77-year-old, Sreedharan was at the IGI Airport when he complained of severe chest pain on early Wednesday morning, Apr 7.
"He is fine. His condition is far better and he is recovering but he will not be discharged," senior cardiologist S K Gupta was quoted by news agency as saying.
Gupta said that the Metro chief is being treated by a multi-disciplinary team of doctors.
"We will have to watch over him for sometime and monitor his vitals before he can be discharged," he added.