A method and system for characterizing an accessibility of potential left ventricular stimulus sites in connection with surgical planning for transvenous implant of a cardiac medical lead in or near a heart of a patient are provided. The method and system include obtaining image data representative of a coronary venous system for the heart of the patient to receive the lead. The method and system generate a venous map, based on the image data, representative of venous pathways for the heart of the patient. The method and system analyze the venous map to identify pathway features of interest (PFOI) within at least one select region of the venous pathways. The method and system assign scores to the PFOI based on at least one of predetermined feature-complexity relations or physician-entered complexity updates. The method and system display treatment planning information to a user based on the scores.