Four high-speed cameras recorded 40,000 records of cardiac electrical activity when the revived tissue disappeared with a bang in the laboratory utensils. These cameras track electrical pulses to identify the source of signal interruption, which can make the heart beat too slowly, too fast or out of rhythm.
By visualizing the resurrected heart with more images and higher resolution than existing patients, scientists can build three-dimensional models and highly detailed heart charts, which can help medical professionals design more targeted methods to treat abnormal heartbeat. [Video of the donor's heart beating again in the laboratory]
In a healthy heart, the electric energy generated by a special heart tissue called the sinoatrial node will contract, resulting in a stable beating-according to the data of the Mayo Clinic, at rest, about 60 to 100 beats per minute. The heart rate is set by synchronously pumping into two upper chambers (called atria) and two lower chambers (called ventricles) of the heart.
Give me a shot. The interruption of ECG system will lead to abnormal heartbeat or arrhythmia. When unstable signals affect the atrium, arrhythmia called atrial fibrillation (AF) will occur. Vadim Fedoroff, an associate professor in the Department of Physiology and Cell Biology at Ohio State University and co-author, told Live Science that this is the most common form of arrhythmia, which may lead to stroke or heart failure.
Surgeons use a technique called ablation to treat atrial fibrillation-once they have a general understanding of the source of chaotic electrical activity, they will place electrodes inside the heart and deliver targeted electrical pulses, which will leave scars in destructive areas and prevent wayward signals.
Researchers at Wechs Medical Center of American State University in Ohio have developed a technology to restore some donated human hearts in the laboratory to find the hidden source of arrhythmia. Fedoroff said, however, doctors' views on energy pulses passing through the hearts of living patients are limited, because clinical imaging technology can only capture the records of 200 hearts from one side at a time. Therefore, ablation may miss the target, the representative of OSU said in a statement. The success rate of ablation is about 70%, which often requires repeated treatment. However, Fedoroff and his colleagues have developed a breakthrough technology that can generate 40,000 3D high-resolution images of the heart and atrium in a laboratory environment. It provides a more accurate view of heart structure and electrical activity, and can provide a better opportunity for cardiac surgeons to intercept unreliable signals. [Heart disease: types, prevention and treatment]
It's alive. In the past four years, Fedoroff and his colleagues have analyzed more than 65,438+000 hearts in OSU, he told Live Science. These "living" hearts usually come directly from the operating room to the laboratory of OSU wexler Medical Center, and are donated by heart transplant patients and Ohio Lifeline, a non-profit organization that coordinates human organ donation. In order to resuscitate the heart, Fedoroff first closed the small blood vessels inside the heart, and then put the heart in an oxygenated solution at 98.6 degrees Fahrenheit (37 degrees Celsius). A special test tube inserted into the coronary artery soaks the heart with warm water containing oxygen to simulate the blood flow and make it beat again.
Then the heart is dyed in a special bath, fluorescent dye is injected to detect the electrical signal, and four cameras are used. Infrared rays penetrate the heart tissue to a depth of 0.4 inches (65,438+0 cm), enabling researchers to see the electrical activities on both sides of the atrium and visualize them in 3D. This enables them to accurately locate irregular signals with high precision.
A part of the donor's heart was reactivated and recorded with four high-definition optical cameras. The heart model (Wechs Medical Center, Ohio State University) found the source of the atrial fibrillation area from the picture, just like a small tornado inside the heart, keeping an irregular beating electrical activity, Fedoroff said.
"When we have three-dimensional imaging, we can see more accurate sources." About electrical activity. When we apply some ablation damage, we can stop atrial fibrillation, "he explained.
So we jump on the internet. Although this level of visualization is impossible in living patients, this study has changed clinicians' views and positioning of atrial fibrillation. According to Dr. johann hummel, co-author of the study, hummel said in a statement:
Confirmed the correctness of the three-dimensional electrocardiogram, because we have not been able to ablate according to the high-resolution imaging in the laboratory, so we have to go back and verify whether the imaging matches the site we successfully ablated. In an interview with Life Science magazine, Federov said that if we can instruct surgeons to turn off the correct electrical signals in the heart with problems, we can adopt the strategy of fighting arrhythmia more successfully. We are studying how to transform it into the body in vitro. To this end, we need to conduct clinical trials, "to confirm our observations," he said. We must conduct between clinical and in vitro studies in order to finally develop a very patient-oriented treatment for atrial fibrillation.
This discovery was published online in the European Journal of Cardiology: Cardiovascular Imaging June 65438+1October 65438+March.
This is an original article about life science.