Biophysics and pathology of catheter energy delivery systems

Catheter ablation has rapidly emerged as the treatment of choice for many symptomatic cardiac arrhythmias. The initial experience with catheter ablation used high-energy DC as the energy source. However, over the last several years radiofrequency (RF) catheter ablation has become the dominant mode of energy delivery. Currently, a major limitation of RF ablation is the small lesion size created by this technique that has reduced its success rate in ablation of larger arrhythmogenic substrates such as coronary artery disease-related ventricular tachycardia. Alternate energy sources such as microwave or ultrasound catheter ablation are being developed that have the potential for producing larger lesions than RF ablation. This review will discuss the biophysics and pathophysiology of the various energy modalities used in catheter ablation.