Which of the following conditions is characterized by decreased all hemodynamic pressures?

The condition characterized by decreased all hemodynamic pressures is hypovolemia. In hypovolemia, there is a deficiency of blood volume, which leads to a reduction in venous return to the heart. As a consequence, this results in decreased cardiac output, decreased preload, and thus lower blood pressures throughout the cardiovascular system.

In hypovolemia, decreased blood volume hampers the heart's ability to pump effectively, leading to reductions in systemic vascular resistance and overall circulatory dynamics. Patients experiencing hypovolemia often present with signs such as tachycardia, hypotension, and diminished urine output due to the body's attempt to compensate for the reduced circulating volume.

Conditions like left heart failure would typically lead to elevated pressures in the pulmonary circulation and possibly systemic circulation, as the heart struggles to maintain adequate output. Hypervolemia, on the other hand, indicates an excess of blood volume, which would increase hemodynamic pressures. Septic shock may also present with a paradoxical state of low blood pressure due to vasodilation, but it is usually accompanied by normal or increased cardiac output and altered systemic vascular resistance rather than a decrease in all hemodynamic pressures.