The club said Kamara heart problem is unusual and if he continues playing at the top level he “risk of sudden death at maximum effort.”
Kamara, who is 21 years old, scored six goals in 14 appearances to help IFK Norrkoping to the Swedish title last season.
The issue was found when he underwent a mandatory heart examination, the Swedish champions said on Friday.
After further investigation, a decision was taken that Kamara could not take part in top-level soccer for the foreseeable future, and more tests will take place to see if an operation could repair the defect.
“It’s not something I expected and it is absolutely not how I wanted it to end my career,” Kamara said.
“I think everyone who has seen me play, during my time here in IFK Norrkoping, have seen me as a very healthy and full of energy person.
“I’ll be strong and fight my way through this.”
Kamara began his playing career with local club Belvic United be free joining FC Kallon in 2010.
The 5ft 11inches striker has also had previous spells with Djurgårdens IF, IK Frej, IFK Värnamo and Johor Darul Takzim