Left Bundle Branch Area Pacing Reduces Pacemaker-Induced Cardiomyopathy and Heart Failure Admissions Compared with Right Ventricular Apical Pacing in High-Degree AV Block

For millions of people around the world, the heart's natural electrical system fails, causing the upper and lower chambers to lose their rhythm. When this happens, doctors often implant a small device called a pacemaker to keep the heart beating. The most common way to do this involves placing a wire in the very tip of the lower right chamber. While this method works well to prevent fainting or sudden stops, it forces the heart muscle to contract in an unnatural, uncoordinated way. Over time, this constant, awkward movement can weaken the heart, turning a healthy pump into a struggling one. This condition, known as pacemaker-induced cardiomyopathy, is a serious risk for patients who rely heavily on the device, leading to hospital visits for heart failure.

Researchers have been searching for a way to pace the heart that feels more like the body's own natural rhythm. A newer technique called left bundle branch area pacing aims to do exactly that by stimulating a specific electrical pathway deep inside the heart's wall, rather than just the tip of the right side. A study posted in August 2026 by a team based at Hospital del Mar in Spain set out to see if this newer approach truly protects the heart better than the traditional method. They focused on patients with a severe block in their heart's electrical signals who were expected to need the pacemaker to fire in more than 60% of heartbeats. By comparing the two methods over a year, the team discovered that the newer technique not only kept the heart's pumping strength stable but also drastically reduced the number of patients who ended up in the hospital for heart failure.

The study looked at 110 consecutive patients who had a high-degree atrioventricular block, a condition where the electrical signal from the top of the heart cannot reach the bottom. All these patients had a heart pumping function that was normal or only slightly reduced before the procedure. The doctors implanted pacemakers in these patients, but the choice of where to place the wire depended on the doctor's preference at the time. About half of the patients received the traditional wire placement in the tip of the right ventricle, while the other half received the newer left bundle branch area pacing. The researchers then followed everyone for a median of about 12 to 14 months, checking their heart function with ultrasound scans and tracking any hospital admissions.

The results showed a clear difference in how the hearts responded to the two methods. In the group with the traditional pacing, the electrical signal took much longer to travel across the heart, creating a wider, slower beat on the heart monitor. In contrast, the group with the newer pacing had a much narrower, faster electrical signal, which is a sign of a more natural, synchronized heartbeat. More importantly, the health of the heart muscle itself changed in opposite directions. In the traditional group, the heart's ability to pump blood dropped significantly over the year. In the newer pacing group, the pumping strength remained stable, showing no decline.

The most critical finding was the development of a specific heart condition caused by the pacemaker itself. The researchers defined this as a drop in the heart's pumping ability of more than 10 percent, resulting in a final pumping score below 50 percent. In the traditional group, nearly one in five patients developed this condition. In the group with the newer pacing, not a single patient developed it. This difference was statistically significant, meaning it was highly unlikely to be a coincidence. The study also looked at how often patients had to be admitted to the hospital for heart failure. The traditional group saw a much higher rate of these admissions, with about one in four patients returning to the hospital, compared to only about one in twenty-five in the newer pacing group.

The researchers also examined whether the specific location of the wire within the newer pacing group mattered. They found that even when the wire did not perfectly hit the main electrical target but still stimulated the left side of the heart wall, the results were generally better than the traditional method. While the perfect placement offered the best preservation of heart strength, the broader category of this newer approach still prevented the heart from weakening in the vast majority of cases. The study noted that the newer procedure took slightly longer to perform and had a slightly lower initial success rate, with a few attempts needing to be converted to a different placement, but the long-term benefits for the heart muscle were substantial.

This research suggests that for patients who will rely heavily on a pacemaker, the way the device is placed matters deeply for their long-term health. The traditional method, while effective at keeping the heart beating, appears to carry a hidden cost of weakening the heart muscle over time. The newer approach, by mimicking the heart's natural electrical path, seems to preserve the heart's strength and keep patients out of the hospital. The authors conclude that for patients with a normal heart function who need constant pacing, this newer technique should be considered the preferred strategy. However, they also note that because this was a retrospective study based on past records rather than a randomized trial where patients are assigned by chance, larger and more controlled studies are needed to confirm these findings and to understand exactly which variations of the new technique work best for different types of patients.