Maintenance of aerobic metabolism during global ischemia with perfluorocarbon cardioplegia improves myocardial preservation.
We used phosphorus-31 nuclear magnetic resonance to test the ability of a perfluorocarbon blood substitute that has been shown in previous studies to improve oxygen delivery to hypothermic myocardium to maintain aerobic high-energy phosphate metabolism during total global ischemia. Twenty-three isolated perfused rabbit hearts were subjected to 180 min of hypothermic (23 degrees C) global ischemia followed by 45 min of normothermic reperfusion. Hearts received multiple doses of a cardioplegic solution that contained either oxygenated perfluorocarbon (Fluosol O2), nonoxygenated perfluorocarbon (Fluosol N2), or standard crystalloid hyperkalemic cardioplegic solution (STD-KCl) at 30 min intervals. Recovery of isovolumic left ventricular developed pressure (LVDP) was used to assess preservation of contractile function. Recovery of LVDP was 84 +/- 19% of preischemic control values with Fluosol O2, 68 +/- 16% with Fluosol N2, and 67 +/- 17% with STD-KCl (p = .058 vs Fluosol N2 and p = .056 vs STD-KCl). During 3 hr of ischemia intracellular pH (pHi) fell to 6.68 +/- 0.20 with STD-KCl and to 6.71 +/- 0.14 with Fluosol N2 but remained above 7.00 throughout the ischemic period with Fluosol O2 (p less than .0001 vs Fluosol N2 or STD-KCl). Myocardial ATP content was better preserved at 107 +/- 14% of control values with Fluosol O2 compared to 60 +/- 18% of control with Fluosol N2 and 75 +/- 21% of control with STD-KCl (p less than .001 vs Fluosol N2, p = .002 vs STD-KCl). Phosphocreatine (PCr) was also better preserved with Fluosol O2.(ABSTRACT TRUNCATED AT 250 WORDS)
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001802:Blood Substitutes; D003327:Coronary Disease / Q000378:metabolism* / Q000503:physiopathology; D004734:Energy Metabolism; D005260:Female; D005466:Fluorocarbons; D006324:Heart Arrest, Induced / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D009200:Myocardial Contraction; D010100:Oxygen / Q000097:blood*; D010477:Perfusion; D010725:Phosphocreatine / Q000378:metabolism; D011817:Rabbits; D013997:Time Factors
D001802:Blood Substitutes; D005466:Fluorocarbons; D010725:Phosphocreatine; D000255:Adenosine Triphosphate; D010100:Oxygen