THE INFLUENCE OF ELECTRICAL CARDIOVERSION ON SUPEROXIDE ANIONS (O-2(-)) PRODUCTION BY POLYMORPHONUCLEAR NEUTROPHILS, HYDROGEN-PEROXIDE (H2O2) PLASMA-LEVEL AND MALONDIALDEHYDE SERUM CONCENTRATION

We studied the influence of electrical cardioversion on unstimulated a nd stimulated superoxide anion production by polymorphonuclear neutrop hils in 22 patients with atrial flutter or atrial fibrillation. We als o estimated hydrogen peroxide plasma level, as well as malondialdehyde serum concentration, in these subjects. We noted an increase in spont aneous production of superoxide anions from 14.9+/-1.8 nmol/10(6) neut rophils per 20 min to 21.37+/-2.7 nmol/10(6) neutrophils per 20 min (P =0.002) in neutrophils obtained after electrical cardioversion. Simila rly, stimulated production of O-2(-) also increased after electrical c ardioversion (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 p eroxide plasma level increased significantly after electrical cardiove rsion (39.9+/-6.2 mu mol/l vs. 53.4+/-7.6 mol/l, P=0.003). Serum malon dialdehyde concentration also increased after countershock (2.56+/-0.2 6 nmol/ml vs. 2.94+/-0.26 nmol/ml, P=0.023). These results seem to ind icate that electrical cardioversion may lead to polymorphonuclear neut rophils activation, increased H2O2 production and lipid peroxidation.