On the relation of the independent components of fibrillation to ionic currents in the atrial muscle cell

Fibrillation is a dangerous episode in cardiac muscle and so any new work towards the understanding of this process is important to the development of new methods in diagnosis and therapy. In this work we have used surface and intracardiac ECGs of patients with chronic atrial fibrillation (AF). By means of the blind source separation (BSS) algorithm, which is a well-known method in signal processing, the AF process has been deconstructed into its independent components and we can show that from the point of view of these components the surface ECGs contain the same information as the intra atria electrogram. Then the important components have been related to the ionic currents of the cell. We show that one of these independent components can be influenced by the sodium-calcium exchange current, (iNaCa) and hence by controlling iNaCa we may be able to control the fibrillation process. This new idea can bring about new strategies in drug therapy.