Abstract: A intraventricular multielectrode catheter for mapping an activation sequence of a ventricle of a person's heart includes a plurality of solid mapping catheter elements, which have first expandable distal end portions, with a plurality of leads arranged along each of the first portions, and second portions bonded together and forming an inner tubing; a plurality of conductive wires extending along a longitudinal extend of each mapping catheter element and connected with its leads, respectively; a central skeleton element extending through the inner tubing and having at its distal end a tip cap to which the ends of the first portions are attached; and an outer flexible tube which surrounds the mapping catheter elements and is displaceable therealong for exposing a predetermined length of the first portions.