[Membrane modifications in myocardial infarction following emergency reperfusion]

The effects of revascularization on the morphological aspects of myocardial infarction have been studied in 87 animals. After permanent ligation of a coronary artery, the aspects are stereotyped and the histo-enzymatic and ultrastructural evolution is quite well known. On the contrary, early revascularization of this infarction at different times causes specific alterations: alteration of the membrane permeability with an intense edema of myocardial cells, restriction of the negative succinate dehydrogenase zone, cleavage of the sarcolemma membrane, intra-mitochondrial calcium deposits and destruction of endothelial membranes. These lesions are responsible for the non-revascularization phenomenon which limits considerably the metabolic recovery of the ischemic area. These spectacular membrane destructions of the revascularization could be linked to the release of free radicals. Besides, the use of Mannitol and Allopurinol, with their known protective effect on the free radicals, enables to greatly reduce the size of the resulting infarction (60 animals). 12 patients, after failure of a coronary dilatation, were treated in the first six hours with a cardioplegic perfusion with allopurinol followed by a by-pass. The long term results show the retrogression of the Q waves in 11 out of 12 cases and the functional recovery of the akinetic area on the echocardiogram.