Spatial resolution of epicardial pace mapping using body surface potentials.

Area of Science:

• Cardiology
• Medical Imaging
• Electrophysiology

Background:

• Body surface potential mapping (BSPM) is a non-invasive technique for localizing cardiac electrical events.
• Previous studies established high spatial resolution (<10 mm) for endocardial pacing sites using BSPM.
• The spatial resolution of BSPM for epicardial pacing sites remained to be determined.

Purpose of the Study:

• To assess if BSPM can achieve similar spatial resolution for epicardial pacing sites as previously shown for endocardial sites.
• To evaluate the feasibility of non-invasively resolving epicardial breakthrough sites with high precision.

Main Methods:

• Four cardiac surgery patients underwent intraoperative placement of epicardial electrodes on the right ventricle (10 mm apart).
• Post-surgery, 35-lead ECGs were recorded during pacing from each electrode.
• QRS integral distributions were mapped and statistically compared between pacing sites using Student's t-test.

Main Results:

• Statistically significant differences (p < 0.01) in QRS integral map distributions were observed between adjacent epicardial pacing sites in all patients.
• The study demonstrated that epicardial pacing sites could be resolved within a 10 mm spatial resolution.

Conclusions:

• Non-invasive body surface ECG acquisition can effectively resolve epicardial breakthrough sites within 10 mm.
• This technique holds potential for guiding therapeutic ablations in patients with ventricular tachycardias.