AUCKLAND, New Zealand — We may be on the medical precipice of turning back time, or actually reversing the heart rhythm effects of cardiac events. A potentially game-changing “bionic” pacemaker capable of restoring the human heart’s naturally irregular beat is set to undergo trials involving heart patients in New Zealand this year.
“Currently, all pacemakers pace the heart metronomically, which means a very steady, even pace. But when you record heart rate in a healthy individual, you see it is constantly on the move,” says professor Julian Paton, a lead researcher and director of Manaaki Manawa, the Centre for Heart Research at the University of Auckland, in a university release.
Current pacemakers just can’t mimic the perfectly irregular pace of a naturally healthy human heart, Paton explains. This new version, though, may change everything. “If you analyze the frequencies within your heart rate, you find the heart rate is coupled to your breathing. It goes up on inspiration, and it goes down on expiration, and that is a natural phenomenon in all animals and humans. And we’re talking about very ancient animals that were on the planet 430 million years ago.”
Moreover, Prof. Paton was actually part of a scientific team 12 years ago that had concluded a more varied approach to pacemaker rhythms would be more efficient and energy-saving than a uniform metronome beat. Considering metronomic heartbeat pacemakers are routinely given to heart failure patients with low energy levels, Paton couldn’t help but wonder, “Why aren’t we pacing them with this variability?”
‘We have now found a way to reverse heart failure’
The loss of one’s typical, irregular heartbeat is a near universal symptom among heart disease patients, and often a first sign that something is off. “People with high blood pressure, people with heart failure, their heart rate is not being modulated by their breathing. It may be a little bit, but it’s very, very depressed, very suppressed,” Paton says. “We decided that we would put the heart rate variability back into animals with heart failure and see if it did anything good.”
Most recently, experiments with the new irregular pacemakers have produced very promising results on a large animal model of heart failure. Earlier, similar tests with rats have produced similarly positive findings.
“And the big news is that we believe we have now found a way to reverse heart failure,” adds study co-author Dr. Rohit Ramchandra.
‘Bionic pacemaker has far exceeded our expectations’
“There’s nothing really on the market that will cure heart failure. All the drugs will do is make you feel better. They don’t address the issue that you’ve got damaged tissue that’s not contracting as efficiently as it was,” notes research fellow Dr. Julia Shanks. “Our new pacemaker brings back this variability, which of course is natural, in a way you could call it ‘nature’s pacemaker’.”
According to Dr. Ramchandra, the irregular beat promoted by these new pacemakers improves the heart’s ability to pump blood throughout the human body by up to 20 percent — “a big number,” he points out.
“We typically see improvements in heart function with current pacemakers, but this bionic pacemaker has far exceeded our expectations. This discovery may revolutionize how heart failure patients are paced in the future,” comments Dr. Martin Stiles, a cardiologist from Waikato Hospital, which will be leading the first human trials.
The study is published in Basic Research in Cardiology.