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@#Objective To evaluate the effect of left atrial enlargement on atrial myocardial fibrosis degree and levels of the angiotensinⅡ (AngⅡ)/Rac GTPase activating protein 1 (Rac1)/signal transducersand activators of transcription 3 (STAT3) signaling pathways expressing in patients with persistent atrial fibrillation and rheumatic heart disease (RHD). Methods From March to December 2011, 30 patients with RHD who underwent prosthetic valve replacement in our hospital were enrolled, including 16 males and 14 females, aged 42-70 (56.9±6.8) years. Twenty RHD patients with persistent atrial fibrillation as a research group and ten RHD patients with sinus rhythm as a control group (group A) underwent transthoracic echocardiography and right atrial appendage (RAA) tissue samples were obtained from these patients during mitral/aortic valve replacement operation. The research group according to left atrial diameter (LAD) was divided into two groups, ten patients in each group: a group B with LAD of 50–65 mm and a group C with LAD of LAD>65 mm. For each sample, histological examination was performed by hematoxylin-eosin and Masson’s trichrome staining. Light-microscopic pictures of atrial tissues samples were stained and tissue fibrosis degree in each group was analyzed. AngⅡ concentration was measured by enzyme linked immunosorbent assay. Rac1 and STAT3 were measured by western blotting. Results LAD was significantly greater in AF patients with RHD than in the control group. Hematoxylin-eosin staining demonstrated highly organized arrangement of atrial muscles in the control group and significant derangement in both group B and group C with reduced cell density and increased cell size. Moreover, Masson’s trichrome staining showed that atrial myocytes were surrounded by large trunks of collagen fibers in both group B and group C, but not in the group A. There was a positive correlation between atrial tissue fibrosis and LAD. AngⅡ content was positively correlated with LAD. Similarly, Rac1 and STAT3 protein levels were found considerably higher in the group C and group B than in the group A with excellent correlation to LAD. Conclusion In patients with RHD complicated with persistent atrial fibrillation, the degree of atrial fibrosis and the expression level of AngⅡ/Rac1/STAT3 signaling pathways significantly increase with the left atrialenlargement.
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@#Objective We probed how to predict left ventricular ejection fraction (LVEF) of the ischaemic cardiomyopathy (ICM) patients would be improved apparently after revascularization. Methods Between July 2010 and December 2015, 245 ICM patients (30%≤LVEF≤40%) with coronary bypass grafting (CABG) were retrospectively observed. Among them, 146 patients were accompanied by ischemic mitral regurgitation (IMR) (146/245, 59.6%), and 41 patients underwent mitral valvuloplasty or replacement because of more than moderate IMR. There were 13 patients early death, and other 232 patients who were followed up over 6 months were divided into two groups based on whether or not post-operative LVEF increased by 10%: a LVEF recovered group (group A, 124 patients) and a non-recovered group (group B, 108 patients). Results Preoperative NT-proBNP in the group A was significantly higher than that in the group B (P=0.036). There were less patients with myocardial infarction in the group A than that in the group B (P=0.047), and more with angina pectoris in the group A than that in the group B (P=0.024). There was no significant difference in the extent of mitral regurgitation or mitral surgery between the groups A and B (P>0.05). There were lower left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD) and left ventricular end-diastolic volume (LVEDV) in the group A than those in the group B (P<0.05). Multivariate analysis revealed that preoperative LVEDD dilated apparently and no angina pectoris existed before surgery were independent risk factors for LVEF with no recovery in the ICM patients (30%≤LVEF≤40%) after revascularization. The LVEDD of 245 patients (including 13 early deaths) was 41-71 mm. We found that the ICM patients with LVEDD ≥60 mm were more likely to signify the unfavourable prognosis (χ2=8.63, P=0.003, OR=2.21, 95% confidence interval 1.25 to 3.91). Conclusion Preoperative LVEDD dilated and no angina pectoris before surgery are independent risk factors for LVEF with no recovery in the ICM patients (30%≤LVEF≤40%) after revascularization. LVEDD≥60 mm can be regarded as the preoperative forecasting factors for the unfavourable prognosis in the ICM patients (30%≤LVEF≤40%) after revascularization.