Prof. Nele Vandersickel, Ghent University, Belgium

nothing to disclose

  • AT is a regular arrhythmia
  • AT has a large incidence:  2.3/1000 people.  Also ablation of atrial fibrillation can result in (complex) atrial tachycardia
  • Possible sources of AT

                    1. Rotating electrical waves:

  •   around a piece of scar
  •   around the veins
  •   around the mitral valve ...
  • ...

                    2. Focal source

Atrial tachycardia

Measurements give rise to a color map.

Needs to be interpreted manually: challenging and operator dependent.

Local activation time

Atrial tachycardia: current stategy

  • In electrophysiology there exist still no good algorithms to automatically detect these sources.
  • Therefore, we developed a novel methodology to determine these sources automatically: we describe the electrical propagation in the heart as a directed network: 

Directed Graph(DG)-mapping

Network theory has many applications...



Search algorithm

We can find rotating electrical waves very easily, they are just the cycles in our network

But was not yet applied to the heart...

Applied to CARTO (Biosense Webster)

Collaboration with AZ Sint-Jan Bruges (Belgium):

Prof. Dr. Mattias Duytschaever

Prof. Dr. Sebastien Knecht

Dr. Jan De Pooter

Dr. Teresa Strisciuglio

Optimization protocols

DG-mapping on clinical AT cases (Biosense Webster)

Also works for focal sources!

  • 31 cases tested post-ablation:
    Ablation target 100% correct
  • 51 (complex) cases: mechanism analyzed in detail during ablation with entrainment mapping:
    DGM 74% correct <-> expert with HDAM 64% correct
    We still have room for improvement of max 16%

16% were double loops, we are working on a methodology to determine the dominant loop

DG-mapping on clinical AT cases (Biosense Webster)

Applied to RHYTHMIA (Boston Scientific)

Collaboration with Lyric, Bordeaux (Prof. N. Derval)

Atrial tachycardia

Some examples:

Localized reentry at 2 o’clock of the MV

Atrial tachycardia

Some examples:

Localized reentry at the anterior wall

Atrial tachycardia

Some examples:

Mitral valve reentry

Atrial tachycardia

Some examples:

Reentry around the right pulmonary vein

Atrial tachycardia

Illustration of A13 - Case 1 - period 215 ms


29 cases tested post-ablation (preliminary results):

  • 25 cases (86%): DGM had the same ablation target as performed (albeit with an additional loop with a common isthmus!)
  • 2 cases (7%) were uninterpretable
  • 2 cases DGM suggested in addition to the performed ablation target, an additional ablation target which was not performed

DG-mapping can automatically find the mechanism of an AT without manual interpretation of the colormap of the atrium

  1. ​Operator independent and in some cases better than the operator: DG-mapping removes intuition and multiple interpretations, is thus more robust

  2. Faster: DG-mapping is almost instantaneous

  3. Goal? no more entrainment mapping (PPI)


Summary on AT

Future perspective: DG mapping on Atrial fibrillation

PM = phase mapping (like TOPERA uses)

Martinez-Mateu, Jalife, Saiz et al, PLOS COMP BIOLOGY (PM analysis)

Research: Van Nieuwenhuyse et al, to be submitted

Presentation number D-PO04-174

Future perspetive: DG mapping on Atrial fibrillation

Enid Van Nieuwenhuyse




Alexander Panfilov

Clinical expert

Mattias Duytschaever

Nele Vandersickel

Ghent University and AZ-Sint Jan Bruges

Clinical expert

Clinical expert

Dr. Sebastien Knecht

Teresa Strisciuglio


Lars Lowie

Network specialists

Clinical expert

Jan Goedgebeur

Nico Van Cleemput

Anthony de Molder



Javier Saiz

Laura Martinez-Mateu

Nicolas Derval

Heart Rhythm

By Nele Vandersickel

Heart Rhythm

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