Ventricular function in thyrotoxicosis complicated by atrial fibrillation.

The radionuclide gated ventriculogram was used to study the association between thyrotoxic atrial fibrillation and underlying ischaemic heart disease. Comparison between ten patients with atrial fibrillation induced by thyrotoxicosis which reverted to sinus rhythm after return to a euthyroid state, and ten age-matched controls with treated hyperthyroidism who never developed atrial fibrillation, showed no significant difference in the incidence of underlying ischaemic heart disease. This study suggests that further investigation for underlying coronary arterial disease is not indicated in simple, reversible, thyrotoxic atrial fibrillation.