How is possible to live with 2 LP in the ventricle after implantation of a bicameral LP in a patient with a unicameral LP?
It is possible—and sometimes preferable—for a patient to live with two leadless pacemakers (LPs) in the right ventricle. The unicameral LP is left in place (turned off) to avoid extraction risks, while the bicameral LP is activated to provide dual-chamber pacing. Clinical experience so far supports the safety of this approach, although long-term surveillance is important.
How the two devices communicate (or are managed) so that they don’t “compete” with each other inside the ventricle?
The unicameral LP is programmed off and left in place as a passive implant. The bicameral LP system assumes full control, with its atrial and ventricular modules communicating directly via wireless intracardiac conduction. This prevents competition, ensures proper AV synchrony, and avoids the risks of explanting the old LP.
Step-by-step sequence of what happens during the actual upgrade procedure (implantation day)?
1. Pre-procedure: Interrogate old LP. 2. Access: Insert sheath via femoral vein. 3. Implant new atrial and ventricular LPs. 4. Pair devices for bicameral pacing. 5. Deactivate old LP. 6. Confirm synchrony and separation by testing and fluoroscopy. 7. Post-procedure monitoring. This ensures smooth transition from unicameral to bicameral pacing.
Is it better to make the choice of transvenous conduction system pacing (CSP) when the unicameral device doesn’t work?
It depends. Bicameral LPs avoid leads and pockets, which is safer for elderly or infection-prone patients. CSP offers more physiologic pacing and long-term flexibility, especially in younger patients with high pacing burden or potential CRT/ICD needs. The choice is individualized based on infection risk, venous access, age, pacing needs, and future device planning.
Decision framework when to choose Bicameral LP vs CSP?
Bicameral LP favored in: high infection risk, poor venous access, low pacing burden, older/frail patients, preference to avoid pocket. CSP favored in: low infection risk, good venous access, high pacing burden, younger patients, possible CRT/ICD needs. A decision table guides which therapy is most appropriate.
If a leadless pacemaker device creates fibrosis over time, is it standard to develop LPs unable to remove? Is it based on short life expectancy?
Yes, early LPs were designed as non-removable because fibrosis made safe extraction unrealistic and most recipients had shorter life expectancy. The assumption was device life > patient life. Newer devices (e.g., Abbott Aveir) are retrievable, reflecting use in younger patients with longer horizons. Strategy has evolved from 'leave in place' to 'retrievable designs'.