INTRODUCTION
Atrial fibrillation (AF) is the most common clinically significant arrhythmia. It is a major public health concern affecting an estimated 2.3 million people in North America and 4.5 million people in Europe . It has been projected that the prevalence of AF will increase 2.5 times during the next 50 years in the United States . AF is associated with increased cardiovascular morbidity and mortality and the prevalence increases over time due to the aging population and increase in age-specific occurrence of AF . Currently, catheter ablation for AF is a widely recognized treatment in patients with drug refractory arrhythmia. The predominant strategy is isolation of the pulmonary veins (PVI) by circular radiofrequency lesions around their ostia in patients with both paroxysmal and persistent AF supplemented by additional ablations, such as linear lesions in the left atrium or ablation of fractionated atrial potentials . The number of technological improvements is growing. For example single shot ablation catheters, high resolution ablation catheters, contact force-sensing technologies and improved navigation technologies, which are aimed to improve outcomes of ablation procedures. Despite technological innovations, currently point-by-point radiofrequency (RF) ablation remains the most common technique to achieve PVI. Despite significant improvements in catheter ablation strategies to treat AF in recent years, recurrence rates of AF after RF ablation due to electrical reconnections still remains relatively high, ranging from 20-55% . In the the GAP-AF study, 70% of patients had PV reconnections at 3 months post-ablation. This may be attributed to lack of durable, contiguous, and transmural lesions . Although the point by point method is principally simple, creating a transmural, continuous lines around the PV ostia may be a major challenge. The major improvement in the ablation technology in the last ten years is technology of irrigated tip catheters. Saline irrigation of the tip of the catheter decreased the incidence of thrombus and char formation on the ablation tip and increase lesion size. However saline irrigation limits the temperature feedback and those catheters are typically operated in power control mode. Overall settings of irrigated catheters can cause inadequate lesion creation during PVI.
DiamondTemp™ (DT) Cardiac Ablation System (DiamondTemp Catheter, EPIX Therapeutics, Santa Clara, California, USA, formerly known as Advanced Cardiac Therapeutics, which was acquired by Medtronic, Inc. (Dublin, IR) in March 2019), is a recently developed ablation system based on composite-tip, diamond-embedded, temperature sensing, saline-irrigated RF ablation catheter with 6 insulated thermocouples on the ablation tip surface which directly measure the tissue surface temperature. The DT catheter allows ablation in temperature control mode with rapid diffusion of heat due to an industrial diamond embeded catheter tip with the potential to fastly create deeper and more transmural lesions. According to animal data, 92.7% of lesions during ablation of pig´s atria were transmural The aim of our work is to describe the first multicenter clinical experience with the DT ablation system during ablation of drug refractory, recurrent, symptomatic paroxysmal AF (TRAC-AF study).