Endocrine Abstracts

A 55-year-old female presented to the Endocrine Clinic with Graves’ disease which was treated with carbimazole for 18 months. Her initial symptoms were facial sweating and dry lips on background of a multinodular goitre confirmed on thyroid ultrasound. TSH was <0.01 mU/l, free T₄ was 42.2, and free T₃ 18 pmol/l. Thyrotoxicosis recurred in an attempt to taper down the dose of carbimazole and a decision was made to proceed with radioactive iodine treatment. Four days after radioiodine administration, our patient presented to the Emergency Department with chest tightness and dyspnoea. TSH was undetectable and free T₄ was 77.7 pmol/l. ECG was consistent with sinus tachycardia and borderline ST elevation in II/III leads. Troponin was elevated at 438 ng/l. Our patient was transferred to the local cardiothoracic center, where echocardiography revealed left ventricular ejection fraction of 30–35%. Coronary angiography showed no obstructive coronary disease. This is a case of stress cardiomyopathy which developed in the context of radiation thyroiditis. Complete recovery was achieved after treatment with propylthiouracil, ramipril, carvedilol, and a course of steroids. Six weeks later left ventricular function was noted to be normal on echocardiography and hypothyroidism was evident on thyroid function testing. This the second case of stress cardiomyopathy following radioactive iodine therapy reported in the literature, to the best of our knowledge. Left ventricular dysfunction is reversible in stress cardiomyopathy although patients can present quite unwell. High index of suspicion along with early thyroid testing may lead to successful treatment without unnecessary diagnostic investigations.