Flower catheter for mapping and ablating veinous and other tubular locations

A catheter adapted for use in a tubular structure at or near a heart, comprising:

• an elongated catheter body having a proximal end, a distal end and at least one lumen extending longitudinally therethrough;
• a distal assembly distal of the catheter body and comprising at least two spines, each spine having a free distal end and a proximal end that is affixed to the catheter body, wherein each spine comprises a distal tip electrode, at least one ring electrode and a dedicated irrigation pathway, at least one of the distal tip electrode and the at least one ring electrode being adapted for irrigation;
• a main irrigation pathway extending through the catheter body and being adapted to introduce irrigation fluid to outside the catheter in a region between the spines;
• and
• wherein each spine has a support arm adapted to support the spine in a generally L-shaped configuration such that the free distal end of each spine is positioned radially outwardly from the proximal end when the spine is in a neutral state, and in a generally U-shaped configuration such that the tip electrode and the at least one ring electrode of each spine are simultaneously in contact with tissue of the tubular structure upon exertion of a contact force on the distal assembly by the tubular structure, wherein in the U-shaped configuration the distal tip electrode of each spine defines an angle with the proximal end of the corresponding spine of about 90 degrees to about 135 degrees.