Some embodiments of a balloon catheter device for introduction into a body vessel, in particular the coronary sinus, can include a catheter shaft which carries an inflatable balloon on its distal portion and in which a plurality of different lumens are formed. In particular embodiments, a system for treating heart tissue can include a coronary sinus occlusion catheter configured for improved deliverability to the coronary sinus and for thereafter performing intermittent occlusion of the coronary sinus.