A system for treating heart failure in a patient, the system comprising: a catheter having a proximal end and a distal region, the catheter configured for placement though a subclavian or jugular vein of a patient so that the distal region is within a superior vena cava of the patient; a flow limiting element disposed on the distal region of the catheter, the flow limiting element configured to be selectively actuated to at least partially occlude the superior vena cava; one or more sensors configured to measure one or more physiologic parameters of the patient indicative of fluctuations in the patient's hemodynamic state; and a controller configured to be operatively coupled to the catheter to intermittently actuate the flow limiting element by transitioning the flow limiting element from a contracted state to an expanded state to at least partially occlude the superior vena cava over multiple cardiac cycles and to transition the flow limiting element to the contracted state, the controller including a processor programmed to: apply a stored value corresponding to a predetermined flow limiting interval based on the patient's resting heart rate to cause the flow limiting element to be actuated to the expanded state for the predetermined flow limiting interval; receive an input from the one or more sensors corresponding to the one or more physiologic parameters of the patient indicative of fluctuations in the patient's hemodynamic state; generate an output corresponding to an adjustment of the predetermined flow limiting interval; and apply the output to revise the predetermined flow limiting interval. a catheter having a proximal end and a distal region, the catheter configured for placement though a subclavian or jugular vein of a patient so that the distal region is within a superior vena cava of the patient; a flow limiting element disposed on the distal region of the catheter, the flow limiting element configured to be selectively actuated to at least partially occlude the superior vena cava; one or more sensors configured to measure one or more physiologic parameters of the patient indicative of fluctuations in the patient's hemodynamic state; and a controller configured to be operatively coupled to the catheter to intermittently actuate the flow limiting element by transitioning the flow limiting element from a contracted state to an expanded state to at least partially occlude the superior vena cava over multiple cardiac cycles and to transition the flow limiting element to the contracted state, the controller including a processor programmed to: apply a stored value corresponding to a predetermined flow limiting interval based on the patient's resting heart rate to cause the flow limiting element to be actuated to the expanded state for the predetermined flow limiting interval; receive an input from the one or more sensors corresponding to the one or more physiologic parameters of the patient indicative of fluctuations in the patient's hemodynamic state; generate an output corresponding to an adjustment of the predetermined flow limiting interval; and apply the output to revise the predetermined flow limiting interval. apply a stored value corresponding to a predetermined flow limiting interval based on the patient's resting heart rate to cause the flow limiting element to be actuated to the expanded state for the predetermined flow limiting interval; receive an input from the one or more sensors corresponding to the one or more physiologic parameters of the patient indicative of fluctuations in the patient's hemodynamic state; generate an output corresponding to an adjustment of the predetermined flow limiting interval; and apply the output to revise the predetermined flow limiting interval.