Updated July 16, 2013, with information from Medtronic.

Medical device giant Medtronic (NYSE:MDT) is asking hospitals to return certain cardiac resynchronization therapy pacemakers (CRT-Ps) after the company discovered manufacturing issues that could keep the devices from functioning properly.
Medtronic recalled its Consulta and Syncra CRT-Ps amid a "recent trend of increasing manufacturing rejects related to the weld of a connector bracket," according to an urgent field safety notice. The company has received no reports of device failures as a result of the defect, but warned that an "out-of-specification" weld on the devices could mean that the devices aren’t properly hermetically sealed.
"This may allow body fluids to enter the device, which could cause it to not function properly," according to an Australian Therapeutics Good Administration warning. "If this happens, it may cause loss of pacing output, which could potentially result in return of symptoms, including: fainting or lightheadedness, dyspnoea (shortness of breath), fatigue, oedema (swelling)."
The recall affects certain lots of the Consulta and Syncra devices manufactured between April 1 and May 13, 2013, according to a June 10 Medtronic field safety notice. The likely rate of malfunction is very low (affecting an estimated 1-2% of this subset of devices) and as of June 21 there have no reported issues in any implanted devices, but the device maker wants to re-inspect the connector brackets to confirm that they meet specifications.
Medtronic noted that the manufacturing issue is unique to the 2 models specified, not affecting any other devices or models. An FDA notice put the quantity of affected devices "in commerce" at just over 1,900. Medtronic had initially estimated that less than 700 patients had been implanted with the affected devices, but has since lowered that figure to approximately 265, with about 44 of those in the U.S., a company spokesperson told MassDevice.com today.*
In an updated notice issued July 1 Medtronic issued new recommendations for patient care, telling physicians to warn patients to immediately seek medical attention if they experience symptoms of device failure and advising healthcare providers to make a case-by-case assessment if considering prophylactic replacement of any implanted devices. Medtronic also recommended that physicians continue with routine follow-up practices for these patients.
The FDA labeled the recall a Class II measure, reserved for "products that might cause a temporary health problem, or pose only a slight threat of a serious nature."
*Correction filed July 16, 2013: This article mistakenly stated that the Consulta device is not cleared for use in the U.S.