A, Comparison of FS between control and β2a in sham or post-MI myocytes with or without Iso (sham control, n=19 and β2a, n=9; post-MI control, n=9 and β2a, n=21). B, Comparison of [Ca2+]i transients between control and β2a in sham or post-MI myocytes with or without Iso (sham control, n=8 and β2a, n=9; post-MI control, n=5 and β2a, n=9). C and D, Representative example of caffeine-induced [Ca2+]i transients in control and β2a myocytes. E and F, Average data of peak caffeine-induced [Ca2+]i transients and rate of decay in control and β2a myocytes. *P<0.05 between control and β2a VMs; #P<0.05 with or without Iso.