Protection of immature myocardium by the addition of mannitol to crystalloid cardioplegic solution.
The current method of myocardial protection for the immature heart with crystalloid cardioplegic solution remains unsatisfactory. In pursuit of a better method, mannitol, mixed into the St. Thomas' Hospital cardioplegic solution, was investigated for its effect on myocardial protection. The experiment consisted of three groups of young dogs, six in each group. Animals were maintained under ischemia for 60 minutes followed by reperfusion for 30 minutes. Those perfused with the St. Thomas' Hospital cardioplegic solution alone (group A) had poorer results, namely, a lower recovery rate (80% only) of peak left ventricular systolic pressure (LVSP), decline in left ventricular compliance, a lower preservation level (70%) of the myocardial ATP content and moderate ultrastructural damage. By contrast, in animals perfused with the cardioplegic solution containing mannitol (20mmol/L of mannitol in group B; 50 mmol/L in group C), not only the recovery of peak LVSP was higher, 130% in group B and 109% in group C, but the preservation of myocardial ATP content was also higher, 94% and 82%, respectively. The ultrastructure was well-preserved in group B, but mildly distorted in group C. Slight elevation of LVEDP was also noted in group C. These results suggest that the myocardial protective effect of the St. Thomas Hospital cardioplegic solution for immature hearts can be improved with the addition of mannitol. However, the dose dependent effects of mannitol, not revealed in this study, warrant further research.
Department of Surgery, National Cheng-Kung University Hospital, Tainan, Taiwan, R.O.C.
Y J
YJ
Yang
D000255:Adenosine Triphosphate / Q000378:metabolism; D000328:Adult; D000818:Animals; D001639:Bicarbonates / Q000494:pharmacology; D002122:Calcium Chloride / Q000494:pharmacology; D002314:Cardioplegic Solutions / Q000494:pharmacology*; D004285:Dogs; D004489:Edema, Cardiac / Q000517:prevention & control; D006321:Heart / Q000187:drug effects* / Q000254:growth & development; D006324:Heart Arrest, Induced / Q000379:methods*; D006801:Humans; D007231:Infant, Newborn; D008274:Magnesium / Q000494:pharmacology; D008353:Mannitol / Q000494:pharmacology*; D015428:Myocardial Reperfusion Injury / Q000517:prevention & control; D009206:Myocardium / Q000378:metabolism / Q000648:ultrastructure; D011189:Potassium Chloride / Q000494:pharmacology; D012965:Sodium Chloride / Q000494:pharmacology
D001639:Bicarbonates; D002314:Cardioplegic Solutions; C041711:St. Thomas' Hospital cardioplegic solution; D008353:Mannitol; D012965:Sodium Chloride; D011189:Potassium Chloride; D000255:Adenosine Triphosphate; D008274:Magnesium; D002122:Calcium Chloride