When a heart attack damages the heart, the injured muscle is replaced by scar tissue. That scar can interfere with the electrical signals that coordinate each heartbeat, increasing the risk of dangerous rhythm disorders known as arrhythmias. Scientists have long been able to map electrical activity in the heart, but it has been difficult to see how those signals relate to the underlying scar tissue. A new imaging system now brings both views together, creating a detailed map of heart structure and function across the entire surface of a living heart.
As reported in the Journal of Biomedical Optics (JBO) , researchers at George Washington University developed a technique that combines hyperspectral imaging, which identifies different tissue types based on how they interact with light, with optical mapping, a method that tracks electrical activity in heart muscle. The result is a panoramic view that shows where scar tissue is located and how electrical signals move around it.
Most existing optical mapping systems can show the spread of electrical activity but provide limited information about the condition of the tissue itself. This can make it difficult to determine why abnormal heart rhythms begin in some locations. The new system was designed to fill that gap by simultaneously measuring both tissue composition and electrical behavior.
The researchers built a six-camera imaging platform that captures the heart from multiple angles. Four high-speed cameras recorded electrical signals using a fluorescent dye that responds to changes in voltage. Another camera collected detailed spectral information from the tissue, while an additional camera was used to reconstruct the heart's three-dimensional shape. Specialized software then combined all of the data into a single map of the heart surface.
To test the technology, the team studied rat hearts four weeks after a heart attack had been induced. The hearts were removed, kept alive through a perfusion system, and scanned while researchers recorded both tissue properties and electrical activity.
The hyperspectral measurements proved especially useful for identifying scar tissue. The researchers found that scarred regions emitted a stronger light signal associated with collagen, a major component of connective tissue that accumulates after cardiac injury. This allowed them to distinguish healthy heart muscle, damaged tissue, and the border zone between the two. Laboratory analysis of heart tissue confirmed the imaging results.
Using the combined maps, the researchers could see how electrical signals behaved near the scar. In several hearts, abnormal beats originated close to the border between healthy and damaged tissue. Electrical waves often traveled rapidly around the scar but slowed down or became blocked when moving through scarred regions. These disruptions can create conditions that support arrhythmias.
The system also revealed differences in the electrical properties of various tissue types. Signals recorded from scarred regions remained active longer than those from healthy tissue, while border-zone tissue showed intermediate behavior. This pattern was consistent across all hearts examined and reflects known changes that occur after a heart attack.
Beyond studying heart attacks, the researchers believe the technology could help investigate other conditions that alter heart tissue, including aging, fibrosis, heart failure, and the effects of treatments such as cardiac ablation. By linking tissue structure directly to electrical function, the approach gives researchers a new tool for understanding how arrhythmias develop and how they might be prevented.
The work represents the first panoramic imaging system to combine detailed tissue characterization with electrical mapping across the entire surface of a living heart, providing a more complete picture of how structural damage can alter the heartbeat.
For details, see the original Gold Open Access article by G. Kowalik et al., “ Panoramic hyperspectral optical mapping of cardiac membrane potential and tissue type ," J. Biomed. Opt. 31(7), 076004 (2026), doi: 10.1117/1.JBO.31.7.076004
Journal of Biomedical Optics
Panoramic hyperspectral optical mapping of cardiac membrane potential and tissue type
22-Jul-2026