Simulation of atrial electrophysiology and body surface potentials for normal and abnormal rhythm.

The effect of different atrial electrical activation sequences (sinus rhythm and atrial flutter circling in the right atrium) on the body surface potentials is investigated in this study. A realistic volume conductor model consisting of atria, lungs, chest and blood masses is generated from image stacks recorded by magnetic resonance imaging. The electrical sources-the transmembrane potentials-within the atrial volumetric model are simulated for different atrial rhythms employing a cellular automaton capable of considering different parameters depending on the specific properties of the tissues. The potentials on the torso surface are computed applying the finite element method for solving the differential equations derived from the bidomain theory. Both the simulated atrial activation patterns and the computed torso potentials for atrial sinus rhythm and atrial flutter are in qualitatively and quantitatively good agreement with data measured in humans. The simulation of body surface potentials generated by different electrical activation sequences in the atria or ventricles allows testing and assessing noninvasive imaging of cardiac electrophysiology, as both the potentials on the body surface and the reference activation in the heart are available.