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CARDIOVASCULAR
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Volume 8, 2003, No 1-2 |
Impact of Crystalloid HTK and St. Thomas’
Cardioplegia on Myocardial Fluid Balance and Postcardioplegic Stunning
H. H. Sauer, S. J. Allen, G. A. Laine
Objective: Crystalloid cardioplegia may alter
microvascular barrier integrity. These alterations in myocardial fluid balance
contribute to post cardiopulmonary bypass (CPB) edema formation and cardiac
dysfunction.
Methods: 17 dogs were subjected to CPB and one hour of hypothermic arrest
followed by 30 min of reperfusion. Dogs received either HTK cardioplegia (HTK),
St. Thomas’ cardioplegia (STH), or STH with mannitol equimolar to HTK (m-STH).
Myocardial water content was determined using microgravimetry, and preload
recruitable stroke work (PRSW) using sonomicrometry and micromanometry.
Myeloperoxidase (MPO) activity was measured to quantify polymorphonuclear
neutrophils (PMN) infiltration.
Results: Compared with STH, HTK dogs had an increased PRSW two hours post
CPB (p<0.05), which was associated with better recovery of contractility
(p<0.05) and lower myocardial water content 15 and 40 min after cardioplegic
arrest (p<0.05). Addition of mannitol to STH (m-STH) resulted in better
recovery of contractility and less edema formation compared to STH and similar
to HTK. No difference in MPO activity was observed between HTK and STH.
Conclusions: Our study demonstrates the impact of crystalloid
cardioplegia on myocardial fluid balance. Moreover, data show differences with
intra- and extracellular cardioplegic solutions as measured by LV function and
edema formation. Findings also suggest that mannitol contributes to the
superiority of HTK cardioplegia. Since PMN accumulation does not appear to be
modulated by mannitol, the observed alterations might be related to its
hyperosmolarity.
(CVE. 2003; 8 (1/2): 58-65)
Key words: cardioplegia, myocardial edema, PRSW, mannitol,
PMNs
H. Henning Sauer, M.D.
Dept. of Cardiothoracic Surgery
Klinikum Oldenburg
Dr.-Eden-Str. 10
D-26133 Oldenburg
Germany
E-mail: henning.sauer@ewetel.net
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