A comparative study between blood and crystalloid cardioplegia during prolonged aortic occlusion in dogs
Shiki, K.
Nihon Kyobu Geka Gakkai 34(11): 1954-1965
1986
ISSN/ISBN: 0369-4739 PMID: 3819495 Document Number: 276529
This study was undertaken to assess the effect of temperature of blood cardioplegia and to compare the protective effect of blood cardioplegia (BC) and oxygenated or non-oxygenated crystalloid cardioplegia (CC) during 3 hours of hypothermic arrest. Twenty four dogs for metabolic study and twenty four dogs for functional study were equally divided into four experimental groups: Group I 20.degree. C BC, Group II 5-10.degree. C BC, Group III 4.degree. C oxygenated CC, Group IV 4.degree. C non-oxygenated CC. Each cardioplegic solution was infused every 30 minutes during arrest, and myocardial temperature was maintained at 15-20.degree. C in Group I and at 5-10.degree. C in Group II, III and IV using topical hypothermia. In dogs for metabolic study, ventricular biopsies were serially obtained for measurement of myocardial creatine phosphate (CP), adenine nucleotides (ATP, ADP, and AMP) and lactate. Total high energy phosphate content (HEP) was calculated as CP + (2 .times. ATP) + ADP. Change in left ventricular (LV) function was expressed as percentage change in left ventricular stroke work at the same left atrial pressure (5 mmHg). Oxygen extraction from cardioplegic solution was 3.32 .+-. 0.32 vol% in Group I, 2.18 .+-. 0.16 vol% in Group II, 1.95 .+-. 0.14 vol% in Group III and 0.65 .+-. 0.01 vol% in Group IV. During arrest the utilization of oxygen was well reflected in the sequential changes of HEP and CP. The HEP at the end of arrest was 18.1 .+-. 1.5 in Group I, 15.1 .+-. 1.5 in Group II, 15.4 .+-. 1.0 in Group III and 12.4 .+-. 0.2 in Group IV (.mu.mole/gr wet wt., p < 0.01 I vs IV, p < 0.05 III vs IV). Group II hearts showed higher coronary vascular resistance during infusion of cardioplegic solution and significant accumulation of myocardial lactate during arrest compared with Group I. ATP at 30 minutes after reperfusion was 5.27 .+-. 0.30 in Group I, 4.68 .+-. 0.23 in Group II, 5.10 .+-. 0.27 in Group III and 4.58 .+-. 0.16 in Group IV (.mu.mole/gr wet wt. NS). LV function percentage recovery was 89.8 .+-. 6.2% in Group I, 80.7 .+-. 5.3% in Group II, 93.7 .+-. 7.7% in Group III and 66.4 .+-. 3.5% in Group IV (p < 0.01 III vs IV). It was concluded that 1) oxygen was utilized effectively even in hypothermia less than 10.degree. C, 2) oxygen had a significant additive effect in CC, 3) 20.degree. C BC was more effective than 5-10.degree. C BC, 4) 5-10.degree. C BC resulted in higher coronary vascular resistance and significant lactate accumulation during arrest, and 5) 4.degree. C oxygenated CC was as effective as 20.degree. C BC.