Her Royal Highness Princess Maha Chakri Sirindhorn was admitted to King Chulalongkorn Memorial Hospital on Monday night for treatment of coronary artery disease.
The Princess developed chest pains and an irregular pulse before a medical team providing care recommended she be admitted to the hospital, the Royal Household Bureau said on Monday night.
A coronary angiography revealed narrowed sections in the heart's blood vessel but angioplasty was not required, it added.
Doctors recommended the Princess refrain from conducting functions and remain in hospital for a course of treatment, it said.
