Polarized arrest with warm or cold adenosine/lidocaine blood cardioplegia is equivalent to hypothermic potassium blood cardioplegia.
BACKGROUND
Hypothermic depolarizing hyperkalemic (K + 20 mEq/L) blood cardioplegia is the "gold standard" in cardiac surgery. K + has been associated with deleterious consequences, eg, intracellular calcium overload. This study tested the hypothesis that elective arrest in a polarized state with adenosine (400 micromol/L via adenosine triphosphate-sensitive potassium channel opening) and the Na + channel blocker lidocaine (750 micromol/L) as the arresting agents in blood cardioplegia provides cardioprotection comparable to standard hypothermic K + -blood cardioplegia.


METHODS
Anesthetized dogs were placed on cardiopulmonary bypass and assigned to 1 of 3 groups receiving antegrade cardioplegia delivered every 20 minutes for 1 hour of arrest: cold (10 degrees C) K + -blood cardioplegia (n = 6), cold (10 degrees C) adenosine/lidocaine blood cardioplegia (n = 6), or warm (37 degrees C) adenosine/lidocaine blood cardioplegia (n = 6). After an hour of arrest, cardiopulmonary bypass was discontinued, and reperfusion was continued for 120 minutes.


RESULTS
Time to arrest was longer with cold and warm adenosine/lidocaine blood cardioplegia (175 +/- 19 seconds and 143 +/- 19 seconds, respectively) compared with K + -blood cardioplegia (27 +/- 2 seconds; P < .001). Postcardioplegia left ventricular systolic function (slope of the end-systolic pressure/dimension relationship) was comparable among the 3 groups (K + -blood cardioplegia, 15.2 +/- 2.1 mm Hg/mm; cold adenosine/lidocaine blood cardioplegia, 15.9 +/- 3.4 mm Hg/mm; warm adenosine/lidocaine blood cardioplegia, 14.1 +/- 2.8 mm Hg/mm; P = .90). Plasma creatine kinase activity in cold and warm adenosine/lidocaine blood cardioplegia was similar to that in K + -blood cardioplegia at 120 minutes of reperfusion (cold adenosine/lidocaine blood cardioplegia, 11.5 +/- 2.1 IU/g protein; warm adenosine/lidocaine blood cardioplegia, 10.1 +/- 0.9 IU/g protein; K + -blood cardioplegia, 7.6 +/- 0.8 IU/g protein; P = .17). Postcardioplegia coronary artery endothelial function was preserved in all groups.


CONCLUSIONS
Intermittent polarized arrest with warm or cold adenosine/lidocaine blood cardioplegia provided the same degree of myocardial protection as intermittent hypothermic K + -blood cardioplegia in normal hearts.
Corvera
Joel S
JS
Cardiothoracic Research Laboratory and Carlyle Fraser Heart Center, Emory University School of Medicine, Altanta, GA 30308, USA.
Kin
Hajime
H
Dobson
Geoffrey P
GP
Kerendi
Faraz
F
Halkos
Michael E
ME
Katzmark
Sara
S
Payne
Christopher S
CS
Zhao
Zhi-Qing
ZQ
Guyton
Robert A
RA
Vinten-Johansen
Jakob
J
D000241:Adenosine; D000818:Animals; D002314:Cardioplegic Solutions; D003402:Creatine Kinase / Q000097:blood; D004285:Dogs; D004730:Endothelium, Vascular / Q000503:physiopathology; D006324:Heart Arrest, Induced / Q000379:methods*; D008012:Lidocaine; D011188:Potassium
D002314:Cardioplegic Solutions; D008012:Lidocaine; D003402:Creatine Kinase; D000241:Adenosine; D011188:Potassium