A clamp is provided for attachment to the left atrial appendage (LAA). The clamp can be locked in a closed position so as to remain in place on the LAA. After being attached to the LAA, the clamp can be moved to a desired position such that the LAA can be retracted to a desired extent. The clamp can be held in any desired position, preferably by being connected to a thoracic retractor that is being used to retract the patient's sternum or ribs. A movable member is connected between the clamp and a stationary portion of the retractor. By locking the movable member in a fixed position relative to the stationary portion, the clamp can be maintained in a desired position and the LAA can be retracted as desired.