Class I indication for unfractioned heparin therapy in theilast 2-3 days  before cardioversion:
- CHF + NYHA Class II - IV symptoms + AF requiring urgent cardioversion + patients who have not been treated with oral anticoagulant.

Class I indication for unfractioned heparin therapy in the first 2-3 days after cardioversion:
- CHF + NYHA Class II - IV symptoms + AF undergoing effective urgent cardioversion + patients who have not been treated with oral anticoagulant.
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