Advances in leadless conduction and Bachmann’s bundle pacing next frontier in physiologic pacing

"Last year we presented the data on the first-in-human study where we actually put the device in to look at the safety and feasibility of whether we can take a leadless device and put it in the conduction system area from the right ventricle," Nair explained. "We showed that it's possible, but we also learned from our initial experience that there are things we have to change."

Investigators incorporated several modifications into the chronic implant study, including the use of a deflectable sheath and changes to the device itself. Procedures utilized intracardiac echocardiography, fluoroscopy and contrast guidance. Nair emphasized that further refinement is needed before there could be broader adoption.

"What we showed is that we are able to safely deliver it. There is a learning curve to it," she said. "The data tell us that we need to do more. There is work to be done."

The next logical step, according to Nair, would be a U.S. Food and Drug Administration investigational device exemption (IDE) trial that incorporates additional improvements to both the delivery system and the implant itself.

Expanding leadless therapy beyond current limitations

Current leadless pacemaker technology is largely limited to pacing the right ventricle. Conduction system pacing could potentially overcome some of those limitations by providing more physiologic activation of the heart and reducing the risk of pacing-induced cardiomyopathy. 

Nair said future iterations of leadless conduction pacing may have applications in heart failure patients who could benefit from more physiologic ventricular activation. 

"This is going to push that boundary," she said. "It will actually help us take care of some of the heart failure patients too and prevent pacing cardiomyopathy." 

Another challenge facing the technology is the delivery approach. Both the original first-in-human study and the LEAP2 chronic implant study utilized internal jugular vein access rather than the femoral approach commonly used for leadless pacemaker implantation. 

While internal jugular access is already approved and routinely used in selected patients, Nair said engineers are exploring ways to transition the procedure to femoral access to facilitate wider adoption with EPs who are more comfortable with that access route.

"How do you change that to a femoral access procedure as well for easier adoption?" she said. "Those are all things that are absolutely in the minds of the engineers." 

Bachmann’s bundle pacing gains momentum

Beyond conduction system pacing, Nair highlighted growing interest in Bachmann’s bundle pacing as another emerging physiologic pacing strategy.

Bachmann’s bundle serves as the primary electrical connection between the right and left atria, making it an attractive target for more physiologic atrial pacing. While most current work involves conventional transvenous leads, researchers are beginning to explore the possibility of implanting leadless devices in the Bachmann’s bundle region as well.

"I think one of the other important things in physiologic pacing picking up momentum is Bachmann's bundle pacing," Nair said.

The growth of Bachmann’s bundle pacing is also being supported by advances in imaging and procedural planning technologies. Nair pointed to emerging tools from Cara Medical that use cardiac CT imaging to identify the location of Bachmann’s bundle and other components of the cardiac conduction system. The imaging can provide both pre-procedural planning and intraprocedural guidance, helping physicians more accurately target pacing locations and potentially improve outcomes. 

As physiologic pacing continues to evolve, Nair sees leadless conduction system pacing and Bachmann’s bundle pacing as complementary developments that could further reduce reliance on conventional pacing approaches, while improving long-term cardiac function. 

"We are starting to see a lot of work with transvenous leads in the Bachmann's bundle, and also now potentially leadless devices in the Bachmann's bundle area," she said, signaling what may be the next phase in the evolution of cardiac pacing technology.