Extracorporeal mechanical pulsatile pump and its significance for myocardial function recovery and circulatory support.

The authors performed 12 acute (on dogs) and 12 chronic (on calves) assisted circulation experiments with the use of the total extracorporeal mechanical pump (TEMP) artificial ventricles. The functional morphological research of the myocardium suggests that in addition to the possibility of the biological heart function full replacement, the artificial ventricle also helps recover damages in both the myocardial infarction and distal zones. The critical time period up to the onset of artificial circulation is not more than 2 h, and after that myocardial changes are irreversible.

Biomedical aspects of cardiac massage in experiments and clinical practice.

Despite current successes in modern cardiology and heart surgery, the problem of restoring and maintaining cardiac function in cases of sudden arrest or ventricular insufficiency is still urgent. Different methods of mechanically assisting the heart and replacing its pumping function exist, and direct mechanical cardiac massage (DMCM) is one of the more important. Experimental results with dogs and calves on 2- to 4-h DMCM, cardiac massage lasting for up to 48 h, subsequent restoration of cardiac activity, and cardiac massage during experimentally induced myocardial infarction permitted clinical application in patients with myocardial infarction complicated by ventricular fibrillation. DMCM also permits extension of the possibilities of obtaining and transplanting donor organs. It is one of the variants for solving the problem of total and partial replacement of the pump function of the heart, and now makes it possible to solve some important problems in transplantation and cardiac resuscitation.

[Hemosorption as a treatment method in digitalis poisoning of heart failure patients with myocardial infarct]. / Gemosorbtsiia kak metod lecheniia digitalisnoi intoksikatsii u bol'nykh s serdechnoi nedostatochnost'iu pri infarkte miokarda.

Results of haemosorption in treating digitalis intoxication are analyzed. In 2 patients haemosorption was used for 90 min at the volume speed of 100 ml/min. Digoxin clearance at the start of haemosorption was 98.4 and 83.8 ml/min, at the end 85.7 and 70.3 ml/min. Digoxin concentration decreased by 44.8 and 13.0%. Hemosorption enabled performing electric defibrillation with restoration of the sinus rhythm.

[Study of the pumping function of devices for direct mechanical heart massage]. / Issledovanie nasosnoi funktsii ustroistv dlia priamogo mekhanicheskogo massazha serdtsa.

A method permitting to define the efficiency of devices designed for direct cardiomassage on a special hydrodynamic stand is given. The results are presented, obtained with the variation of the main functional parameters which ensure maximum capacity of the device. Factors influencing the cardiomassage efficiency were determined. The devices investigated were claimed to provide the capacity sufficient for entire or partial substitution of the cardiac pumping function.

[Maintenance of the circulation and the restoration of heart function in the donor body by means of direct mechanical heart massage for subsequent transplantation (an experimental study)]. / Podderzhanie tsirkuliatsii i vosstanovlenie funktsii serdtsa v organizme donora s pomoshch'iu priamogo mekhanicheskogo kardiomassazha dlia posleduiushchei transplantatsii (éksperimental'noe issledovanie).

The possibility of maintenance of circulation and subsequent restoration of the function of the heart in the organism of the donor, after 10-minute arrest of circulation, for transplantation of the heart was investigated. Study of the hemodynamic, biochemical, metabolic, and structural changes in the myocardium after 2-hour mechanical massage without and with pharmacological protection of the myocardium (glucose--insulin--potassium, hydrocortisone, dipyridamole), without and with restoration of cardiac activity in the organism of the donor and the recipient after transplantation of the second heart by the method suggested by Moory et al. in artificially created left ventricular insufficiency showed that direct mechanical massage of the heart may be used for its short-term preservation in the donor organism.

[Effect of adrenaline on the contractility of different portions of the myocardium of homeotherms]. / Vliianie adrenalina na sokratimost' razlichnykh otdelov miokarda teplokrovnykh.

The contractility of myocardial strips from the atrium and ventricle of rabbit heart had some differences in the parameters of single contraction, interval--tension relationship, and transitional process. These differences were eliminated by increasing the concentration of epinephrine in bath solution. Epinephrine changed the mode of time--force relation of contraction and induced appearance of extremum in all the parts of the heart. The linear relation between the force of atrium contraction and that of ventricle contraction (homochromity) during change of contraction frequency in normal solution, was shown. The homochromity of atrium and ventricle was broken by high epinphrine concentrations. The level of endogenous catecholamines which modulate the excitation--contraction relations, is believed to determine the differences in the physiological reactions of atrial and ventricular strips. The use of atrium of the heart as a transducer for management of artificial heart is proposed.

[Synchronous mechanical heart massage during assisted circulation]. / Sinkhronnyi mekhanicheskii massazh serdtsa pri vspomogatel'nom krovoobrashchenii

In tests on dogs specially devised cardiac massage appliances and a monitoring system synchronizing the mechanical massage with the R wave on the ECG were used in carrying out a synchronous mechanical chest massage in conditions of an experimentally induced incompetence of the cardiac ventricles. Optimal parameters of the hemodynamics were recorded with the massage proceeding in such a manner, when mechanical action on the cardiac ventricles coincided with termination of the maximum pressure period of the myocardium. The synchronous ancillary cardiac massage effected under conditions of ventricular incompetence was found to be attended by a rise of cardiac output and increased aortic pressure, falling tension in the auricles and normalization of the acid-base equilibrium figures. Synchronization of the massaging appliance operation with cardiac contractions is an effective method of assisted circulation in acute incompetence of the heart valves.

[Components of an implanted artificial heart and the medico-technical requirements]. / Sostavnye elementy implantiruemogo iskusstvennogo serdtsa i pred'iavliaemye k nim mediko-tekhnicheskie trebovaniia

The task of designing and providing power supply for an implanted artificial heart (AH) is a many-sided complex problem that includes a number of medico-biological, technical, physical, power-supply and other factors. The analysis of the AH components and the mentioned basic medico-technical requirements permits it to outline the ways and means for a rational solution of this complicated problem. The greatest attention is paid to the analysis of and future prospects for the use of different power sources and methods of power conversion.

[New construction of an orthotopic heart prosthesis made of fluorosiloxane rubber]. / Novaia konstruktsiia ortotopicheskogo proteza serdtsa iz ftorsiloksanovogo kauchuka

A new design of orthopedic heart prosthesis with artificial ventricles of the saccular type -- model (see text) is described and results of its test-trials are reported. All the components of the heart prosthesis are made of fluorosiloxan rubber.