A review of the culture of Northern Ireland's regional cardiac unit uncovered behaviour which was "shocking and indefensible", health chiefs have said.
A leaked copy of the review report detailed what has been described an apparent power struggle among some doctors.
Around 70 staff spoke anonymously to those carrying out the review.
They reported tensions between different groups of staff.
It was reported that instruments had been thrown during surgery, and there had been incidents of verbal abuse and nurses had felt bullied.
The unit is a regional service for Northern Ireland with around 1,000 operations carried out each year.
The story was first reported by UTV.
The BBC in Northern Ireland was then leaked a copy of the review report.
In a statement issued by the Belfast Health and Social Care Trust, which has responsibility for cardiac services, it accepted the detail of the as yet unpublished report had been "appalling".
It reassured the public that the regional cardiac services were "clinically safe" but accepted that the behaviour of some staff had been "shocking and indefensible".
The issue has already been raised at the Northern Ireland Assembly.
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Speaking this afternoon, Health Minister Mike Nesbitt told a Stormont health committee that the report had been "devastating".
"A very bad culture was allowed to develop which was demonstrated in behaviours and in fact there was a terrible breakdown in relations where one surgeon was walking into the building and others leaving saying that they were working from home."
Mr Nesbitt said he had written an extremely "robust" letter to the chair of the Belfast Trust to arrange an imminent meeting to discuss the controversy.
He said the team that carried out the review would be the same one which ensured its recommendations were implemented.
Mr Nesbitt said he could not guarantee that such a difficult culture did not also exist in other clinical teams in other trusts.
He said the Health Department was now on standby for whistleblowers coming forward.
Asked whether the report would be published, Mr Nesbitt said he had been advised that legal advice would be necessary to prevent the identification of any of the doctors involved which might lead to legal action.
Fully acknowledge 'the hurt'
Belfast Trust said the review had found "excellent outcomes" for patients.
"We are reassured that the independent external review contains a universal recognition of the technical competence and clinical skills of all staff who work there.
"However, the Trust fully acknowledges that the details in this independent review, are appalling and the behaviour described within it, is shocking and are indefensible.
"When patients come into our care, they are cared for by a team of more than 200 dedicated and passionate professionals who over-deliver and whose outcomes are excellent as reinforced by patient feedback.
"We fully acknowledge staff have felt hurt and unable to speak out.
"This is unacceptable and we are wholeheartedly committed to making changes which we have begun implementing.
"The Trust continues to support staff who wish to tell us of their experiences and we have offered a number of options for them to do that.
"We encourage staff to talk to us and we also have a firm commitment to our whistleblowing policy."
