This invention is directed to a partitioning device for separating a patient's heart chamber into a productive portion and a non-productive portion. The device is particularly suitable for treating patients with congestive heart failure. The partitioning device has a reinforced, expandable membrane which separates the productive and non-productive portions of the heart chamber and a support or spacing member extending between the reinforced membrane and the wall of the patient's heart chamber. The support or spacing member has a non-traumatic distal end to engage the ventricular wall.