Customer Communications
Potential Loss of High Voltage and ATP Therapy

Potential Loss of High Voltage and ATP Therapy

EnTrust® and Escudo® VR/DR/AT ICDs
Original Date of Communication: June 2018

View specific models that this applies to


All models of EnTrust and Escudo VR/DR/AT ICDs devices.


EnTrust and Escudo implantable cardioverter defibrillators (ICDs) have the potential for loss of high voltage and anti-tachycardia pacing therapy as they near elective replacement indicator (ERI) voltage.  Under certain circumstances, the device may display an immediate End of Life (EOL) Observation with no prior ERI alert.  Though no ERI alert is triggered, there may not be enough remaining battery capacity to charge the high voltage circuits, resulting in an excessive charge time EOL Observation (refer to Image 1) , leading to a loss of high voltage and anti-tachycardia pacing therapy. Bradycardia therapies will continue to operate as expected.

Through June 15, 2018, Medtronic confirmed 25 charge timeout events related to this issue, with no (0) patient deaths or complications. All events occurred during routine capacitor formation or in-clinic charge testing. Twenty-one (21) events occurred with no ERI alert; four (4) events followed an ERI alert. Time from implant to the devices experiencing the issue ranges from 7.9 – 11.7 years.

EnTrust and Escudo ICDs were last manufactured in 2010. Approximately 25,000 sold devices globally are in-scope of this advisory. As of June 2018, an estimated 2,770 of those devices remained actively implanted worldwide (209 confirmed as active in the U.S.).  The rate of occurrence in remaining active devices is estimated to be 0.00098 in single chamber ICDs and 0.00005 in dual chamber devices.

Patient Management Recommendations

We realize that each patient requires unique clinical considerations. In consultation with the Independent Physician Quality Panel, Medtronic recommends the following actions:

  • Consider scheduling an in-office patient follow-up as soon as possible to assess the potential for this issue per the steps described below.
  • Ensure the Excessive Charge Time EOL…and the Low Battery Voltage ERI… Patient Alerts have been programmed to “On-High” (Refer to Image 2).
  • Instruct patients to contact your office if they hear device alert tones. Consider utilizing the “Demonstrate Tones...” function to ensure patients recognize the audible tone.
  • If this issue has occurred, an “EOL: replace device immediately” Observation will be displayed on the QuickLook report. Schedule device replacement immediately.  

Additionally, Medtronic recommends the following actions to help ensure patient safety and effective high voltage therapy remain as the device battery voltage approaches its 2.61V ERI threshold.

If Battery Voltage ≤ 2.64V:

Prophylactic device replacement should be strongly considered since the device is near its elective replacement and additional programming would provide only minimal additional months of service. For patients for whom it is determined that delaying replacement is clinically desirable, contact Medtronic Technical Services.

If Battery Voltage > 2.64V:

Step 1: If the Auto-Cap Formation Interval is set to “Auto”, reprogram the value to “6” (Refer to Image 3).

Change from an “Auto” value to a fixed numeric value will ensure that an excessive charge time will trigger an audible patient alert.

Step 2: Conduct an in-clinic manual high voltage charge in “Tests – Charge/Dump” (Refer to Image 4a).

DO NOT Dump the Test Charge as it will dissipate on its own and allow for capacitor reformation to occur.

Step 3: Retrieve Data after the Test Charge (Refer to Image 4b)

- If Charge Time is less than 16 seconds, no further action is required. Continue with routine follow-up per clinic practice (recommend 3-month follow-up sessions per labeling).

- If Charge Time is 16 seconds or longer, or an “EOL” Observation is displayed, schedule device replacement immediately.


Status Update

As of October 15, 2019, there have been 31 confirmed events related to this issue. An estimated 800 remain active WW with less than 50 in the US. 



Image 1 - Excessive Charge Time EOL (Observation)

Image 2 – Excessive Charge Time EOL Alert (Programming Screen)

Image 3 –  Programming Steps to Change Auto-Cap Formation Interval to Fixed value of 6-month intervals

Images 4a and 4b – Programming Screens to Conduct In-clinic High-Voltage Test Charge


Specific Models This Applies To 726050