PVC Response Feature

Premature ventricular contractions, or PVCs, can cause retrograde P waves to occur. Retrograde conduction following a PVC can disrupt AV synchrony and affect pacing mode timing. For tracking modes (DDDR and DDD), retrograde conduction following a PVC can initiate a pacemaker-mediated tachycardia (PMT). For nontracking modes (DDIR and DDI), retrograde conduction following a PVC can cause a loss of AV synchrony. PVC Response extends the PVARP following a PVC to avoid tracking a retrograde P-wave and to prevent retrograde conduction from inhibiting an atrial pace.
 
This feature can be found in some Medtronic Pacemaker, ICD, CRT-P, and CRT-D devices. Please go to manuals.medtronic.com or consult with your local Medtronic representative regarding device models available in your geography.

PVC response is nominally On but can be programmed Off.

To program this feature in pacemakers, go to Params -> Additional Features -> PVC Response.

To program this feature in ICDs, go to Params -> Pacing -> Additional Features.

The pacemaker defines a PVC as any ventricular sensed event (refractory or nonrefractory) that follows a ventricular event (pace, refractory sense, or nonrefractory sense) without an intervening atrial event (pace, refractory sense, or nonrefractory sense). In the VDD mode, a ventricular paced event delivered at the Lower Rate and not preceded by an atrial sensed event is also considered a PVC.

Premature Ventricular Contraction (PVC) Response serves one of two purposes, depending on the programmed pacing mode:

  1. DDDR (including MVP), DDD, and VDD modes – PVC Response is intended to prevent tracking of retrograde P waves generated by PVCs. This response helps prevent initiation of pacemaker-mediated tachycardia.
  2. DDIR and DDI modes – PVC Response prevents inhibition of atrial pacing that can result from retrograde P-waves generated by PVCs.

The operation of PVC response is described in the diagram below.

Interaction with other features 
PVC Response interacts with other pacemaker features as follows:

  • The PVC Response feature always enables Non-Competitive Atrial Pacing (NCAP) for one cycle when NCAP is programmed Off. This occurs even when the PVARP extension occurs.
  • If Mode Switch is On, PVC Response is temporarily disabled when the pacemaker switches to the non-atrial tracking mode. It is re-enabled upon return to the atrial tracking mode.

If PVC Response is programmed to On and PMTs are observed, consider programming PMT Intervention, or evaluate the atrial and ventricular lead performance or positions, or consider drug therapy to reduce retrograde conduction.

PVC Response Off

PVC Response On

In the EGM strip above:

  • PVARP is programmed to 200 ms (shown by small green box).
  • After the sensed PVC, PVC Response extends PVARP to 400 ms (shown by red box).
  • The retrograde P-wave following the PVC now falls into the extended PVARP, as indicated by its AR annotation.

References

Sources: Medtronic Adapta/Versa/Sensia Reference Guide; Medtronic Consulta CRT-P Clinician Manual;Medtronic Protecta XT DR Clinician Manual; Medtronic Protecta XT CRT-D Clinician Manual.

Last updated: 
27 Mar 2013