Localization of intramural necrotic regions using electrocardiographic imaging

Area of Science:

• Biomedical Engineering
• Cardiac Electrophysiology
• Medical Imaging

Background:

• Electrocardiographic imaging (ECGI) is a novel noninvasive technique for studying cardiac electrical activity.
• Localized myocardial necroses can alter electrical activation patterns, posing challenges for diagnosis.

Purpose of the Study:

• To evaluate the capability of ECGI in reconstructing epicardial potentials and electrograms in ventricles with small, localized areas of necrosis.
• To assess the accuracy of ECGI in identifying specific patterns associated with different necrosis locations.

Main Methods:

• Anatomical human ventricular models were used to simulate electrical activation from 428 pacing sites.
• Extracardiac potentials were simulated on epicardial and torso surfaces using a boundary element model.
• ECGI, employing L-curve regularization, computed epicardial potentials and unipolar electrograms.

Main Results:

• Inversely computed electrograms showed strong correlation (r > 0.9 at 68% of sites) with simulated data.
• ECGI accurately identified characteristic epicardial potential patterns, including a central minimum and two maxima.
• The technique detected transient losses or gaps in activation patterns corresponding to subepicardial, intramural, or subendocardial necrosis.

Conclusions:

• ECGI provides detailed reconstruction of myocardial activation patterns even in the presence of localized necroses.
• Findings suggest ECGI's potential utility in the clinical assessment of arrhythmogenic substrates.
• The study validates ECGI's ability to characterize electrical abnormalities caused by myocardial damage.