Thyroid disease and the heart

Cardiologists encounter thyroid disorders frequently. Hyperthyroidism causes and may present with atrial fibrillation, while hypothyroidism is a risk factor for coronary artery disease. Moreover, the use of amiodarone may precipitate a variety of thyroid disorders, and severe heart disease, such as left ventricular failure or acute myocardial infarction, can cause confusing disturbances in thyroid function tests.#### Key points #### Key points Hyperthyroidism is a common condition with a prevalence of approximately 1%; it affects predominantly women aged 30–50 years and is usually (70%) caused by Graves' disease which is characterised by diffuse goitre, orbitopathy, pretibial myxoedema, and the presence of stimulating thyrotrophin (TSH) receptor antibody in the serum. Most of the remaining cases (20%) are caused by autonomous production of thyroid hormones by a nodular goitre. ### Effects of thyroid hormones on the cardiovascular system The thyroid secretes two active hormones: thyroxine (T4) which …