AGT and Myocardial fibrosis: The present study, from the aspects of pathology and protein and mRNA expression levels, found that the expression of HIF-1α in the ISO group was significantly higher than that in the control group, while when administering the HIF-1α inhibitor rapamycin intervention in the Rapa group, HIF-1α expression decreased significantly, and was positively correlated with myocardial fibrosis degree (CVF), which proves that AngII is involved in atrial fibrosis by regulating the expression of HIF-1α.