Complications With Levothyroxine Therapy in Goiter Management: Atrial Fibrillation

The patient is a 69-year-old woman with a 9-year history of nodular goiter. She has a mild neck swelling sensation and occasional dysphagia. There are no symptoms suggesting hyperthyroidism or hypothyroidism. The patient has no history of childhood neck irradiation, no known cardiac disease, and no known family history of thyroid disease.

The patient is a fit and clinicaly euthyroid-appearing older woman who weighs 168 pounds with a blood pressure of 136/84 mmHg and a pulse of 72 bpm regular. Her thyroid is symmetrically enlarged with lobulated contour and firm consistency with no dominant nodule; it is mobile and nontender. There is no cervical adenopathy. Her heart, lungs, and abdomen are all within normal limits, and there is no presence of tremor.