Patent ID: 7794455

Claim:
A cryotherapy device for modifying the electrophysiological properties of cardiac tissue having an uneven surface topography, the device comprising: a catheter body having a substantially fixed diameter, and having a proximal end and a distal end; a first lumen for permitting passage of a cooling fluid from the proximal end to the distal end; a second lumen permitting return of the cooling fluid from the distal end to the proximal end; and an ablation element expandable from a first diameter that is substantially the same as the diameter of the catheter body to a second diameter that is at least twice the diameter of the catheter body, wherein the ablation element includes a flexible element that is deformed by moving the distal end of the catheter toward the proximal end of the catheter, the ablation element having a surface portion that conforms to the uneven surface topography of the cardiac tissue.