The hemodynamic changes that occur are complex; however, the ultimate result is a decrease in left ventricular preload ... to reduce afterload for diagnostic purposes in the cardiac ...

Nitroprusside is the treatment of choice since it reduces both preload and afterload with great efficacy. Dobutamine may be needed if the patient remains hypotensive with a low cardiac output.

An increase in afterload accompanied by potent ... contractility by directly activating their respective cardiac receptors and augment preload (by increasing the tone of the venous compartment ...