Minnesota-based medical device company St. Jude Medical is pausing enrollment in a clinical trial for one of its more promising devices, the slender Nanostim pacemaker that fits entirely inside the heart.

St. Jude said in statement Friday that the company decided to temporarily halt implants of the pill-sized pacemaker because of problems with electronic data reporting from seven devices, representing 0.5 percent of devices in the Leadless II trial.

The statement described the problem as “lost telemetry and pacing output” from the Nanostim leadless cardiac pacemaker, but it said there have been no reports of patient injuries associated with the observations.

“We put our patients first, and our voluntary pause of Nanostim implants worldwide is another example of our commitment to protecting patients, and we are currently working to ensure our physician partners worldwide have the information they need to effectively manage those patients,” said Dr. Mark Carlson, St. Jude’s chief medical officer, in the statement.

St. Jude acquired the technology for $123.5 million in 2013 shortly after the Nano­stim device was approved for sale in Europe. But U.S. approval has remained ­elusive.

Competitor Medtronic received Food and Drug Administration approval for a similarly small pacemaker called the Micra in April.

Earlier this year, St. Jude told investors it expected the FDA would approve the Nanostim during the second half of this year. The presentation touted the Nanostim as one of several new devices whose U.S. approval would help return the company to leadership in the field of cardiac rhythm management.

“We remain committed to developing leadless pacing technology and will continue to work to redefine the pacing options available to patients in the future,” ­Carlson said.

According to the federal website clinicaltrials.gov, the Leadless II trial includes two study sites in Minnesota — Fairview Southdale Hospital in Edina and the Mayo Clinic in Rochester.

St. Jude shares closed ­Friday at $77.97, down about 1 percent.