Cardiac functional reserve and left ventricular parameters in patients with diffuse toxic goiter after drug correction of euthyroidism with thiamazol

Abstract

The aim of the investigation was to assess the time course of structural-and-functional and spatiogeometric changes following drug correction of euthyroidism in patients with diffuse toxic goiter and to determine prospects for restoring the cardiac functional reserve after elimination of thyrotoxicosis. The geometric parameters of the left ventricle (LV) and the readings of tissue Doppler echocardiography and exercise tests were compared in 27 female patients (mean age 53.3±9.2 years) who had thyrotoxicosis and 6 months after thyrosole-induced normalization of thyroid-stimulating and thyroid hormone. There were significant increases in myocardial mass and peak systolic and diastolic mitral ring motion rates and an increasing trend for LV linear sizes after correction of euthyroidism. Despite the fact that there were no significant differences in the majority of LV geometric parameters, with euthyroidism achievement, the cardiac functional reserve doubled as compared with the baseline values (105.7±11.4 and 57.8±14.7 W, respectively; p < 0.001), but remained below the control level (148.7±11.7 W; p < 0.05), which may contribute to the development of heart failure in future under certain conditions.