ECG-Derived Respiratory Rate in Atrial Fibrillation.

Spyridon Kontaxis,Valentina D A Corino,Jesus Lazaro,Pablo Laguna,Frida Sandberg,Leif Sornmo,Raquel Bailon

doi:10.1109/tbme.2019.2923587

Abstract

The present study addresses the problem of estimating the respiratory rate from the morphological ECG variations in the presence of atrial fibrillatory waves (f-waves). The significance of performing f-wave suppression before respiratory rate estimation is investigated. The performance of a novel approach to ECG-derived respiration, named "slope range" (SR) and designed particularly for operation in atrial fibrillation (AF), is compared to that of two well-known methods based on either R-wave angle (RA) or QRS loop rotation angle (LA). A novel rule is proposed for spectral peak selection in respiratory rate estimation. The suppression of f-waves is accomplished using signal- and noise-dependent QRS weighted averaging. The performance evaluation embraces real as well as simulated ECG signals acquired from patients with persistent AF; the estimation error of the respiratory rate is determined for both types of signals. Using real ECG signals and reference respiratory signals, rate estimation without f-wave suppression resulted in a median error of 0.015 ± 0.021Hz and 0.019 ± 0.025Hz for SR and RA, respectively, whereas LA with f-wave suppression resulted in 0.034 ± 0.039Hz. Using simulated signals, the results also demonstrate that f-wave suppression is superfluous for SR and RA, whereas it is essential for LA. The results show that SR offers the best performance as well as computational simplicity since f-wave suppression is not needed. The respiratory rate can be robustly estimated from the ECG in the presence of AF.

Highlights

R ESPIRATORY dysfunction is associated with atrial fibrillation (AF) since reduced lung function, decreased oxygenation, hypercapnia, pulmonary hypertension, chronic obstructive pulmonary disease, and sleep-disordered breathing (SDB) have been identified as independent predictors of AF [1]–[4]
It is obvious that f-wave suppression deteriorates the performance of dRA(n) and dSR(n), while it significantly improves the performance of dLA(n)
For all considered respiratory rates, the median errors (μ, σ) Hz across all respiratory rates are below 0.01±0.01 Hz for signal-to-noise ratios (SNRs)> 12 dB without fwave suppression for slope range” (SR) and R-wave angle (RA), while f-wave suppression is required for loop rotation angle (LA) to achieve this particular limit

Summary

Introduction

R ESPIRATORY dysfunction is associated with atrial fibrillation (AF) since reduced lung function, decreased oxygenation, hypercapnia, pulmonary hypertension, chronic obstructive pulmonary disease, and sleep-disordered breathing (SDB) have been identified as independent predictors of AF [1]–[4]. Alterations in respiratory physiology due to a progressive decline in lung function may provoke alterations in cardiac structure and function through changes in atrial. The computation was performed by the ICTS “NANBIOSIS”, by the High Performance Computing Unit of the CIBER in Bioengineering, Biomaterials & Nanomedicine (CIBERBBN) at the University of Zaragoza. Laguna, are with CIBER de Bioingenierıa, Biomateriales y Nanomedicina (CIBER-BBN), Spain

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