ABSTRACT
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.
Subject(s)
Assisted Circulation , Heart-Assist Devices , Adenine Nucleotides/blood , Animals , Cattle , Electrophysiology , Energy Metabolism , Evaluation Studies as Topic , Hemodynamics , Myocardial Contraction , Myocardium/metabolism , Ventricular Fibrillation/physiopathology , Ventricular Fibrillation/therapyABSTRACT
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.
Subject(s)
Atrial Function , Heart, Artificial , Myocardial Contraction , Animals , Dogs , Electric Stimulation , Female , Male , Mathematics , Transducers , Ventricular FunctionABSTRACT
The effect of preliminary administration of alpha-tocopherol acetate (1 mg/kg) and sodium selenite (1 mg/kg) on RNA synthesis rate and changes in the macroergic content in ischemic myocardium was studied. It was shown to be conducive to ATP level maintenance after 30- and 60-minute heart ischemia. A statistically significant accumulation of RNA by the myocardium following I-hour ischemia as well as this polynucleotide synthesis activation were recorded. Preservation of the energetic resources by the cell along with RNA metabolism returning to normal contributes to inhibiting the emergence of irreversible cell damage and increases regenerative potentialities of the myocardium.
