The team says a full recovery is expected.
Hamilton had a procedure Monday to repair what was diagnosed as an atrial flutter. The team says he will be sidelined for a few days, then go through about three weeks of non-contact exercise before returning.
He felt light-headed during a training camp practice and was evaluated, where the heart rhythm was detected.
Hamilton averaged 3.3 points in eight NBA games last season, seven of those coming with the Heat.