Epicardial High-intensity Focused Ultrasound Cardiac Ablation for Surgical Treatment of Atrial Fibrillation

Background

The available alternatives to an effective but technically complex Cox maze procedure for surgical treatment of atrial fibrillation include ablation using radiofrequency, microwave, laser, cryotherapy or ultrasound energy sources. The purpose of this study was to evaluate the safety and efficacy profile of high-intensity focused ultrasound cardiac ablation for the surgical treatment of atrial fibrillation.

Methods

14 patients underwent epicardial high-intensity focused ultrasound treatment for atrial fibrillation using the Epicor cardiac ablation system between August 2006 and August 2007. The procedure was performed on the beating heart prior to the commencement of cardiopulmonary bypass for concomitant cardiac procedures. Physical examination, electrocardiography and 24-h Holter monitoring were used to determine the postoperative heart rhythm.

Results

There were no deaths directly related to the procedure. One patient with myelodysplastic syndrome died of septic complications. Three patients required cardioversion at 1 day, 3- and 4-month intervals postoperatively. The mean follow-up period was 9 months. Currently 10/13 (77%) patients are in sinus rhythm, one patient required insertion of a permanent pacemaker, one patient is in atrial fibrillation and another patient is in atrial flutter.

Conclusion

Epicardial high-intensity focused ultrasound ablation is a viable alternative to the Cox maze procedure for the surgical treatment of atrial fibrillation. It is a safe and efficient procedure that does not require cardiopulmonary bypass and may potentially be performed using less invasive surgical techniques.

Keywords: High-intensity focused ultrasound, Epicardial ablation, Atrial fibrillation, Cardiac surgery