Suppressive doses of thyroxine are recommended in well-differentiated thyroid carcinoma after surgical procedures and radiotherapy. In cytologically benign tumours of the thyroid, TSH suppressive therapy is intended to reduce tumour mass or to prevent further proliferation. A decrease in TSH below normal level produces subclinical state of hyperthyroidism, which can provoke changes in cardiovascular system. The aim of this work was to analyse the mass as well as systolic and diastolic function of left ventricle of the heart in children with non-toxic goiter, who had been on thyroid stimulating hormone suppressive therapy. Examinations included a group of 17 children aged 11-18 years, with nodular goiter treated with suppressive L-thyroxine dose during the period of 6-36 months. Morphological and functional evaluation of left ventricle was performed with the use of Sonos 1000 Hewlett Packard echocardiographic apparatus. Study group of children with non-toxic goiter was compared with healthy subjects without the history of heart and thyroid diseases, who were selected according to their age and body size. Results showed that parameters determining LV diastolic function were decreased whereas systolic function in compared groups was normal. Statistically significant increase in heart rate and LVMi were observed in patients with non-toxic goiter when compared to control group.

Keywords: Goiter, treatment, cardiovascular system effects