An electrophysiology mapping system is provided with modules which can be attached thereto, each module including an item of subcutaneous interventional equipment and information about the item of subcutaneous interventional equipment, including shape information and size information. At least one sensor is placed upon the item of subcutaneous interventional equipment at a known location thereon. This sensor allows for position, and also preferably orientation, of the item within an image presented on a display of the electrophysiology mapping system. The at least one sensor can be at least one electrode or two or more electrodes, with different known positions for the electrode, or electrodes. The at least one sensor can be one or more magnetic field sensors interacting with a magnetic field associated with the electrophysiology mapping system. Transthoracic ultrasound fitted with sensors thereon can also be utilized as a further module attachable to the electrophysiology mapping system.