High breath pentane concentrations during acute myocardial infarction.

To investigate whether reperfusion after myocardial ischaemia leads to free-radical-mediated peroxidation of membrane lipids and cell damage, we measured pentane, a product of lipid peroxidation, in the breath of 10 healthy control subjects and in 20 consecutive patients with suspected acute myocardial infarction. 10 of these patients showed no myocardial damage on electrocardiography (patient control group) and 10 satisfied standard diagnostic criteria for acute myocardial infarction. The three groups were well matched for age, sex, underlying disease, and smoking habits. The time from onset of chest pain to breath collection was similar in the patient control and acute myocardial infarction groups. The breath pentane concentration was higher (p less than 0.0001) in the acute myocardial infarction group (4.96 [1.15] nmol/l) than in the patient control (1.96 [1.04] nmol/l) and healthy control groups (1.71 [0.87] nmol/l). Lipid peroxidation during acute myocardial infarction reflects action of oxygen radicals and their potential for contribution to the pathogenesis of tissue damage.