"The general concept that the failing heart is an energy-deprived states helps us understand why in a number of clinical trials inotropic agents failed to produce a beneficial long-term effect. Although these drugs improve symptoms of heart failure, the do so at the expense of drugs improve symptoms of heart failure, they do so at the expense of cardiac energy expenditure, which can only be expected to worsen cardiac performance." See: Douglas L. Mann & G. Michael Felker. Heart Failure: Companion to Braunwalds's Heart Disease. 3rd edition. p.255.