Improved local activation time annotation of fractionated atrial electrograms for atrial mapping

Improved local activation time annotation of fractionated atrial electrograms for atrial mapping

Abdi, Bahareh (TU Delft Circuits and Systems)
Hendriks, R.C. (TU Delft Circuits and Systems)
van der Veen, A.J. (TU Delft Circuits and Systems)
de Groot, N.M.S. (TU Delft Biomechanical Engineering; Erasmus MC)

Biomechanical Engineering

2020

Background: Local activation time (LAT) annotation in unipolar electrograms is complicated by interference from nonlocal atrial activities of neighboring tissue. This happens due to the spatial blurring that is inherent to electrogram recordings. In this study, we aim to exploit multi-electrode electrogram recordings to amplify the local activity in each electrogram and subsequently improve the annotation of LATs. Methods: An electrogram array can be modeled as a spatial convolution of per cell transmembrane currents with an appropriate distance kernel, which depends on the cells’ distances to the electrodes. By deconvolving the effect of the distance kernel from the electrogram array, we undo the blurring and estimate the underlying transmembrane currents as our desired local activities. However, deconvolution problems are typically highly ill-posed and result in unstable solutions. To overcome this issue, we propose to use a regularization term that exploits the sparsity of the first-order time derivative of the transmembrane currents. Results: We perform experiments on simulated two-dimensional tissues, as well as clinically recorded electrograms during paroxysmal atrial fibrillation. The results show that the proposed approach for deconvolution can improve the annotation of the true LAT in the electrograms. We also discuss, in summary, the required electrode array specifications for an appropriate recording and subsequent deconvolution. Conclusion: By ignoring small but local deflections, algorithms based on steepest descent are prone to generate smoother activation maps. However, by exploiting multi-electrode recordings, we can efficiently amplify small but local deflections and reveal new details in the activation maps that were previously missed.

Atrial fibrillation
Atrial mapping
Deconvolution
Electrogram model
Electrograms
Fractionation
Local activation time estimation
Transmembrane current

http://resolver.tudelft.nl/uuid:c08824c2-fae1-46a6-976c-98ec875602f2

https://doi.org/10.1016/j.compbiomed.2019.103590

0010-4825

Computers in Biology and Medicine, 117

Institutional Repository

journal article

© 2020 Bahareh Abdi, R.C. Hendriks, A.J. van der Veen, N.M.S. de Groot