Figure 50-47 View of the failing heart as a sick, tired horse pulling a wagon up a steep hill. Although application of a whip (inotropes) encourages the horse to move faster, such treatment can kill the animal. Unloading the wagon (vasodilators) would seem to be advantageous, but in heart failure, this approach can harm the horse by activating harmful neurohumoral responses. Slowing the horse (β-adrenergic blockers) while delaying the journey can be beneficial, especially if this also helps heal the horse. Replacing the horse (cardiac transplantation) is useful as long as enough spare horses are available, and getting a tractor is a solution only if reliable machines are available. The ideal solution, of course, is to learn what ails the animal and to use this information to heal the horse. (From Silber EN, Katz LN: Therapeutic strategies for managing heart failure. In Katz AM [ed]: Heart Failure: Pathophysiology, Molecular Biology and Clinical Management. Philadelphia, Lippincott Williams & Wilkins, 2000, pp 309–339.)