Polyglandular endocrine emergency: lessons from a patient, which a book cannot teach.

A 30-year-old woman with polyglandular autoimmune type 2 syndrome was found collapsed at home with a cardiac arrest, which required direct current cardioversion. On admission, she was hypothermic, hypotensive and bradycardic. Initial biochemical investigations were consistent with a pre-renal acute kidney injury, metabolic acidosis and a possible sepsis. She had significantly elevated thyroid-stimulating hormone levels on admission with the clinical profile consistent with dual Addisonian and myxoedema crisis. She received intravenous liothyronine and hydrocortisone along with supportive therapy. Echo showed severe left ventricular impairment with apical ballooning although coronary angiogram disclosed nothing abnormal. She made a gradual recovery and was discharged home after 2 weeks. She was diagnosed to have primary autoimmune hypothyroidism, Addison's diseaseand type 1 diabetes and coeliac disease in October 2006, July 2007, May 2010 and September 2016, respectively. Her inability to stick to gluten-free diet at her workplace was considered a significant contributory factor for out-of-hospital cardiac arrest.

Thyroid disease and vascular function.

Altered cardiac function in thyroid disease is well recognized and has been extensively investigated, vascular function has however been less well studied in those with thyroid dysfunction. Thyroid hormones, thyroxine (T(4)) and triiodothyronine (T(3)) are important regulators of cardiac function and cardiovascular hemodynamics. The cardiovascular system responds to minimal but persistent changes in circulating thyroid hormone levels producing changes in vascular reactivity and endothelial function. The detection of endothelial dysfunction and/or arterial stiffness allows early identification of individuals at risk as these occur in both patients with risk factors for coronary artery disease and in those with established disease. This may allow treatment to be targeted at high risk individuals with the aim of slowing the progression of vascular disease. The various methods used to assess arterial function are reviewed and the changes demonstrated in human and animal models of thyroid dysfunction.