Animal model of left atrial thrombus in congestive heart failure in rats.
Am J Physiol Heart Circ Physiol. 2019 May 10;:
Authors: Chen J, Strauss B, Liang L, Hajjar RJ
The aim of present study is to develop and study a new model of left atrial thrombus (LAT) in rat of congestive heart failure (CHF).
METHODS: CHF was induced by aortic banding for two months, followed by ischemia/reperfusion (I/R), and subsequently aortic de-banding for one month. Cardiac function and the presence of LAT were assessed by echocardiography. Masson’s staining was performed for histological analysis.
RESULTS: All CHF rats presented with significantly decreased cardiac function, fibrosis in remote myocardium and pulmonary edema. The incidence rate of LAT was 18.8% in the rats. LAT was associated with severity of aortic constriction, aortic pressure gradient, aortic blood flow velocity and pulmonary edema, but not myocardial infarction or degree of left ventricular depression. The progressive process of thrombogenesis was characterized by myocyte hypertrophy, fibrosis and inflammation in the left atrial wall. Fibrin adhesion and clot formation were observed, while most LAT presented as a relatively hard “mass,” likely due to significant fibrosis in the middle and outer layers. Some LAT mass showed focal necrosis as well as fibrin bulging. Most LAT occurred at the upper anterior wall of left atrial appendage. Aortic de-banding had no significant impact on large LATs (> 5 mm2) that had formed, whereas small LATs (< 5 mm2) regressed one month after aortic release.
CONCLUSION: LAT is found in a rat model of aortic banding plus I/R followed by aortic de-banding. The model provides a platform to study molecular mechanisms as well as potential new pathways for LAT treatment.
PMID: 31074653 [PubMed – as supplied by publisher]