Dick Cheney, heart implant modified for fear of terrorist attack.

Dick Cheney, the former US vice-president, has revealed that he had his heart implant modified for fear of terrorist attack.

Mr Cheney's doctor disabled the heart defibrillator's wireless function in 2007 to prevent would-be assassins from interfering with it and causing a fatal heart attack.

A similar scenario featured in an episode of the hit TV series Homeland.

"I found it credible," Mr Cheney told CBS TV's 60 Minutes programme.

"I know from the experience we had, and the necessity for adjusting my own device, that it was an accurate portrayal of what was possible,'' said Mr Cheney, who was President George W Bush's right-hand man during the "war on terror".

'Close proximity'

"Implantable Cardioverter Defibrillators (ICDs) can be vulnerable to a range of electronic signals," said Adrian Culley, global technical consultant for security company Damballa.

"Research has been undertaken which shows it is entirely feasible to potentially exploit someone's ICD, given close proximity to the individual."

But he said the chance of a successful attack on Mr Cheney would have been "slim".

An ICD monitors heartbeat and if it detects an irregular rhythm, sends low-energy electrical pulses to prompt the heart to beat at a normal rate.

In 2008, researchers from the University of Washington, the University of Massachusetts Amherst, and Harvard Medical School, claimed that they could carry out software radio-based attacks on ICDs that could "compromise patient safety and patient privacy".

More recent research has also highlighted the security and data privacy weaknesses of some implantable medical devices.

"Since the experiments in 2008, experts have acknowledged that greater security of these devices is required, and encryption has been introduced to prevent the loss of personal data," a spokesman for the Institute of Risk Management said.

"As with all electronic devices, the possibility of targeted hacking still exists given the right physical situation, expert knowledge of the device and the necessary equipment.

"However, it is much more likely that a strong electromagnetic field will cause the device to malfunction," he said.

Cardiac arrest

The American Heart Association warns ICD users against too much close-range exposure to a number of electronic devices, from mobile phones to metal detectors, retail security systems to powerful CB radios.

But it points out that, in most cases, the risks are small.

Cardiologist Jonathan Reiner has co-written a book with Mr Cheney called, Heart: An American Medical Odyssey, chronicling the former vice-president's many heart problems.

Mr Reiner told 60 Minutes that on 11 September 2001, the day of the al-Qaeda attacks on New York and Washington, the potassium in Mr Cheney's blood rose to levels that could have caused abnormal heart rhythms and cardiac arrest - a condition called hyperkalemia.

Mr Reiner feared the vice-president was going to die that night.

Mr Cheney, 72, has a long history of heart troubles culminating in a heart transplant last year.