Sonny Colbrelli required defibrillation following Monday’s collapse at the Volta a Catalunya, say his team.
Italian Colbrelli, 31, was attended to by medics behind screens near the finish line before being taken to hospital in Girona by ambulance.
Bahrain Victorious said he had “suffered from an unstable cardiac arrhythmia that required defibrillation”.
The team earlier said he was “conscious and OK” but will have more tests.
Its statement added: “Cardiac tests showed no signs of compromised functions.”
Colbrelli finished second to Michael Matthews on stage one to Sant Feliu de Guixols.
In defibrillation a controlled electric shock is administered to try to restore the normal rhythm of the heart.
European champion Colbrelli missed the recent Tirreno-Adriatico and Saturday’s Milan-San Remo ‘monument’ classic with bronchitis.
He won last year’s Paris-Roubaix, his biggest career victory, and also finished second in road cycling’s traditional spring classics curtain-raiser, Omloop Het Nieuwsblad.
