[Auxiliary blood circulation and the artificial heart: forty years of development].

The article summarizes forty-year experience in working over the problem of the artificial heart and auxiliary blood circulation in Laboratory and later Research Institute of Transplantology and Artificial Organs. This work has resulted in the development of balloon pumps for intraaortic contrapulsation, the technique of balloon installation, and indications to its application. The results of the clinical application of the method in patients with various pathologies have been estimated. Preclinically, left ventricular bypass techniques have been tested on more than twenty models of membrane type artificial ventricles. The results of the clinical application of left ventricular bypass have been analyzed. The authors adduce data on the development of the thermomechanical implantable bypass system "Micron-M". After achieving 100-day survival of calves with an artificial heart, an artificial heart with external power supply was used as a "bridge" to heart transplantation, but there was only one patient in whom transplantation was performed. The authors consider development of implantable auxiliary blood circulation devices and the artificial heart to be of great prospective value.

[External counterpulsation: experience of institution of transplantology and artificial organs].

External counterpulsation produces profound impact on hemodynamics especially in patients with myocardial ischemia. However the use of the method is not indicated in patients with left ventricular failure in whom in can provoke development of shock and pulmonary edema.

Pulsate regimes of the centrifugal pump operation for assisted circulation.

This paper focuses on the evaluation of dynamic pumps as an element of the assist unit from the standpoint of its capacity to pass and change the left ventricle's pulsations. Analyses of the dynamic equations of the pipelines and pump have been performed. The pump intensification capacity of the disc and blade pumps was computed. Theoretically it was determined and experimentally confirmed that the pump intensification capacity was defined by the performance of the pump head. It was also determined that the existing pumps (e.g., The BioMedicus Biopump and the Moscow Aviation Institute, OK) pass and attenuate the left ventricle pressure pulsations.

[Abdominal compression as a method of resuscitation and assisted circulation]. / Abdominal'naia kompressiia kak metod reanimatsii i vspomogatel'nogo krovoobrashcheniia.

Experiments on animals have been carried out to investigate the hemodynamic changes during manual abdominal compression (AC) under conditions of heart fibrillation and acute heart failure. The possibility to increase the efficacy of left ventricular bypass (LVB) has been studied. Manual AC enhanced the pressure and blood flow in low-pressure compartments and increased aortic systolic and diastolic pressure. It has been also noted that LVB efficacy was increased in simultaneous assisted perfusion and abdominal compression. The first clinical data confirm the experimental findings.

[Axial micro-pump system of assisted circulation]. / Sistema vspomogatelnogo krovoobrashcheniia s osevym mikronasosom.

An assisted circulation system having a HART-02 axial-flow micropump has been developed. The diameter of the micropump is 7 mm and its length is 20 mm, which allows it to be introduced into the ascending aorta through a peripheral artery. The system has a good biocompatibility, a low hemolysis and its productivity is as much as 3.5 liter/min.

[Role of the arterial reservoir during assisted circulation in acute heart failure]. / Znachenie "arterial'nogo rezervuara" v khode provedeniia vspomogatel'nogo krovoobrashcheniia pri ostroi serdechnoi nedostatochnosti.

The role of "arterial reservoir" (AR) has been assessed experimentally in 20 mongrel dogs during the onset of acute heart failure (AHF) and in left ventricular bypass (LVB). The criteria evaluating AR function were as follows: diameter and volume of aorta filling (dA; VA), aortic wall distensibility (D). Va in the range of BPm 30.4 to 171 mm Hg changed from 12.62 to 49.32 ml, i.e. two-three-fold. D at maximum and minimum BRm values decreased by 10 and more times. A direct correlation between relative Va and da changes with a coefficient 2 has been observed in any aortic section. BPm (but not BPsy st or BPdia st which characterizes a degree of "tense" AR filling can serve as an adequate index of LVB efficacy.

[The potentials of using artificial pulmonary ventilation for maintaining systemic blood flow]. / Vozmozhnosti ispol'zovaniia IVL dlia podderzhaniia sistemnogo krovotoka.

Hemodynamics was studied experimentally in 36 mongrel dogs during ventricular fibrillation (VF) in conditions of controlled lung ventilation with tidal volumes (TV) 7, 14 and 21 ml/kg and minute ventilation (MV) 140 ml/(min.kg). Cardiac output determined in ascending aorta varied from 4.1 to 7.3 ml/(min.kg) depending on TV and evaluation period with initial values prior to VF 101-110 ml/(min.kg). In 12 experiments using TV of 14 ml/kg acid-base balance and blood gas composition in central and peripheral circulation compartments have been determined. High HbO2 and pO2 levels in peripheral vessels have been noted; HbO2 difference between aortic blood and caudal vein blood was 37% on minute 30 and 28% between aortic and peripheral venous (femoral vein) blood.

[Noninvasive assisted blood circulation]. / Neinvazivnoe vspomogatel'noe krovoobrashchenie.

The experience of the use of noninvasive assisted circulation in patients with cardiac pathology is summarized. It has been demonstrated that rhythmic pneumo-compression of the lower extremities, abdominal compression, muscular electrical stimulation of the lower extremities and the abdomen have a pronounced effect on circulation compartments with low pressure. All the above pre-determines the role of these techniques in the management of cardiac failure and in intensive care.

[Schemes for implanting shovel pumps for assisted circulation]. / Skhemy implantatsii lopatochnykh nasosov dlia ispomogatel'nogo krovoobrashcheniia.

The authors propose a design of an axial shovel pump for extracorporeal circulation. They show how to introduce it into various cardiovascular segments and make a comparative assessment of its efficacy in relation to the type and severity of heart failure, surgical access, and treatment policy.

[Biventricular auxiliary system for restoration of cardiac activity]. / Biventrikuliarnaia vspomogatel'naia sistema dlia vosstanovleniia serdechnoi deiatel'nosti.

Thirty experiments were conducted on calves for hemodynamic study of mechanical aid to the heart (biventricular bypass by two artificial ++"Module"+ ventricles of the heart) in acute cardiac failure. The cavities of the heart were cannulated with a special perforating device which, when necessary, is an obturator of the main line. Analysis of the hemodynamic values showed a sufficiently high efficacy of biventricular shunting in acute cardiac failure. The device for draining the heart cavities has advantages over the traditional main lines, in particular the number of complications from bleeding and air embolism reduces with its use.

Perspectives for pneumatic and hydraulic circulatory assist devices and their application for heart transplantation.

Intraventricular blood-forcing-principle-based pneumo- and hydraulic assistance circulation device test results are proposed. The system consists of a uninipple valveless dome pump, a pneumo- or hydraulic drive, and an artificial pericardium. Stand tests of these systems and medical-biologic experiments on dogs and 17 calves were performed. The duration of these experiments was up to several days. In this report, the features of surgical techniques, perfusion parameters, control principles, hemodynamic variations, complications, and other problems concerning realization of the proposed method are discussed.

[New pneumatic and hydraulic devices for assisted and artificial circulation (a hybrid artificial heart)]. / Novye pnevmaticheskoe i gidravlicheskie ustroistva vospomogatel'nogo i isskusstvennogo krovoobrashcheniia ("gibridnoe iskusstvennoe serdtse").

The authors offer a system for auxiliary circulation (a "hybrid man-made heart"), review design varieties, describe the functioning of the system. The paper is of interest for designers of the systems for extracorporeal circulation and for practicing physicians concerned with the problems of cardiology.

[Choosing the structure of the control system for an external counterpulsation complex]. / Vybor struktury sistemy upravleniia kompleksa naruzhnoi kontrpul'satsii.

The paper is concerned with the principles of choosing the structure of the external counterpulsation control on an a.c. hydrodrive. An autonomous control mode and the control principles using a specialized microprocessor as well as computer-aided feedback control have been investigated.

[Clinical use of artificial heart ventricles]. / Klinicheskoe primenenie iskusstvennykh zheludochkov serdtsa.

The article discusses the results of applying for the first time Soviet-made "Modul" and "Yasen" artificial ventricles of the heart (AVH) in a left ventricular bypass regimen in patients with refractory cardiac insufficiency. Improvement of AVH design and rational tactics of attendant drug therapy allowed the period of the safe application of the AVH in the organism to be increased to more than 8 days.

[Electric stimulation of skeletal muscles as the optimal method of left-ventricular bypass]. / Elektrostimuliatsiia skeletnykh myshts kak sredstvo optimizatsii levozheludochkovogo obkhoda.

Experiments were performed on 15 mongrel dogs to evaluate the influence of electrostimulated contractions of the hind limb and abdominal skeletal muscles on the efficacy of assisted circulation (AC). The influence of massage of the abdomen on AC efficacy was studied in 10 experiments. In electrostimulation of the hind limb muscles the drainage along the femoral vein, measured by the direct method, increased threefold: from 58 +/- 9 to 162 +/- 7 ml/min under conditions of an intact heart and from 5.8 +/- 0.8 to 15 +/- 1.2 ml/min in cardiac insufficiency. The efficacy of AC by the method of left-ventricular bypass by means of the Module artificial heart ventricle (AHV) increased through the flow of blood to the heart, which was manifested by greater AHV performance with rise of systolic and diastolic pressure to 7-8 mm Hg. In cardiovascular insufficiency the influence of electrostimulation on AC efficacy was weaker, the systolic and diastolic pressure increased only by 2-4 mm Hg, in massage of the abdomen both indices increased by 8-10 mm Hg.

[Devices for temporary replacement of the pumping function of the heart]. / Ustroistva dlia vremennoi zameny nasosnoi funktsii serdtsa.

The article gives the analysis of the authors' experience in developing the systems of mechanical maintenance of blood circulation: AvIK-9M, Sinus-BK, and the cylinder pump with an additional distal chamber, which has not only high hemodynamic efficiency but also, to a considerable extent, improves the bioenergetics of the myocardium. It also gives a detailed description of the device for the retrograde counterpulsation and periodic occlusion of the coronary sinus. All the systems have successfully undergone testing by experiment and in the clinic.