[Catheter ablation of cardiac arrhythmias : Forms of energy and biophysical principles].

Catheter ablation of cardiac arrhythmias has evolved over the years and has become a cornerstone in the modern treatment of various supraventricular and ventricular arrhythmias. The goal of ablation is to permanently damage myocardium that is critically involved in the individual arrhythmia mechanism. Different catheters and forms of energy are available. Radiofrequency (RF) ablation is most common. Application of an alternating current at the catheter tip induces heating of tissue and, thus, leads to ablation of a targeted arrhythmogenic substrate. High temperatures (>70 °C at the catheter tip and >95 °C within the tissue) bear the risk of coagulum formation and steam pops and should be avoided, which limits power application. The evolution of irrigated RF ablation catheters enables the transfer of more power to the tissue and thereby increases the dimensions of the lesions. Cryoablation represents a valuable alternative. Cooling of tissue to -80 °C causes the intra- and extracellular formation of ice crystals, finally resulting in a dense circumscribed scar. The cryomapping procedure grants improved surveillance of the safety of ablation. Cryoenergy is very popular for pulmonary vein isolation (PVI) using the cryoballoon. In addition to the laser balloon that is established for PVI, ultrasound, microwaves, and stereotactic irradiation complete the arsenal.