Enhanced myofilament responsiveness upon β-adrenergic stimulation in post-infarct remodeled myocardium

► Left ventricular (LV) responsiveness to β-adrenergic receptor stimulation is blunted in pigs with a recent myocardial infarction (MI). ► We studied if myofilament dysfunction underlies poor response to β-adrenergic activation post-MI. ► Myofilament responsiveness to dobutamine is significantly enhanced in MI compared to sham and may involve activation of Ca2+-dependent calmodulin kinase II.