BackgroundChronic Chagas cardiomyopathy in humans is characterized by segmental left ventricular wall motion abnormalities (WMA), mainly in the early stages of disease. This study aimed at investigating the detection of WMA and its correlation with the underlying histopathological changes in a chronic Chagas cardiomyopathy model in hamsters.Methods and ResultsFemale Syrian hamsters (n=34) infected with 3.5×104 or 105 blood trypomastigote Trypanosoma cruzi (Y strain) forms and an uninfected control group (n=7) were investigated. After 6 or 10 months after the infection, the animals were submitted to in vivo evaluation of global and segmental left ventricular systolic function by echocardiography, followed by euthanasia and histological analysis for quantitative assessment of fibrosis and inflammation with tissue sampling in locations coinciding with the left ventricular wall segmentation employed at the in vivo echocardiographic evaluation. Ten of the 34 infected animals (29%) showed reduced left ventricular ejection fraction (<73%). Left ventricular ejection fraction was more negatively correlated with the intensity of inflammation (r=−0.63; P<0.0001) than with the extent of fibrosis (r=−0.36; P=0.036). Among the 24 animals with preserved left ventricular ejection fraction (82.9±5.5%), 8 (33%) showed segmental WMA predominating in the apical, inferior, and posterolateral segments. The segments exhibiting WMA, in comparison to those with normal wall motion, showed a greater extent of fibrosis (9.3±5.7% and 7±6.3%, P<0.0001) and an even greater intensity of inflammation (218.0±111.6 and 124.5±84.8 nuclei/mm², P<0.0001).ConclusionsIsolated WMA with preserved global systolic left ventricular function is frequently found in Syrian hamsters with experimental chronic Chagas cardiomyopathy whose underlying histopathological features are mainly inflammatory.

The prolonged use of DIPY in this experimental model of CCC has reduced the rest myocardial perfusion defects, supporting the notion that those areas correspond to viable hypoperfused myocardium.

Symptoms in post-COVID-19 patients who require hospitalization can persist for months, significantly affecting their health-related quality of life (HRQoL). Thus, the present study aimed to discuss the main findings regarding HRQoL in post-COVID-19 patients who required hospitalization. An electronic search was performed in the MEDLINE, EMBASE, CINAHL, Web of Science, LILACS, and Scopus databases, without date and language restrictions, until July 2021. Twenty-four articles were included in the analysis. It seems that HRQoL partially improved soon after hospital discharge, although the negative impact on HRQoL may persist for months. The physical and mental aspects are affected because patients report pain, discomfort, anxiety, and depression. The HRQoL of COVID-19 infected patients was worse than that of uninfected patients. Additionally, HRQoL seemed worse in patients admitted to the intensive care unit than in those who remained in the ward. Improvements in HRQoL after hospital discharge are independent of imaging improvement, and there seems to be no association between HRQoL after hospital discharge and disease severity on hospital admission. Many factors have been identified as determinants of HRQoL, with women and advanced age being the most related to worse HRQOL, followed by the duration of invasive mechanical ventilation and the need for intensive care. Other factors included the presence and number of comorbidities, lower forced vital capacity, high body mass index, smoking history, undergraduate education, and unemployment. In conclusion, these findings may aid in clinical management and should be considered in the aftercare of patients.

BackgroundImaging techniques enable in vivo sequential assessment of the morphology and function of animal organs in experimental models. We developed a device for high-resolution single photon emission computed tomography (SPECT) imaging based on an adapted pinhole collimator. ObjectiveTo determine the accuracy of this system for quantification of myocardial infarct area in rats. MethodsThirteen male Wistar rats (250 g) underwent experimental myocardial infarction by occlusion of the left coronary artery. After 4 weeks, SPECT images were acquired 1.5 hours after intravenous injection of 555 MBq of 99mTc-Sestamibi. The tomographic reconstruction was performed by using specially developed software based on the Maximum Likelihood algorithm. The analysis of the data included the correlation between the area of perfusion defects detected by scintigraphy and extent of myocardial fibrosis assessed by histology. ResultsThe images showed a high target organ/background ratio with adequate visualization of the left ventricular walls and cavity. All animals presenting infarction areas were correctly identified by the perfusion images. There was no difference of the infarct area as measured by SPECT (21.1 ± 21.2%) and by histology (21.7 ± 22.0%; p=0.45). There was a strong correlation between individual values of the area of infarction measured by these two methods. ConclusionThe developed system presented adequate spatial resolution and high accuracy for the detection and quantification of myocardial infarction areas, consisting in a low cost and versatile option for high-resolution SPECT imaging of small rodents.