ECGSIM: an interactive tool for studying the genesis of QRST waveforms

Area of Science:

• Computational electrophysiology
• Biophysics of cardiac signals

Background:

• Interpreting electrocardiogram (ECG) diagnostic features requires understanding signal genesis.
• Advances in computational power enable interactive simulation of ECG signal generation.

Purpose of the Study:

• To develop a simulation package for interactively studying the genesis of ECG signals.
• To provide a tool grounded in electrophysiology and physics for ECG interpretation.

Main Methods:

• A numerical method was employed to compute ECG signals on the thorax and electrograms on the heart's endocardium and epicardium.
• The myocardial electric activity was represented using an equivalent double layer source model.
• Transfer factors were calculated between electric sources and potentials on heart and body surfaces using a realistic thorax model.

Main Results:

• Transfer factors were integrated into an interactive simulation program.
• The program visualizes the instantaneous effects of altering depolarization/repolarization timing and source strength on electrograms and body surface potentials.
• Visualizations include waveforms, potential maps, and movies.

Conclusions:

• The simulation program facilitates interactive study of ECG signal genesis.
• Users can manipulate cardiac electrical parameters to observe their effects on ECG.
• The simulation package is available free of charge at www.ecgsim.org.