title: Delivery pressure of the cardioplegic solution influences myocardial protection.
abstract: To investigate whether cardioplegic solution (CS) delivery pressure influences myocardial protection, intermittent infusions of CS at different pressures were used in an isolated Langendorff rat heart preparation. In group 1 the hearts were kept arrested for 210 min at 12 degrees C with intermittent infusions of 5 ml CS every 20 min at 30 cm H2O (22 mmHg) pressure, in group 2 the same volume of CS was infused at 100 cm H2O (73.5 mmHg) pressure, in group 3 at 145 cm H2O (106.5 mmHg) pressure and in group 4 at 238 cm H2O (175 mmHg) pressure. There was a significantly higher coronary resistance in groups 1 and 4 (7.3 +/- 0.2 RU and 6.9 +/- 0.2 RU) than in groups 2 and 3 (4.2 +/- 0.2 RU and 4.2 +/- 0.2 RU) (P < 0.05) during the ischemic period. There were no significant differences between group 2 and 3 in the reperfusion period. Groups 2 and 3 showed higher coronary flow and left ventricle developed pressure than group 1 and 4. Hearts from group 1 and 4 had lower adenosine triphosphate (7.88 +/- 0.44 mumol.g-1, 5.56 +/- 0.56 mumol.g-1) (P < 0.05) and creatine phosphate (24.66 +/- 0.47 mumol.g-1, 15.34 +/- 0.94 mumol.g-1) (P < 0.05) content at the end of the reperfusion period than group 2 (10.56 +/- 0.41 mumol.g-1, 30.06 +/- 0.38 mumol.g-1) and group 3 (14.13 +/- 0.69 mumol.g-1, 35.25 +/- 0.78 mumol.g-1).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Surgery, University of Tromsø, Norway.
authors.forename: O
authors.initials: O
authors.lastname: Irtun
authors.forename: D G
authors.initials: DG
authors.lastname: Sørlie
mesh_terms: D000249:Adenosine Monophosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002314:Cardioplegic Solutions / Q000008:administration & dosage*; D003326:Coronary Circulation / Q000502:physiology; D006324:Heart Arrest, Induced / Q000379:methods*; D006439:Hemodynamics / Q000502:physiology*; D006874:Hydrostatic Pressure; D007036:Hypothermia, Induced; D008297:Male; D008955:Models, Cardiovascular; D015428:Myocardial Reperfusion Injury / Q000503:physiopathology*; D009206:Myocardium / Q000378:metabolism; D010725:Phosphocreatine / Q000378:metabolism; D017680:Potassium Compounds / Q000008:administration & dosage; D051381:Rats; D017208:Rats, Wistar; D014655:Vascular Resistance / Q000502:physiology
chemical_list: D002314:Cardioplegic Solutions; D017680:Potassium Compounds; C018369:potassium cardioplegic solution; D010725:Phosphocreatine; D000249:Adenosine Monophosphate; D000255:Adenosine Triphosphate