Patent ID: 8231613

Claim:
A cardiac ablation instrument assembly comprising: a deflectable first catheter adapted for disposition within a heart having at least one lumen therein extending from a proximal end to a distal end, the catheter having a deflectable end section formed of a plurality of flexible polymeric segments, at least one polymeric segment having a different stiffness as compared to another polymeric segment of the deflectable end section thereby allowing the deflectable end section to form a compound curve upon deployment and deflection within the heart; an elongate second catheter for disposition within a heart; an expandable balloon member having a wall coupled to the elongate second catheter and sized for positioning proximate to a pulmonary vein; a cryogenic ablation element within the balloon member, the cryogenic ablation element being configured to create at least one lesion in tissue proximate the pulmonary vein by conveying sufficient energy through the balloon wall to ablate the tissue; and wherein the lumen is sized and configured to allow passage of the elongate second catheter, the balloon member, and the ablation element contained within the balloon member.