Bipolar electrogram Shannon entropy at sites of rotational activation implications for ablation of atrial fibrillation

Ganesan, Anand N., Kuklik, Pawel, Lau, Dennis H., Brooks, Anthony G., Baumert, Mathias, Lim, Wei Wen, Thanigaimani, Shivshankar, Nayyar, Sachin, Mahajan, Rajiv, Kalman, Jonathan M., Roberts-Thomson, Kurt C., and Sanders, Prashanthan (2013) Bipolar electrogram Shannon entropy at sites of rotational activation implications for ablation of atrial fibrillation. Circulation: Arrhythmia and Electrophysiology, 6 (1). pp. 48-57.

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Background - The pivot is critical to rotors postulated to maintain atrial fibrillation (AF). We reasoned that wavefronts circling the pivot should broaden the amplitude distribution of bipolar electrograms because of directional information encoded in these signals. We aimed to determine whether Shannon entropy (ShEn), a measure of signal amplitude distribution, could differentiate the pivot from surrounding peripheral regions and thereby assist clinical rotor mapping. Methods and Results - Bipolar electrogram recordings were studied in 4 systems: (1) computer simulations of rotors in a 2-dimensional atrial sheet; (2) isolated rat atria recorded with a multi-electrode array (n=12); (3) epicardial plaque recordings of induced AF in hypertensive sheep (n=11); and (4) persistent AF patients (n=10). In the model systems, rotation episodes were identified, and ShEn calculated as an index of amplitude distribution. In humans, ShEn distribution was analyzed at AF termination sites and with respect to complex fractionated electrogram mean. We analyzed rotation episodes in simulations (4 cycles) and animals (rats: 14 rotors, duration 80±81 cycles; sheep: 13 rotors, 4.2±1.5 cycles). The maximum ShEn bipole was consistently colocated with the pivot zone. ShEn was negatively associated with distance from the pivot zone in simulated spiral waves, rats, and sheep. ShEn was modestly inversely associated with complex fractionated electrogram; however, there was no relationship at the sites of highest ShEn. Conclusions - ShEn is a mechanistically based tool that may assist AF rotor mapping.

Item ID: 62535
Item Type: Article (Research - C1)
ISSN: 1941-3084
Keywords: Arrhythmia, Atrial fibrillation, Electrophysiology, Mapping
Copyright Information: © 2012 American Heart Association, Inc.
Funders: Heart Rhythm Society, National Heart Foundation of Australia, National Health and Medical Research Council of Australia (NHMRC), Australian Research Council (ARC), University of Adelaide
Date Deposited: 19 Mar 2020 02:29
FoR Codes: 11 MEDICAL AND HEALTH SCIENCES > 1102 Cardiovascular Medicine and Haematology > 110201 Cardiology (incl Cardiovascular Diseases) @ 100%
SEO Codes: 92 HEALTH > 9201 Clinical Health (Organs, Diseases and Abnormal Conditions) > 920103 Cardiovascular System and Diseases @ 100%
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