Ramanathan Parameswaran1, Christophe P Teuwen2, Troy Watts3, Chrishan J Nalliah4, Alistair Royse5, John Goldblatt6, Marco Larobina6, Prashanthan Sanders7, Peter Kistler8, Andres Orozco-Duque9, Geoffrey Lee4, Jonathan M Kalman10. 1. Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia; Department of Medicine, University of Melbourne, Melbourne, Australia; Heart Centre, Alfred Hospital, Melbourne, Australia. 2. Department of Cardiology, Erasmus Medical Center, Rotterdam, the Netherlands. 3. Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia. 4. Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia; Department of Medicine, University of Melbourne, Melbourne, Australia. 5. Department of Medicine, University of Melbourne, Melbourne, Australia; Department of Cardiothoracic Surgery, Royal Melbourne Hospital, Melbourne, Australia. 6. Department of Cardiothoracic Surgery, Royal Melbourne Hospital, Melbourne, Australia. 7. Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia. 8. Department of Medicine, University of Melbourne, Melbourne, Australia; Heart Centre, Alfred Hospital, Melbourne, Australia; Baker IDI Heart and Diabetes Institute, Melbourne, Australia. 9. Department of Applied Sciences, Instituto Tecnológico Metropolitano, Medellín, Colombia. 10. Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia; Department of Medicine, University of Melbourne, Melbourne, Australia. Electronic address: jon.kalman@mh.org.au.
Abstract
OBJECTIVES: The goal of this study was to describe functional endocardial-epicardial dissociation (FEED), signal complexities, and three-dimensional activation dynamics of the human atrium with structural heart disease (SHD). BACKGROUND: SHD commonly predisposes to arrhythmias. Although progressive remodeling is implicated, direct demonstration of FEED in the human atrium has not been reported previously. METHODS: Simultaneous intraoperative mapping of the endocardial and epicardial lateral right atrial wall was performed by using 2 high-density grid catheters during sinus rhythm, pacing drive (600 ms and 400 ms cycle length), and premature extrastimulation (PES). Unipolar electrograms (EGMs) were exported into custom-made software for activation and phase mapping. Difference of ≥20 ms between paired endocardial and epicardial electrodes defined dissociation. EGMs with ≥3 deflections were classified as fractionated. RESULTS: Sixteen patients (mean age 60.5 ± 4.1 years; 18.7% with a history of atrial fibrillation) with SHD (43% ischemia, 57% valvular disease) were included. A total of 9,218 EGMs were analyzed. Compared with sinus rhythm, phase and activation analyses showed significant FEED during pacing at 600 ms and 400 ms (phase mapping 22.4% vs. 10% [p < 0.0001] and 25.8% vs. 10% [p < 0.0001], respectively; activation mapping 25.4% vs. 7.8% [p < 0.0001] and 27.7% vs. 7.8% [p < 0.0001]) and PES (phase mapping 34% vs. 10% [p < 0.0001]; activation mapping 29.5% vs. 7.8% [p < 0.0001]). Fractionated EGMs occurred significantly more during PES compared with sinus rhythm (50.2% vs. 39.5%; p < 0.0001). Activation patterns differed significantly during pacing drive and PES, with preferential epicardial exit during the latter (15.9% vs. 13.8%; p = 0.046). CONCLUSIONS: Simultaneous endocardial-epicardial mapping revealed significant FEED with signal fractionation and preferential epicardial breakthroughs with PES. Such complex three-dimensional interaction in electrical activation provides mechanistic insights into atrial arrhythmogenesis with SHD.
OBJECTIVES: The goal of this study was to describe functional endocardial-epicardial dissociation (FEED), signal complexities, and three-dimensional activation dynamics of the human atrium with structural heart disease (SHD). BACKGROUND: SHD commonly predisposes to arrhythmias. Although progressive remodeling is implicated, direct demonstration of FEED in the human atrium has not been reported previously. METHODS: Simultaneous intraoperative mapping of the endocardial and epicardial lateral right atrial wall was performed by using 2 high-density grid catheters during sinus rhythm, pacing drive (600 ms and 400 ms cycle length), and premature extrastimulation (PES). Unipolar electrograms (EGMs) were exported into custom-made software for activation and phase mapping. Difference of ≥20 ms between paired endocardial and epicardial electrodes defined dissociation. EGMs with ≥3 deflections were classified as fractionated. RESULTS: Sixteen patients (mean age 60.5 ± 4.1 years; 18.7% with a history of atrial fibrillation) with SHD (43% ischemia, 57% valvular disease) were included. A total of 9,218 EGMs were analyzed. Compared with sinus rhythm, phase and activation analyses showed significant FEED during pacing at 600 ms and 400 ms (phase mapping 22.4% vs. 10% [p < 0.0001] and 25.8% vs. 10% [p < 0.0001], respectively; activation mapping 25.4% vs. 7.8% [p < 0.0001] and 27.7% vs. 7.8% [p < 0.0001]) and PES (phase mapping 34% vs. 10% [p < 0.0001]; activation mapping 29.5% vs. 7.8% [p < 0.0001]). Fractionated EGMs occurred significantly more during PES compared with sinus rhythm (50.2% vs. 39.5%; p < 0.0001). Activation patterns differed significantly during pacing drive and PES, with preferential epicardial exit during the latter (15.9% vs. 13.8%; p = 0.046). CONCLUSIONS: Simultaneous endocardial-epicardial mapping revealed significant FEED with signal fractionation and preferential epicardial breakthroughs with PES. Such complex three-dimensional interaction in electrical activation provides mechanistic insights into atrial arrhythmogenesis with SHD.
Authors: Aleksei V Mikhailov; Anuradha Kalyanasundaram; Ning Li; Shane S Scott; Esthela J Artiga; Megan M Subr; Jichao Zhao; Brian J Hansen; John D Hummel; Vadim V Fedorov Journal: J Mol Cell Cardiol Date: 2020-10-29 Impact factor: 5.000