Preservation of spatial transfer coefficients in surface ECG atrial fibrillation analysis

Abstract This study demonstrates empirically that rhe transfer coeflcients, relating epicardial potentids and ECG potentials, are preserved approximately throughout several seconds of real atrial fibrillation (AF) recordings. The methodology has consisted of applying independent component analysis over an AF segment to obtain both atrial and ventricular activities along with the mixing matrix of the process, whose enrries can be associated to the spatial filter coefJicients that relate cardiac activities with ECG potentials. Next, it is demonstruted that the coeflcients from one AF segment can be used to extract the atrial activity (AA) present in different segments of the same recording. thus proving rhe preservation of the spatial filters. Results over 32 AF segments Show a mean crosscorrelation of Bdp = 81 5% between the directly estimated AA and the estimated using the preservafion proper@ Changes in spectral concentration fmm one case to the other ( ΔSC_dp, = 1.4%) are negligible.