The Journal of Thoracic and Cardiovascular Surgery, Vol 84, 406-412, Copyright © 1982 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
Pulsatile reperfusion does not modify global myocardial ischemic injury
NA Silverman, S Levitsky, J Kohler, M Trenkner and H Feinberg
In an attempt to arbitrate the reputed clinical efficacy of pulsatile flow
during reperfusion in minimizing ischemic injury, 32 mongrel dogs supported
by normothermic cardiopulmonary bypass were subjected to 30 minutes (Groups
IC and IP) or 60 minutes (Groups IIC and IIP) of global myocardial
ischemia. The effect of pulsatile flow (P) initiated during 30 minutes of
reperfusion on the recovery of myocardial adenosine triphosphate (ATP) and
creatine phosphate (CP) stores, coronary blood flow, and myocardial water
content (MWC) was compared to the effect of linear reperfusion (C) in
another group of animals. ATP stores, which significantly decreased to 43%
and 53% of preischemic levels (Groups IC and IP, respectively, p less than
0.01) and 36% and 31% of control values (Groups IIC and IIP, respectively.
p less than 0.001), did not increase with either pulsatile or linear
reperfusion. CP stores, depleted 97% during ischemia in all groups,
returned to preischemic levels regardless of the mode of reperfusion flow.
Coronary blood flow measured 30 minutes after aortic unclamping was not
significantly different from control flow in any group. MWC significantly
decreased during ischemia from 80.5% +/- 0.8% to 76.5% +/- 1.1% in Group IC
and from 81.8% +/- 1.2% to 76.8% +/- 0.8% in Groups IP (p less than 0.05)
and returned to preischemic levels with reperfusion. However, following 60
minutes of ischemia, pulsatile reperfusion prevented the significant
increase in MWC that accrued after linear reperfusion (80.7% +/- 1.5% to
84.0% +/- 0.7%, p less than 0.05). These data indicate that pulsatile
reperfusion initiated after an ischemic injury that results in a 50% or
greater depletion of myocardial ATP stores does not restore myocardial
nucleotide levels or enhance coronary blood flow, although the pathological
increase in MWC may be avoided.