Implant Detection Feature

Implant Detection is a pacemaker feature designed to ensure that pacing and sensing polarities are set appropriately at time of implant. In the event an out-of-range impedance is detected, the device ensures capture by switching automatically to unipolar operation.

This feature can be found in some Medtronic Pacemaker and CRT-P devices. Please go to or consult with your local Medtronic representative regarding device models available in your geography.

Implant Detection is nominally programmed to On/Restart. The other programming option is Off/Complete.

To program this feature, go to Params -> Additional Features -> Implant Detection.

Immediately following insertion of the leads, it is imperative to ensure capture. Implant Detection allows the polarity of the lead to be programmed to unipolar if there is an out-of-range bipolar impedance due to damage of the lead or incomplete insertion.

Implant Detection will also initiate features and data collection.

The Implant Detection period begins when the leads are connected and establishes lead polarity (both atrial and right ventricular). In CRT-P devices the LV lead is not configured by the Automatic Polarity Configuration feature.

During the 30 minute Implant Detection period, impedance is measured at every paced event. In the event of an out-of-range bipolar impedance measurement, a backup unipolar pace – Autopace – is provided to ensure capture.

Auto Polarity Configuration delivers three asynchronous pulses at 85 bpm five minutes after lead connection and again after 30 minutes to measure the impedance and determine which polarity should be set.

  • If the system fails the bipolar test at the 5 minute mark, polarity is permanently set to unipolar.
  • If the lead is bipolar, a second test at the 30 minute mark is conducted to further confirm polarity.
  • Once polarity is set, Lead Monitor Only is switched on; this measures impedance at every paced event and records out-of-range values.
  • Note that plugged lead ports exhibit out-of-range impedances and will prevent completion of the Implant Detection process. Therefore, if a plugged lead port is present, no data collection will begin until Implant Detection is manually programmed to Off/Complete.

An overview of the 30 minute Implant Detection process can be seen in this flow chart:

After 30 minutes, the pacemaker completes Implant Detection and activates the following features:

  • Operating polarity (automatic configuration occurs during Implant Detection).
  • MVP™ operations including conduction checks and mode changes.
  • Adaptive sensitivity settings (Sensing Assurance).
  • Rate Response, including adaptive rate profile optimization (Rate Profile Optimization).
  • Adaptive ventricular output settings for threshold management (Atrial Capture Management™, Left Ventricular Capture Management, or Ventricular Capture Management).
  • Diagnostic data collection.
  • Search AV™+ initializes 60 minutes after Implant Detection is complete.
  • All automatically adaptive features and diagnostics (eg. CareLink data) are enabled after a successful Implant Detection Period. The adaptive features are identified by the up/down arrow symbols on the programming screen available via the Parameters icon. All automatic diagnostics are enabled. 
  • In the event that the implanting physician requests stopping Implant Detection in order to see Rate Response or MVP in operation – two of the features suspended during Implant Detection, it is possible to manually program the correct lead polarity and Implant Detection to Off/Complete.
  • Mode Switch is automatically turned on after the leads are connected, and remains on throughout the 30 minute detection period. Atrial sensing and arrhythmia detection also continue during the Implant Detection period.


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

Last updated: 
03 Apr 2013