Minimally diluted tepid blood cardioplegia.
BACKGROUND
To evaluate the effects of minimally diluted tepid blood cardioplegia, a prospective, randomized study was undertaken.


METHODS
Thirty-seven patients undergoing isolated primary coronary artery bypass grafting were randomized to receive standard 4:1 diluted tepid blood cardioplegia (4:1 group, n = 18) or minimally diluted tepid blood cardioplegia (Mini group, n = 19). Cardioplegic solution was delivered in an intermittent antegrade fashion in both groups. Myocardial oxygen and lactate metabolism, release of the MB isoenzyme of creatine kinase and thiobarbituric acid reactive substances, and cardiac function were measured during and after the operation.


RESULTS
Myocardial oxygen consumption was significantly greater and lactate release was significantly lower in the Mini group than in the 4:1 group during cardioplegia. Minimally diluted blood cardioplegia resulted in more prompt resumption of lactate extraction, lower levels of release of the myocardial-specific isoenzyme of creatine kinase and thiobarbituric acid reactive substances during reperfusion, and better postoperative left ventricular function compared with the standard 4:1 cardioplegia.


CONCLUSIONS
Minimally diluted tepid blood cardioplegia may provide superior myocardial protection than the standard 4:1 dilution technique by optimizing the aerobic environment through an increase in oxygen supply during intermittent cardioplegia.
Hayashida
N
N
Second Department of Surgery, Kurume University, Fukuoka, Japan.
Isomura
T
T
Sato
T
T
Maruyama
H
H
Higashi
T
T
Arinaga
K
K
Aoyagi
S
S
D000328:Adult; D000368:Aged; D001026:Coronary Artery Bypass; D003402:Creatine Kinase / Q000378:metabolism; D005260:Female; D006324:Heart Arrest, Induced / Q000379:methods*; D006439:Hemodynamics; D006801:Humans; D007527:Isoenzymes; D007773:Lactates / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism; D010101:Oxygen Consumption; D011446:Prospective Studies
D007527:Isoenzymes; D007773:Lactates; D003402:Creatine Kinase