Introduction
Catheter ablation is a safe and effective treatment strategy of cardiac arrhythmias and is increasingly performed world-wide. Beside the fact that cardiac arrhythmias are very versatile atrial fibrillation (AF) is the most common form which affects increasing numbers of patients.
Pulmonary vein isolation (PVI) by catheter ablation has shown high success rates for treatment of paroxysmal (PAF) and persistent AF (PersAF). Novel single-shot ablation devices implementing diverse energy sources (cryothermal, laser, pulse field ablation (PFA), radiofrequency (RF)) have shown excellent acute and long-term success rates with decreased procedure time compared to RF based 3D mapping and point-by-point PVI. Due to the fact that single-short devices are mainly designed for PVI they have several limitations concerning versatility, flexibility and adaptability to different anatomies.
Recently 3D mapping and point-by-point based catheter ablation achieved several improvements by implementing contact force (CF), ablation index (AI) or lesion size index (LSI)
guided RF ablation which have been shown to decrease procedure time, improving safety and patients outcome. Latest achievements are high-power short-duration (HP-SD) ablation with a maximum of 50W and very HPSD (vHPSD) ablation with maximum of 70-90W which have been introduced to clinical practice. In CF guided ablation procedures power is limited to 50W, while in a power-controlled ablation mode without CF sensing catheter power is limited to 70W. Although these concepts seem to be safe and effective, no real time temperature monitoring is possible because conventional catheters were utilized in those studies.
However, it has been shown that real-time subendocardial tissue temperature monitoring during RF energy delivery is a direct indicator of lesion formation but measurements by temperature sensors embedded in the catheter tip have been shown to be not an accurate indicator of actual tissue temperature.