1. Approaches to Ablate Persistent in 2019: The Problems with Mapping AF
Gregory F. Michaud, MD
Professor of Medicine
Vanderbilt University School of Medicine
Chief, Arrhythmia Service VHVI
Western AF 2019
Park City , UT

2. Disclosures 2019 Boston Scientific – Honoraria Medtronic – Honoraria
St Jude Medical – Honoraria
Biosense-Webster – Honoraria
Biotronik – Honoraria
Pfizer – Consulting
S4 Medical - Consulting
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3. Targets to Enhance Success of Persistent AF
Identification and ablation of triggers
Atrial fibrosis/scar
Ganglionated plexus ablation
Anatomic: PVI, posterior LA, LAA isolation?
Identifying and ablating critical mechanisms for persistence
Foci
Rotors
????

4. Nattel Circ Research 2018
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5. Rotors
Wavefronts bend and possibly break when they encounter complex anatomy or tissue heterogeneity
Wavefronts under certain conditions can rotate around a phase singularity which represents the point of maximal curvature, slowest conduction velocity and shortest refractory period
Unlike reentry in the leading circle theory, the core of rotors can migrate
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6. Phase Singularities Tend to Move
Waks, Josephson Arrhythmia Electrophysiol Rev 2014
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7. Experimental sheep models of atrial fibrillation with optical mapping show rotors (after some math)
Gray RA, Pertsov AM, Jalife J. Spatial and temporal organization during cardiac fibrillation. Nature. 1998; 392:75–78.
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8. Rotors demonstrated by FIRM phase mapping are often stable
Compared with optical mapping, basket catheters have low resolution
Not a unifying theory based on other data
Naryan

9. Some mapping systems do not rely on contact electrodes: meandering rotation
Cardioinsight Haissaguerre Circ 2014
Acutus high density noncontact intracardiac map

10. Alternative hypotheses raised by activation mapping in humans…
Alessie, Waldo and Kalman
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11. Two-Layer Hypothesis in Long-Standing Persistent AF
Numerous, transient and widespread epi to endo (or the other way around) breakthrough
de Groot NMS, Houben RP, Smeets JL, et al. Circulation. 2010;122:

12. Hansen, JACCEP 2017 Jun;3(6):531-546. doi: 10.1016 Federov lab OSU
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13. Surgical Epicardial Mapping of Persistent AF Patients
Activation sequence maps of bipolar and unipolar activation (500 electrodes for 32 s)
No reentry was observed
Foci – drivers (QS) and breakthroughs
Lee S, Circ Arrhythm Electrophysiol Oct 23
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14. Wannabe reentry VanderbiltHeart.com
Lee S, Sahadevan J, Khrestian CME, Cakulev I, Markowitz A, Waldo AL, Simultaneous bi-atrial high density (512) electrodes) epicardial mapping of persistent atrial fibrillation in patients: new insights into mechanism of its maintenance. Circ Arrhythm Electrophysiol Oct 23;doi: /CIRCULATIONAHA
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15. Continued obstacles to AF mapping…
From preclinical data, AF mapping requires high resolution, simultaneously and continuously recorded electrograms.
Complex transformation is required to get from EGMs to phase maps, which may create artifact, particularly in low resolution systems.
Epicardial and endocardium are dissociated.
Focal sources may actually represent breakthrough points and not clear targets.
How do we interpret what we’re seeing without a solid understanding of predominant mechanisms?
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16. Thank you
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