Madrid (AFP)

The 81-year-old former king of Spain, Juan Carlos, is going to undergo a heart surgery on Saturday with no special gravity, the Royal Palace announced on Wednesday.

"King Juan Carlos spent his annual medical exam on June 11 and 12. The need to program a cardiac surgery for the end of August was then noted," a spokesman for the royal palace told AFP.

"It does not seem to be a serious case (...): it was scheduled in June for the end of August, and he led a normal life" since then, added the spokesman.

The exact causes of the operation, which will take place Saturday in a private hospital on the outskirts of Madrid, have not been unveiled.

Juan Carlos I, 81, including 38 (1975-2014) on the throne, retired last June from public life, five years after abdicating for the benefit of his son Felipe.

However, he continued to appear in public this summer, attending bullfights in Madrid or participating in a sailing competition in Finland, two of his passions.

© 2019 AFP