The Annals of Thoracic Surgery, Vol 27, 49-54, Copyright © 1979 by The Society of Thoracic Surgeons
Ultrastructural integrity of human ventricular myocardium following cardioplegic arrest
VW Fischer and HB Barner
The appearance of the ventricular myocardium in 6 patients electing
coronary bypass operation was evaluated by electron microscope before and
after aortic cross-clamping. Bypassing protocol included the induction of
hypothermic cardioplegia by intermittent aortic root perfusion, with
potassium chloride added to cold blood serving as the cardioplegic agent.
Cross-clamp intervals ranged from 66 to 125 minutes. Ultrastructural
alterations following bypass manipulations, and distinct from those
observed before cross-clamping, were limited to the presence of extensive
myocardiocytic pooling of glycogen. Scrutiny of the intramyocardial
capillary bed following perfusion with the cardioplegic solution revealed
no abnormalities attributable to, or intensified by, the bypass maneuver.
These findings indicate that hypothermic potassium cardioplegia, as
specified, is not injurious to human myocardial ultrastructure.