Blood flow to the heart often is interrupted during a heart attack or cardiac surgery. But when blood flow resumes, the heart may still falter. That's because collateral damage can occur as blood re-enters the heart, potentially slowing recovery and causing future cardiac troubles.
Researchers investigating this type of secondary heart damage have been stymied by the inability to see in real time how restoring blood flow leads to inflammation that can cause further injury. Now, working in mice, surgeons and scientists at Washington University School of Medicine in St. Louis, have captured the first images of a beating heart at a resolution so detailed they can track individual immune cells swarming into the heart muscle, causing inflammation.
The achievement is detailed in the July issue of the Journal of Clinical Investigation.
The researchers say that the imaging technique, called intravital two-photon imaging, is a powerful tool for understanding the inflammation that occurs when blood flow to the heart is temporarily stopped and later restarted.
"Inflammation is quite common after a heart attack, open-heart surgery, heart transplants and in atherosclerosis, and it can severely hamper recovery and lead to death," says senior author Daniel Kreisel, MD, PhD, a Washington University cardiothoracic surgeon who operates at Barnes-Jewish Hospital. "But little is known about how inflammation ramps up in the heart. Now that we have the ability to see all the cellular players involved, we can begin to think about new therapeutic targets for treatment."
Two-photon imaging has been used to image other organs in living mice but never the heart. Scientists had assumed that the flutter of the beating heart, which pulses about 500 times a minute in a mouse, would blur any images of individual cells.
"No one thought we could get clear images of cells inside the beating heart," says Wenjun Li, MD, research inst
|Contact: Caroline Arbanas|
Washington University School of Medicine