Investigation of Atrial Vulnerability by Analysis of the Sinus Node EG From Atrial Fibrillation Models Using a Phase Synchronization Method

Abstract

Abstract-Atrial fibrillation (AF) can result in life-threatening arrhythmia, and a clinically convenient means for detecting vulnerability remains elusive. We investigated atrial vulnerability by analyzing the sinus electrogram (EG) from AF animal models using a phase synchronization method. Using acetylcholine (ACh)-induced acute canine AF models (n = 4), a total of 128 electrical leads were attached to the surface of the anterior and posterior atria, and the pulmonary veins to form an electrocardiological mapping system. ACh was injected at varying concentrations with ladder-type adjustments. Sinus EGs and induced AF EGs that pertain to specific ACh concentrations were recorded. We hypothesize that the atrial vulnerability may be correlated with the Shannon entropy (SE) of the phase difference matrix that is extracted from the sinus EG. Our research suggests that the combination of SE with the synchronization method enables the sinus node EG to be analyzed and used to estimate atrial vulnerability.

Several insights into the preprocessing of electrograms in atrial fibrillation for dominant frequency analysis

“…8 flexible patches containing a total of 128 unipolar electrodes were carefully attached to right atrium, left atrium and the root of pulmonary veins. AF was induced by rapid pacing (with a frequency of 20 Hz) at the atrial appendages of the canine heart with an intravenous injection of acetylcholine (see details of experimental procedures and mapping sites in [ 21 ] and [ 22 ]). Then real data were recorded at a sampling frequency of 2 kHz from the 128-channel unipolar epicardial mapping system developed by the Electrophysiology Laboratory in Fudan University [ 21 , 22 ].…”

“…AF was induced by rapid pacing (with a frequency of 20 Hz) at the atrial appendages of the canine heart with an intravenous injection of acetylcholine (see details of experimental procedures and mapping sites in [ 21 ] and [ 22 ]). Then real data were recorded at a sampling frequency of 2 kHz from the 128-channel unipolar epicardial mapping system developed by the Electrophysiology Laboratory in Fudan University [ 21 , 22 ]. The hardware of our mapping system included amplifying and filtering, and the hardware filters were a notch filter at 50 Hz and a band pass filter (BPF) at 3–500 Hz.…”

Quantitative description of the 3D regional mechanics of the left atrium using cardiac magnetic resonance imaging

“…Current methods of cardiac mechanical function assessment are based on imaging methods such as computed tomography (Nakazato et al 2011), magnetic resonance imaging (MRI) (Bergvall et al 2006, Moore et al 2000, magnetic resonance velocitometry (Wong et al 2009), positron emission tomography (Shen et al 1999, Slart et al 2004, echocardiography (Thomas 2007, Corsi et al 2005 and catheterization (Gepstein et al 1997). Regional function of the atria has been assessed using several approaches (Stefanadis et al 2001) including: pulsed wave and colour Doppler tissue imaging (Thomas et al 2003), two-dimensional speckle-tracking echocardiography (Appleton et al 2009, Sun et al 2013, Henein et al 2012, velocity vector imaging (Kojima et al 2012), strain Doppler imaging (Matsumoto et al 2006), cardiac MRI (Nori et al 2009, Muellerleile et al 2012 and three-dimensional (3D) electrophysiological mapping systems (Kuklik et al 2010, Chen et al 2012. Ultrasound-based methods characterize regional function through analysis of the motion of a fixed point in a given region, thus not providing the true average function of the whole region.…”