The mean firing rate of atrial fibrillation as estimated from the ECG evaluation using a biophysical model

The correspondence between the firing rates of atrial myocytes during atrial fibrillation and the dominant frequencies observed in the Fourier spectra of the corresponding surface ECG signals was studied. The observations were based on signals simulated using a biophysical model of the atria and of the volume conduction effects of the thorax. Different substrates for AF were generated, each resulting in a different type of AF dynamics. The results indicate that the full Fourier spectrum yields more information on the complexity of a particular variant of AF than the analysis of just its dominant frequency. The same applies to analyzing the spectra of multiple leads rather using just single lead signals.