The Annals of Thoracic Surgery, Vol 27, 230-234, Copyright © 1979 by The Society of Thoracic Surgeons
Ventricular fibrillation during cardiopulmonary bypass: long-term effects on myocardial morphology and function
W Schraut, JJ Lamberti, K Kampman and S Glagov
Mongrel dogs were subjected to hypothermic (28 degrees to 30 degrees C)
cardiopulmonary bypass with hemodilution by 50%. In two groups of 8 dogs
each, ventricular fibrillation was induced for 60 and 90 minutes,
respectively, while the dogs were on bypass. A group of 6 dogs with the
heart beating but nonworking served as control. Seven weeks after
operation, hemodynamic measurements were made in the survivors (6 in each
group) and the heart was fixed by perfusion with glutaraldehyde. Multiple
transmural samples were taken from both ventricles. Light microscopy
revealed solitary left ventricular scars (0.5 to 3 mm wide) in 2 hearts
each from Groups 2 and 3. None of the hearts exhibited diffuse
subendocardial fibrosis indicative of healed ischemic injury. All animals
were hemodynamically normal. We conclude that in the nonhypertrophied
heart, ventricular fibrillation up to 90 minutes with continuous
bypass-sustained coronary perfusion (perfusion pressure at or above 70 mm
Hg) offers protection from permanent myocardial injury.