1. A method for producing a patient-specific implantable pacemaker electrode, comprising the steps of: using an electronic 3D representation of the coronary sinus vessel tree of a patient in whom a pacemaker electrode is to be implanted, said 3D representation including an indication of an implantation site in the coronary sinus vessel tree for a pacemaker electrode having a mechanical structure comprising an elongate lead body terminating in an electrode tip segmenting the 3D representation of the coronary sinus vessel tree to visually indicate the interior surface of the coronary sinus vessel tree and a representative line from an opening of the coronary sinus vessel tree to the implantation site; generating a computerized model of only of said mechanical structure of said electrode, and including computerized deformation properties in said model that model mechanical behavior of said electrode in response to mechanical influences on said mechanical structure; conducting a computerized virtual implantation of said electrode through said 3D representation of said coronary sinus vessel tree to said implantation site using at least said model and said internal surface and including simulating deformation of said electrode caused by a size and shape of said coronary sinus vessel tree and said deformation information representative line; from said deformation in said virtual implantation, making an implantation determination as to whether an electrode conforming to said model can be guided to and implanted at said implantation site in a medically acceptable manner; if said implantation determination is positive, producing an actual electrode conforming to said model; and if said implantation determination is negative, iteratively modifying said model and repeating said virtual implantation until a positive implantation determination is achieved by a last-modified model, and producing an actual electrode conforming to said last-modified model.