The Annals of Thoracic Surgery, Vol 24, 315-322, Copyright © 1977 by The Society of Thoracic Surgeons
Does local cardiac hypothermia during cardiopulmonary bypass protect the myocardium from long-term morphological and functional injury?
W Schraut, JJ Lamberti, K Kampman, C Anagnostopoulos, R Replogle and S Glagov
Twenty-eight dogs were subjected to 90 minutes of hypothermic (30 degrees
C) cardiopulmonary bypass with moderate hemodilution. In 6 dogs the heart
was vented and beating for 60 minutes. Eight dogs underwent ventricular
fibrillation with coronary perfusion (VF + CP). In 14 dogs the aorta was
cross-clamped for 60 minutes while the myocardium was protected by local
cardiac hypothermia (ICA + LCH). Eighteen animals survived. Hemodynamic
studies at seven weeks revealed no major differences among the three
groups. At postmortem examination, no gross scarring was noted in any
heart. Microscopical examination of 14 hearts was completely-normal. In the
VF + CP group, 2 hearts had isolated microscopical scars. Similar linear
subendocardial scars (less than or equal to 1.5 X 0.5 mm) were noted in 2
hearts subjected to ICA + LCH. Survival after 60 minutes of VF + CP or ICA
+ LCH did not result in long-term morphological injury to or functional
impairment of the myocardium.