Two series of experiments were conducted to assess the potential of artificial ventricular bypass in restoring cardiac activity. One series evaluated use of a paracorporeal left ventricle in 17 calves; the other evaluated biventricular bypass in 11 calves. Module pumps with a seamless blood chamber of polyurethane were used. Pump function and system parameters were controlled by a Sinus VK-2 control system. Assisted perfusion began with the induction of ventricular fibrillation. The experiments showed that left ventricular bypass was an effective method for long-term maintenance of the hemodynamics during fibrillation, leading to certain biochemical corrections and restored electrical activity and myocardial contractile function. The hemodynamic state was maintained at a higher level with biventricular bypass and was accompanied by a greater percentage of restored myocardial function. Uneven restoration of contractile activity in the left and right ventricles points to the need for adequate support of both ventricles.

The study of informativeness of varying parameters of induced chemifluorescence reflecting the intensity of free-radical oxygenation of lipids and their dependence on the degree of necrotic damage of the myocardium, determined by the activity of creatine phosphokinase and its cardiospecific isoenzyme MB. 19 patients and 20 healthy individuals were examined. The results show that inhibition of induced chemifluorescence of the blood serum in the period of developing necrotic changes is directly dependent on the content of products of the ischaemic destruction of the myocardium.

A possibility of the artificial ventricle regulation using information on the atrial contraction is discussed. Correlations between atrial wall tension and ventricle tension as well as the pressure under radom heart rhythm variations were studied. The wall tension of the appropriate heart portion was recorded by the arched tensiometers, and intraventricular pressure under cavity catheterization by the electric manometer. The cardiac rhythm varied between 2.0 c-1 and 4.0 c-1. A correlation between the tension and interpulse interval, (correlation coefficient being 0.62 +/- 0.05) was established. The close relationships "atrial wall tension-intramuscular pressure" were observed. For such relationships the correlation coefficient changed from 0.713 +/- 0,09 to 0,874 +/- 0.02 depending on the average value of interpulse interval. It is concluded that the information on the atrial contraction can be used for artificial heart regulation.

The possibility of using the atrial myocardium to control artificial ventricles is examined. Correlation was studied between the tension of the atrial wall and the tension and pressure in the ventricles during random variation of the cardiac rhythm was studied. Tension in the wall of the corresponding part of the heart was recorded by means of arch strain gauges and the intraventricular pressure by means of an electromanometer during catheterization of the chambers of the ventricles. The cardiac rhythm varied from 2.0 to 4.0 sec−1. Correlation was demonstrated in the atria between the tension and interspike interval (coefficient of correlation 0.62±0.05). Close correlation was detected between tension in the atrial wall and the intraventricular pressure. The coefficient of correlation in this case varied from 0.713±0.09 to 0.874±0.02 depending on the mean duration of the interspike interval. Information on atrial contractions can be used to control an artificial heart.