46 patients (19 women and 27 men, aged 42±14 years) with congestive cardiomyopathy (left ventricular ejection
fraction < 30%) and 10 healthy subjects (aged 36±12 years) were evaluated echocardiographically.Plasma activities of MnSOD and CuZnSOD were measured. A statistically significant negative correlation was found between MnSOD activity and the CI (r=0.64). The mean MnSOD activity in patients with the CI<2.41/min/m2 was 16.58±5.82 NU/I, and in patients with the CI>2.41/min/m2 it was 9.92±3.28NU/I (p<0.001). The mean CuZnSOP activity in patients with the CI<2.41/min/m2 was 4.5NU/I and in patients with CI>2.41/min/m2 it was 6.9±2.32 (p<0.01). The activity of MnSOD and CuZnSOD in healthy subjects was comparable to that found in patients with the CI>2.41/min/m2. Patients with the CI<2.41/min/m2 were reexamined following 6 weeks of pharmacological treatment (Drugs used: digoxin, captopril, furosemide, isosorbide dinitrate). A significant increase of the CI (p<0.01) accompanied by a decrease of MnSOD activity (p<0.05), and an insignificant increase of CuZnSOD activity were found. Our results indirectly confirm the increase of oxygen free radical concentration levels in patients with heart failure.

Keywords: cardiomyopathy, Free Radicals, Isoenzymes