Light Beams Will Help Battle Cardiac Arrhythmia

A group of scientists from the Leiden University Medical Center (LUMC, Netherlands), which includes Alexander Panfilov—Candidate of Physical and Mathematical Sciences from the UrFU Laboratory of Computational Biology and Medicine,—has come very close to solving the problem of influencing spiral electric waves and eliminating arrhythmias by sparing means. The scientists have published the article on the results of the research in one of the leading biomedical journals eLife: Optogenetics enables real-time spatiotemporal control over spiral wave dynamics in an excitable cardiac system.

'To remove spiral waves, we use the recently invented technique called optogenetics,' Alexander Panfilov says. 'The bottom line is that when cells are "infected" with special viruses, they will produce the photosensitive protein rhodopsin (a similar protein is found in eye's retina; it provides visual perception). Our team led by Daniël Pijnappels—one of the world's leading experts in this field based at Leiden University Medical Center—is working on making cardiac tissue cells photosensitive. In other words, eliminating arrhythmia and restoring normal heart rhythm, using light beams, rather than electrical discharges.'

Computer simulations and experiments on lab-grown culture of cardiac tissue showed that the core of the spiral wave (the source of arrhythmias) tends to be drawn to a directional light spot.

'That means, it is not even necessary to know where the core of the spiral wave is located—it will be drawn to the light,' the scientist explains.

Thus, the spiral wave can be eliminated by "capturing" it with a micro-LED beam and "pulling" it beyond the boundaries of the cardiac tissue. This leads to the termination of the arrhythmia.

'Cardiologists have been struggling with the problem of arrhythmias for decades. For the first time, we managed to exercise precise and complete control over spiral waves and over related controlled spatiotemporal manipulations. This will pave the way to the removal of spiral waves and arrhythmias even in remote areas of the heart, and without destroying the cardiac tissue. We are moving towards a non-traumatic, painless, affordable and effective way to prevent cardiac arrhythmia mortality,' Alexander Panfilov adds.

Experiments have confirmed the reliability of this method, which was named AAD (attract, attach, drag). The research continues at Leiden University Medical Center and the Max Planck Institute (Göttingen, Germany). The objective is to improve the methodology in order to move on to conducting clinical trials.
Reference

According to the World Health Organization, the two main causes of death in the world are coronary heart disease and stroke. Moreover, cardiac arrhythmia caused a third of deaths by strokes and 90% of deaths due to coronary heart disease.

Arrhythmia occurs when the electrical waves triggered by the self-oscillating cells of the cardiac pacemaker and determining the normal frequency of its contractions (60-80 bpm) are broken and vortices occur, often called spiral electrical waves. The vortices impose their own rhythm of heart contractions, and sometimes they might disrupt cardiac performance completely by self-reproducing, constantly arising and disintegrating in different parts of the heart, leading to sudden cardiac death.

The only known way to cope with lethal arrhythmias and bring a person back to life when the heart stops is to apply a heart defibrillator, which generates a powerful electric field of 2-3 kilovolts. With a strong discharge, the whole heart tissue is excited, all the vortices disappear, the medium becomes homogeneous, goes into a state of rest and is restored. However, the use of a defibrillator damages the tissue of the heart and is extremely painful, which can even lead to mental disorders (if the patient is conscious during a heart attack and defibrillation).

Provided by Ural Federal University