Swiss Finance Minister Hans-Rudolf Merz is in stable condition following heart surgery on Sunday evening but has not regained consciousness, doctors have reported.
Heart specialist Thierry Carrel told a news conference at Bern University hospital on Sunday evening that the quintuple bypass operation had gone well but it was too early to say whether Merz's brain would be affected.
Carrel described the two-and-a-half hour operation as routine and noted that the attack had not been severe.
Merz, aged 65 and this year's vice-president, suffered the heart attack on Saturday evening in his hometown of Herisau in eastern Switzerland.
Initially treated in the local hospital before being transferred to the cantonal hospital in St Gallen, he was flown by helicopter to Bern on Sunday.
The attack came at the end of a week in which Merz had been under particular stress, against a background of the ongoing global financial crisis. However, the media and Swiss politicians said he had shown no signs of strain.
The Swiss president, Pascal Couchepin, has cancelled a trip to New York where he was due to attend a meeting of the United Nations General Assembly.
The Swiss government held informal talks on Sunday afternoon and is set to hold an extraordinary meeting on Monday. Merz's deputy, Justice Minister Eveline Widmer-Schlumpf, is expected to take over the duties in the finance ministry for the time being.
The president of the centre-right Radical Party, Fulvio Pelli, said he was concerned about the health problems of Merz, a party colleague.
Taken by surprise
He told the Associated Press news agency that everyone had been taken by surprise because Merz had looked in good health.
"Mr Merz was at the present time an anchor for the stability of Switzerland... I wish him the best," he added.
Christian Levrat, president of the centre-left Social Democratic Party also wished Merz a speedy recovery.
He commented that the illness had come at a bad time, with the world financial system in crisis.
"From my point of view, the government is being too passive. It must take its responsibilities to prevent a crisis in Switzerland."
swissinfo with agencies
Hans-Rudolf Merz of the centre-right Radical Party replaced Kaspar Villiger in the Swiss cabinet at the beginning of 2004.
Between 1997 and his entry into the government, he represented canton Appenzell Outer Rhodes in the Swiss Senate.
Merz is married and has three sons.