Endocrine Abstracts

Case History: A 74-year-lady with a background of COPD presented to the emergency department with precordial chest pain radiating to the left arm. The pain had been ongoing since a few hours, and was associated with diaphoresis. She was hemodynamically stable, with no tachycardia

Investigations: ECG showed significant ST-segment elevations, predominantly in the chest leads, with elevated troponins. Assuming it to be STEMI, she was transferred to the tertiary cardiology centre for an urgent PCI. She underwent a PCI which showed moderate LAD disease with no obstruction, hence not stented. She had an echocardiogram which showed ballooning of the apex of the left ventricle, suggestive of Takotsubo cardiomyopathy (TCM)

Results and Treatment: She was started on bisoprolol and was repatriated back to us. She remained pain-free and hemodynamically stable, with a normal pulse rate. We received a call from her tertiary centre, mentioning the results of the low TSH of <0.05 mIU/l (normal range 0.2–4.0 mIU/l), the elevated free T4 of 28.8 pmol/l (normal range 10–20 pmol/l) and the elevated free T3 of 2.8 nmol/l (normal range 0.9–2.5 nmol/l) that were done at their centre as routine tests. She never gave a history of thyrotoxic features. She reported occasional palpitations prior to this presentation. Her clinical examination showed no enlargement of the thyroid gland or exophthalmos. No family history of thyroid disease. Her anti-TPO antibodies were positive, but her TSH-receptor antibodies were negative, suggesting Hashimoto’s thyroiditis. She was commenced on carbimazole and the bisoprolol continued

Conclusion and points for discussion: TCM is a condition in which left ventricular dysfunction, patterns of regional wall motion abnormalities and myocardial ischemia occur; in the absence of obstructive coronaries. TCM can occur in patients with Graves’ disease, Hashimoto thyroiditis, thyroid storm, after radioactive iodine treatment, following thyroidectomy and even in hypothyroid/euthyroid states. Elevated levels of thyroid hormones exaggerate the inotropic and chronotropic responses to catecholamines. TCM occurs more commonly in females, and is probably related to the role of oestrogens and the myocardial sensitivity to catecholamines. The treatment of hyperthyroidism-associated TCM involves using beta-blockers to disrupt the positive feedback mechanism between thyroid hormone activation and up-regulated beta-adrenoceptors. Anti-thyroid drugs block the effects of thyroid hormone excess. Our case is unique since she didn’t have the classical features of hyperthyroidism and she presented with angina and diaphoresis secondary to TCM