Devices and methods for increasing a patient's pulmonary arterial compliance are disclosed. The devices include catheters designed to create a connection between a patient's venous anatomy and the patient's pulmonary artery. With the arteriovenous connection various devices can be implanted in order to increase the volumetric compliance of the pulmonary artery. The devices include collapsible and expandable mechanisms which allow the effective pulmonary arterial volume to expand during systole and contract during diastole. The devices may include a balloon or balloon-like implants which cyclically shuttle a working fluid from the pulmonary artery to the vein and back. The devices may be adjustable to provide desired hemodynamic benefits. Methods are disclosed for making and using the inventive devices.
