MRCP2-1593

MRCP2-1593

An 80-year-old man comes to the endocrine clinic for evaluation. He has been taking amiodarone for the past few months for short episodes of VT diagnosed after a heart attack. Over the last 2 months, he has experienced weight loss and heat intolerance, along with short runs of an irregular, fast heartbeat. During the clinic visit, his BP is 112/82, pulse is 88 and regular, and his BMI is 21. Thyroid function testing reveals an abnormality, with a suppressed thyroid-stimulating hormone (TSH) suggestive of thyrotoxicosis. Radioiodine uptake scan is normal, as is serum interleukin 6 (IL-6). A recent ECHO cardiogram showed an ejection fraction of 38%.
After a repeat ECHO cardiogram and a 72 h tape, which shows paroxysmal AF but no episodes of VT, the cardiologist discontinues his amiodarone. What is the best initial therapy for this patient?