It is claimed staff morale is being damaged by the problems

One heart patient has told BBC Wales he waited 24 hours on a trolley in the casualty department at University Hospital in Cardiff, only to be told that he did not need to be admitted after all.

Health workers' union Unison says problems are leading to low morale amongst staff.

BBC Wales has also received an anonymous letter claiming to be from the nursing team at UHW expressing concern about patient safety due to a backlog of emergency admissions.

Managers at Cardiff and Vale NHS Trust say they are taking measures to improve the situation.

Haydn Hopkins was admitted to casualty at University Hospital after being taken seriously ill at work.

"I arrived at about two o'clock and was seen very quickly by staff," he said.

"It was eventually decided that I should be admitted but should be prepared for a long wait.

As a result of not being admitted, to carry out subsequent tests I've had to go private Haydn Hopkins

"I was told that if a bed became available in the night I would be taken up - but one didn't."

Mr Hopkins waited all night, and was told the next morning that he would not be admitted.

"As a result of not being admitted, to carry out subsequent tests I've had to go private, which has been very expensive."

He said he sympathised with staff at the hospital.

"They worked so hard and under very difficult conditions."

He added: "It was apparent that they were very unhappy about the situation."

Last week, Glan Clwyd Hospital in Bodelwyddan, north Wales, apologised after an 87-year-old woman who suffered a stroke was forced to wait in the back of an ambulance for two hours before a bed became available.

Elizabeth Jones was forced to wait as the accident and emergency department was full.

Haydn Hopkins was taken seriously ill at work

A hospital spokesman said they would be looking at their procedures to see if they could make any improvements, but admitted that Mrs Jones' situation was not unprecedented.

At the beginning of November, Wales' biggest hospital, the University Hospital of Wales in Cardiff, left patients waiting in ambulances outside the accident and emergency department because of a shortage of space inside.

At the time, a spokeswoman said only a small number of patients with minor injuries were delayed and no one was treated inside an ambulance.

On Friday evening, the Welsh Assembly Government responded to Mrs Jones' case, and the other problems.

In a statement it said all emergency pressures were being monitored, and the government was now planning to hold a summit with all interested parties.

This would discuss the "range of measures already in place to deal with the pressures...over the winter, and to ensure that planning is fully in place throughout the service."