TNNI3 and Myocardial fibrosis: This study demonstrated that HW/BW and LW/BW ratios, myocardial fibrosis, and the expressions of hypertrophic genes, ANP, BNP, and β-MHC, as well as the biomarker of myocardial injury, cTnI, were significantly increased by ISO treatment; while, XJEK and metoprolol reversed these changes.