[Importance of determination of the activity of lactate dehydrogenase and its isoenzymes in blood serum for differential diagnosis of myocardial infarct, thromboembolism of the pulmonary artery and acute pancreatitis].

In 12 patients with macrofocal myocardial infarction and in 14 others with rheumatic mitral cardiac defects and congestion in the greater circulation complicated by thromboembolism of the pulmonary artery the activity of total lactate-dehydrogenase (LDG) and of its isoenzymes was determined in the blood serum. As shown by investigations the intercurrence of the lastly named complication was accompanied in these patients by an augmented activity of the total LDG and by readjustment of its isoenzymatic spectrum. The latter involved a progressive percentage growth of the activity displayed by LDG3 and LDG4 fractions. In patients with myocardial infarction without thromboembolism of the pulmonary artery the nature of the isoenzymatic spectrum changes is dissimilar, this enabling the method to be used in the differential diagnosis of the affections. The blood serum of patients with acute pancreatitis shows an increased activity of the total LDG, this being conditioned by a growing activity of the LDG3 and LDG4 fractions. The determination of the blood serum LDG isoenzymes activity as a test supplementing other methods of investigation may, with due account of the clinico-electrocardiographic picture, be used in the differential diagnosis of myocardial infarction and acute pancreatitis.