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).