Effects of ischemic preconditioning in human heart.
BACKGROUND
The aim of this study is to investigate the effects of ischemic preconditioning (IP) on myocardium and the level of nitric oxide (NO) in patients undergoing aorta-coronary bypass surgery.


METHODS
Twenty consecutive patients with coronary artery disease were subjected into two equal groups; the IP group and the control group. Following the onset of cardiopulmonary bypass in the study group, hearts were preconditioned with two 3-minute periods of cross-clamping separated by 2 minutes of reperfusion. In the control group, cardiopulmonary bypass was continued for 10 minutes without using cross-clamp. Arterial and coronary sinus blood samples were used to determine serum NO, malondialdehyde (MDA), creatine phosphokinase-MB (CKMB), and lactate dehydrogenase (LDH) levels. Need for defibrillation after cross-clamp removal, ECG changes, postoperative arrhythmias, ejection fraction, and fractional shortening rates were recorded as hemodynamic data.


RESULTS
Serum NO level was higher in the study group 5 minutes after aortic clamp removal (199.3 +/- 92.7 vs. 112.2 +/- 35.8 micromol; p = 001). Serum MDA (2.55 +/- 0.4 vs. 4.06 +/- 0.5; etamol/ml; 5 minutes after the aortic clamp removal; p = 0.0002); CK-MB (22.8 +/- 2.5 vs. 37.4 +/- 4.1; U/L 12 hours after the operation, p < 0.0001), and LDH (501.8 +/- 46.7 vs. 611.4 +/- 128.3; IU/L 48 hours after the operation, p = 0.02) levels were significantly lower in the preconditioned group when compared with the control group. Also, need for electrical defibrillation was significantly lower in the study group; Ejection fraction (64.3 +/- 6.3 vs. 57.6 +/- 7.6; p = 0.04) and fractional shortening (31.7 +/- 3.9 vs. 26.2 +/- 4.0; p = 0.04) rates were better in the study group postoperatively.


CONCLUSIONS
These data may suggest that cardioprotection by ischemic preconditioning offers higher NO production, a lower myocardial ischemia, and better functional recovery of the hearts in coronary artery surgery patients.
Buyukates
Mustafa
M
Department of Cardiovascular Surgery, Gazi University Faculty of Medicine, Ankara, Turkey.
Kalaycioglu
Sedat
S
Oz
Eser
E
Soncul
Halim
H
D000368:Aged; D015415:Biomarkers / Q000097:blood*; D016022:Case-Control Studies; D001026:Coronary Artery Bypass / Q000379:methods* / Q000401:mortality; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000401:mortality / Q000601:surgery*; D003402:Creatine Kinase / Q000097:blood; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006439:Hemodynamics / Q000502:physiology*; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D019194:Ischemic Preconditioning / Q000379:methods*; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D009569:Nitric Oxide / Q000097:blood; D011183:Postoperative Complications / Q000401:mortality; D011300:Preoperative Care / Q000379:methods; D011336:Probability; D011446:Prospective Studies; D011859:Radiography; D012016:Reference Values; D018570:Risk Assessment; D018709:Statistics, Nonparametric; D015996:Survival Rate; D016896:Treatment Outcome
D015415:Biomarkers; D009569:Nitric Oxide; D008315:Malondialdehyde; D003402:Creatine Kinase