Can a cardioverter-defibrillator (ICD) be implanted in a patient with a single‑chamber leadless pacemaker?

Short answer: Yes. An ICD can be implanted in a patient who already has a single‑chamber leadless pacemaker (e.g., Aveir VR or Micra VR). The devices function independently and do not communicate, so careful pre‑implant screening and programming are required.

How it’s typically configured

Leadless pacemaker + Transvenous ICD

Good when bradycardia pacing and shock therapy are needed without CRT. ICD senses/defibrillates independently; program sensing to avoid oversensing pacing artifacts.

Leadless pacemaker + Subcutaneous ICD (S‑ICD)

Popular “lead‑minimal” combo. S‑ICD detects via body‑surface vectors; leadless device handles pacing. Requires careful S‑ICD vector screening to avoid double counting.

Key limitations

No inter‑device communication: Current systems cannot coordinate therapies.
Oversensing risk: ICD may sense pacemaker pulses; mitigate with vector/sensitivity programming.
No CRT/atrial pacing: This combo cannot provide resynchronization or atrial support.

When this approach is useful

History of device infection or high infection risk (e.g., dialysis).
Limited/occluded venous access or prior lead extraction.
Desire to minimize transvenous hardware.

Looking ahead

Modular, wire‑free systems that allow communication between an intracardiac pacemaker and a defibrillator are in clinical evaluation, aiming to coordinate pacing and shock therapies without transvenous leads.