A patient with atrial fibrillation who converts in less than 48 hours has a low risk for thromboemboli. The authors are from Beth Israel Deaconess Medical Center, Harvard Medical School and the University of Connecticut Health Center.

Patient selection: atrial fibrillation that has lasted less than 48 hours


Rate of thromboembolism in 357 patients: 0.8%


Recommendation for anticoagulation therapy with heparin:

(1) Intravenous heparin is started on admission for all patients.

(2) Heparin is continued for at least 24 hours after cardioversion to normal sinus rhythm.

(3) Greater precautions should be taken if there is a history of thromboembolism or if there is rheumatic heart disease.


A patient with a history of atrial fibrillation for less than 48 hours is a candidate for early cardioversion.


Transesophageal echocardiography may be able to detect left atrial thrombi following cardioversion.


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