The main aim of the study was to test the hypotheses that (a) concentrations of
endogenous digoxin-like factor (EDLF) are increased in the initial period after acute
myocardial infarction (AMI) and (b) may contribute to the onset of ventricular arrhythmias. 54 patients of both sexes with a first transmural AMI were included in a retrospective study. Plasma concentrations of EDLF were measured repeatedly during days 1-14 after AMI using DELFIA
digoxin fluoroimmunoassay. 16 male patients with
unstable angina pectoris and suspected AMI as well
as 8 healthy subjects of both sexes served as controls. Plasma concentrations of EDLF in patients during the first day of AMI were increased (1.25 + (-)0.26 ng/ml,
digoxin equivalents, p < 0.05) as compared with both healthy controls (0.34 + (-)0.08 ng/ml) and patients with
unstable angina pectoris (0.4 + (-)0.06 ng/ml). First day after AMI plasma levels of EDLF in 7 patients with primary
ventricular fibrillation were higher (2.54 + (-)0.67 ng/ml, p < 0.03) than in 47 patients without
ventricular fibrillation (1.05 + (-)0.27 ng/ml). In 14 patients with AMI and
congestive heart failure (class III, Killip) plasma concentrations of EDLF were significantly lower (0.32 + (-)0.09 ng/ml, p < 0.03) than in 40 patients with AMI without
congestive heart failure (1.51 + (-)0.32 ng/ml). Starting from the second day of AMI plasma EDLF decreased to the level of control and did not change during two weeks of observation. These results, being in agreement with our previous experimental data, show an increase of plasma EDLF after AMI and suggest that EDLF may be involved in
myocardial ischemia-induced arrhythmogenesis and participate in pathogenesis of
congestive heart failure after AMI.