Objective:To investigate the cardiac electrical injuries caused by the applied weak steady DC EFs in rabbits. Methods:A pair of Pt electrodes were paral el y placed on the cardiac apex epicardium at the two sides of the main branch of the left coronary artery in the rabbit hearts by thoracotomy without endotracheal intubation, fol owed by which a DC EFs range of 0 to 6.0V/cm was applied. The limb-lead ECGs and the epicardial temperature in the anelectrode were monitored. Results:In 17 rabbits EFs of 0 to 3.5 V/cm failed to cause any ventricular arrhythmia, but increasing EFs from 4.0 to 6.0 V/cm led to ventricular arrhythmia, tachycardia or even to fibril ation and the sudden death syndrome.12 of the rabbits recovered from ventricular fibril ation to normal rhythm when EFs were gradual y lowered to 3.0 V/cm. Furthermore, Electrical stimulation for 1h at 3.5 V/cm and 4.0 or 4.5 V/cm only increased the epicardial temperature in the anelectrode by(1.05±0.81)0C、(1.14±0.23)0C respectively, but having no statistical significance(P>0.05). .Conclusion:The weak steady EFs(≤3.5V/cm) failed to cause any ventricular arrhythmia obviously .
direct currentelectrical stimulationelectrical injuriesheart
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