Dasmunsi, 62, suffered a cardiac arrest at around 11 pm last night and was admitted to the hospital soon after, the hospital said.
A multi-discipline team of doctors, led by cardiologist Dr Rakesh Yadav, was treating him.
"He had a complete left ventricular failure of the heart when he was admitted," AIIMS Spokesperson Y K Gupta said.
He is currently at the cardiac intensive care unit, doctors said, adding his vital organs are functioning normally but he was in a critical condition.
The minister was taken to the hospital with severe breathlessness and lung congestion and was first taken to the casualty wing. After his condition stabilised, he was admitted to Coronary Care Unit (CCU).
"His vital organs are stable but his condition is serious," the doctors said.