Paradoxical euthyroid hormone profile in a case of Graves' disease with cardiac failure

Thyroid hormones have multiple effects on the cardiovascular system [1]. Although many of the characteristic signs and symptoms of hyperthyroidism are cardiovascular, cardiac failure is seen only in up to 6% cases [2] and is more common in older age with underlying ischemic or hypertensive cardiomyopathy [1,2]. There are very few reports in the literature of cardiac failure in juvenile hyperthyroidism in the absence of underlying heart disease [3].A state of cardiac failure is known to cause changes in the thyroid hormone profile, especially low total tri-iodothyronine (T3) [4,5]. This phenomenon of non-thyroidal illness syndrome (NTIS) may be attributable to various mechanisms including changes in hypothalamic-pituitary axis, altered thyroid hormone binding and altered de-iodinase activity [6]. The same phenomenon has not been well documented in cardiac failure due to hyperthyroidism.Herein we describe an adolescent boy who presented in cardiac failure due to Graves' disease and had a paradoxical euthyroid profile.A 13 year old boy presented with palpitations of six months duration, fever and hyperdefecation for a month and generalized edema since three days. Fatigue, diaphoresis, tremors, polyphagia and weight loss were present for six months. He was diagnosed to have hyperthyroidism five months before presentation to us. He was started on carbimazole 15 mg daily at the time of diagnosis, which was increased to 45 mg daily one week prior to presentation at our hospital.On examination, the patient was febrile with a heart rate of 130 per minute and a blood pressure of 140/60 mm Hg. There was generalized edema and raised JVP (12 cm of water). He had exophthalamos. The thyroid gland was diffusely enlarged to approximately 60 grams and a bruit was heard over the thyroid. Cardiomegaly was present as well as a grade 3/6 apical ejection systolic murmur. There was mild weakness (grade 4 power) of hips, knees and shoulders, with hyperreflexia. Hepatosplenomegaly was presen