Variant angina in thyrotoxicosis.

Thyrotoxicosis may exacerbate angina pectoris in patients with coronary artery disease but angina also occurs in thyrotoxic patients with normal coronary arteries. Four female severely thyrotoxic patients presented with apparent angina pectoris as a manifestation of their thyrotoxicosis. Two of them had transiently abnormal ECGs during pain. Treatment for thyrotoxicosis immediately stopped the chest pain, which did not recur. All patients had negative exercise ECGs, and one had a normal coronary angiogram. The possible mechanisms to explain this phenomenon are discussed. Coronary artery spasm has been demonstrated in thyrotoxic patients previously and may explain the features in these patients. An alternative hypothesis is that myocardial metabolism is fundamentally changed by thyrotoxicosis. We would recommend that thyroid function assessment should be considered in young female patients with atypical angina.