Adding bupivacaine to high-potassium cardioplegia improves function and reduces cellular damage of rat isolated hearts after prolonged, cold storage.
BACKGROUND
Bupivacaine retards myocardial acidosis during ischemia. The authors measured function of rat isolated hearts after prolonged storage to determine whether bupivacaine improves cardiac protection compared with standard cardioplegia alone.


METHODS
After measuring cardiac function on a Langendorff apparatus, hearts were perfused with cardioplegia alone (controls), cardioplegia containing 500 microm bupivacaine, or cardioplegia containing 2 mm lidocaine; were stored at 4 degrees C for 12 h; and were then reperfused. Heart rate and left ventricular developed pressures were measured for 60 min. Maximum positive rate of change in ventricular pressure, oxygen consumption, and lactate dehydrogenase release were also measured.


RESULTS
All bupivacaine-treated, four of five lidocaine-treated, and no control hearts beat throughout the 60-min recovery period. Mean values of heart rate, left ventricular developed pressure, maximum positive rate of change in ventricular pressure, rate-pressure product, and efficiency in bupivacaine-treated hearts exceeded those of the control group (P < 0.001 at 60 min for all). Mean values of the lidocaine group were intermediate. Oxygen consumption of the control group exceeded the other groups early in recovery, but not at later times. Lactate dehydrogenase release from the bupivacaine group was less than that from the control group (P < 0.001) but did not differ from baseline.


CONCLUSIONS
Adding bupivacaine to a depolarizing cardioplegia solution reduces cell damage and improves cardiac function after prolonged storage. Metabolic inhibition may contribute to this phenomenon, which is not entirely explained by sodium channel blockade.
Ross
James D
JD
Department of Physiology and Biophysics, University of Illinois College of Medicine at Chicago, and Jesse Brown Veterans Affairs Medical Center, Chicago, IL, USA.
Ripper
Richard
R
Law
William R
WR
Massad
Malek
M
Murphy
Patricia
P
Edelman
Lucas
L
Conlon
Beth
B
Feinstein
Douglas L
DL
Palmer
June W
JW
DiGregorio
Guido
G
Weinberg
Guy L
GL
D000779:Anesthetics, Local / Q000494:pharmacology*; D000818:Animals; D002045:Bupivacaine / Q000494:pharmacology*; D002314:Cardioplegic Solutions / Q000494:pharmacology*; D003080:Cold Temperature; D005217:Fat Emulsions, Intravenous; D006321:Heart / Q000187:drug effects*; D006324:Heart Arrest, Induced; D006334:Heart Function Tests; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology; D066298:In Vitro Techniques; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008297:Male; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D019188:Organ Preservation Solutions / Q000494:pharmacology*; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D011188:Potassium / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014021:Tissue Preservation
D000779:Anesthetics, Local; D002314:Cardioplegic Solutions; D005217:Fat Emulsions, Intravenous; D019188:Organ Preservation Solutions; D007770:L-Lactate Dehydrogenase; D011188:Potassium; D002045:Bupivacaine