• high power
• radiofrequency
• procedural outcomes

Catheter Ablation of Atrial Fibrillation (AF CA) is a well-established treatment for rhythm control strategy. When performed by appropriately trained operators, AF CA is a safe and superior alternative to antiarrhythmic drugs for maintenance of sinus rhythm and symptom improvement. CA by radiofrequency (RF) is an effective treatment strategy for AF, with pulmonary vein isolation (PVI) being the corner- stone of this approach. The factors that influence the formation of tissue injury, such as power, contact, local thermal heating (resistive and conductive), electrode diameter of the radiofrequency catheter, and lesion size and depth were modified over time. The RF current used for catheter ablation causes controlled thermal injury to the tissue by two mechanisms: Resistive heating is caused directly by electrical current and this only directly affects tissue close to the electrode interface; Conductive heating, characterized by heat which spreads to the adjacent tissues, is responsible for most of the thermal injury. In order to reduce side effects of the thermal injury product by conductive heating the application of High Power strategy for AF ablation is increasing. This study compares two different approaches to AF ablation in consecutive patients undergoing a first ablation for AF, in particular the study compares efficiency, safety and efficacy of LSI-Guided High Power Short Duration Strategy (HPSD) (≥45 W) to a standard ablation strategy with Standard Power (SP) settings (≤40 W).