A graduate of the Wanganui School of Nursing, she later obtained a BA and MBA. On her appointment in 2008 she said "Whanganui Hospital is where I began in the health sector.
"Now I am back here and very, very pleased to be here."
Several people the Chronicle spoke to yesterday were surprised at the news.
Former WDHB chairwoman Kate Joblin worked with Mrs Patterson since her appointment in 2008 until 2013.
"I will be sad to see Julie leave although I am confident that the progress made at WDHB will endure - thanks to the team that she has built around her" said Ms Joblin.
"Julie came to the DHB at a difficult time, and her passion for good health care and commitment to this community, has seen Whanganui DHB's national reputation go from strength to strength.
"I am hugely thankful for the time that Julie has spent in this role and wish her well."
Mrs McKinnon said the DHB's financial position has improved dramatically under Mrs Patterson's watch and gone from a deficit of $10 million nine years ago to being on budget in the last financial year.
Mrs McKinnon said having a leader with a strong nursing background as well as business acumen has been much appreciated by the WDHB's 900 plus staff.
As well as heading the DHB, Mrs Patterson was also a national spokesperson for District Health Boards and dealt with the resident doctors' strikes in October and January.
Mrs McKinnon said WDHB mental health services have transformed from a struggling service to one that is now held up as an example of best practice among New Zealand's 20 District Health Boards during Mrs Patterson's tenure.
She said the WDHB board is committed to ensuring that Mrs Patterson's replacement shares her values and demonstrates the same level of competence and commitment to the community.
The Chronicle could not reach Mrs Patterson for comment.