Scientists from the University of Auckland are getting ready to assess a ground-breaking pacemaker that restores natural heartbeat in human trials, following positive results in animal studies.
Pacemakers that are currently available for heart patients pace the heart metronomically, according to researchers. What this means is that the devices pace the heart at a regular rate.
Scientists have observed, however, that the heart does not really beat at a regular interval. The rate is constantly changing.
With this new pacemaker, it is possible to mimic how the heart beats naturally and, thus, tackle heart failure more effectively. The new study reveals that imitating the natural heartbeat variation can enhance the ability of the heart to pump blood, thus boosting cardiac output in patients.
The research, led by scientists from the University of Auckland’s Manaaki Manawa, was published in Basic Research in Cardiology.
Heart rate variability
While pacemakers usually pace the heart at a steady rate, researchers say the loss of variability is a sign of cardiovascular disease. A healthy organ paces at a variable rate.
“If you analyze the frequencies within your heart rate, you find the heart rate is coupled to your breathing,” explained lead researcher Professor Julian Paton, the director of Manaaki Manawa. “It goes up on inspiration, and it goes down on expiration, and that is a natural phenomenon in all animals and humans.”
Paton said this is how it has been in animals since 430 million years ago.
According to scientists, heart rate is not properly modulated by breathing in high blood pressure or heart failure patients.
Paton and some other scientists probed what purpose heart rate variability serves 12 years ago. With the aid of a mathematical model, they observed this was necessary for energy preservation. This made them wonder why pacemakers don’t pace the heart at a variable rate.
Researchers, including Paton, then decided to study what difference variability would make in animals with heart failure.
Reversing heart failure
Heart medications do not really do much other than help heart failure patients to control symptoms. They typically lack the ability to tackle the underlying tissue problem.
Researchers in this new study believe they have something better that can reverse heart failure.
After successful testing in rats, scientists also trialed the device on a heart failure model in large animals. The results were impressive.
Dr. Rohit Ramchandra, one of those who carried out the research, said the device may be called a “natural pacemaker.” It essentially reinstates the lost natural variability.
“The pacemaker is almost like a bionic device,” Paton said. “It understands the body signals that tell the device when we’re breathing in and when we’re breathing out. And then the device has to communicate back to the body and pace the heart up during breathing in and down during breathing out.”
The pacemaker promoted a “20 percent improvement in cardiac output,” according to Ramchandra. It efficiently replicates the heart’s natural ability to pump blood through the body.
The researchers are planning to carry out a trial involving heart patients in New Zealand later this year. Dr. Martin Stiles, a cardiologist who will lead the planned trial, said this device could positively transform the treatment of patients with heart failure because it far exceeded researchers’ expectations.