Norway's King Harald V has undergone "successful" surgery to replace a heart valve, the royal palace said on Friday.
The 83-year-old king was awake during the procedure and did not need to undergo open-heart surgery.
A probe was introduced via the groin through a vein to access the heart while he was under local anaesthesia at Oslo University Hospital.
He received the artificial heart valve in 2005. Its life span was 10 to 15 years and the procedure was needed to improve his breathing, his personal physician, Bjorn Bendz, said in a statement.
After the procedure, the king was taken to an intensive care unit for monitoring, Bendz added.
According to the palace, the king would be on sick leave for the rest of October.
Harald, who ascended to the throne in 1991, last month spent a few days at the hospital after suffering from breathing difficulties. Tests showed he did not have Covid-19.
During his sick leave, his son, Crown Prince Haakon, will serve as regent. Haakon attended the state opening of parliament last week.
Queen Sonja, the king's wife, has cancelled a trip to Trondheim to attend a ceremony on Sunday for Olav Fykse Tveit, the former general secretary of the World Council of Churches.
In December, Harald cancelled a few engagements due to a viral infection, but gave his annual New Year's speech as scheduled. In early January, he spent a week in hospital after suffering from dizziness.
The king was also briefly hospitalized for an infection in November 2017. He underwent successful treatment for bladder cancer in 2003.