The Annals of Thoracic Surgery, Vol 35, 530-534, Copyright © 1983 by The Society of Thoracic Surgeons
Single aortic clamping for proximal and distal anastomoses in coronary operations: study of myocardial temperatures in nonvented hearts
JP Heaton and TA Salerno
A prospective analysis of myocardial temperatures (septum, left and right
atria, and right ventricle) in coronary operations was carried out in
nonvented human hearts during a single period of aortic cross- clamping for
construction of all anastomoses, proximal and distal. Also a comparison was
made of normothermic versus hypothermic perfusion during cardiopulmonary
bypass (CPB). Results indicate that (1) immediately after cross-clampling
and infusion of the cardioplegic solution, the septal temperature was
identical for hypothermic and normothermic perfusion; (2) at 20 minutes of
clamping, however, hypothermic patients had lower septal temperatures than
normothermic patients; and (3) at the end of the cross-clamping period, the
septal temperature was lower in hypothermic hearts. The left and right
atrial and right ventricular temperatures were lower throughout CPB in
patients with hypothermic perfusion. It is concluded that if a single
period of aortic cross-clamping under cardioplegic arrest is to be used for
construction of all anastomoses in nonvented hearts during a coronary
operation, core hypothermia is necessary and should be maintained until the
aorta is unclamped. The surgeon cannot rely on cold slush and cardioplegia
alone to cool the heart while the proximal anastomoses are being performed,
since blood from the bronchial (left atrium) and systemic (right atrium)
circulations warms the heart.
