Health Canada has issued a warning that batteries in two types of implantable defibrillators from St. Jude Medical pose a risk of depleting earlier than anticipated.

Patients with the affected implantable cardioverter defibrillators (ICD) and cardiac resynchronization therapy devices (CRT-D) are urged to contact their doctors for follow-up care and advice.

"Early battery depletion may occur suddenly, anywhere between hours and days, and without warning," Health Canada said in a statement.

No Canadians have died as a result of the issue, but two patients reported symptoms "such as loss of consciousness necessitating CPR, shortness of breath and fatigue."

Health Canada says there have been two deaths and 10 "serous events (e.g., fainting, chest pain)" associated with the battery problem internationally.

The problem has also been identified and corrected in patients who did not exhibit symptoms.

The warning applies to the following devices:

  • Fortify Assura DR
  • Fortify Assura VR
  • Fortify DR
  • Fortify ST DR
  • Fortify ST VR
  • Fortify VR
  • Quadra Assura
  • Quadra Assura MP
  • Unify Assura
  • Unify
  • Unify Quadra CRT-D

St. Jude Medical says the chance of depletion is small, and appears to occur two to three years after implantation. Doctors can determine whether a device is at risk of depletion through an in-person visit or via remote monitoring.

The medical community has been told not to use any more of the affected devices in new procedures.