We performed surgical correction and treatment of a common atrium and
chronic impure flutter using a computerized mapping system in a 49-yea
r-old man. A reentrant circuit was observed to exist around the left a
trial appendage. In contrast to the regular activation in the left atr
ium, the activation sequence of the right atrium was extremely chaotic
. Cryolesions were applied to the area of the reentrant pathway. After
the operation, sinus rhythm was restored. (C) 1997 by The Society of
Thoracic Surgeons.