[Selective pacemaker interruption and disorders of atrial automaticity during induction of lipid peroxidation]

The influence of lipid peroxidation (LPO) inductor H2O2 on spontaneous contractility and electrical activity of the right atrium was studied. LPO induction caused positive inotropic catecholamine-like effect, followed by brady-arrhythmia with the action of potential prolongation, blockade of electrical activity and atrial arrest. Electrical pacing during atrial arrest caused regular contractions of the same force as before electrical activity blockade. The results suggest that the arrest of spontaneous atrial activity under the influence of LPO inductor is due to the impairment of sinus node automaticity.