Thyroid disease and the heart

Duncan J Topliss



Hyperthyroidism and hypothyroidism are common endocrine conditions that can seriously affect cardiovascular health.

Key Points

  • Hyperthyroidism and hypothyroidism can both lead to heart disease, and thus to increased mortality.
  • Hyperthyroidism is associated with tachycardia, raised systolic blood pressure, arrhythmia and atrial fibrillation, mitral valve prolapse and cardiac failure.
  • Hypothyroidism is associated with bradycardia, dyslipidaemia and ischaemic heart disease, and contributes to cardiac failure.
  • Amiodarone, an important antiarrhythmic drug, can cause hyperthyroidism and hypothyroidism. Amiodarone-induced hyperthyroidism can be especially challenging to treat.
  • Careful monitoring of clinical thyroid status, thyroid hormone levels and heart function will guide treatment of these conditions.
  • Nonthyroidal illness can alter in vitro thyroid function tests and presents a diagnostic challenge versus thyroid disease, particularly in severe heart illness.