Some cardiologists are also concerned that the multi-billion dollar medical device industry has too much control over devices being implanted in Australians, and that this could lead to over-servicing to boost profits.

For the past year, Australian and American health authorities have been issuing warnings that medical devices connected to the internet for remote monitoring have vulnerabilities that could be exploited.

Last month, the US Federal Drug Administration highlighted potential weaknesses with St. Jude Medical's systems for cardiac devices, saying it was possible for an unauthorised user to remotely access a patient's cardiac device.

This could result in "rapid battery depletion and/or the administration of inappropriate pacing or shocks", the regulator said. On the same day, the company said it was making improvements to further reduce an already "extremely low" risk.

A spokesman for the company which recently merged with Abbott, said no patients had been targeted. He declined to say how many Australians had the company's devices, although doctors say they are used locally.

Medicare data shows thousands of patients are being fitted with cardiac devices from a range of companies with remote monitoring capacity each year.

Australian cardiologist Bradley Wilsmore said while remote monitoring of cardiac devices was "booming" because it allowed abnormalities to be detected sooner than they might otherwise be, there were potential privacy and security risks.

Because the monitoring systems use mobile technology, pinging towers wherever users go, he said there is potential for people's movements to be tracked, medical information to be leaked, and the device's functioning to be interfered with.

"If you're the President of the United States there might be a few people out there keen to program that device. You can literally take a person's life, stop a pacemaker, start a pacemaker or discharge a shock from the device," he said.

"We do these things at the moment with the patient present, but we are moving to do it remotely."

Writing in the Medical Journal of Australia today (Monday), Dr Wilsmore and another cardiologist James Leitch, said there were also concerns about medical device companies taking charge of this remote monitoring because of potential "conflicts of interest".

They said a consensus statement endorsed by the Asia Pacific Heart Rhythm Society clearly advises that industry "should refrain from direct patient care, either within the clinic or at home" and "should not perform, collect, or triage data".

It does not specify why, but Dr Wilsmore said a company's desire for profits could lead to up-selling or over-servicing.

Despite the consensus statement, he said many doctors were regularly allowing companies to perform remote monitoring because doctors do not have the resources to do it themselves 24 hours a day, 365 days a year - an undertaking that could open them up to legal risks.

Nor is there any financial incentive. Medicare pays doctors $50.15 for remotely monitoring a pacemaker and $142.15 for a defibrillator. In contrast, a company in the private system will get $1960 from Medicare. There is no such incentive for it in the public system.

This has created a conundrum for cardiologists, Dr Wilsmore said, because they cannot follow guidelines and put patients at the mercy of risks associated with companies managing their data and devices.

Or they can discourage remote monitoring, exposing patients to the risk that an abnormality won't be detected between six monthly visits to their doctor. The remote monitoring system can pick up a defect in the device or an abnormal rhythm in the patient's heart, prompting the company to call the patient, who can then contact their doctor to get it checked out.

Dr Wilsmore is now hoping doctors can work with hospitals and the federal government to find a better solution.

"I worry most for the poor cardiologist who gets sued and the patients who miss the opportunity for up to date care because cardiologists are concerned about being sued," he said.

Last year, Australia's Therapeutic Goods Administration issued a general warning about cyber security vulnerabilities in medical devices, urging doctors and companies to observe precautions.

The regulator said devices incorporating wireless communications are particularly vulnerable as potential hackers can operate remotely. Such devices include insulin pumps, neural stimulators and infant monitors.

"Although there have been no reports of hacking attacks on medical devices in Australia, there have been reports of such attacks overseas. Cyber security experts in Australia have demonstrated a wide range of potential vulnerabilities in simulated attacks," the TGA said in February 2016.

On Sunday, a spokeswoman for the department of health said it was not aware of any breaches of patients' medical device data in Australia and said companies were required to comply with the Privacy Act, which includes disclosing how patient data will be stored and used.

The spokeswoman declined to say whether the government would change its payments to companies and doctors for remote monitoring, but said Medicare payments for cardiac services were being reviewed as part of the Medicare Benefits Schedule Review Taskforce, which is aiming to refine payments for medical services to better reflect up-to-date evidence.

"The Cardiac Services Clinical Committee is close to finalising its recommendations and anticipates there will be public consultation in the next few months," she said.

A spokesman for the Medical Technology Association of Australia said safety of patients was always a priority for the industry which is continuously assessing security.

"The risk associated with potential cyber security breaches to an individual patient is low and the benefits of medical device therapy outweigh these risks," he said.

"Regulators worldwide including the TGA recognise the importance of device cyber security. We will continue to work with the TGA, our members, and stakeholders to ensure patient safety and protection from such issues."