The stress of management

The 62-year-old underwent the procedure several days ago and was back behind his desk inside 24 hours.

Ferguson had been suffering from an irregular heartbeat and said: "I want to reassure fans everything is OK.

"It was an option for me to get this done. The club knew about it and I feel great. It's business as usual."

Ferguson informed chief executive David Gill of his plans before having the operation, which lasted for 90 minutes.

PACEMAKER FACTS Pacemakers are given to people whose hearts need help to beat as they should They conduct electrical impulses down the electrode lead to the heart, stimulating heartbeats The devices last for an average of six to 10 years Q&A: Ferguson's heart problems

The procedure is now routine in Britain, with over one and a half million people, including singer Sir Elton John, having the device fitted.

Last year, Ferguson was diagnosed with a condition called supraventricular tachycardia (SVT), which can cause palpitations and dizziness.

There were fears that the stress of football management had brought on the condition, but Ferguson returned to work a day after the diagnosis and agreed a new contract with Manchester United in January this year.

Ferguson went some way to removing part of his professional burden by bringing old friend Walter Smith in as his assistant until the end of the season.