St Jude Medical has issued a letter to doctors saying that Riata and Riata ST family of cables had a 0.47% rate of insulation abrasion, which can cause the malfunction of the defibrillators.

The company said that cables with newer insulating material have lower rate of issues, and these newer cables represent 97% of sales.

The company is planning to phase out the older cables by the end of the year, and has asked the doctors not to preemptively remove these cables, which can be a complicated procedure.