Pacemakers May Soon Go Biological!
Richard Robinson and his colleagues at Columbia and Stony Brook Universities highlight the fact that the body's own natural pacemaker, called the sinoatrial (SA) node, is extremely vulnerable to damage during a heart attack, often leaving the patient with a weak, slow or unreliable heartbeat.
Since the heart has limited ability to recover from the damage, an electronic device is fitted to monitor and control the beat directly.
Even though a much better solution can be to use therapies to raise the heart rate biologically, according to the researchers, there are some major hurdles.
The research team point out that the way electrical signals are generated in the SA node - and hence the heart rate - are far from simple.
There are three separate electrical pathways between cells, known as HCN or 'funny' channels, which could be involved.
Dr Robinson says that his study sheds light on the secrets of the HCN channels.
His work also describes a cell culture developed by his team, which accurately mimics HCN function in whole mammalian hearts, making future research in the area far quicker and easier.
Using their new cellular model, the researchers genetically rewired two of the HCN channels.
They said that the resulting heart rate was very rapid with irregular pauses, just as has already been observed in dogs and mice.
Dr. Robinson believes that the valuable new computer and cellular models are ideal for testing potential new drugs to influence heart rate, and pave the way for new genetic biological pacemakers to be developed.
He says that the new developments "will facilitate the development of practical biological pacemakers by allowing more complete and rapid assessment of individual channel mutations through combined culture and simulation studies prior to full testing in animal models."
A research article on the study has been published in The Journal of Physiology.