NHL star Jay Bouwmeester underwent surgery after he frighteningly collapsed mid-game this week ... but Blues officials say it was successful and the D-man is doing better.
As we previously reported ... Jay passed out on the Blues' bench during the first period of St. Louis' game against the Anaheim Ducks on Tuesday and was rushed to the hospital.
Team officials said Bouwmeester suffered a "cardiac episode" and needed a defibrillator to revive him.
On Friday, St. Louis GM Doug Armstrong revealed Bouwmeester had an Implantable Cardioverter Defibrillator (ICD) placed in his chest after the incident in order to prevent a similar issue from happening again.