The present invention relates to therapeutic devices to work in conjunction with a diseased or failing heart to satisfy the hemodynamic needs of a patient. More particularly, the invention relates to a fully implantable device for assisting a heart to pump blood by intermittently applying pressure to at least a portion of the ventricular surface of the heart (if not the entire surface), preferably both the atrial and ventricular surfaces, at predetermined or possibly pre-programmed intervals to assist the heart to provide adequate hemodynamic output by sensing demand of the human body. In short, the present invention assists the maintenance of, or reestablishes, the normal contraction sequence of a healthy heart.