Brussels - Cycling legend Eddy Merckx has been fitted with a cardiac pacemaker to correct a heart rhythm problem, he was quoted as saying in a newspaper interview on Friday.
The 67-year-old told the Belgian daily Het Nieuwsblad that the operation was performed at a clinic in the northern city of Genk on Thursday and was done as a precautionary measure.
"I was operated on by doctor Johan Van Lierde, a friend of mine," said Merckx, a five-time winner of cycling's greatest race, the Tour de France.
"My heart rate has been under 40 (beats per minute) since birth or thereabouts.
"As a result it was wise to take preventative measures to avoid certain problems, particularly at night."
The pacemaker is designed to give an electric charge allowing the heart to beat at a more regular frequency.
"I'm now happy about all this," added Merckx, who was due to leave hospital on Friday and could be given the all-clear to get back on his bike in about two weeks' time.
A biography of the cyclist, published in March last year, said that he had a heart problem from the start of his career and should never have even competed professionally.
"Eddy Merckx, The Cannibal", by Daniel Friebe, quoted Italian cardiologist Giancarlo Lavezzaro, who examined the cyclist during the 1968 Tour of Italy, as saying that he "rode his entire career with a sword of Damacles over his head".
Lavezzero concluded that Merckx had a non-obstructive hypertrophic cardiomyopathy - a genetic condition in which the heart muscle thickens, affecting its functioning.
Symptoms include shortness of breath, chest pain, palpitations, lightheadedness, fatigue and fainting. The condition is the leading cause of sudden death in young athletes.
Merckx, who was not told the doctor's conclusions, said later that he always knew he had an "odd heart" that was "particularly big", adding that his father and uncles all died young of heart problems.