St. Jude warns of more battery problems with another of its cardiac devices

For the second time in a month, St. Jude Medical ($STJ) has issued a warning of possible problems with one of its implantable heart devices. This time the company has told doctors to cease using its Nanostim leadless cardiac pacemakers.

In a statement issued last week, the company cited reports of problems with the device’s electronic data reporting that were apparently caused by a battery malfunction, Reuters reported. There were seven reports of lost telemetry and heart pacing output from the Nanostim pacemakers. 

Earlier in October, St. Jude warned of a possible problem with a lithium-based battery used in some of its high-voltage cardiac rhythm management devices that could result in a short circuit.

The news of a second warning comes amid Abbott’s ($ABT) $25 billion acquisition of St. Jude.

"We are currently working to ensure our physician partners worldwide have the information they need to effectively manage their patients," Mark Carlson, St. Jude’s chief medical officer, said in a statement.

The company estimates that of 1,423 Nanostim devices that have been implanted globally, 1,397 remain in service and represent a potential risk to patients.

Doctors have been told not to implant any more Nanostim pacemakers and to return what devices they may have in stock. No patient injuries related to the device have been reported.

In the earlier warning, the company said there was a risk the batteries used in the devices could produce “lithium clusters” during high-voltage charging in a subset of its ICD and CRT-D devices manufactured before May 23, 2015.