Publications

Publications

Cortex’s AF solution is supported by a substantial and growing body of research
June 5, 2024

A randomized trial of electrographic flow-guided redo ablation for nonparoxysmal atrial fibrillation (FLOW-AF)

Reddy VY, Langbein A, Petru J, Szili-Torok T, Funasako M, Dinshaw L, Wijchers S, Rillig A, Spitzer SG, Bhagwandien R, Metzner A, Kong MH, Neuzil P
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.
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in
JACC: EP
November 10, 2023

Electrographic flow mapping of persistent atrial fibrillation: intra- and interprocedure reproducibility in the absence of 'ground truth'

Reddy VY, Kong MH, Petru J, Mann A, Funasako M, Minami K, Ruppersberg P, Dukkipati S, Neuzil P
Electrographic flow mapping generates reproducible intra- and inter-procedural maps, providing rationale for randomized clinical trials targeting these putative AF sources.
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in
Europace
September 1, 2023

Visualization of electrographic flow fields of increasing complexity and detection of simulated sources during spontaneously persistent AF in an animal model

Avitall B, Kong MH, Ruppersberg P
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.
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in
Heart Rhythm
June 1, 2023

Electrographic flow mapping guided catheter ablation offers advantages for patients with persistent atrial fibrillation

Gagyi R, Bhagwandien R, Yap SC, Hoogendijk M, Wijchers S, Szili-Torok T
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.
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in
Pacing Clinical Electrophysiol
May 18, 2023

Interprocedural reproducibility of electrographic flow mapping between procedures separated by 3 months or longer

Neuzil P, Kong MH, Ruppersberg P, Funasako M, Petr J, Reddy VY
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.
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in
Heart Rhythm
May 18, 2023

Electrographic flow consistency correlates with high-density bipolar voltage maps in sinus rhythm and atrial fibrillation

Haines DE, Castellano S, Kong MH, Sommer P
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.
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in
Heart Rhythm
May 18, 2023

Characterization of electrographic flow-identified source signatures in sinus rhythm and atrial fibrillation

Sommer P, Castellano S, Kong MH, Haines DE
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.
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in
Heart Rhythm
May 18, 2023

Atrial arrhythmia prediction using electrographic flow mapping metrics

Hummel JD, Castellano S, Haeusser P, Kong MH
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.
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in
Heart Rhythm
May 18, 2023

Pulse field ablation and lesion formation using a unique integrated multielectrode focal, linear, and loop ablation catheter

Chen P, Avitall B, Koblish J, Mou J, Berliner K, Chun D, Lizama KS, Kong MH
Evaluate PFA lesions created using an innovative catheter design combining focal, linear and pulmonary vein (PV) ablation.
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in
Heart Rhythm
May 18, 2023

Phenotyping persistent atrial fibrillation with electrographic flow mapping

Reddy VY, Castellano S, Szili-Torok T, Petru J, Funasako M, Hoogendijk M, Wijchers S, Spitzer SG, Rillig A, Neuzil P, Kong MH
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.
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in
Heart Rhythm
May 18, 2023

Left atrial v. right atrial electrographic flow consistency in persistent atrial fibrillation

Goyal SK, Castellano S, Kong MH, Nilsson KR, Derejko P, Szili-Torok T, Verma A, Turagam MK
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.
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in
Heart Rhythm
April 23, 2023

Electrographic flow-guided ablation in Redo patients with persistent atrial fibrillation (FLOW-AF): design and rationale

Szili-Torok T, Neuzil P, Langbein A, Petru J, Funasako M, Dinshaw L, Wijchers S, Bhagwandien R, Rillig A, Spitzar SG, Metznar A, Kong MH, Reddy VY
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.
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in
Heart Rhythm
October 30, 2022

Electrographic flow mapping improves outcome of catheter ablation procedures for persistent atrial fibrillation

Gagyi R, Bhagwandien R, Wijchers S, Yap SC, Szili-Torok T
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.
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in
Circulation
September 28, 2022

Left atrial anatomical variations correlate with atrial fibrillation sources near the left atrial ridge

Gagyi R, Szegedi N, Simon J, Wijchers S, Bhagwandien R, Kong MH, Ruppersberg P, Szili-Torok T
Our data suggests that non-abutting LAA-LSPV is associated with the presence of AF sources near the LA ridge.
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in
Frontiers in Cardiovascular Medicine
August 15, 2022

Electrographic flow mapping for atrial fibrillation: theoretical basis and preliminary observations

Haines DE, Kong MH, Ruppersberg P, Haeusser P, Avitall B, Szili-Torok T, Verma A
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.
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in
J Interv Card Electrophysiol
May 1, 2022

Anatomic distribution of active sources identified using electrographlc flow mapping

Haines DE, Kong MH, Ruppersberg P, Reddy VY, Neuzil P, Spitzer SG, Rillig A, Ahapov K, Szili-Torok T
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.
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in
Heart Rhythm
May 1, 2022

Electrographic flow angle variability enables atrial rhythm discrimination

Hummel J, Kong MH, D'Arcy J, Perekrestenko D, Ruppersberg P
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.
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in
Heart Rhythm
May 1, 2022

Effect of pulmonary vein isolation on EGF-identified extra-pulmonary vein sources pre- v. post-ablation

Neuzil P, Kong MH, D'Arcy J, Petru J, Funasako M, Skoda J, Kralovec S, Mudroch M, Ruppersberg P, Reddy VY
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.
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in
Heart Rhythm
May 1, 2022

Atrial fibrillation time correlation of source activity with bipolar fractionation

Avitall B, Ruppersberg P, D'Arcy J, Lizama KS, Kong MH
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.
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in
Heart Rhythm
May 1, 2022

Electrogram fractionation is dependent on atrial fibrillation and its degree of organization

Verma A, Ruppersberg P, Kong MH, Rillig A, Szili-Torok T
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.
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in
Heart Rhythm
May 1, 2022

Use of a neural network to generate a whole atrium 3D reconstruction of electrographic flow and basket catheter geometry from biosignals alone

Gagyi R, Szili-Torok T, Grund A, Ahapov K, Ruppersberg P, Kong MH, Haeusser P
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.
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in
Heart Rhythm
August 1, 2021

Visualization of electrographic flow fields of increasing complexity during sinus rhythm, pacing and persistent AF

Avitall B, Kong MH, Ruppersberg P.
EGF mapping is an effective new technology capable of recording and visualizing complex atrial activity and may define ablation targets during AF.
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in
Heart Rhythm
August 1, 2021

Automated detection of QS unipolar morphology at electrographic flow mapping-identified sources pre- and post-ablation

Verma A, Kong MH, Neuzil P, Reddy VY, Spitzer SG, Szili-Torok T, Ruppersberg P
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.
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in
Heart Rhythm
August 1, 2021

Dependency of outcome on electrographic flow mapping parameters

Spitzer SG, Langbein A, Kong MH, Ruppersberg P, Rillig A, Szili-Torok T
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.
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in
Heart Rhythm
July 29, 2021

Analysis of behavior of AF sources with electrographic flow mapping

Haines DE, Kong MH, Ruppersberg P, Spitzer SG, Noelker G, Rillig A, Szili-Torok T
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.
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in
Heart Rhythm
June 8, 2021

First-in-human case report of 18-month spatiotemporal stability of electrographic flow mapping in persistent atrial fibrillation

Szili-Torok T, Kong MH, Wijchers S, Hoogendijk M, Ruppersberg P
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.
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in
Heart Rhythm
May 26, 2021

Functional electrographic flow patterns in patients with persistent atrial fibrillation predict outcome of catheter ablation

Szili-Torok T, Kis Z, Bhagwandien R, Wijchers S, Yap SC, Hoogendijk M, Dumas N, Haeusser P, Geczy T, Kong MH, Ruppersberg P
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.
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in
J Cardiovasc Electrophysiol
May 26, 2021

Functional electrographic flow patterns in patients with persistent AF predict outcome of catheter ablation

Szili-Torok T, Kis Z, Bhagwandien R, Wijchers S, Yap SC, Hoogendijk M, Dumas N, Haeusser P, Geczy T, Kong MH, Ruppersberg P
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.
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in
J Cardiovasc Electrophysiol‍
March 24, 2019

Comparing phase and electrographic flow mapping for persistent atrial fibrillation

Swerdlow M, Tamboli M, Alhusseini Ml, Moosvi N, Rogers AJ, Leef G, Wang PJ, Rillig A, Brachmann J, Sauer, WH, Ruppersberg P, Narayan SM, Baykaner T.
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.
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in
Pacing Clin Electrophysiol‍
February 11, 2019

Velocity characteristics of atrial fibrillation sources determined by electrographic flow mapping before and after catheter ablation

Bellmann B, Zettwitz M. Lin T, Ruppersberg P, Guttmann S, Tscholl V, Nagel P, Roser M, Landmesser U, Rillig A
Electrographic-Flow-(EGF)-Mapping is a novel method to identify Atrial Fibrillation (AF) drivers. Sources of excitation during AF can be characterized and monitored.
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in
Int J Cardiol‍
May 9, 2018

Identification of active atrial fibrillation sources and their discrimination from passive rotors using electrographical flow mapping

Bellmann B, Lin T, Ruppersberg P, Zettwitz M, Guttmann S, Tscholl V, Nagel P, Roser M, Landmesser U, Rillig A
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.
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in
Clin Res Cardiol‍