Hemodynamic effects of sternum closure after open-heart surgery in infants and children.

Eight children (age 4 months - 9 years) were studied after surgical correction of congenital heart defects. Sternum closure reduced mean arterial pressure by 7% (p less than 0.05) and cardiac output by 14% (p less than 0.01), and increased central venous pressure by 2 mmHg (p less than 0.05). There was evidence of a decrease in intracardiac blood volume. It is suggested that the circulatory effects of sternum closure were due to increased pressure outside the heart, which reduced the pressure across the heart wall and the end-diastolic volume.