The LVEF, LVFS and LVPWd were significantly decreased, while the LVIDd and LVIDs were significantly increased, in Syt1+/−-TAC mice as compared to WT-TAC mice, indicating a severe cardiac hypertrophy and dysfunction in the Syt1+/−-TAC mice relatively to the WT-TAC mice (Fig. 3B − F). This evidence concerns the gene SYT1 and cardiac hypertrophy.