Certain Medtronic pacemakers may have batteries that drain faster than expected without alerting patients or healthcare professionals, the FDA cautioned.

The devices — implantable and cardiac resynchronization therapy pacemakers — provide pacing for slow heart rhythms and heart failure. They are placed under the skin in the upper chest area and connected to the heart via wires.

The agency said that three medical device reports alerted it to cracks in the device’s capacitor that caused the battery to fully drain without warning, which could pose serious risks to patients heavily reliant on pacemakers. Nearly 132,000 of the devices have been sold in the U.S.