Endocardial-epicardial phase mapping of prolonged persistent atrial fibrillation recordings. High prevalence of dissociated activation patterns.

Ramanathan Parameswaran, Jonathan M. Kalman, Alistair Royse, John Goldblatt, Marco Larobina, Troy Watts, Tomos E. Walters, Chrishan J. Nalliah, Geoffrey Wong, Ahmed Al-Kaisey, Robert Douglas Anderson, Aleksandr Voskoboinik, Hariharan Sugumar, David Chieng, Prashanthan Sanders, Peter M. Kistler, Edward P. Gerstenfeld, Geoffrey Lee

Research output: Contribution to journalArticle


BACKGROUND: Endocardial-epicardial dissociation and focal breakthroughs in humans with atrial fibrillation (AF) have been recently demonstrated using activation mapping of short 10-second AF segments. In the current study, we used simultaneous endo-epi phase mapping to characterize endo-epi activation patterns on long segments of human persistent AF. METHODS: Simultaneous intraoperative mapping of endo- and epicardial lateral right atrium wall was performed in patients with persistent AF using 2 high-density grid catheters (16 electrodes, 3 mm spacing). Filtered unipolar and bipolar electrograms of continuous 2-minute AF recordings and electrodes locations were exported for phase analyses. We defined endocardial-epicardial dissociation as phase difference of ≥20 ms between paired endo-epi electrodes. Wavefronts were classified as rotations, single wavefronts, focal waves, or disorganized activity as per standard criteria. Endo-Epi wavefront patterns were simultaneously compared on dynamic phase maps. Complex fractionated electrograms were defined as bipolar electrograms with ≥5 directional changes occupying at least 70% of sample duration. RESULTS: Fourteen patients with persistent AF undergoing cardiac surgery were included. Endocardial-epicardial dissociation was seen in 50.3% of phase maps with significant temporal heterogeneity. Disorganized activity (Endo: 41.3% versus Epi: 46.8%, P=0.0194) and single wavefronts (Endo: 31.3% versus Epi: 28.1%, P=0.129) were the dominant patterns. Transient rotations (Endo: 22% versus Epi: 19.2%, P=0.169; mean duration: 590±140 ms) and nonsustained focal waves (Endo: 1.2% versus Epi: 1.6%, P=0.669) were also observed. Apparent transmural migration of rotational activations (n=6) from the epi- to the endocardium was seen in 2 patients. Electrogram fractionation was significantly higher in the epicardium than endocardium (61.2% versus 51.6%, P<0.0001). CONCLUSIONS: Simultaneous endo-epi phase mapping of prolonged human persistent AF recordings shows significant Endocardial-epicardial dissociation marked temporal heterogeneity, discordant and transitioning wavefronts patterns and complex fractionations. No sustained focal activity was observed. Such complex 3-dimensional interactions provide insight into why endocardial mapping alone may not fully characterize the AF mechanism and why endocardial ablation may not be sufficient. Graphic Abstract: A graphic abstract is available for this article.

Original languageEnglish
Pages (from-to)e008512
JournalCirculation. Arrhythmia and electrophysiology
Issue number8
Publication statusPublished - 1 Aug 2020


  • atrial fibrillation
  • atrium
  • endocardial-epicardial
  • fractionation
  • human
  • mapping
  • wavefronts

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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