Related Experiment Video
Updated: Jul 5, 2026
Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System
Published on: April 11, 2025
Can noncontact mapping distinguish between endo- and epicardial foci?
Frederik Voss1, Alexander Bauer, Steffen Witte
1Department of Cardiology, University of Heidelberg, Heidelberg, Germany. frederik_voss@med.uni-heidelberg.de
Objectives:
Noncontact mapping has been demonstrated to facilitate RF ablation of ventricular arrhythmias, but the reproducibility in the localization of endocardial exit sites during focal ventricular tachycardia ("VT") originating from defined myocardial layers has not been systematically studied. Furthermore, it remains unclear whether noncontact mapping can distinguish between endo- and epicardial foci.
Methods:
In six dogs, constant pacing was applied through octopolar needle electrodes in the left ventricle to mimic VT of subendocardial, midmyocardial (mid1; mid2) or subepicardial origin. Using noncontact mapping, the site of origin was determined for each of 50 consecutive beats of all "VTs" and the variation between respective exit sites was measured. Exit sites were reconstructed for 50 consecutive beats of each "VT" and the time span between site of origin and exit site was measured as a parameter of intramural conduction.
Results:
While subendocardial and midmyocardial (mid1, mid2) foci were pinpointed with a variation of
Conclusions:
Except for subepicardial foci, noncontact mapping localized focal activity in the LV with high reproducibility. In contrast to morphological parameters, the determination of intramural conduction provides a fair estimate of the depth of foci and is proposed as a novel parameter to identify a subepicardial origin.
