Have you tested for thyroid functions also?
You have been having palpitations
since 15-20 years. It was treated with Mirtaz
7.5 mg since 4-5 months. With treatment, you were better - less restlessness, better sleep and less stress
. So Mirtaz is not the cause for frequent palps.
If you consult your psychiatrist
again, she/he will increase the dose, or change the antidepressant, or add another drug or therapy.