Preamrudee PoomthavornPat MahachoklertwattanaSuthep WanitkunAlisa LimsuwanMahidol University2018-08-242018-08-242007-01-01Endocrinologist. Vol.17, No.1 (2007), 17-19105121442-s2.0-33846783040https://repository.li.mahidol.ac.th/handle/20.500.14594/25039We report a 12-year-old girl with long-standing severe hypothyroidism due to autoimmune thyroiditis. She presented with congestive heart failure as a result of dilated cardiomyopathy, multiple-valve regurgitation, and pericardial effusion. She also had severe short stature (-5 standard deviation) and profound retarded bone age (3 years). Despite severe growth retardation, she had breast development without galactorrhea. She had a prepubertal response to luteinizing hormone-releasing hormone. Multicystic ovaries were noted on pelvic sonography. Magnetic resonance imaging of the brain revealed pituitary hyperplasia. Treatment with l-thyroxine and digoxin was promptly initiated with a subsequent clinical improvement and near-normal thyroid function tests. Unfortunately, she developed digitalis intoxication at 6 weeks, and eventually expired. Thus, titrating the dose of digoxin and frequent monitoring of serum digoxin levels are essential to prevent digitalis intoxication in the hypothyroid patient. © 2007 Lippincott Williams & Wilkins, Inc.Mahidol UniversityMedicineArticleSCOPUS10.1097/01.ten.0000257438.76047.83