A: Pooled data of heart weight/body weight ratios from five Ctrl versus four Sm22-Cre+/0;Smad5fl/− mice (KO). B: Pooled data of primary cell dimensions (cell length and cell width) from 40 cells per animal (n = 5 for Ctrl females versus n = 4 for Sm22-Cre+/0;Smad5fl/− females). C: Averaged data on the contractile properties of Ctrl (29 cells from five mice) and Sm22-Cre+/0;Smad5fl/− (22 cells from four mice) cells. FS, fractional shortening; TTP, time to peak shortening; T to RT50, time to half-relaxation. *P < 0.05. BW, body weight; HW, heart weight.