The FDA has labeled a Medtronic (NYSE:MDT) HeartWare HVAD system battery charger as Class I — it’s most serious level.

A notice out March 9 from the FDA said that the Fridley, Minn.-based medtech giant recalled 5,489 total battery charger devices due to the potential for an HVAD system user to mistakenly insert the charger’s AC adapter into an HVAD controller power port. The FDA determined that the cause of the issue is the device’s design. The recall only affects devices distributed outside the U.S., and Medtronic said there are no affected devices in the country.

In January, customers were notified of the potential for the battery adapter to be inserted into an HVAD controller power port. When this mistake occurs, communication circuits between the battery and controller can be damaged, making it necessary for the user to exchange the controller to restore communication.

Included device instructions advise users to follow the guidance in the patient manual when connecting to a power source, according to the FDA notice. Users are urged to report persistent, unexpected audible tones to their clinician for additional instructions.

Medtronic’s HeartWare HVAD is indicated for hemodynamic support in people with advanced, refractory left ventricular heart failure, either as a bridge to cardiac transplantation (BTT), myocardial recovery or as destination therapy (DT).

The system is inserted through a small, lateral incision between the left ribs with a second incision for the pump’s outflow graft, all put in place through thoracotomy implantation. In July, Medtronic said results presented at the annual meeting of the American Society for Artificial Internal Organs showed that 95% of thoractomy patients were free from disabling stroke at two years.

This story was updated with a clarification from Medtronic.