Chea Sim, president of the ruling Cambodian People’s Party and president of the Senate, left for Singapore on Sunday for emergency treatment for high blood pressure, said government spokesman Khieu Kanharith. He said that Chea Sim, 77, who has suffered from high blood pressure for many years, left Cambodia on Sunday morning after experiencing a problem with his circulation. “You can see that at official ceremonies he never wears a tie,” Khieu Kanharith said, adding that it was not clear when Chea Sim would return to Cambodia.