[The effect of mechanical support of the heart on the extent of experimental myocardial necrosis. I].

The authors investigated the influence of mechanical cardiac support with a non-pulsating blood flow on the size of an ischaemic after ligature of the descendent branch of the left coronary artery in the dog. As compared with a control group of experimental animals where mechanical cardiac support was not used, the size of the necrotic focus of the heart muscle diminished by 50% (p less than 0.01).

[Possibilities of limiting myocardial infarct in an experiment].

A total of 31 dogs were investigated with the aim to evaluate possibilities of pharmacological reduction of ischaemic perfusion damage of the heart muscle. In the experiment two-hour complete ischaemia was used (ligature of the ramus interventricularis anterior) and a subsequent two-hour period of reperfusion. The magnitude of the infarction focus evaluated as the percentage of the ischaemic risk area, using the triphenyltetrazolium method, extended by colour detection of collaterals, was evaluated.

The phosphate pool of isolated dog heart during global ischaemia: comparison of two cardioplegic solutions with 31P NMR spectroscopy.

31P NMR spectroscopy was used to study the time course of changes in the concentration of high-energy metabolites and intracellular pH in the dog myocardium during hypothermic ischaemia at 9 degrees C in Bretschneider (HTK-B) and St. Thomas' Hospital (StTH) cardioplegic solutions. It was found that ATP and phosphocreatine degrade slowlier in HTK-B than in StTH, with phosphocreatine depletion occurring within 7.

Cardioprotective effects of N-acetylcysteine: the reduction in the extent of infarction and occurrence of reperfusion arrhythmias in the dog.

We have studied the cardioprotective effect of N-acetylcysteine in the dog. In mongrel dogs of either sex, the left anterior descending coronary artery was ligated for a period of 2 hours behind the origin of its first diagonal branch. After this period, dogs in a treated group were administered 100 mg of N-acetylcysteine/kg body weight while a control group remained untreated.