Mr Yeltsin, aged 64, is being treated at Moscow's elite Central Clinical Hospital. His new bout of heart trouble, which occurred less than four months after his first episode, added a new element of uncertainty to an already unsettled domestic political scene.
"The head of the presidential medical centre, Sergei Mironov, still does not recommend contact between the President and any of his staff," Interfax news agency quoted Mr Yeltsin's press secretary Sergei Medvedev as saying.
But Interfax said urgent documents requiring the President's attention might nevertherless be delivered to him.
Sergei Krasavchenko, a Russian presidential aide, told the agency Mr Yeltsin's condition has been diagnosed as ischaemia - the same blood supply problem that affected him for around four weeks in July and August.
n The Central Electoral Commission yesterday barred the party of Alexander Rutskoi, a leader of the 1993 revolt against President Boris Yeltsin, from taking part in a Russian parliamentary election due on 17 December.