Repetitive monomorphic ventricular tachycardia in a 4-year-old boy with toxic multinodular goiter.

A case of toxic multinodular goiter associated with repetitive monomorphic ventricular tachycardia (VT) is reported. A 4-year-old boy was found to have asymptomatic VT. When treatment with antiarrhythmic agents turned out to be ineffective, thyrotoxicosis was suspected due to the rapid enlargement of the left thyroid gland and associated thyroid function studies. A diagnosis of toxic multinodular goiter was made on the basis of subsequent scintigraphy and ultrasonography. Treatment with antithyroid drugs and inorganic iodine restored the thyroid function to normal, and was accompanied by the disappearance of VT. A left thyroid lobectomy was performed, and the pathological findings were compatible with toxic multinodular goiter. After the operation, the patient was transiently hypothyroid and had no VT without medication. A review of the literature revealed no previously documented cases of VT with toxic multinodular goiter.