1. Can be focused to create continuous, circumferential lesions (transmural) in one energy application for PV isolation.

2. Does not require tissue contact to ablate tissue, as ultrasound energy transmits freely through blood.

3. Focus mechanism eliminates formation of thrombi and char at currently required energy levels.

4. The focus mechanism enables the titration of the energy dose so that less energy is needed to accomplish transmural ablation. (Test data on file.)

5. The focus mechanism results in the deposit of less energy in collateral tissue where it is unwanted and ablation is not desired. Tissue damage to collateral tissue has not been reported in animal tests to date.

6. Relatively short procedure times and expectation for low rates of recurrence due to the creation of uniform circumferential lesions that are transmural.

7. Placement of balloon catheter in the atrium at the ostium of the PV may reduce complexity and skill required to position the catheter for ablation (which is in the wall of the atrium “outside” the ostium).

8. Short time required for the application of energy (40-60 seconds) may potentially reduce complications inherent with ablation in a beating heart.