[Effects of taurine and dipeptide Tyr-Tyr on ventricular defibrillation]. / Vliianie taurina i dipeptida Tyr-Tyr na defibrilliatsiiu zheludochkov serdtsa.

Results of the study of taurine and dipeptide Tyr-Tyr effect on the threshold values of functional lesions of the myocardium and heart defibrillation are reported. The experiments were carried out on 27 narcotized mongrel dogs weighing 12-30 kg. Defibrillation was performed using Lifepak-7 defibrillator (USA). Lesion threshold (LT), defibrillation threshold (DT) and electrotherapeutic index (ETI) as a LT:DT ratio were determined. In 14 experiments (control group) these parameters were evaluated during 3 h. In group 1 (6 experiments) taurine (100 mg/kg) was infused intravenously by the end of the 1st hour, in group 2--Tyr-Tyr (25 mg/kg). It was shown that infusion of taurine did not have a noticeable effect of the LT, DT and ETI values. Infusion of Tyr-Tyr resulted in an increase in LT and DT. The possibility to use dipeptide Tyr-Tyr in the complex of measures aimed at ceasing ventricular fibrillation is discussed.

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).