Patent ID: 8439866

Claim:
An assembly for treating a tissue region comprising a catheter tube having a distal end, an expandable structure comprising an array of spines to define a basket assembly projecting beyond the distal end of the catheter tube and including a far end; and an elongated distal tail projecting beyond the far end of the basket assembly, the distal tail having a proximal end, a distal end and a sidewall and including a guidewire lumen that accommodates passage of a guidewire without threading the guidewire through the catheter tube, the proximal end of the distal tail overlapping a portion of the spines, and an orifice in the sidewall of the distal tail communicates with the guidewire lumen and is spaced distally of the proximal end of the distal tail, whereby the distal tail provides a gradient of decreasing stiffness from a proximal region of the distal tail to a distal region of the distal tail.