The former Russian President, Boris Yeltsin, has admitted having five heart attacks while in office.
Boris Yeltsin's health was a frequent topic of international speculation
Mr Yeltsin often disappeared from public view at critical moments during his presidency.
His most notable absence came shortly before he was re-elected in 1996 when he faced a strong challenge from the Communist Party.
At the time, Russian officials said Mr Yeltsin had flu, or was still working on documents.
"While I was president, I survived five heart attacks," Mr Yeltsin told the RIA Novosti news agency.
As his appearances grew rarer and health more critical, he finally admitted to the nation that he had heart problems and underwent a multiple bypass operation in November 1996.
The former Russian president said his health had improved greatly since he retired in the year 2000 and he now felt "active, both mentally and physically".