[Management of acromegaly in pregnancy: case report and literature review].

date of tachycardia-induced cardiomyopathy secondary to hyperthyroidism due to selective pituitary resistance to thyroid hormone. Our patient experienced left chamber dilation combined with severe pulmonary artery hyperten-sion which was caused by persistent sinus tachycardia and frequent ventricular extrasystoles secondary to hyperthy-roidism. Triiodothyroacetic acid is a T3 analogue with a predominant pituitary and hepatic effect which has been shown to be of value for the treatment of selective pituitary resistance to thyroid hormones at doses ranging from 1.4 to 2.8 mg/day, 1,7 although partial or no response has been reported in some cases. 8 Dextrothyroxine is another agent with a TSH-suppressing effect greater than levothyroxine which does not significantly affect cardiac function and has been shown to be effective in patients not responding to triiodothyroacetic acid. In the near future, new specific analogues of TRˇ2 and TRˇ1 receptors could be more effective for the treatment of pituitary resistance to thyroid hormones. On the other hand, ablation treatment with radioiodine and/or thyroid surgery may be detrimental in these patients, because it induces a chronic, sustained elevation of TSH levels with the probable subsequent occurrence of thyroid hyperplasia or adenoma. 4,7 Treatment with bisoprolol 10 mg/day before the final diagnosis of our patient was unable to control tachycardia or extrasystole. Once the final diagnosis of selective pituitary resistance to thyroid hormones had been made, treatment was started with triiodothyroacetic acid at a dose of 1.4 mg daily, which achieved an excellent response at 6 months, with the disappearance of symptoms and thyroid hormone normalization. An adequate control of heart rate and 24-hour Holter monitoring (mean heart rate of 64 bpm, no extrasystoles) was also achieved. Echocardiography showed a significant improvement in pulmonary artery pressure, with a return to the baseline state of moderate pulmonary artery hypertension and the disappearance of left ventricular and atrial dilation. Systolic function also normalized. In conclusion, tachycardia-induced cardiomyopathy associated with hyperthyroidism due to selective pituitary resistance to thyroid hormones is an exceptional and reversible cause of dilated cardiomyopathy and pulmonary artery hypertension. Triiodothyroacetic acid is currently a safe and effective drug for the adequate management and treatment of this condition. References 1. Bernal J. Síndromes de resistencia a las hormonas tiroideas. Selective pituitary resistance to thyroid hormone in a patient treated with amiodarone. A 46-year-old patient with atrial fibrillation, elevated thyroid hormones and normal thyrotropine. due to familial pituitary resistance to thyroid hormone: successful control with 3,5,3 ′-triiodothyroacetic …