1. A non-invasive method of producing a three-dimensional cardiac electrogram characteristic map for use in catheter ablation of ventricular tachycardia, comprising: receiving left ventricle three-dimensional image data of a patient's heart; segmenting a left ventricle image of said patient's heart based on said left ventricle three-dimensional image data into scar tissue, normal myocardium tissue and left ventricle cavity regions; determining scar tissue thickness and normal myocardium tissue thickness for a plurality of portions of said left ventricle image of said patient's heart; receiving predetermined data that associate a value of at least one electrogram characteristic to each scar tissue thickness and each normal myocardium tissue thickness for said plurality of portions of said left ventricle image of said patient's heart; and generating said three-dimensional cardiac electrogram characteristic map of said at least one electrogram characteristic corresponding to said left ventricle image of said patient's heart based on said predetermined data.