Sinus Tachycardia. Advised for any test!

My mother is of 57 years of age.She has undergone an ECG today.The interpretation of ECG are Sinus Tachycardia and ST-T Abnormality V6 which the doctor has written in his prescription as Lateral wall Ischemia.The prescribed medicines are GTN Sorbitrate-CR and Prolomote XL 25.She also takes cetanil for pressure and clonotril 0.5 additionally. The doctor has given tests for hs-crp,lipid profile,TC,DC. But he has not advised for any test regarding thyroid. My queries are- a)Is the thyroid test in her case important? b)For a second opinion,I want to know whether the treatment plan is in right course. c)Can this condition be completely cured or she has to continue the medication . d)Does she have to take a restricted diet,because the doctor has not advised any. e)She has a symptom of bacillary dysentery for two weeks now.But otherwise she does not have any as such symptoms relating to heart problems .I want to know how severe this condition can be and what are necessary precautions.