Researchers have discovered that the pulse we know is not the only one that our body harbors. Explanations.
The pulse indicates our heart rate, it has been observed since 1820: it is fast when we play sports, slower when we are at rest, absent in deceased people. What we feel is the rush of blood in our arteries, which results from heartbeats. Until then, we only measured that. But researchers have just discovered that there is another, which they have called “bending wave”, as they explain in Science Advances.
As Inserm explains, this second pulse was discovered somewhat by chance, while scientists were testing a tool for examining the retina. “The researchers who had developed this tool wanted to know if it could make it possible to calculate the speed of propagation of the pulse wave in the retina”, notes Inserm. By carrying out this examination, which consists of taking photos of this organ at very high speed, they came across two signals: the classic pulse, which circulates at about 1 meter per second, and another, a thousand times slower.
A wave due to a torsion
We had never looked for any wave other than the classic pulse, that’s why it had never been detected. But the scientists managed to verify it on the carotid artery of several patients. They explain that the classic pulse (wave of dilation) is “symmetrical with respect to the central axis of the vessel and corresponds to the dilation of the walls of the arteries with an increase in diameter”, and the second, “bending wave” is for its part asymmetrical due to the “torsion of the tube”.
To help us understand, they use the image of a snake swallowing prey: it slides along the digestive tract, but the snake undulates at the same time, so there are two simultaneous movements.
A priori, this bending wave could have a clinical interest in its own right: “by continuing to propagate in the veins where the main pulse wave is no longer detectable there due to the distance from the heart, it would also provide information on the rigidity of the vein wall“, underlines the researcher Stephan Catheline in the Inserm article.
Sources: ScienceAdvances, Inserm