The influence of electrical cardioversion on superoxide anions (O2-) production by polymorphonuclear neutrophils, hydrogen peroxide (H2O2) plasma level and malondialdehyde serum concentration.

We studied the influence of electrical cardioversion on unstimulated and stimulated superoxide anion production by polymorphonuclear neutrophils in 22 patients with atrial flutter or atrial fibrillation. We also estimated hydrogen peroxide plasma level, as well as malondialdehyde serum concentration, in these subjects. We noted an increase in spontaneous production of superoxide anions from 14.9 +/- 1.8 nmol/10(6) neutrophils per 20 min to 21.37 +/- 2.7 nmol/10(6) neutrophils per 20 min (P = 0.002) in neutrophils obtained after electrical cardioversion. Similarly, stimulated production of O2- also increased after electrical cardioversion (41.8 +/ 3.4 nmol/10(6) neutrophils per 20 min vs. 59.0 +/- 5.9 nmol/10(6) neutrophils per 20 min, P = 0.0027). Moreover, hydrogen peroxide plasma level increased significantly after electrical cardioversion (39.9 +/- 6.2 mumol/l vs. 53.4 +/- 7.6 mol/l, P = 0.003). Serum malondialdehyde concentration also increased after countershock (2.56 +/- 0.26 nmol/ml vs. 2.94 +/- 0.26 nmol/ml, P = 0.023). These results seem to indicate that electrical cardioversion may lead to polymorphonuclear neutrophils activation, increased H2O2 production and lipid peroxidation.