A system includes an intravascular reperfusion therapy device configured to be positioned within a coronary vein to deliver reperfusion therapy to a myocardium of a heart associated with the coronary vein. The intravascular reperfusion therapy device includes a flexible elongate member, a sensor, and a balloon. The balloon is configured to generate back pressure within the coronary vein to deliver the reperfusion therapy. The system includes a processor circuit in communication with the intravascular reperfusion therapy device. The processor circuit is configured to receive, from the sensor, physiological data associated with blood flow through the coronary vein, determine, based on the physiological data, a progression of the reperfusion therapy delivered to the myocardium, and control, based on the progression of the reperfusion therapy, inflation of the balloon while the intravascular reperfusion therapy device is positioned within the coronary vein such that the back pressure within the coronary vein is controlled.

In a method for intermittently occluding the coronary sinus, in which the coronary sinus is occluded using an occlusion device, the fluid pressure in the occluded coronary sinus is continuously measured and stored, the fluid pressure curve is determined as a function of time, and the occlusion of the coronary sinus is triggered and/or released as a function of at least one characteristic value derived from the measured pressure values. The pressure increase and/or pressure decrease per time unit each occurring at a heart beat are used as characteristic values.