Princess Bajrakitiyabha of Thailand has not regained consciousness, more than three weeks after the 44-year-old collapsed due to a heart problem while training her dog for a competition. The eldest child of Thai King Maha Vajiralongkorn and potential heir to the throne, the princess had a bacterial infection that led to inflammation, which then caused the severe heart arrhythmia that led to her collapse, Reuters and the Bangkok Post report. "Doctors continue to provide medicine and use equipment to support the functions of the heart, lung and kidney as well as using antibiotics while monitoring her condition closely," the palace said in a statement issued Saturday. Under Thai law, the king designates his heir, and he has not done so yet. (More Thailand stories.)