Problems with Medtronic’s Viva Cardiac Resynchronization Therapy Defibrillators (CRT-Ds) and Evera Implantable Cardioverter Defibrillators (ICDs) could result in rapid battery depletion, which has caused nearly 10% of the units to fail.
Medtronic issued an urgent field safety notice last month for the Viva CRT-D and Evera ICD, indicating that at least 78 affected devices have a low resistance path in one of the circuits, which could quickly drain the battery.
Already, seven of the 78 devices have been confirmed to have failed, and Medtronic predicts another six will likely fail among the remaining population. The company notes that in case where the circuit became a problem, the battery depleted in seven days or less.
The failures of the ICD or CRT-D units presented clinically during doctors’ visits, as one or more electrical resets, a lack of pacing or defibrillation therapy output, no telemetry, or a programmer screen display that warns of “SERIOUS DEVICE MEMORY FAILURE.” Medtronic warned that patient audible alerts and CareAlerts may not be reliable.
Patients who suffered device failures suffered symptoms including:
- Shortness of breath
- Pocket heating
- Low heart rate
- Early device explant
The manufacturer indicates that no deaths have been reported in connection with the Medtronic Viva CRT-D and Evera ICD Battery Problems, however doctors have been advised to tell patients to seek medical attention if they begin to suffer symptoms like fainting or lightheadedness, or if they hear an audible patient alert. Doctors should consider device replacement for those patients who are pacemaker-dependant or at higher risk of Ventricular Tachycardia or Ventricular Fibrillation.
The company also provided a list of recommendations for patients with lower risks. The notice included a complete list of affected product names, models and serial numbers.