New pacemaker completely changes the functioning of a failing heart, Oxford scientists reveal
19th January 2026
New pacemaker completely changes the functioning of a failing heart, Oxford scientists reveal
New pacemaker completely changes the functioning of a failing heart by retraining it to use fat for energy. Oxford-led research offers fresh hope for heart failure patients.
A Breakthrough That Rewrites How the Heart Survives
A new pacemaker has shown the potential to fundamentally alter how a failing heart works, offering renewed hope to millions living with heart failure. In a study described by researchers as both unexpected and promising, scientists have found that the device does more than correct irregular heartbeats. Instead, it appears to reprogramme the heart’s energy system, helping it recover strength and function by changing how it fuels itself.
The research, led by experts from the University of Oxford in partnership with the British Heart Foundation, suggests that heart failure may not only be a mechanical problem, but also a metabolic one — and that technology could help correct both.
New pacemaker completely changes the functioning of a failing heart
The study focused on a specialised device known as cardiac resynchronisation therapy, or CRT, a type of pacemaker already used in some heart failure patients. What surprised researchers was how rapidly the device influenced the heart’s metabolism.
In healthy hearts, fat is the primary source of energy. However, in heart failure, this system often breaks down. The heart shifts to using sugar, or glucose, which provides quicker energy but places greater strain on already weakened heart muscle. Over time, this contributes to further damage and declining performance.
Researchers found that the CRT pacemaker could reverse this process in just two minutes, effectively switching the heart’s fuel preference back from sugar to fat. By restoring this balance, the heart appeared to function more efficiently and with less stress.
Inside the Study: Small Numbers, Big Changes
Fourteen patients with heart failure took part in the trial, all of whom were fitted with the CRT pacemaker. Over the following six months, researchers closely monitored changes in heart structure, performance, and patient wellbeing.
The results were striking. The heart’s main pumping chamber, the left ventricle, reduced in size by an average of 50%, indicating a significant reversal of the damaging enlargement commonly seen in heart failure. At the same time, pumping efficiency improved by more than a third.
Patients also reported meaningful improvements in daily life. Many experienced less breathlessness, greater mobility, reduced pain, and improvements in mental health, including lower levels of anxiety and depression.
Electrical Signals and Energy Recovery
According to the research team, the key lies in how electrical signals travel through the failing heart. In heart failure, these signals often become delayed or uncoordinated, disrupting the message that tells heart cells to burn fat for energy.
The CRT pacemaker works by restoring proper electrical timing across the heart muscle. By slowing and coordinating these signals, it appears to reactivate the heart’s natural ability to use fat as fuel — a process researchers describe as “retraining” the heart.
This discovery links electrical rhythm directly to energy metabolism, an insight that could reshape how doctors understand and treat heart failure.
What This Means for the Future of Heart Failure Care
While the researchers caution that this was an early-stage study involving a small number of patients, the implications are significant. The findings suggest future heart failure treatments could focus not only on improving blood flow and rhythm, but also on restoring the heart’s energy balance.
Experts say larger clinical trials will be needed before the approach can be widely adopted. However, the study offers a compelling glimpse into a future where devices do more than support the heart — they help it heal itself.
As scientists continue to explore this connection, the message is clear: this new pacemaker completely changes the functioning of a failing heart, and could mark the beginning of a new era in heart failure treatment.