Now after treatment he's been given the all clear to play again.
"I am feeling fine and am just looking at getting back into training," Vidmar told the Sydney Morning Herald.
His heart condition was detected after a freak training accident in May when a teammate at Dutch club NAC Breda crashed into him, leaving him winded.
A routine examination the next day by FIFA medical staff, as part of their assessments on all potential World Cup participants, revealed Vidmar to be short of breath. Doctors then discovered a blood clot on his left coronary artery.
The test results ruled Vidmar out of the World Cup because FIFA refused to allow players with health concerns to be selected for the tournament. This policy began after the tragic death of Cameroon international Marc-Vivien Foe during a match at the 2003 Confederations Cup in France.
Vidmar's focus now is on winning a new club contract after his one-year deal with NAC Breda expired on June 30.