Influence of Limb Electrodes Placement on the Simulated ECG Signals

The influence of the limb electrodes' placement on the simulated standard ECG signals during premature ventricular contractions (PVC) using a patient-specific torso model was studied in this article. Simulated electrical activation in the ventricular model was started at the position of the initial ectopic activation in the area near the His bundle. The propagation of electrical activation in the ventricular model was modeled using bidomain reaction-diffusion (RD) equations with the ionic transmembrane current density defined by the modified FitzHugh-Nagumo equations. The torso was modeled as a homogeneous passive volume conductor. The RD equations were numerically solved in the Comsol Multiphysics environment. Simulated body surface potentials (BSPs) and corresponding ECG signals were compared with those measured in a real PVC patient. The shape of simulated ECG signals during the PVC varied with the changed positions of the limb electrodes on the torso model, resulting in 11% average change of QRS complex amplitudes and 9% average change of correlation coefficients between simulated and measured QRS complexes in ECG leads I, II, and III.