Use of artificial heart ventricles in cardiovascular insufficiency of extreme degree and in heart arrest

: Experiments were conducted on 26 mongrel dogs and 10 calves to evaluate the effect of uni- and biventricular bypass created by means of artificial heart ventricle on hemodynamics in acute cardiovascular insufficiency (ACVI) and heart arrest (HA). The use of unilateral right-ventricular (RVB) and left-ventricular bypass (LVB) was shown to be equivocal: in sufficient functional reserve of the left-ventricular myocardium the volume blood flow in the aorta was increased to a greater degree by RVB (to 2.1 +/- 0.3 l/min) than by LVB (to 2.0 +/- 0.5 l/min). Experiments during HA allowed the authors to evaluate selectively the bypasses in maintenance of the systemic blood flow. It was found that in univentricular bypass the other half of the heart had an effect on hemodynamics, which depended on the initial hemodynamic parameters of the divisions of circulation with high and low pressure, the filling of the heart cavities with blood, and the effect produced through the interventricular septum. The increase of the volume blood flow in the aorta in RVB to 0.6 +/- 0.1 l/min is linked to a great measure by the authors with the conducted artificial ventilation of the lungs. It was noted that the greatest difficulties in maintaining the systemic blood flow in ACVI were associated with the development of disproportion of the contractile function of the right and left parts of the heart. With consideration for this circumstance, the indications for univentricular bypass are determined. A clinical case with prolonged use of LVB (8 days) is discussed.