Please understand that you 100% need treatment with levothyroxine
irrespective of your heart condition which the doctors have already told is not anything major at all. The symptoms, in fact, might be just that of such a gross hypothyroidism
(do not get mislead due to pulse going upto 100/min!). The ECG does not show significant problems when the TSH
is so high. Your symptoms should reduce by 4 to 5 weeks with treatment. Please see an Endocrinologist
for appropriate dose of levothyroxine as 50 microgram is not at all sufficient for such a gross hypothyroidism.
Get back for further queries. Take care.