“Our work is the first to suggest a non-electrical approach to cardiac resynchronization therapy. Before this, there have been a number of elegant gene therapy and cell therapy approaches for generating biological pacemakers that can pace the heart from a single spot. However it was impossible to use such approaches to activate the heart simultaneously from a number of sites for resynchronization therapy.”
Globally, more than 3 million people have had electronic pacemakers implanted. The most common indication for a pacemaker is the treatment of a slow heart beat which can put patients at risk for fainting, heart failure, and even death.
Pacemakers traditionally function by sending electrical signals to the heart to regulate the heart beat.
Pacemakers can also be used for cardiac resynchronization therapy (CRT), an approach aiming to synchronize the contraction of the heart’s two ventricles in order to improve heart function, symptom status and decrease mortality in some patients who suffer from heart failure.
If the new optogenetic approach for cardiac pacing and resynchronization, can be adapted for humans, it could help patients avoid many of the drawbacks of electrical pacemakers. These include:
surgical procedure needed to implant the device
risk of infection
limitations on the number and locations of the pacing wires used
possible decline in cardiac function resulting from the change in the normal electrical activation pattern
limitations on implantation in children
Pacing the heart with light is just one part of the emergent field of optogenetics, which has gained considerable momentum in the field of brain research. Researchers working in the field have been taking light-sensitive genes from algae and placing them in cells where they act like a switch, turning certain behaviors on or off when the cells are exposed to pulses of light.
“This is a very important proof-of-concept experiment, which for the first time, demonstrates a mechanism to pace the heart without the need for wires and allows for simultaneous pacing from multiple sites,” said Dr. Jeffrey Olgin, chief of the Division of Cardiology and co-director of the Heart and Vascular Center at the University of California, San Francisco. “The most common site of failure of current pacemakers are the leads or wires that connect the heart muscle to the electrical impulse. The approach demonstrated in this paper has the potential to eliminate these wires or have a single lead excite multiple sites simultaneously.”