Patent ID: 7288089

Claim:
A method of treating atrial fibrillation while preventing tissue damage to the atrial septum, comprising: inserting a trocar wire capable of rupturing the atrial septum from the femoral vein into the right atrium; forming a hole using the trocar wire in the atrial septum between the right atrium and the left atrium; inserting an introducer sheath into the hole, the introducer sheath at least partially contacting the atrial septum; inserting a guide wire through the introducer sheath into the right atrium and left atrium and further into a pulmonary vein; disposing an ablation catheter over the guidewire into a volume defined by the joint of the left atrium and the pulmonary vein; flowing a cryofluid into a balloon disposed within the ablation catheter to ablate tissue adjacent the joint of the left atrium and the pulmonary vein; and operating and controlling a heater disposed adjacent or within the introducer sheath, the heater thermally coupled to the atrial septum.