β-Adrenergic blocking agents are standard treatment for patients with mild-to-moderate
heart failure. When patients receiving β-blockers decompensate they often need treatment
with a positive inotropic agent. The β-agonist dobutamine may not produce much increase in
cardiac output during full-dose β-blocker treatment and may increase systemic vascular
resistance via α-adrenergic stimulation. In contrast, phosphodiesterase inhibitors (PDEIs)
such as milrinone or enoximone retain full hemodynamic effects during complete β-blockade …