Analysis of Right Ventricular Function in Patients with Hypothyroidism

Presentation Number: SAT 525
Date of Presentation: April 1st, 2017

Gustavo Demasi Quadros de Macedo*1, Jean Jorge Silva de Souza1, Mario Jorge Quadros de Macedo1 and Maria Luiza Gazzana2
1Federal University of Amazon, Manaus, Brazil, 2Universidade do Estado do Amazonas, Manaus, Brazil

Abstract

Background: Thyroid hormones deficiency compromises cardiac muscle contraction, slowing myocardial relaxation, thus impairing left ventricular filling. In patients with hypothyroidism, short-term occurs a cardiac output decrease, associated to a reduction of left ventricle (LV) ejection volume and lower heart rate. After a lot of studies about the left ventricle, little is known about the effect of thyroid hormones deprivation at the right ventricle (RV). This study was aimed to evaluate the right ventricular function in patients who had hypothyroidism in different degrees of disease severity.Methods: Eighteen patients were submitted to two-dimensional echocardiography evaluation, of which 10 (55,6%) had TSH <12 mIU/L (highest TSH group) and 8 (44,4%) had TSH >12 mIU/L (less high TSH group). Global RV systolic function was evaluated by myocardial performance index (Tei index) and by percentage of systolic change in the area in the apical four-chamber view. Regional RV systolic function was evaluated by tricuspid annular plane systolic excursion (TAPSE) and by peak systolic velocity. Diastolic RV function was evaluated by transtricuspid peak early diastolic velocity/transtricuspid peak late diastolic velocity ratio (E/A tricuspid ratio) and by transtricuspid peak early diastolic velocity/early diastolic tricuspid annular velocity ratio (E/E’ tricuspid ratio).Results: Sixteen (88,9%) patients had at least one cardiovascular symptom (dyspnea, chest pain or palpitations). Patients in the highest TSH group had lower body mass index (BMI) than those in the less high TSH group (23.9 ± 3.5 vs. 27.8 ± 3.7 kg/m2; p<0.05). By comparing the two groups, there were no differences in respect of LV global systolic function, represented by ejection fraction (LVEF), or diastolic function. There was neither difference related to right atrium area and volume, nor RV diastolic and systolic areas, nor right ventricular diameter. About the right ventricular function, it was shown a difference in the myocardial performance index (Tei index), which was higher in patients who had TSH>12 compared with patients who had TSH<12 (0.52 ± 0.13 vs. 0.39 ±0.08; p<0.05), indicating worse right ventricular global function in those patients with the highest TSH levels. No differences were observed between these groups related to other variables, which are: percentage of systolic change in the VD area, TAPSE and peak systolic velocity. Variables of RV diastolic function (E/A tricuspid ratio and E/E’ tricuspid ratio), as well as pulmonary vascular resistance and pulmonary artery systolic pressure were not different between groups.Conclusion: Patients with hypothyroidism who had the highest TSH levels, as compared to those with less high TSH, presented with a reduction at the overall right ventricular function, evaluated by myocardial performance index, not observed in other parameters of RV function evaluation

 

Nothing to Disclose: GDQDM, JJSDS, MJQDM, MLG