A method is provided for electrical mapping of a pulmonary vein of a heart, including
introducing into the heart a catheter having a curved section and a base section,
the base section having a distal end attached to a proximal end of the curved section.
At a location on the curved section, a first position signal is generated having
fewer than six dimensions of position and orientation information. At a vicinity
of the distal end of the base section, a second position signal is generated having
six dimensions of position and orientation information. The method also includes
measuring, at one or more locations on the curved section, an electrical property
of the pulmonary vein.