Patent ID: 8366705

Claim:
A cardiac ablation instrument, comprising: a first elongate catheter configured to deliver a distal end of the catheter to a position within a patient's heart; a second elongate catheter slidably disposed within an inner lumen of the first elongate catheter; an expandable member coupled to the distal end of the first elongate catheter, the expandable member configured to be positioned adjacent a target area thereby defining a treatment area between the expandable member and the target area; an irrigation mechanism configured to dispense an irrigation fluid from at least the second elongate catheter to the treatment area thereby displacing an amount of blood from the treatment area, wherein the irrigation mechanism includes at least one first port and at least one second port formed in the second elongate catheter, the first port being formed in the second elongate catheter at a location within an interior of the expandable member to allow irrigation fluid to flow into the interior of the expandable member to control inflation thereof and the second port being formed in the second elongate catheter at a location outside the expandable member and open to an exterior of the instrument for dispensing the irrigation fluid to the treatment area; and an energy emitter configured to deliver ablative energy to a tissue located within the treatment area, wherein the energy emitter is slidably disposed within an inner lumen of the second elongate catheter and is positioned within the expandable member for delivering ablative energy through the expandable member to the target area.