Effects of clod plasma cardioplegia on the function and structure of immature myocardium in rabbits / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effects of clod plasma cardioplegia on the function and structure of immature myocardium. Methods Thirty-two new Zealand white rabbits of 17-26 days weighing (512 ?56) g were anesthetized and heparinized. Their hearts were excised and perfused in a Langendorff apparatus with warm (37℃) oxygenated (95%O2, 5%CO2) Krebs-Henseleit buffer(KHB) at 60 cm H2O perfusion pressure. After the isolated heart had been beating regularly for 10 min, the heart was perfused with clod (10℃) St. Thomas cardioplegic solution (group C, n = 16) or cold cardioplegic solution mixed with plasma (St. Thomas solution plasma = 14) (group P, n=16). The K+ concentration of the cardioplegic solution in both groups was the same. After 30 min cardiac arrest the heart was again perfused with KHB. The following observations were made (1) the interval from the beginning of cardioplegic solution infusion to cardiac arrest and the amount of cardioplegic solution used; (2) the duration from KHB reperfusion after 30 min cardiac arrest to the recovery of regular heart beat; (3) heat rate after recovery from cardioplegia; (4) coronary flow; (5 ) myocardial water content; (6) myocardial structural changes shown by microscopic examination. Results (1) There was no significant difference in the time needed to induce cardiac arrest and for recovery of regular heart beat from cardioplegia. (2) The heart rate was (129 ?5)beat/min in group P and (120?) beat/min in group C, the coronary flow was (5.10?0.20) ml?L-1 in group P and (3 50? 0.50) mi ?L -1 in group C, the differences were statistically significant (P