Myocardial protection during ischemic cardiac arrest. Hemodynamic study of the effects of allopurinol in a cardioplegic solution

: The effects of the addition of 20 mg sodium allopurinate to a litre of ionic cardioplegic solution were studied. The experimental model was the working isolated perfused rat heart in oxygenated Krebs-Henseleit solution. The cardiac outputs were compared after 1 hour of ischaemia with three different methods of myocardial protection; group I: protection by hypothermia at 4 degrees C, group II: protection by ionic cardioplegic solution A, group III: by ionic cardioplegic solution B (with 20 mg Allopurinol). The results were expressed in percentage of the preischemic cardiac output. The best results were obtained in group III, especially after 15 minutes recovery (80.7 +/- 4.5 p. 100 at 15 minutes, 90.6 +/- 3.1 p. 100 at 30 minutes., 88.3 +/- 4.6 p. 100 at 1 hour). The results in group II were significantly better than in group I after 10 minutes recovery. Myocardial protection bu ionic cardioplegia associated with hypothermia at 4 degrees C gives a better post ischaemic recovery than hypothermia alone. When allopurinol is added to the cardioplegic solution, the protection is increased. These effects are similar to the haemodynamic effects of allopurinol on ischaemic myocardium together with the possible limitation of experimental myocardial infarction with regression of the oedema that has been observed with this drug.