Wavelet leader multifractal analysis of heart rate variability in atrial fibrillation

J Electrocardiol. 2018 Nov-Dec;51(6S):S83-S87. doi: 10.1016/j.jelectrocard.2018.08.030. Epub 2018 Aug 23.

Abstract

Background: Accurate and timely detection of atrial fibrillation (AF) episodes is important in primarily and secondary prevention of ischemic stroke and heart-related problems. In this work, heart rate regularity of ECG inter-beat intervals was investigated in episodes of AF and other rhythms using a wavelet leader based multifractal analysis. Our aim was to improve the detectability of AF episodes.

Methods: Inter-beat intervals from 25 ECG recordings available in the MIT-BIH atrial fibrillation database were analysed. Four types of annotated rhythms (atrial fibrillation, atrial flutter, AV junctional rhythm, and other rhythms) were available. A wavelet leader based multifractal analysis was applied to 5 min non-overlapping windows of each recording to estimate the multifractal spectrum in each window. The width of the multifractal spectrum was analysed for its discrimination power between rhythm episodes.

Results: In 10 of 25 recordings, the width of multifractal spectrum was significantly lower in episodes of AF than in other rhythms indicating increased regularity during AF. High classification accuracy (95%) of AF episodes was achieved using a combination of features derived from the multifractal analysis and statistical central moment features.

Conclusions: An increase in the regularity of inter-beat intervals was observed during AF episodes by means of multifractal analysis. Multifractal features may be used to improve AF detection accuracy.

Keywords: Atrial fibrillation; Inter-beat (RR) intervals; Multifractal analysis; Wavelet leaders.

MeSH terms

  • Atrial Fibrillation / diagnosis*
  • Atrial Fibrillation / physiopathology*
  • Databases, Factual
  • Diagnosis, Computer-Assisted
  • Electrocardiography / methods*
  • Fractals*
  • Heart Rate / physiology
  • Humans