Impact of mechanical deformation on pseudo-ECG: a simulation study

Aims Electrophysiological simulations may help to investigate causes and possible treatments of ventricular conduction disturbances. Most electrophysiological models do not take into account that the heart moves during the cardiac cycle. We used an electro-mechanical model to study the effect of mechanical deformation on the results of electrophysiological simulations. Methods and results Pseudo-electrocardiogram (ECG) were generated from the propagation of electrical signals in tissue slabs undergoing active mechanical deformation. We used the mono-domain equation for electrophysiology with the Bueno-Orovio ionic model and a fully incompressible Guccione-Costa hyperelastic law for the mechanics with the Nash-Panfilov model for the active force. We compared a purely electrophysiological approach (PE) with mono-directional (MD) and bi-directional (BD) electromechanical coupling strategies. The numerical experiments showed that BD and PE simulations led to different S-and T-waves. Mono-directional simulations generally approximated the BD ones, unless fibres were oriented along one short axis of the slab. When present, notching in the QRS-complex was larger in MD than in BD simulations. Conclusions Tissue deformation has to be taken into account when estimating the S-and T-wave of the ECG in electrophysiological simulations.