For generations, the pacemaker has been the heart’s little electrical helper, stepping in when the body’s natural wiring system fails to keep the heartbeat regular.
But today’s pacemaker technology is becoming more sophisticated. Rather than simply telling the heart muscle to contract, physicians increasingly can place the device where it can tap into the heart’s own electrical conduction system, allowing the two lower chambers to contract in a more natural, coordinated fashion.
Dr. Ravi Choxi, a new electrophysiologist with Cleveland Clinic Indian River Hospital, utilizes one of those newer approaches, called left bundle branch area pacing, or LBBAP.
To understand why the technique matters, it helps to understand what happens when the heart’s electrical system goes awry.
“An arrhythmia is an abnormal heart rhythm,” Dr. Choxi explained. “The heart can beat too quickly, too slowly or irregularly. While some fast rhythms can be treated with procedures such as catheter ablation, a heart that beats too slowly or has a problem with the electrical signal traveling between the upper and lower chambers may require a pacemaker.”
When those electrical signals don’t travel properly, the heart’s chambers can fall out of sync. The result can be fatigue, shortness of breath, dizziness or fainting.
A traditional pacemaker solves the immediate problem by delivering electrical impulses to make the heart beat at an appropriate rate. But there is a catch.
The heart’s natural electrical system is designed to send its signal through the center of the heart, activating the right and left sides simultaneously so they contract together. Conventional pacemakers deliver an electrical impulse from the right side of the heart instead.
“That’s not how normal conduction goes,” Dr. Choxi said.
With conventional right-ventricular pacing, the electrical signal can reach one side of the heart before the other, creating a slight electrical and mechanical delay. For patients who need a great deal of pacing over many years, that lack of synchronization can potentially contribute to weakening of the heart muscle.
LBBAP takes a different approach.
Instead of positioning the electrical lead in the right ventricle, the physician guides a specialized lead through the muscular wall of the heart’s septum, the thick wall separating the right and left ventricle, toward the area of the left bundle branch, part of the heart’s natural electrical highway.
The goal is to make the heart beat in a way that more closely resembles its natural rhythm.
“We’re trying to capture the electrical signature of the heart that mimics the same electrical pulse that a normal heartbeat would get,” Dr. Choxi said.
When the electrical impulse travels through the conduction system, the right and left ventricles can contract together more efficiently. For someone who may depend on a pacemaker for years, maintaining that coordination helps reduce the risk of pacing-related weakening of the heart muscle.
The technology is relatively new compared with conventional pacemakers, but its use has been growing rapidly over the past five or six years.
“Most of my patients are now getting this conduction system pacemaker over traditional pacemakers,” Dr. Choxi said.
The Heart Rhythm Society and several international heart-rhythm organizations now recognize conduction-system pacing, including LBBAP, as an option for selected patients who require substantial ventricular pacing. The 2023 guidelines specifically note that patients expected to need high levels of ventricular pacing may be considered for physiologic pacing to reduce the risk of pacing-induced cardiomyopathy.
Early clinical evidence is encouraging. In one observational registry involving 703 patients receiving pacemakers for slow heart rhythms, the combined outcome of death, hospitalization for heart failure or needing an upgrade to biventricular pacing occurred in just 10 percent of patients receiving LBBAP compared with 23.3 percent of those receiving conventional right-ventricular pacing.
That does not mean LBBAP is automatically the right choice for everyone who needs a pacemaker. The appropriate pacing strategy depends on the patient’s rhythm problem, heart function and how much pacing will be required.
For patients with an already weakened heart, LBBAP may be used when physicians upgrade an existing pacemaker system. An additional lead can be placed in the conduction-system region to improve the coordination of the heart’s contractions.
Dr. Choxi said the procedure itself isn’t dramatically different from a conventional pacemaker implantation. The lead is introduced through a vein in the chest and guided into the heart. Positioning the LBBAP lead requires additional work and typically adds about 15 minutes to the procedure.
The procedure is generally performed on an outpatient basis, allowing most patients to return home the same day. Some soreness is expected for about a week, but patients can generally return to their normal routines afterward.
As the technology continues to evolve, the latest leads and delivery systems are making it easier for physicians to target the heart’s conduction system, and Dr. Choxi envisions a future in which leadless devices may be capable of delivering physiologic pacing from within the heart itself.
The goal is no longer simply to keep the heart beating when its electrical system fails. Increasingly, the goal is to help the heart contract in harmony with the way it was designed to work.
“People feel better when their heart contracts in a physiological way,” Dr. Choxi said.
Ravi Choxi, DO is an electrophysiologist specializing in treating arrhythmias and heart pacing at Cleveland Clinic Indian River Hospital. He completed medical school at Edward Via College of Osteopathic Medicine (VCOM) in Blacksburg, Virgina, then completed a cardiovascular medicine fellowship at Reading Hospital, Pennsylvania, and an electrophysiology fellowship at Beth Israel Lahey Hospital in Burlington, Massachusetts. He is board-certified in Internal Medicine, Echocardiology, Nuclear Cardiology and Adult General Cardiology. He sees patients at the Rosner Family Health and Wellness Center, 3450 11th Court, Vero Beach. The phone number is 877-463-2010.
