Randwick Rugby Club's doctor is being sued for hundreds of thousands of dollars by a patient who will suffer lifelong disabilities after he was misdiagnosed as having a panic attack when he was in fact having a major heart attack.

Dr Paul Raftos, a GP at Maroubra, in Sydney's east, sent Steven Iacovone home with a script for the anti-anxiety medication Xanax after the then 35-year-old patient visited his surgery complaining of chest pains on June 7, 2010.

About two hours later Mr Iacovone suffered a very serious heart attack resulting in cardiac arrest and hypoxic brain damage. His heart stopped beating for at least eight minutes and he remained in an induced coma for about 10 days.

Mr Iacovone sued Dr Raftos for damages for injuries and disabilities he suffered and continues to suffer as a result of the GP's medical negligence, including a very rare condition known as Lance Adams Syndrome.

At the time of his heart attack Mr Iacovone had his own business, Yakka's Electrical, but he has not returned to work since.

Dr Raftos, via his insurer Avant, admitted liability and the NSW Supreme Court is deciding how much damages Mr Iacovone will receive.

The court has heard experts agree that it is unlikely he will ever work again.

As his heart stopped for eight minutes Mr Iacovone suffered a hypoxic brain injury which has resulted in cognitive impairment and sudden, involuntary jerking. He also has impaired lung function, serious depression and is being treated for epilepsy.

Less than 150 cases of Lance Adams Syndrome have been reported in worldwide medical literature, a 2011 report in the medical journal Annals of Rehabilitation Medicine, said.

During a hearing this month the court heard the parties are in dispute as to the amount of future care Mr Iacovone requires, the length of time during which that care will be required and the extent of his economic loss. The court heard there is a disagreement as to Mr Iacovone's life expectancy.

His de facto relationship broke down in August 2014 and he lives with his elderly parents.

A number of expert witnesses, including cardiologists, accountants, psychiatrists, occupational therapists and a neurologist, have been or will be called.

Dr Raftos is the club doctor at Randwick Rugby Club and last year was made a lifetime member. The club, established in 1882, has produced many Wallabies including Phil Kearns, Ewen McKenzie, David Campese, Chris Whitaker and George Gregan.

Fairfax attempted to contact Dr Raftos but he did not respond.

The case returns to court in July.