Criteria of efficiency and safety of the defibrillating impulse.

The effectiveness and safety of the defibrillating effect of a bipolar impulse produced by a Soviet DK1-01 defibrillator and the Monopolar impulse Ed-Mark have been tested in 14 experiments on the anaesthetized dogs. A quantitative criterion to compare the safety of different defibrillators and an electro-therapeutic index of the defibrillating action are being suggested. It is defined as the ratio of the thresholds of energy in joules causing lesions to that causing defibrillation. In the above experiments the mean value of this therapeutic index was 1.59 +/- 1.41 for the Ed-Mark impulse and 4.32 +/- 2.78 for the defibrillator DK1-01 impulse. The difference of the mean values was statistically significant (P = 0.02).