PMID- 37492643
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20230727
IS  - 1664-042X (Print)
IS  - 1664-042X (Electronic)
IS  - 1664-042X (Linking)
VI  - 14
DP  - 2023
TI  - Impact of electrode orientation, myocardial wall thickness, and myofiber 
      direction on intracardiac electrograms: numerical modeling and analytical 
      solutions.
PG  - 1213218
LID - 10.3389/fphys.2023.1213218 [doi]
LID - 1213218
AB  - Intracardiac electrograms (iEGMs) are time traces of the electrical potential 
      recorded close to the heart muscle. We calculate unipolar and bipolar iEGMs 
      analytically for a myocardial slab with parallel myofibers and validate them 
      against numerical bidomain simulations. The analytical solution obtained via the 
      method of mirrors is an infinite series of arctangents. It goes beyond the solid 
      angle theory and is in good agreement with the simulations, even though bath 
      loading effects were not accounted for in the analytical calculation. At a large 
      distance from the myocardium, iEGMs decay as 1/R (unipolar), 1/R (2) (bipolar and 
      parallel), and 1/R (3) (bipolar and perpendicular to the endocardium). At the 
      endocardial surface, there is a mathematical branch cut. Here, we show how a 
      thicker myocardium generates iEGMs with larger amplitudes and how anisotropy 
      affects the iEGM width and amplitude. If only the leading-order term of our 
      expansion is retained, it can be determined how the conductivities of the bath, 
      torso, myocardium, and myofiber direction together determine the iEGM amplitude. 
      Our results will be useful in the quantitative interpretation of iEGMs, the 
      selection of thresholds to characterize viable tissues, and for future inferences 
      of tissue parameters.
CI  - Copyright (c) 2023 Leenknegt, Panfilov and Dierckx.
FAU - Leenknegt, Lore
AU  - Leenknegt L
AD  - Department of Mathematics, KU Leuven Campus KULAK, KU Leuven, Kortrijk, Belgium.
AD  - iSi Health-KU Leuven Institute of Physics-based Modeling for In Silico Health, KU 
      Leuven, Leuven, Belgium.
FAU - Panfilov, Alexander V
AU  - Panfilov AV
AD  - Department of Physics and Astronomy, Ghent University, Ghent, Belgium.
FAU - Dierckx, Hans
AU  - Dierckx H
AD  - Department of Mathematics, KU Leuven Campus KULAK, KU Leuven, Kortrijk, Belgium.
AD  - iSi Health-KU Leuven Institute of Physics-based Modeling for In Silico Health, KU 
      Leuven, Leuven, Belgium.
LA  - eng
PT  - Journal Article
DEP - 20230710
PL  - Switzerland
TA  - Front Physiol
JT  - Frontiers in physiology
JID - 101549006
PMC - PMC10364610
OTO - NOTNLM
OT  - EGM
OT  - bidomain
OT  - modeling
OT  - openCARP
OT  - simulations
OT  - solid angle
COIS- The authors declare that the research was conducted in the absence of any 
      commercial or financial relationships that could be construed as a potential 
      conflict of interest.
EDAT- 2023/07/26 06:42
MHDA- 2023/07/26 06:43
PMCR- 2023/07/10
CRDT- 2023/07/26 03:55
PHST- 2023/04/27 00:00 [received]
PHST- 2023/06/14 00:00 [accepted]
PHST- 2023/07/26 06:43 [medline]
PHST- 2023/07/26 06:42 [pubmed]
PHST- 2023/07/26 03:55 [entrez]
PHST- 2023/07/10 00:00 [pmc-release]
AID - 1213218 [pii]
AID - 10.3389/fphys.2023.1213218 [doi]
PST - epublish
SO  - Front Physiol. 2023 Jul 10;14:1213218. doi: 10.3389/fphys.2023.1213218. 
      eCollection 2023.