Graves' disease complicated by ventricular fibrillation in three men who were smokers.

Background: Thyrotoxicosis is known to be associated with sinus tachycardia and supraventricular tachyarrhythmias, but rarely with ventricular fibrillation (Vf), which has only occurred in some patients with hypokalemic periodic paralysis or ischemic heart disease. Patient Findings: We present three men who were transferred to our hospital with Graves' disease who developed idiopathic Vf. None of them had hypokalemic periodic paralysis or ischemic heart disease but all were smokers. None of other patients with thyrotoxicosis (587 females and 155 males) who were seen at our hospital, in the period during which the three men were seen, had idiopathic Vf. In our three men with thyrotoxicosis and idiopathic Vf, there was no identifiable underlying heart disease. One of the three patients died of hypoxic encephalopathy. The other two men did not have recurrent Vf after their thyroid function normalized. Summary: These cases and a review of similar cases in the literature imply that improving thyrotoxicosis see...