Abstract: A feedthrough connector for use on an implantable electronic cardiac pacer. A single structure provides a means for connecting a heart lead to the pacer and feedthrough into the body of the pacer. The feedthrough may include filtering means to protect against external interferences. The entire structure has provisions for physical compliance to absorb stresses due to different heat coefficients and as may be caused during assembly and use. Also disclosed is a method for making the feedthrough connector.

Abstract: A demand cardiac pacer having provisions for determining power source life status both during normal heart operation and during heart stimulation by the pacer. An external magnetic pulse of relatively long duration induces a test mode in the circuit, the pacer reverting to the pacing mode immediately after removal of the magnetic stimulus. When producing pacing pulses in the pacing mode, testing of the patient's heart is facilitated by providing an external magnetic pulse of relatively short duration which is insufficient to place the pacer in the test mode but of sufficient length to inhibit pacing pulses. This invention applies to preset frequency pacers as well as to programmable pacers and includes means for observing the preprogrammed pulse frequency immediately after programming.