Endocrine Abstracts

67 y/o old female, with long history of hyperthyroidism, without treatment and hypertension. Two months prior to admission, she received amiodarone 200 mg daily due to cardiac arrhythmia. One week prior to admission, she developed symptoms of Congestive Heart Failure and weight loss. Family history: hyperthyroidism in two sisters. Physical examination: acutely ill, thin female, in moderate respiratory distress. Alert, oriented x 3.BP: 155/119 mmHg HR: 150.Prominent findings: multinodular goiter. Bilateral crackles up to 2/3 lung fields. Irregular rhythm. Bilateral pitting edema. EKG: A-Fib with fast ventricular response. Echocardiogram: Left/Right atrial enlargement. Diuretics, nitrates, morphine, valsartan, anticoagulants and an Amiodarone drip were started. Laboratory tests: Thyroid panel compatible with hyperthyroidism. Positive Anti -TPO. 24 hours urine iodine: 6428.1 ug/L. TSI: negative.

Thyroid sonogram: hypervascular multinodular goiter. Normal 24 hours thyroid uptake. Thyroid scan: multinodular goiter with functional and non functional nodules. After Endocrinology evaluation, Amiodarone drip was discontinued. Patient improved and was discharged on methimazole 30 mg daily, carvedilol, digoxin and warfarin. At OPD, methimazole was switch to PTU due to body rash. FNAB: negative for malignancy. Three months after discharge patient remained clinically and biochemically hyperthyroid.

Amiodarone is an iodinated compound with 37% iodine by weight. Thyroid dysfunction has been reported to affect 2–24% of amiodarone users. Amiodarone-induced thyrotoxicosis (AIT) is 3%. Excess iodine-induced thyroid hormones synthesis is known as type I AIT, usually occurs in patient with underlying thyroid pathology; whereas destruction of thyroid follicles resulting in a thyroiditis is known as type II AIT. Distinguishing one type from the other may be troublesome and is important because it has a major influence on subsequent management. AIT is associated with a 2.7 fold increased risk of major adverse cardiovascular events. AIT is a condition that is difficult to manage, because of the long half-life of amiodarone.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector