TMT Positive for inducible ischemia.

When I had a blood test and lipid profile,it was reported that my TSH was raised to 10.3 . Doctor increased the dose of medicine to 125 mg(earlier i was taking 100mg).After 25 days, I again underwent through routine examination in which my TSH level decreased to 0.70 to which doctor again advised me to decrease the dose of medicine to 75mg.Also, my TMT reported positive for inducible myocardial ischemia although my ECG and Echo cardiography reports are normal.Doctor has asked me to undergo angiogram due to positive TMT. So,I wanted to know if my positive TMT report is due to fluctuations in TSH level or not... Do I need to undergo angiogram as soon as possible? Can there be chances of any cardiac problems inspite of the fact that ECG and echo cardiography reports are normal?