The health of Thai Princess Bajrakitiyabha has deteriorated significantly, with doctors struggling to stabilise her irregular heart rate amid multiple organ infections, the Royal Palace announced on Thursday.

The 47-year-old princess, who is King Vajiralongkorn’s eldest daughter, has been in a coma since December 2022, following her collapse from a heart condition and other infections that led to her hospitalisation.

The daughter of King Maha Vajiralongkorn had collapsed on 15 December while training her dogs in the Pak Chong district of the Nakhon Ratchasima province, local media reported at the time.

A statement from the palace detailed that physicians identified a stomach infection in April, which subsequently caused inflammation in her intestines. This complication led to a dangerous drop in her blood pressure and further exacerbated her irregular heartbeat. Despite the administration of medication and the deployment of medical devices to support her lungs and kidneys, her condition has continued to decline.

The palace confirmed that medical staff would maintain close monitoring and continue to provide treatment. The news follows the death of Thailand's influential Queen Mother last year, who passed away at the age of 93.

Princess Bajrakitiyabha has a PhD in law from Cornell University and was Thailand’s ambassador to Austria from 2012-14. She has worked on a number of projects with the United Nations and was appointed as a representative of Thailand for UN Women in September 2008.

In 2021, she was appointed chief of staff of the Royal Security Command, with the rank of general. She was widely viewed as the most suitable successor for her father.