Targeted ablation strategies balance the risks of insufficiently ablating atrial fibrillation triggers with exacerbating disease through additional scar formation. EGF mapping leverages spatiotemporal relationships in voltage to localize sources and quantify substrate health. Further research is needed to optimize phenotyping and treatment efforts.

In nonparoxysmal AF patients undergoing redo ablation, EGF mapping identified AF sources in 60% of patients, and could be successfully ablated in 95%. Compared with PVI alone, PVI + source ablation improved AF-free survival by 51% on an absolute basis.

Electrographic flow mapping generates reproducible intra- and inter-procedural maps, providing rationale for randomized clinical trials targeting these putative AF sources.

EGF mapping can be used to visualize flow patterns and accurately identify sources of AF in an animal model. Source activity was not correlated to spectral properties of f-waves in concurrently obtained EGMs. The locations of sources could be pinpointed with high precision, suggesting that they may serve as prime targets for focal ablations.

Our data suggest that patients treated with EGF-guided CA developed fewer AF recurrences. Although the procedure times are longer, it seems to be safe and offers a more targeted, patient-specific ablation strategy beyond PVI than adjunctive empiric lines and substrate ablation in this complex group of patients.

EGF mapping produces reproducible results from one procedure to the next, such that if a clinically relevant source was detected post-PVI during the first procedure, but was not ablated, the source was again detectable at remapping performed at 3-mo after de novo PVI. This inter-procedural reproducibility may enable longitudinal follow-up of individual patients’ AF pathophysiology.

Both EGFC and bipolar voltage values were higher in SR v. AF. EGFC correlated with voltage across both atria and in both SR and AF. Global EGFC can be obtained with 1-minute recordings in 2-3 basket positions per atria and may provide another measure of the degree of atrial myopathy similar to the information gained from high-density bipolar voltage mapping.

Electrographic flow patterns vary significantly in both magnitude and direction depending on the rhythm. AF sources emanate flow during ongoing AF, but when inactivated during SR, appear more as flow sinks possibly due to surrounding abnormal substrate with slow and/or anisotropic conduction due to arrhythmogenic remodeling.

Summative EGF metrics that characterize vector flow provide signature patterns of global atrial wavefront propagations in different atrial arrhythmias that can be used to successfully discriminate these arrhythmias.

Evaluate PFA lesions created using an innovative catheter design combining focal, linear and pulmonary vein (PV) ablation.

Using EGF mapping algorithms to detect the presence of functional mechanisms of AF, the clinically heterogeneous population of PerAF patients can be stratified into distinct EGF phenotypes that guide the minimum-required ablation strategy, and also provide post-ablation prognosis. A larger prognostication study is warranted.

With progressive substrate remodeling, mean electrographic FC decreases and mean FC is lower in LA than RA, which may reflect that pathophysiologically, fibrosis tends to originate in LA and spread to RA. FC below the mean in both atria may indicate biatrial disease with more progressive substrate remodeling and hence worse outcomes. More outcomes data is required to understand the utility of biatrial FC as a marker for AF disease.

The primary objective of the FLOW-AF trial is to evaluate the reliability of the EGF algorithm technology (Ablamap software) to identify AF sources and guide ablation therapy in patients with persistent AF.

Our data suggest that patients treated with combined EGF and CARTO mapping-based CA have less AF recurrences at one-year. The procedure is safe and seems to be a promising treatment alternative for this complex group of patients.

Our data suggests that non-abutting LAA-LSPV is associated with the presence of AF sources near the LA ridge.

Given the novelty of EGF mapping and relative unfamiliarity of most clinical electrophysiologists with the mathematical principles powering the EGF algorithm, this paper provides an in-depth explanation of the technical/mathematical foundations of EGF mapping and demonstrates clinical applications of EGF mapping data and analyses.

EGF mapping can detect and visualize extra-pulmonary sources of AF throughout the RA and LA. Most extra-PV source locations represent anatomically feasible targets for ablation. No sources were localized to valves or mid-chamber regions.

Flow angle variability as an indicator of stability of electrographic flow directionality over time shows significant differences between varying atrial arrhythmias and may enhance the differentiation of these arrhythmia types.

Elimination of electrical conduction from PV triggers results in increased extra-PV SAC; slowing AF CL and stabilization of FAV. PVI may unmask extra-PV AF drivers and stepwise elimination of drivers starting with PV triggers followed by extra-PV sources simplifies AF conduction patterns.

Although time-dependent dominant frequency and f-wave amplitude during AF can be recorded with MiFi electrodes colocalized to basket locations of EGF-identified sources, it does not correlate with the dynamic broader atrial electrical activity identified by EGF mapping as AF source activity, confirming the unlikely contribution of fractionated activity alone as a driver of AF or as a primary ablation target. Local fractionation is not useful when it comes to understanding the global atrial electrical activity and identifying the driving sources of AF.

Fractionation has been associated with substrate modification and seen as a mechanism of AF sources. However, we demonstrate here that AF complexity is a prerequisite to detect fractionation resulting from spontaneous action potential generation of AF sources.

Novel 3D reconstruction from QRS signatures enables integration of EGF maps from multiple basket recordings that can be aligned with CT anatomy. Due to the real-time EGF map acquisition, synthesizing maps from more than 1 basket position provides a more panoramic visualization of complex atrial flow patterns.

EGF mapping is an effective new technology capable of recording and visualizing complex atrial activity and may define ablation targets during AF.

Putative AF sources identified by EGF mapping algorithms are characterized by a dominant QS unipolar morphology present over the course of a 1 minute recording that is significantly higher than at randomly selected locations. Post-ablation, %QS levels diminish at targeted sources vs randomly selected locations.

EGF mapping enables the dynamic detection of distinct AF mechanisms including active sources, active fractionation, stable re-entry circuits. The presence or absence of 1 or more of these AF mechanisms correlates with 12 months FFAF.

Complex AF conduction patterns make ablation challenging but with EGF mapping, time-dependent AF behaviors can be detected and summarized. Although low prevalence sources are detected, they may not be clinically relevant. A recording duration of 1 minute enables identification of dominant sources.

This is the first in-human report of an AF mapping technology that demonstrates interprocedural map reproducibility with spatiotemporal stability of EGF-identified sources of AF in the same patient during procedures performed 18 months apart. Additional prospective EGF mapping reproducibility studies are in progress.

Electrographic flow (EGF) mapping is a method to detect action potential sources within the atria. In a double-blinded retrospective study we evaluated whether sources detected by EGF are related to procedural outcome.

EGF mapping enables the visualization of active AF sources. Sources with SAC > 26% appear relevant and their presence post-ablation correlates with high rates of AF recurrence.

EGF is a novel vectorial-based AF mapping method, which can detect sites of AF termination, agreeing with, and complementary to, an alternative AF mapping method using phase analysis.

Electrographic-Flow-(EGF)-Mapping is a novel method to identify Atrial Fibrillation (AF) drivers. Sources of excitation during AF can be characterized and monitored.

EGF is the first method to identify active AF sources during AF ablation procedures in humans and discriminate them from passive rotational phenomena, which occur if the excitation wavefront passes conduction bariers. EGF mapping may allow improved guidance of AF ablation procedures.