It centres on the ending of a pay-parity deal in 2024 which had long seen salaries for clinical perfusion scientists matched with medical scientists.

This was followed by a Labour Court recommendation in January for the pay arrangement to be reinstated with back-pay to 2024.

Lorraine Browne, a clinical perfusion scientist at CUH, said these specialist staff felt like they were forced into strike action when the ruling was not acted on.

“It is regrettable but it was all avoidable,” she said. 

“The HSE broke an agreement that had been in place since the 1960s.

“It’s ridiculous really, and all we want is for them to restore that and to implement the Labour Court recommendation.” 

She is one of three such specialist cardiovascular professionals in CUH. There are 25 across the country.

The other hospitals involved in the strike action were Galway University Hospital and the Mater and St James’ hospitals in Dublin.

Dr Browne explained: “A perfusionist is part of the cardiac surgery team. We take over the function of the heart and lungs with the heart-lung by-machine while the surgeon operates on the heart.

“So no cardiac surgery can happen without cardiac perfusionists.” 

She said that essentially “we do the bypass” in bypass surgeries.

It is difficult to say how many surgeries might take place usually. Dr Browne said: “Approximately 14 cardiac cases can be completed in a week in CUH, it depends (on many things).” 

She added: “We didn’t want to cancel surgeries today but unfortunately when the HSE doesn’t implement the Labour Court recommendations, this is what had to happen next.” 

With audible support from staff and cars passing by, Dr Browne said: “There are two more strike days planned for next week but we really hope it won’t come to that.” 

Most perfusion scientists are represented by Fórsa which supports the call for action.

Fórsa’s Seamus Smith was also on the CUH picket line on Tuesday and described the strike as “easily avoidable” and “regrettable”.

He said: “All the HSE have to do is honour the recommendation.” 

Fórsa estimates the difference between the two pay rates is €233,000 per year for all 25 perfusionists.

“It’s less than half of 1% of the overall HSE budget,” he said, adding: “This would resolve the pay element of the dispute.” 

A HSE spokeswoman said elective cardiac procedures were deferred in the five hospitals. These will be rescheduled and emergency care is going ahead under agreement with the union.

“Any patient that may have had a cardiac operation scheduled for [Tuesday] has been contacted,” she said.

“The HSE remains firmly committed to continuing engagement with the union in respect of [the Labour Court recommendation[ with a view to avoiding further industrial action.”