Noninvasive assessment of local myocardium repolarization changes using high resolution surface ECG mapping

Area of Science:

• Cardiovascular Physiology
• Biomedical Engineering
• Medical Imaging

Background:

• Myocardial lesions with altered repolarization pose diagnostic challenges.
• Accurate, noninvasive assessment of lesion location and characteristics is crucial for effective treatment.

Purpose of the Study:

• To present a novel method using body surface potential maps for assessing myocardial lesions with changed repolarization.
• To introduce a suitable mapping system for this purpose.
• To evaluate the method's performance in simulated and clinical settings.

Main Methods:

• Utilized body surface potential maps and torso volume conductor models to determine equivalent dipoles representing myocardial lesions.
• Modeled altered repolarization by shortening myocyte action potentials.
• Tested the method on simulated data and patients post-myocardial infarction.

Main Results:

• The equivalent dipole accurately estimated lesion positions (mean error 9+/-4 mm for small lesions, 17+/-14 mm for transmural lesions).
• Dipole orientation reflected lesion depth (subepicardial or subendocardial).
• Clinical tests showed good correlation between dipole position and treated coronary vessels in 7 of 8 patients.

Conclusions:

• The developed method and 128-channel mapping system provide effective noninvasive tools for identifying local repolarization changes in the myocardium.
• This approach aids in assessing myocardial lesion characteristics and treatment efficacy.