145 Characterisation of fractionated atrial electrograms critical for maintenance of AF: a randomised controlled trial of ablation strategies (the CFAE af trial)

Abstract

mice showed a significant reduction in the cardiomyocyte cross sectional area (sham, 26763.4 mm 2 , vehicle treated TAC mice, 48065.8 mm 2 , AP2 treated TAC mice, 31963.9 mm 2 ). A significant reduction in the expression of the hypertrophic marker ANP and BNP and in the percentage of fibrosis was also observed in these mice compared with vehicle treated TAC mice. AP2 treatment led to a significant reduction in the expression of the bona fide calcineurin target RCAN1.4 and a reduction in the NFAT phosphorylation level in vivo and the NFAT transcriptional activity in vitro. In conclusion, we have identified AP2 as a novel PMCA4 specific inhibitor and shown its potential to modify the development of cardiac hypertrophy likely through inhibition of calcineurin/NFAT signalling. This compound has drug-like properties and thus lays the basis for a novel approach for treating cardiac hypertrophy and failure through PMCA4 inhibition.

Impact of pulmonary vein isolation on mechanisms sustaining persistent atrial fibrillation: Predicting the acute response

“…Previous studies investigating the impact of PVI on mechanisms sustaining AF have used surrogates for drivers such as fractionated electrograms or dominant frequency. PVI has been shown to reduce dominant frequency 14 and the burden of fractionated electrograms 12‐14,17 . However, fractionated electrograms and peaks in dominant frequency correlate poorly with drivers in AF 18,19 .…”

“…Mapping studies have shown that the burden of fractionated electrograms, the cycle length (CL) of electrograms, and the dominant frequency of the atria are reduced following PVI which suggests an impact on mechanism sustaining AF in the body of the atria 12‐14 . Targeting of ganglionated plexi has been shown to eliminate areas of continuous fractionation, both locally and at distant sites, and, hence, damage to ganglionated plexi at the pulmonary vein (PV) ostia has been suggested as one potential mediator of wider spread changes in AF mechanisms 15 .…”

The Spatial Distribution of Atrial Fibrillation Termination Sites in the Right Atrium During Complex Fractionated Atrial Electrograms‐Guided Ablation in Patients with Persistent Atrial Fibrillation

“…Sufficient defragmentation at the RA, however, may reduce the critical mass necessary to maintain chronic biatrial AF, subsequently resulting in AF termination . Targeting certain CFAE in LA or RA may also eliminate focal drivers of AF . All these mechanisms may explain why aggressive substrate modification by ablation could not only increase the acute procedural successful rate but also improve the clinical outcome during follow‐up.…”

Panoramic atrial mapping with basket catheters: A quantitative analysis to optimize practice, patient selection, and catheter choice

“…The LA was subdivided into anterior, posterior/inferior, lateral, roof, and septal regions. This was achieved through using a segmented model of the LA, which is a simplified version of a model previously published . The posterior wall was defined as the posterior aspect of the LA enclosed by the PVs.…”

“…This was achieved through using a segmented model of the LA, which is a simplified version of a model previously published. 9 The posterior wall was defined as the posterior aspect of the LA enclosed by the PVs. The inferior wall was the area extending below the inferior PVs down to the mitral valve annulus inferiorly and enclosed by the inferior aspect of the septum and the lateral aspect of the LA.…”