Far-field effect in unipolar electrograms revisited

TY - JOUR

T1 - Far-field effect in unipolar electrograms revisited

T2 - High-density mapping of atrial fibrillation in humans

AU - Podziemski, Piotr

AU - Kuklik, Pawel

AU - van Hunnik, Arne

AU - Zeemering, Stef

AU - Maesen, Bart

AU - Schotten, Ulrich

PY - 2015/8

Y1 - 2015/8

N2 - Unipolar electrogram can detect local as well as remote electrical activity of the heart. Information on how the amplitude and morphology of the recorded signal changes with the distance from the source tissue undergoing depolarization can help to better understand unipolar electrograms fractionation and provide insights into the passive conduction properties of the atrial tissue. Ten second unipolar atrial fibrillation (AF) electrograms were recorded using high-density electrode array from the posterior left atrium (LA) and right atrium (RA) of 19 (8 persistent - PERS & 11 paroxysmal - PAF) AF patients undergoing cardiac surgery. Conduction along lines of conduction block was detected in the recorded activation patterns by a proposed automated algorithm. Changes of the amplitude of the unipolar electrogram with increasing distance from the conduction blocks were assessed and compared to predictions of a theoretical model. For each recording, the median far-field decay space constant (FF0.5) was calculated. Overall, we found a significant difference between FF0.5 for patients with paroxysmal and persistent AF. Estimation of maximum FF0.5 from both RA and LA resulted in a mean FF0.5 of 1.5±0.2 mm for PERS patients and 2.1±0.6 mm for PAF patients (p=0.03). Moreover, detected conduction blocks demonstrated high spatial organization and appeared in distinctive areas of the mapped area in all patients, regardless of the type of AF, while the total number of detected block lines was higher in PERS patients.

AB - Unipolar electrogram can detect local as well as remote electrical activity of the heart. Information on how the amplitude and morphology of the recorded signal changes with the distance from the source tissue undergoing depolarization can help to better understand unipolar electrograms fractionation and provide insights into the passive conduction properties of the atrial tissue. Ten second unipolar atrial fibrillation (AF) electrograms were recorded using high-density electrode array from the posterior left atrium (LA) and right atrium (RA) of 19 (8 persistent - PERS & 11 paroxysmal - PAF) AF patients undergoing cardiac surgery. Conduction along lines of conduction block was detected in the recorded activation patterns by a proposed automated algorithm. Changes of the amplitude of the unipolar electrogram with increasing distance from the conduction blocks were assessed and compared to predictions of a theoretical model. For each recording, the median far-field decay space constant (FF0.5) was calculated. Overall, we found a significant difference between FF0.5 for patients with paroxysmal and persistent AF. Estimation of maximum FF0.5 from both RA and LA resulted in a mean FF0.5 of 1.5±0.2 mm for PERS patients and 2.1±0.6 mm for PAF patients (p=0.03). Moreover, detected conduction blocks demonstrated high spatial organization and appeared in distinctive areas of the mapped area in all patients, regardless of the type of AF, while the total number of detected block lines was higher in PERS patients.

KW - Atrial Fibrillation

KW - Electrophysiologic Techniques, Cardiac

KW - Heart Atria

KW - Heart Block

KW - Heart Conduction System

KW - Heart Rate

KW - Humans

U2 - 10.1109/EMBC.2015.7319681

DO - 10.1109/EMBC.2015.7319681

M3 - SCORING: Journal article

C2 - 26737581

VL - 2015

SP - 5680

EP - 5683

JO - Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference

JF - Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference

SN - 2375-7477

ER -