Sweden's King Carl XVI Gustaf is "feeling well" after a scheduled surgical procedure on Monday morning, the Swedish Royal Court said.
The court had announced last week the procedure, describing it as a "laparoscopic (keyhole) surgery in the heart area" that had been advised by the 76-year-old king's physician.
"The operation has gone according to plan and the king is feeling well," the court said in a statement on Monday.
It added that the king was thankful for "all the support and warmth shown to him" as he marks this year 50 years on the throne.
The court said last week that the king's official engagements between the surgery and March 3 had been postponed to later in the spring.
Born on April 30, 1946, Carl Gustaf Folke Hubertus Bernadotte was nine months old when his father, Prince Gustaf Adolf, was killed in a plane crash in Denmark.
He assumed the throne in 1973 following the death of his grandfather, the long-reigning Gustaf VI Adolf. (AFP)