Giacomel was leading the Olympic mass start when he suddenly lost momentum on the track and then had to stop the race because of chest pain and difficulty breathing.
On Tuesday, the Italian Winter Sports Federation said the biathlete had undergone a procedure - a so-called ablation - at a hospital in Milan. He has also undergone a series of tests.
"An examination showed a disturbance in the heart's electrical system, which led to an ablation that was carried out and was completely successful," the association writes.
Giacomel will be discharged from the hospital on Thursday and will return for a check-up in two weeks. After that, the biathlete may be able to resume normal training.
He will therefore miss the World Cup in Kontiolax, Finland, next week.
