Assessing the impact of a new atrial fibrillation (AF) catheter ablation energy on left atrial structure and function is of crucial importance. The goal of this clinical trial is to assess the effect of pulsed-field ablation of atrial fibrillation on left atrial structure.
Until recently, pulmonary vein ablation was performed using thermal energy; Pulmonary vein ablation (PVA) is the cornerstone of catheter ablation techniques for the treatment of atrial fibrillation (AF). In paroxysmal atrial fibrillation (PAF), PVI achieves a high rate of sustained freedom from AF recurrence, due to the predominant role of AF triggers, primarily represented by the pulmonary veins (PVs). Until recently, two main ablation energies were used to perform PVI: radiofrequency (RF) and cryoablation, both of which rely on thermal injury to the atrial cardiomyocytes surrounding the pulmonary vein ostia. Thermal lesions are associated with coagulative necrosis, oedema, and macro- and microvascular damage. Over time, thermal ablation lesions are replaced by interstitial fibrosis, a non-contractile and inflexible tissue. It has been demonstrated that extensive ablation lesions in the left atrium (LA) exacerbate atrial cardiomyopathy by impairing the LA's reservoir function, which can lead to stiff left atrium syndrome. Furthermore, thermal ablation lesions have been associated with an increased risk of stroke, particularly in patients with a low fibrosis burden in the LA. Pulsed-field ablation of atrial fibrillation, including ablation of the posterior wall, is associated with the absence of left atrial fibrosis or fatty metaplasia, as well as the preservation of left atrial mechanics and blood flow.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
39
Persistent or paroxysmal atrial fibrillation treated by pulse-field ablation. Interventions added by the study are cardiac MRI (pre-ablation and 4 months after ablation) with administration of contrast agent (Dotarem®).
Difference between baseline (pre-ablation) and post-ablation (4 months) in the amount of left atrial fibrosis such as quantified by 3D late gadolinium enhancement (g, %) (MRI measurement).
Time frame: From baseline to 4 months post ablation
Difference between baseline (pre-ablation) and post-ablation (4 months) in global left atrial strain (%)
Time frame: From baseline to 4 months post ablation
Difference between baseline (pre-ablation) and post-ablation (4 months) in regional left atrial strains (%)
Time frame: From baseline to 4 months post ablation
Difference between baseline (pre-ablation) and post-ablation (4 months) LA adipose tissue, measured by CT (cm^2, mm^3, %)
Time frame: From baseline to 4 months post ablation
Difference between baseline (pre-ablation) and post-ablation (4 months) left atrial flow assessed by 4D-flow MRI and quantified by velocity histograms (cm/s); vortices number, characterization (n) and duration (ms) ; LA stasis
Time frame: From baseline to 4 months post ablation
Difference between baseline (pre-ablation) and post-ablation (4 months) in left atrial wall thickness (mm)
Time frame: From baseline to 4 months post ablation
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