Does left atrial epicardial conduction time reflect atrial fibrosis and the risk of atrial fibrillation recurrence after thoracoscopic ablation? Post hoc analysis of the AFACT trial

Abstract

ObjectivesTo determine the association between left atrial epicardial conduction time (LAECT), fibrosis and atrial fibrillation (AF) recurrence after thoracoscopic surgical ablation of persistent AF.SettingSingle tertiary care centre in the Netherlands.ParticipantsPatients with persistent AF from the randomised Atrial Fibrillation Ablation and Autonomic Modulation via Thoracoscopic Surgery (AFACT)-trial were included. Patients eligible for thoracoscopic AF ablation were included, full inclusion and exclusion criteria were previously published. All patients underwent thoracoscopic ablation, encompassing pulmonary vein isolation with an additional roof and trigone lesion. In patients with conduction block across the roof and trigone lesion, LAECT was measured. LAECT was defined as the time to local activation at one side of the roofline on pacing from the opposite side. Collagen fibre density was quantified from left atrial appendage histology.Outcome measuresPrimary outcome: AF recurrence during 2 years of follow-up.Results121 patients were included, of whom 35(29%) were women, age was 60.4±7.8 and 51% (62) had at least one AF recurrence during 2 years of follow-up. LAECT was longer in patients with versus without AF recurrence (182±43 ms vs 147±29 ms, p<0.001). LAECT was longer in older patients, in patients with a higher body mass index (BMI) and in patients using class IC antiarrhythmic drugs. LAECT was shorter in patients with higher collagen fibre density. A previously failed catheter ablation, LAECT and BMI were independently associated with AF recurrence.ConclusionLAECT is correlated with collagen fibre density and BMI and is independently associated with AF recurrence in patients with persistent AF. In these patients, LAECT appears to reflect substrate characteristics beyond clinical AF type and left atrial volume.Trial registration numberNCT01091389.

The frequency of atrial fibrillatory waves is modulated by the spatiotemporal pattern of acetylcholine release: a 3D computational study

“…Particularly, for definition of the conductivity values, we considered ten atrial regions: LA, RA, PV, SAN, coronary sinus (CS), isthmus (IST), the fossa ovalis (FO) and its limb (LFO), the crista terminalis (CT), the Bachmann bundle and the pectinate muscles (BBPM). The defined conductivity values, reported in Supplementary Table S1 , led to a TAT of 180 ms, in line with data reported in the literature for psAF patients ( Wesselink et al, 2022 ).…”

Effects of Acetylcholine Release Spatial Distribution on the Frequency of Atrial Reentrant Circuits: a Computational Study

“…The conductivity betweeen fibroblasts or between myocytes and fibroblasts was reduced 4-fold with respect to the myocytemyocyte coupling. The total activation time (TAT) in our simulations was 180 ms, in line with experimental results reported in the literature for psAF patients [11].…”

Long-term outcomes of thoracoscopic ablation for atrial fibrillation

“…Снижение эффективности ТЛ ФП в отношении длительно-персистирующей ФП обусловлено, более выраженным фиброзом и ремоделированием левого и правого предсердий. До конца не изучено, улучшают ли эффективность ТЛ дополнительные линии аблации, не входящие в схему «Box lesion» [32].…”