title: Complete heart block with hyperthyroidism.
abstract: Thyrotoxicosis developed in a patient while receiving thyroid hormone therapy for clinical hypothyroidism. The development of second-degree heart block of Mobitz type 1 variety was followed by third- and then first-degree heart block. We conclude that the varying degrees of heart block were secondary to hyperthyroxinemia caused by Graves' disease and exogenous thyroid hormone.
mesh_terms: D000328:Adult; D001281:Atrial Fibrillation / Q000175:diagnosis; D004562:Electrocardiography; D005260:Female; D006111:Graves Disease / Q000139:chemically induced* / Q000150:complications; D006327:Heart Block / Q000209:etiology*; D006801:Humans; D007037:Hypothyroidism / Q000188:drug therapy; D008944:Mitral Valve Insufficiency / Q000175:diagnosis; D013963:Thyroid Hormones / Q000009:adverse effects* / Q000627:therapeutic use; D013974:Thyroxine / Q000097:blood*
chemical_list: D013963:Thyroid Hormones; D013974:Thyroxine