In a letter to physicians, Medtronic Inc. has warned that nearly 37,000 of its pacemakers, produced late 1990s onwards, could possibly have wiring defects due to which a malfunctioning of the medical equipment is quite possible.

Saying that almost 1.7 million of the pacemakers have been implanted since 1997, as per the company estimates, Medtronic added that it has received two reports of fatal cases in which malfunctioned pacemakers likely played a role.

Referring to the defect, the Fridley-based Medtronic said that it affects a subset of its Kappa and Sigma pacemakers, thereby leading to either a failure of timely response from the device or causes it to run out of battery power.

During a conference call with investors on Tuesday, Medtronic CEO Bill Hawkins said that most of the affected pacemakers had been distributed overseas. 

Urging the physicians to consider removing the affected lots of pacemakers especially in cases where patients depend on the device for daily survival, Medtronic has also requested patients to call their doctor instantaneously if they feel faint or lightheaded while on a pacemaker.