Simulation of the Vectorcardiogram using a simple Volume Conductor Model

Abstract

In developed countries cardiac diseases are still the number one cause of death. For this reason, research aims to understand physiological and pathological processes of the heart. Proper functioning of the heart and therefore, the supply of organs with blood is triggered by electrical activity. For each contraction of ventricles an excitation of action potentials through the cardiac cells has preceded. Research to model the excitation of the heart is a relevant topic in order to understand ongoing coherences in the heart and be able to test cardiac devices in vitro. Therefore, in this model we demonstrate a physiological motivated abstracted simulation of the vectorcardiogram (VCG). In this model, we developed the conduction pathway of action potentials in the heart by applying a predefined propagation direction. The segmentation of heart was performed in order to distinguish between the different existing heart tissues. A tree structure was implemented, in-which each node of the tree represents a cardiac cell and each edge of the tree structure the transition between cells. Therefore, the edges of the conduction tree are weighted with the conduction velocity in the considered heart area. Due to the predefined conduction orientation a reduction in complexity can be achieved. The choice of a simple volume conductor facilitates the transfer from the source signals to the chosen observing points on the volume conductor. The simulation of a lead system similar to the Frank lead system shows morphological reasonable results, so that for further investigation the simulation of pathological scenarios is conceivable. Typical characteristics of the VCG like P-Loop, QRS-Loop and the T-Loop are clearly identifiable. The reduction of complexity promises to reach real-time capability using this model for testing in ECG-triggered medical devices [1].