Decreased inotropic but relatively preserved relaxation response to cyclic adenosine monophosphate-dependent agents in myopathic human myocardium.

Background: Increased intracellular concentrations of cyclic adenosine monophosphate (AMP) stimulate a positive inotropic and lusitropic response in healthy myocardial tissue. Heart failure results in an attenuated inotropic response to cyclic AMP-dependent agents. This study compares the inotropic versus relaxation response to cyclic AMP-dependent and cyclic AMP-independent agents in myocardium from patients with end-stage heart failure and control patients without heart failure.