A method for quantifying recurrent patterns of local wavefront direction during atrial fibrillation

Comput Biol Med. 2017 Oct 1:89:497-504. doi: 10.1016/j.compbiomed.2017.08.027. Epub 2017 Sep 1.

Abstract

Introduction: Spiral wave reentry is a potential mechanism of atrial fibrillation (AF), but is difficult to differentiate clinically from multiple wavelet breakup using standard bipolar recordings. We developed a new methodology using bipolar recordings to estimate the direction of local activation wavefronts during AF by calculating the electrogram conformation (Egm-C). We subsequently used recurrence quantification analysis (RQA) of Egm-C to differentiate regions of spiral wave reentry from wavelet breakup.

Methods: A 2D computer simulation was created with regions containing a stable spiral wave and also regions of wavebreak. A grid of 40 × 40 unipolar electrodes was superimposed. At each site, the actual wavefront direction (WD) was determined by comparing relative activation timings of the local intracellular recordings, and the estimated wavefront direction (Egm-C) was determined from the morphology of the local bipolar electrogram. RQA of Egm-C was compared to RQA of actual WD in order to differentiate AF mechanisms.

Results: RQA of actual WD and Egm-C both distinguished regions of spiral wave reentry from wavelet breakup with high correlation between the two methods (recurrence rate, r = 0.96; determinism, r = 0.61; line max, r = 0.95; entropy, r = 0.84; p < 0.001 for all). In areas of stable spiral wave reentry, the recurrence plots of both Egm-C and actual WD demonstrated stable, periodic dynamics, while regions of wavelet breakup demonstrated chaotic behavior largely devoid of repetitive activation patterns.

Conclusion: Calculation of Egm-C allows RQA to be performed on bipolar electrograms during AF and differentiates regions of spiral wave reentry from multiple wavelet breakup.

Keywords: Atrial fibrillation; Computer modeling; Multiple wavelet reentry; Nonlinear dynamics; Recurrence quantification analysis; Spiral wave; Wavefront direction.

MeSH terms

  • Atrial Fibrillation / physiopathology*
  • Computer Simulation*
  • Electrocardiography*
  • Humans
  • Models, Cardiovascular*