Effect of RF Ablation on St. Jude Medical Implantable Cardiac Rhythm Devices

Background

RF ablation conducts electrical current in the range of radiofrequency signals between the needle electrode and a ground plate. This current then creates heat around the electrode—destroying the target/surrounding cells. RF ablation performed in a patient with a pacemaker or implantable cardioverter defibrillator (ICD) may cause device malfunction or damage. Additionally, loss of capture may be observed but this is usually temporary and capture returns after the RF ablation procedure has been completed. It is also possible that during RF ablation the Sense Amp signal may appear as a flat line under programmer telemetry due to the large RF ablation signal saturating the sense amplifier.

Potential effects

A summary of potential effects is provided in the table below and is based on device testing at St. Jude Medical, clinical experience and/or a review of the scientific literature.

Potential Effect Estimated Frequency
  Pacemakers ICDs
Single-beat inhibition of pacing Common Common
Loss of capture (usually temporary) Common  Common
Total inhibition of pacing Uncommon Uncommon
Asynchronous pacing/noise reversion Common Common
Increased pacing rate (up to programmed Maximum Rate) Uncommon Uncommon
Arrhythmia induction Uncommon Uncommon
Inappropriate therapy delivery Not applicable Uncommon
Failure to deliver needed therapy Not applicable Rare
Damage to pacemaker/ICD Rare Rare

Recommendations

In order to minimize RF cardiac ablation risks, the following precautions should be considered:

  • Programming the pacing outputs to 5.0 volts or higher during the RF ablation procedure may reduce the incidence of loss of capture.
  • The device can be programmed to an asynchronous mode in dependent patients to prevent inhibition of pacing. Clinicians may opt to place a magnet over a pacemaker in lieu of reprogramming to an asynchronous mode.
    • ICDs: Magnet application does not force asynchronous pacing in ICDs; therefore program HV therapy to Off/Disable and then program the mode to an asynchronous mode. Programming the ICD to Defib Off would also prevent inappropriate therapy.
  • Monitor the patient’s heart rate. Surface ECG may be unreliable due to artifacts from the RF ablation procedure. Alternative methods such as pulse oximetry can be used.
  • Avoid direct contact between the ablation catheter and the implanted leads/pacemaker/ICD.
  • Position the ground plate so that the current pathway does not pass near the pacemaker or ICD system, i.e., place the ground plate under the patient’s buttocks or legs.
  • Have external defibrillation equipment available.

If you have any questions please contact St. Jude Medical CRM Technical Services.

PDF Effect of RF Ablation on St. Jude Medical Implantable Cardiac Rhythm Devices (122kb)
Rev. 01/16