Comparison between Radionuclide Ventriculography and Echocardiography for Quantification of Left Ventricular Systolic Function in Rats Exposed to Doxorubicin

Abstract

BackgroundRadionuclide ventriculography (RV) is a validated method to evaluate the left ventricular systolic function (LVSF) in small rodents. However, no prior study has compared the results of RV with those obtained by other imaging methods in this context.ObjectivesTo compare the results of LVSF obtained by RV and echocardiography (ECHO) in an experimental model of cardiotoxicity due to doxorubicin (DXR) in rats. MethodsAdult male Wistar rats serving as controls (n = 7) or receiving DXR (n = 22) in accumulated doses of 8, 12, and 16 mg/kg were evaluated with ECHO performed with a Sonos 5500 Philips equipment (12-MHz transducer) and RV obtained with an Orbiter-Siemens gamma camera using a pinhole collimator with a 4-mm aperture. Histopathological quantification of myocardial fibrosis was performed after euthanasia.ResultsThe control animals showed comparable results in the LVSF analysis obtained with ECHO and RV (83.5 ± 5% and 82.8 ± 2.8%, respectively, p > 0.05). The animals that received DXR presented lower LVSF values when compared with controls (p < 0.05); however, the LVSF values obtained by RV (60.6 ± 12.5%) were lower than those obtained by ECHO (71.8 ± 10.1%, p = 0.0004) in this group. An analysis of the correlation between the LVSF and myocardial fibrosis showed a moderate correlation when the LVSF was assessed by ECHO (r = -0.69, p = 0.0002) and a stronger correlation when it was assessed by RV (r = -0.79, p < 0.0001). On multiple regression analysis, only RV correlated independently with myocardial fibrosis.ConclusionRV is an alternative method to assess the left ventricular function in small rodents in vivo. When compared with ECHO, RV showed a better correlation with the degree of myocardial injury in a model of DXR-induced cardiotoxicity.

Increased Dietary Leucine Reduces Doxorubicin-Associated Cardiac Dysfunction in Rats

“…Rats treated with different cumulative doses of doxorubicin, administered over 8 weeks, totaling 8, 12, and 16 mg/kg had a higher area of fibrosis in the animals' heart when compared to the animals in the control group (Oliveira et al, 2017 ). We observed the structural preservation of the rat heart in the leucine+doxorubicin group, maintaining the amount of collagen fibers interstitial compared to the doxorubicin group alone.…”

“…Among the effects of chemotherapeutic agents on the cardiovascular system, cardiomyopathy, being highly frequent and serious, is the most prominent leading to heart failure with severe ventricular dysfunction and death (Takemura and Fujiwara, 2007 ; Albini et al, 2010 ). Evidence show that dysfunctions in the left ventricle are closely related to the use of cumulative doses of anthracyclines (Oliveira et al, 2017 ). Multiple mechanisms are involved in heart failure induced by doxorubicin.…”

Emprego de métodos de imagem de alta-resolução in vivo para estudo das alterações perfusionais e inflamatórias miocárdicas em modelo experimental de cardiomiopatia chagásica crônica no hamster

“…Nas últimas décadas, métodos de imagens avaliando parâmetros da função e estrutura cardíaca in vivo têm sido amplamente utilizados para estudar mecanismos de disfunção ventricular em diferentes modelos de doenças cardíacas (CROTEAU et al, 2003;MORGAN et al, 2004;OLIVEIRA et al, 2013;DESROIS et al, 2014;OLIVEIRA et al, 2017). Esses métodos permitem o estudo longitudinal dos animais, aumentando o poder estatístico e reduzindo os custos dos estudos.…”

“…Esses métodos permitem o estudo longitudinal dos animais, aumentando o poder estatístico e reduzindo os custos dos estudos. Em muitos modelos de cardiopatias, a função sistólica do VE é o parâmetro mais utilizado para acompanhar a progressão da doença ou o impacto de intervenções farmacológicas (FRANKEN et al, 1997;TANAKA et al, 2016;OLIVEIRA et al, 2017).…”