Related Experiment Video
Updated: Jan 3, 2026
Advanced Cardiac Rhythm Management by Applying Optogenetic Multi-Site Photostimulation in Murine Hearts
Published on: August 26, 2021
Cardiac pacing using transmural multi-LED probes in channelrhodopsin-expressing mouse hearts
C M Zgierski-Johnston1, S Ayub2, M C Fernández1
1Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen, Medical Center, University of Freiburg, Freiburg, Germany; Faculty of Medicine, University of Freiburg, Freiburg, Germany.
This study introduces an implantable optical probe for intramural cardiac pacing using optogenetics. The device enables precise heart pacing with minimal tissue damage and low light intensity, overcoming limitations of epicardial illumination.
Area of Science:
- Cardiovascular Research
- Optogenetics
- Biomedical Engineering
Background:
- Optogenetics allows cell-specific control of biological functions using light-activated proteins.
- Optical pacing in cardiac research typically uses epicardial illumination, which has limited light penetration in larger hearts.
- Overcoming light penetration issues is crucial for translating optogenetic cardiac therapies to humans.
Purpose of the Study:
- To evaluate an implantable multi light-emitting diode (LED) optical probe (IMLOP) for intramural cardiac pacing.
- To assess the safety and efficacy of IMLOP in mouse hearts expressing channelrhodopsin-2 (ChR2).
Main Methods:
- Developed and tested an implantable multi light-emitting diode (LED) optical probe (IMLOP).
- Assessed IMLOP insertion force, histological tissue damage, and temperature changes during operation.
- Performed in situ optical pacing experiments on mouse hearts expressing cardiac-specific channelrhodopsin-2 (ChR2).
Main Results:
- IMLOP insertion requires minimal force (~20 mN) with confined acute tissue damage.
- LED operation resulted in negligible temperature increase (<1 K), ensuring safety.
- Successful intramural optical pacing was achieved with low light intensities (e.g., 700 μW/mm²), with specific rheobase and chronaxie values determined.
Conclusions:
- The implantable multi light-emitting diode (LED) optical probe (IMLOP) is effective for intramural optical pacing of the heart.
- The probe demonstrates safety, minimal tissue damage, and low light intensity requirements for pacing.
- Further research is needed to evaluate the long-term effects of chronic implantation.
