Sonny Colbrelli had an "unstable cardiac arrhythmia that required defibrillation" at the end of the Volta a Catalunya stage one, his team have said.
Bahrain-Victorious released an update on the Italian on Tuesday afternoon, which said that he was in a "good" situation, despite falling unconscious on Monday.
He collapsed quickly after sprinting to second on the uphill drag in Sant Feliu de Guíxols behind Michael Matthews.
However, the rider will stay in hospital in Girona for a further day in order to have further tests to be performed on him.
Earlier on Tuesday the team said that Colbrelli is conscious and "feeling okay" in hopsital, and tests show no "signs of concern".
The Italian told media from his own country that he did not remember anything of the incident.
“I’m here in the hospital, resting, I don’t remember anything,” Colbrelli told La Gazzetta dello Sport. “Only that I crossed the line, I stopped, I took the water and I collapsed. Then the emptiness, and I woke up in the hospital.”
The updated Bahrain-Victorious statement reads: "Following the end of Stage 1 of Volta a Catalunya, our medical team can confirm that Sonny Colbrelli suffered from an unstable cardiac arrhythmia that required defibrillation.
"The cause is still to be determined, and the Italian rider will undergo further tests tomorrow at the Hospital Universitari de Girona.
"The team would like to thank Borja Saenz de Cos - Emergency Nurse at Sistema d’Emergencies Mediques (Catalan Emergency Service) – for his prompt assistance at the finish yesterday and for supporting our medical staff in the management of the incident.
"Sonny Colbrelli’s clinical situation is good, and we wish him a prompt recovery."
“Now I’m here, they keep me monitored,” Colbrelli told La Gazzetta. “It was a great scare, but I am already thinking about when I will be able to return to the group. “
Dylan Teuns, one of Colbrelli's teammates at Catalunya, told Cycling Weekly that he had been exchanging text messages with the Italian overnight.
"It was just a stressful moment, the unknown moment of what was happening," Teuns said. "Later on we got updates from more teammates and once we knew he was OK we were a bit more relaxed again. We are now focused on the race again."
Colbrelli has been reposting the messages of support he has received on his social media. Among the riders to be in public contact with the Italian were Remco Evenepoel, Wout Poels and Alessandro De Marchi.
