Some embodiments of a system or method for treating heart tissue can include a control system and catheter device operated in a manner to intermittently occlude a heart vessel for controlled periods of time that provide redistribution of blood flow. In particular embodiments, the system and methods may be configured to monitor at least one input signal detected at a coronary sinus and thereby execute a process for determining a satisfactory time period for the occlusion of the coronary sinus. In further embodiments, after the occlusion of the coronary sinus is released, the control system can be configured to select the duration of the release phase before the starting the next occlusion cycle.