"I knew it wasn't right so that's what led me to go to the local doctor."
The GP visit confirmed angina.
Mr Lamb was sent to Auckland where he was asked if he would take part in a trial for Absorb - a new, untested, stent treatment that would dissolve after a few months.
After talking it over with family, Mr Lamb signed up and pharmaceutical company Abott Laboratories, which created Absorb, covered all costs.
Wife Adele Lamb said when her mother-in-law died from cancer years ago, she told doctors "you can try anything on me that you want if it's going to help someone else".
"I knew he would make that same comment," Mrs Lamb said.
Coronary heart disease is the leading cause of death in New Zealand.
Research shows, on average, a New Zealander dies of the disease every 90 minutes and one in 20 adults has been diagnosed with the disease.
The stent used in the operation was created in America and deep frozen before being shipped to New Zealand, with two escorts ensuring its security.
When it came time for Mr Lamb's surgery, doctors asked if he would mind being filmed for research purposes, "which didn't worry me", he said.
"But when I got in the theatre there were probably 20-odd staff in there and there were television cameras and the viewing room was chock-full of people. It absolutely floored me.
"That was really the first time I thought it was big - the first time the sheer enormity of it hit me."
Footage of the surgery was sent live to the research facility in America where the stent was made and history was made.
Minuscule ball bearings built into the stent remain in Mr Lamb's aortic valve after the rest of the stent dissolved, to indicate where the Absorb device had once been.
Within two days, Mr Lamb was back retrieving his mail like nothing had happened.
Aside from six months of taking post-operative medication, Mr Lamb said it was if his angina had not existed.
Nearly 2000 patients in more than 30 countries have since been treated with Absorb.
The treatment is now publicly funded although a Bay of Plenty District Health Board spokeswoman said it was not yet available at Tauranga.
A spokeswoman for Abott Laboratories said the cost of Absorb in private hospitals would depend on the level of health coverage a patient had but would be free in public hospitals.
"We will always recommend that patients discuss their individual circumstances with their physician," she said.