ABSTRACT
We performed surgery for atrial fibrillation and mitral valve disease on 3 patients along with atrial mapping. Macroreentrant circuits were found in 2 patients and the other patient showed a preexcitation ectopic focus in the left atrium. Right atrial excitation was chaotic in all three patients. Of the two patients with reentry circuits, one patient underwent biatrial incisions and the other patient had only a left atrial incision. In the patient with a preexcitation ectopic focus, we performed cryoablation of that focus and made a left atrial incision in order to prevent the reoccurrence of atrial fibrillation after surgery. Following surgery, one patient experienced transient atrial fibrillation, however, continuous atrial fibrillation was resolved by this procedure and all patients returned to a normal sinus rhythm.