A comparative study was performed to elucidate the effect on myocardial protection of multiple dose and single dose coronary perfusion with Bretschneider´s cardioplegic solution during open heart surgery.
A total number of 100 patients were observed in this present study. The patients were divided into two, A and B groups. The A group consisted of 30 patients who received multiple dose coronary perfusion and the B group consisted of 70 patients who received a single dose coronary perfusion. Each of the two group was further subdivided into three subgroups: (1) aortic cross clamping time less than 60 minutes, (2) between 61 and 90 minutes and (3) over 90 minutes.
Effects of two coronary perfusion methods on myocardial protection were evaluated
by comparing changes in serum enzyme levels of SGOT, LDH, and CPK and EKG
findings in two groups and three subgroups. The results obtained were as. follows:
1) Overall frequencies of positive results in serum levels of SGOT, LDH, ands CPK and in EKG findings as markers of myocardial damage was greater in the A group as compared with the B group, showing two-fold higher in SGOT (p < 0.132), and 6-fold in LDH (p < 0.001), 4-fold in CPK (p < 0.016), and 4-fold in EKG (p < 0.05). The results indicate that effect of myocardial protection is clearly superior in the
B group than the A group.
2) Frequencies of positive results in serum levels of SGOT, LDH, and CPK as enzyme markers of myocardial damage were significantly greater in the A group than in the B group in all three subgroups of aortic cross clamping time.. These indicate that effect of myocardial protection in the B group is better than the A group.
3) Frequencies of positive findings in EKG as a marker of muocardial damage were higher in the A group than in the B group, however it was higher in B group than in the A group in aortic cross clamping time over 90 minutes. The results indicate that effect of myocardial protection in the B group reduced rapidly when aortic cross clamping time is prolonged over 90 minutes.
4) The degree of increase in frequencies of positive results on myocardial damage as prolongation of aortic cross clamping time was higher in the B group than in the A group when aortic cross clamping time is prolonged over 90 minutes. It is suggested that effect of myocardial protection in the B group decreased rapidly when aortic cross clamping time is prolonged over 90 minutes and that secondary coronary perfusion for myocardial protection should be done at the aortic cross clamping time between 61 and 90 minutes if aortic cross clamping time is exceed 90 ninutes.
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