A system applies and senses electrical energy to and from tissue within a patient's body. The system includes a steerable delivery catheter, housing a flexible shaft and an electrical generator disposed on or embedded within the flexible shaft. Electrodes coupled to the shaft self-expand radially from a compressed position to an expanded position once the delivery catheter is withdrawn, thereby contacting a wall of the tissue of the patient's body to conduct electrical or other signals. The system may be inserted into the coronary sinus and tributary vein to provide physiological pacing to the His bundle and left ventricle. Further, the system provides for controlled passive transmission of normal electric impulses from the atria to the His bundle and ventricles without the need for an embedded generator.
