SMAD2 and Myocardial fibrosis: In this study, we found that the expression of AT1, TGF-β1, and Smad2/3 in myocardial tissues of rats in the small and large dose groups of LGQHD was significantly reduced, suggesting that the improvement of myocardial fibrosis by LGQHD may be related to the inhibition of TGF-β1/Smad2/3 signaling pathway.