An elderly woman undergoing a new heart surgery technique in Waikato Hospital has died during the operation.
Ailsa Fleming, 88, of Otorohanga, was having an aortic valve replacement using a procedure being performed in the southern hemisphere for the first time.
The procedure involves a key hole incision in the patient's chest, while the heart is still beating.
The hospital says problems began 90 minutes into the operation on Wednesday and are likely to have been caused by a rare complication where calcium on the old valve blocked a main artery.
Clinical director of cardiology Gerry Devlin says problems continued with bleeding and low blood pressure before Mrs Fleming died.
Dr Devlin says the surgical staff are all desperately disappointed for Mrs Fleming and her family.
Another operation on a 77-year-old man from Thames scheduled for Wednesday has been postponed until next week.