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Updated: May 20, 2026
10:17
Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System
Published on: April 11, 2025
Repolarization changes underlying long-term cardiac memory due to right ventricular pacing: noninvasive mapping with
Scott B Marrus1, Christopher M Andrews, Daniel H Cooper
1Cardiovascular Division, Washington University School of Medicine, St. Louis, MO, USA.
Circulation. Arrhythmia and Electrophysiology
|July 10, 2012
Summary
Cardiac memory causes lasting repolarization changes after abnormal heart activation. Ventricular pacing in humans prolonged action potentials and increased repolarization dispersion, potentially causing arrhythmias.
Area of Science:
- Cardiology
- Electrophysiology
- Cardiac Imaging
Background:
- Cardiac memory describes persistent repolarization changes after altered heart activation.
- Previous animal studies showed conflicting results on cardiac memory mechanisms and spatial patterns.
Purpose of the Study:
- To create 3D images of repolarization changes in human cardiac memory.
- Investigate the effects of ventricular pacing on cardiac electrical remodeling.
Main Methods:
- Utilized noninvasive electrocardiographic imaging in 9 adult subjects with pacemakers.
- Reconstructed epicardial activation and repolarization patterns before and after 1 month of ventricular pacing.
Main Results:
- Eight subjects developed cardiac memory following ventricular pacing.
- Ventricular pacing prolonged the activation recovery interval (action potential duration) near the pacing site.
- Observed increased apical-basal and right-left ventricular repolarization gradients, leading to significant repolarization dispersion.
Conclusions:
- Ventricular pacing induces electrical remodeling, prolonging action potentials and increasing repolarization dispersion in humans.
- This dispersion is potentially arrhythmogenic.
- Continuous right ventricular pacing may partially suppress pacemaker-induced cardiac memory.
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