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 journalArticlepeer-review

27 Citations (Scopus)


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.

Original languageEnglish
Article numbere008512
Pages (from-to)792-801
Number of pages10
JournalCirculation: Arrhythmia and Electrophysiology
Issue number8
Publication statusPublished - 1 Aug 2020
Externally publishedYes


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


Dive into the research topics of 'Endocardial-epicardial phase mapping of prolonged persistent atrial fibrillation recordings: high prevalence of dissociated activation patterns'. Together they form a unique fingerprint.

Cite this