An electromagnetic cardiac assembly adapted to assist ventricular output in a human heart includes a magnetic mat adapted for mounting inside a human body adjacent the heart. The mat is made from a material responsive to application of an electromagnetic field so as to be movable into compressive relation with the heart in response to application of the electromagnetic field thereto and movable out of said compressive relation to permit the heart to relax when application of said electromagnetic field is discontinued. The mat has a posterior surface that substantially conforms to an anterior surface of the heart without flexing the mat. The assembly also includes an electromagnetic subassembly adapted for mounting on the human body in functionally cooperative relation with respect to the mat, and for alternately generating and discontinuing the electromagnetic field so that the mat alternately moves into and out of the compressive relation with the heart.
