The device, called Medtronic’s Reveal LINQ, is able to wirelessly monitor a patient’s heartbeat, alerting doctors to any irregularities.

It is about a third of the size of a triple A battery.

Electrophysiologist Dr Brad Wilsmore first inserted the device into a patient at Lake Macquarie Private Hospital last week. The procedure took two minutes.

Dr Wilsmore said the cardiac monitor was free of charge to both public and private patients if they met strict criteria.