The technique and scope of open-heart surgery.

Technique of openheart surgery An open-heart operation, which involves interrupting the pump action of the heart and, therefore, the supply of oxygenated blood to the brain and other vital organs, may be undertaken at normal body temperature, under hypothermic circulatory arrest (in which the patient is first cooled so that the oxygen requirements of the brain are reduced), or by heart-lung by-pass (in which a machine is used to take over the action of the heart and lungs).