronary arteries(tubes that supply blood to the heart). Tread mill test is used to see if the supply to blood is maintained at the time of exertion also. If there is a blockage in any of the three arteries it is reflected as ST-T change in EKG.

However, lead V4, V5, and V6 are considered to be highly sensitive for stress test any even mild changes should be further investigated.

Frankly speaking there can be two approaches for you.

Firstly as you TMT is positive for ischemia as the ST -T depression is upsloping in nature in inferior leads like 2,3 AVF(have no significance)(downsloping have more sensitivity to rule out cardiac disease) so we can assume that coronaries are normal and no further investigations are required.However to mention tread mill test is one of the basic tests of cardiology and is about 70% sensitive to rule out coronary artery disease. In lay man's language, this means that in 30 out of 100 cases TMT misses a coronary problem.

Standard recommended protocol is-
As per the latest XXXXXXX guidelines even changes less then 0.5mm in lateral leads V5 and V6 are highly significant and further testings should be done to rule out the involvement of Coronaries.

As in your case, there are ST-T changes in lateral leads V4, V5, and V6though upsloping) I would recommend you to go for a test called stress thallium.

Stress thallium is a nuclear-based test and will take about 2 hours. It's a painless noninvasive test and is almost 99% sensitive to rule out coronary artery disease(almost equivalent to angiogram). It has no major complications and is very safe.

So if I were your primary I would have asked you to go for Stress thallium.

When we have facilities and investigations why to keep a doubt in mind.

Regards

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