Author + information
- Received February 13, 2020
- Revision received March 24, 2020
- Accepted April 8, 2020
- Published online July 20, 2020.
- Tomos E. Walters, MBBS, PhDa,∗,
- Geoffrey Lee, MBBS, PhDb,∗,
- Adam Lee, MBBS, MMEDa,
- Richard Sievers, BSa,
- Jonathan M. Kalman, MBBS, PhDb and
- Edward P. Gerstenfeld, MS, MDa,∗ (, )@ed_gerst
- aSection of Cardiac Electrophysiology, Department of Medicine, University of California-San Francisco, San Francisco, California
- bDepartment of Cardiology, The Royal Melbourne Hospital and Department of Medicine, The University of Melbourne, Melbourne, Australia
- ↵∗Address for correspondence:
Dr. Edward P. Gerstenfeld, Section of Cardiac Electrophysiology, University of California-San Francisco, 500 Parnassus Avenue, San Francisco, California 94143.
Objectives This study sought to define the extent and spatial distribution of endocardial-epicardial dissociation (EED) in a swine model.
Background The mechanisms underlying persistent atrial fibrillation (AF) remain unclear.
Methods Sixteen swine underwent simultaneous endocardial and epicardial mapping using 32-electrode grid catheters. This included 6 swine with rapid atrial pacing–induced atrial remodeling. Three right atrial (RA) and 3 left atrial (LA) regions were mapped during sinus rhythm, atrial pacing, acute or persistent AF, and AF in the presence of pericardial acetylcholine. Unipolar electrogram recordings over 10-s epochs underwent offline phase analysis using customized software. Regional activation patterns on paired surfaces and the instantaneous phase at each matched electrode location were analyzed. EED was defined as paired electrodes out of phase by ≥20 ms.
Results The mean distance between matched endocardial-epicardial electrode pairs was 4.4 ± 1.8 mm. During episodes of AF, rotational activations with ≥3 full rotations were not seen. EED was seen during 34.4 ± 16.4% of mapped time periods: LA > RA, persistent > acute AF in the LA, and acetylcholine-induced > acute AF in both atria (p < 0.05 for each). Most marked EED in persistent AF was in the LA appendage (47.2 ± 3.7%) and the LA posterior wall (50.3 ± 4.7%).
Conclusions Marked EED was seen in a swine model of AF, particularly during persistent AF. There was significantly more EED in the LA than the RA and, particularly, in the LA PW and LAA. Mapping approaches limited to the endocardium may not sufficiently characterize the complexity of AF.
↵∗ Dr. Walters and Dr. Lee contributed equally to this work and are joint first authors.
The NavX Velocity mapping system and multielectrode mapping catheters were provided for this study without charge by Abbott Inc. The neurostimulators and pacing leads used for device implantation were provided without charge by Medtronic Inc. The study was supported by the Todd Spieker fund. Dr. Gerstenfeld has received an investigator-initiated research grant from Abbott Inc. for the animals used in this study; and has received lecture honoraria from Medtronic, Inc. and Abbott. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
- Received February 13, 2020.
- Revision received March 24, 2020.
- Accepted April 8, 2020.
- 2020 American College of Cardiology Foundation
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