Echocardiographic Evaluation of Left and Right Ventricular Function in Subclinical Hypothyroidism

Abstract

OBJECTIVE: The aim of the present study was to evaluate rest systolic and diastolic cardiac function by echocardiography in subclinical hypothyroidism (SH). METHODS: A cross sectional study was performed and the results obtained in the evaluation of two groups (SH and euthyroidism) were compared. Subjects with systemic arterial hypertension, diabetes or cardiovascular diseases, or that in use of drugs that influence thyroid function were excluded. RESULTS: The two groups (SH=37; euthyroidism=35) had similar demographic characteristics as age, Blood Pressure, Body Mass Index and frequencies of sedentarism, tabagism, menopause. There was a tendency to diastolic dysfunction, with higher median values of Deceleration Time of mitral E wave in the SH group (230 vs. 216 ms; p=0.053), which was also slightly positively associated with serum TSH levels (r s =0.154; p=0.095). As expected, Deceleration Time was negatively correlated with E wave velocity (r s =−0.353; p=0.001) and E/A index (r s =−0.238; p=0.022) and was powerless positively associated with Isovolumic Relaxation Time (r s =0.178; p=0.067) and A wave velocity (r s =0.177; p=0.069). It was not detected left systolic dysfunction, since there were not differences in the means of cardiac output, ejection fraction, ejection time, fractional shortening, isovolumic contraction time and Myocardium performance index of LV. CONCLUSION: We did not detect left systolic dysfunction at rest in SH but the findings corroborate with the possibility of diastolic dysfunction in SH group.