Cardiac ablation technologies

Since 1985, radiofrequency (RF) technology has grown to become the predominant energy source for performing cardiac ablations of various atrial and ventricular arrhythmias. Although the therapeutic advantages of RF have become widely appreciated, it has been somewhat limited by: (1) thrombo-embolization, (2) inability to reach deep tissue, (3) inadvertent collateral damage to surrounding vascular and electrical structures, and/or (4) inability to assess the electrophysiologic effects prior to induced permanent local tissue damage. Alternative energy sources have been developed to meet the needs for more effective and targeted ablation. Today, cryoablation is the second most common energy source that has received extensive clinical testing and use. Additional energy sources capable of a more volumetric ablation are emerging including high-intensity focused ultrasound energy, light amplification by stimulated emission of radiation energy, and microwave energy. This chapter reviews the associated biophysics, available systems, and clinical utility of each of the energy sources currently available for cardiac ablation therapies.