Light Controlled Heart Pacemakers

Heart pacemakers controlled by optical stimulation

(RxWiki News) Just recently heart pacemakers went wireless. Now there is potential to take them even a step further. In the future they could be light-controlled.

A new method of stimulating heart muscle cells could lead to the creation of pacemakers that are remotely controlled with optical stimulation.

Emilia Entcheva, senior study author and associate professor of biomedical engineering at Stony Brook University, noted that though devices such as pacemakers and defibrillators have long been established and successful technologies, they still have problems such as limited battery life, breaking metal leads and interference from strong magnetic fields. She said light-controlled pacemakers could overcome those problems and provide a new way of controlling heart function.

"Ask your cardiologist about pacemaker options."

A pacemaker controlled by light could be operated remotely, and turn on or off a single cell or cell type. That type of technology is not currently available.

Researchers introduced light-sensitive proteins into "excitable" cells that made it possible to control certain activities within those cells. Excitable cells can generate electrical signals such as nerve cells.

A few years ago, investigators found that brain cells could be stimulated by light if they were genetically altered to produce a light-sensitive protein called channelrhodopsin 2 (ChR2).

As part of the new study, researchers created cells that could express the ChR2 protein and coupled them with animal heart muscle cells. This created heart tissue stimulated by light. They discovered that heart muscle contractions and electrical waves triggered by light were indistinguishable from electrically-triggered waves.

Instead of modifying the heart cells, researchers also coupled donor cells optimized for light responsiveness with the heart cells. Such a technique uses less energy and does not require the use of viruses or the introduction of genes from other organisms.

Scientists are able to take cells from a person's bone marrow or skin, culture them and modify them to respond to light. Using a patient's own cells dramatically reduces the chance that the immune system will reject the light sensitive-cells.

The approach could someday be used in pacemakers, which would feature biocompatible, flexible plastic optic fibers. Preliminary research suggests a battery for a light-based pacemaker could last 50 years.

The technology also could be used for defibrillators and to test the side effects of new cardiac drugs.

The research was published in in Circulation: Arrhythmia & Electrophysiology, a journal of the American Heart Association.

Review Date: 
August 8, 2011