The Effects of Total Thyroidectomy on Cardiac Function in Old Rats using Echocardiographic Measures
|Julio Cesar Francisco1,2,4*, Ricardo Correa Cunha1,3, Marco André Cardoso1,2, Rossana Baggio Simeoni4, Luiz Cesar Guarita-Souza4, Nelson Itiro Miyague4 and Katherine Athayde Teixeira de Carvalho1,2|
|1Instituto de Pesquisa Pelé Pequeno Príncipe, Curitiba, Brazil|
|2Universidade Federal do Paraná, Curitiba, Brazil|
|3Universidade Positivo, Curitiba, Brazil|
|4Pontifícia Universidade Católica do Paraná, Curitiba, Brazil|
|Corresponding Author :||Julio Cesar Francisco
Instituto de Pesquisa Pelé Pequeno Príncipe
Av. Silva Jardim, 1632, Curitiba–PR
Brasil CEP 80250-060
Tel: +55 (41) 3310-1035
E-mail: [email protected]
|Received January 07, 2013; Accepted February 19, 2013; Published February 21, 2013|
|Citation: Francisco JC, Cunha RC, Cardoso MA, Simeoni RB, Guarita-Souza LC, et al. (2013) The Effects of Total Thyroidectomy on Cardiac Function in Old Rats using Echocardiographic Measures. J Clin Exp Cardiolog S11:006. doi:10.4172/2155-9880.S11-006|
|Copyright: © 2013 Francisco JC, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.|
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Objectives: Doppler Echocardiography has been shown to reflect thyroid hormone action in primary thyroid dysfunction. The aim of the present study was to evaluate the cardiac function after total thyroidectomy in old rats using echocardiographic measures.
Methods: Female Wistar rats aged 24 months old (referred to as adult) were divided into 2 groups with 15 animals each: Euthyroid (Eut) and Hypothyroid (Hypo) rats. Hypothyroidism was induced by total thyroidectomy. The plasmatic levels of T3, T4, TSH and free ionic calcium were measured. Echocardiographic analysis was performed using the following parameters: left ventricular end-diastolic (LVED) left ventricular end-systolic (LVES), ejection fraction (EF) and Tei index.
Results: In both groups, the LVES ranged from 0.2 to 0.5 p <0.048 and the EF from 50.3 to 45.2 p<0.030.There was not statistically significant difference in HR, LVED and Tei-index values. It was observed decrease in T3 levels (72.0 to 30.4 μg/dl, p<0.001) and T4 levels (3.1 to 0.4 μg/dl, p<0.001) and increase in TSH levels (1.6 to 40.7 mU/mol, p<0.001) in Hypo group. The free ionic calcium levels increased from 0.1 to 0.9 mmol/L (p<0.001) in Hypo group.
Conclusion: It was identified a reduction of cardiac function in old animals with hypothyroidism using Doppler- Echocardiography measures. These results indicated that hypothyroidism is associated with impairment in cardiac function in old patients and that Doppler echocardiography, is a useful and noninvasive tool for the diagnosis of cardiac dysfunction induced by this thyroid disorder.