Surgeries could be cancelled next week due to a planned strike by 25 perfusionists, who are members of the Fórsa trade union.
Perfusionists are cardiovascular specialists who manage the machines that temporarily take over the work of the heart and lungs during surgery.
The Fórsa members, working as perfusionists across five hospital groups, are due to begin a series of work stoppages on Tuesday 9 June in a dispute over pay.
The union has accused the HSE of taking a unilateral decision to break a long-standing pay link between perfusionists and medical scientists.
Fórsa also said that the HSE has refused to implement a Labour Court recommendation to restore that link, issued in January this year.
According to the union, the HSE has not sought engagement on contingency planning or patient safety measures ahead of next week's strike.
"Fórsa served notice of this action two weeks ago and has been available to meet the HSE in line with agreed dispute resolution frameworks, but no such engagement has been sought," said Fórsa National Secretary Linda Kelly.
"It is unacceptable that, with industrial action due to begin next week, there has been no attempt to engage to consider derogations to mitigate the impact on patient care, much less to resolve the matters in dispute," Ms Kelly said.
The HSE said it is committed to continuing engagement in respect of the Labour Court recommendation as part of the Public Service Agreement local bargaining process, with a view to avoiding industrial action.
"In parallel, the HSE is developing contingency plans, focussing on minimising disruption and protecting patient safety, if industrial action proceeds," a spokesperson said.
