Comparison between electrocardiographic and magnetocardiographic inverse solutions using the boundary element method

Area of Science:

• Biomedical Engineering
• Cardiovascular Imaging
• Computational Electrophysiology

Background:

• Accurate cardiac source imaging relies on electrocardiographic (ECG) and magnetocardiographic (MCG) signals.
• Thoracic inhomogeneities, such as lungs and blood masses, significantly impact signal accuracy.
• Understanding these effects is crucial for refining inverse solutions in cardiac electrophysiology.

Purpose of the Study:

• To investigate the impact of thoracic inhomogeneities on inverse solutions for cardiac source imaging.
• To compare the numerical accuracy of body-surface potential maps (BSPM) and magnetic-field maps (MFM) using realistic torso models.
• To evaluate the sensitivity of ECG and MCG inverse solutions to inhomogeneities and noise.

Main Methods:

• A realistic torso model and a single moving dipole source model were employed.
• The node-based boundary element method was utilized for inverse solutions.
• Body-surface potential and magnetic-field lead configurations were kept identical for direct comparison.

Main Results:

• Without added noise, body-surface potential solutions showed less sensitivity to excluded inhomogeneities compared to magnetic-field solutions.
• Noise influenced localization similarly for left-right and foot-head oriented dipoles in both BSPM and MFM.
• Body-surface potential localization was more accurate than magnetic-field localization for anterior-posterior oriented dipoles.

Conclusions:

• Thoracic inhomogeneities pose a challenge for accurate cardiac source imaging using both ECG and MCG.
• Body-surface potential mapping offers greater robustness against inhomogeneities, particularly for certain dipole orientations.
• Further research is needed to optimize inverse methods for improved cardiac imaging accuracy in the presence of thoracic variations.