The authors note the acute responses of 68 children who underwent cardiac operations and describe in detail the grossly abnormal reactions of four, discussing the possible predisposing factors in three of the four children. The major normal reactions were divided into four groups: anxiety, anger, cooperation, and compliance. The relation of these reactions to preoperative personality and preparation and to postoperative medical complications remains uncertain. Careful evaluations of personality, before and after children undergo major operations, are needed to produce information that will be useful in preparing other children for similar operations.Abstract Teaser