Related Experiment Video
Updated: May 14, 2026
Advanced Cardiac Rhythm Management by Applying Optogenetic Multi-Site Photostimulation in Murine Hearts
Published on: August 26, 2021
Altering embryonic cardiac dynamics with optical pacing
L M Peterson1, M McPheeters, L Barwick
1Biomedical Engineering Department, Case Western Reserve University, Cleveland, Ohio 44106, USA.
Insights
Researchers used optical pacing and optical coherence tomography to precisely alter embryonic heart rates and measure blood flow. This allowed detailed study of how blood flow mechanics influence early heart development and congenital heart defects.
Area of Science:
- Developmental biology
- Cardiovascular research
- Biomedical engineering
Background:
- Altering early blood flow can cause congenital heart defects.
- Previous methods for manipulating hemodynamics were imprecise and lacked monitoring.
- Understanding mechanically-transduced signaling in heart development is crucial.
Purpose of the Study:
- To develop precise methods for studying hemodynamics in embryonic heart development.
- To investigate the role of blood flow in valvulogenesis.
- To establish a system for controlled hemodynamic perturbations and measurements.
Main Methods:
- Utilized optical pacing (OP) to noninvasively control quail embryo heart rate using infrared laser light.
- Employed optical coherence tomography (OCT) to generate 4-D shear maps of endocardial shear stress.
- Developed perturbation protocols to modify regurgitant flow and oscillatory shear index (OSI).
Main Results:
- Successfully altered heart rate and measured resultant shear forces on the endocardium.
- Generated 4-D shear maps to visualize spatial and temporal shear stress distribution.
- Demonstrated ability to increase regurgitant flow and modify OSI in the developing heart tube.
Conclusions:
- Optical pacing and OCT provide a precise system for studying embryonic cardiovascular mechanics.
- Hemodynamic forces, specifically regurgitant flow and OSI, are significantly altered by these methods.
- This approach offers a novel way to investigate the role of hemodynamics in heart valve formation.
Abstract:
Several studies have shown that altering blood flow early in development leads to congenital heart defects. In these studies the perturbations to hemodynamics were very gross manipulations (vessel ligation, conotruncal banding, etc.) that would be inappropriate for probing the delicate mechanisms responsible for mechanically-transduced signaling. Also, these perturbations lacked feedback from a monitoring system to determine the exact degree of alteration and the location of its effect. Here, we employed optical pacing (OP) to alter the heart rate in quail embryos and optical coherence tomography (OCT) to measure the resultant shear forces on the endocardium. OP is a new technique utilizing pulsed 1.851 µm infrared laser light to noninvasively capture the heart rate to the pulse frequency of the laser without the use of exogenous agents. To measure shear stress on the endocardium, we extended our previous OCT algorithms to enable the production of 4-D shear maps. 4-D shear maps allowed observation of the spatial and temporal distribution of shear stress. Employing both OCT and OP, we were able to develop perturbation protocols that increase regurgitant flow and greatly modify the oscillatory shear index (OSI) in a region of the heart tube where future valves will develop. Regurgitant flow has been linked with valve development and precise perturbations may allow one to determine the role of hemodynamics in valvulogenesis.
