[Left-ventricular bypass: characteristics of homeostasis].

Experiments were conducted on donkeys to study the peculiarities of homeostasis in establishment of left ventricular bypass (LVB) by means of an artificial heart ventricle (AHV). Preliminary modelling of acute cardiac insufficiency makes the work of the AHV effective and ensures longer survival than that among intact animals. However, arterial hypertension and anemia accompanying prolonged work of the AHV and resulting from the interaction of the last named with the cardiovascular system sharply aggravate homeostasis and the course of LVB and lead to early death of the animals.

[Monitoring of myocardial gases and evaluation of the viability of the preserved heart].

For the evaluation of the viability of a nonfunctioning stored heart, a system of myocardial gases (pO2, pCO2) monitoring was developed and approved . It is shown that myocardial pCO2 monitoring is most informative in evaluation of viability of a stored heart. The character of this curve makes it possible to identify the duration of storage admissible in each concrete case as well as the loss of viability by the heart.

Long-term circulatory and respiratory support using two artificial ventricles and a fluorocarbon oxygenator.

Using a new heart-lung machine developed at our Institute, experiments were conducted on dogs, donkeys, and monkeys, providing complete and assisted artificial circulation, assisted oxygenation, and perfusion preservation of the heart. The new apparatus consists of two sequentially mounted artificial ventricles working in an antiphase mode; blood oxygenation is accomplished by a reusable oxygenator with a fluorocarbon preoxygenator. Experimental results indicate that clinical use of the apparatus is promising and deserves consideration.

[Treatment of heart failure by draining blood from the coronary sinus].

A method of coronary sinus drainage is suggested for the treatment of acute heart failure. This ensures an increase in the arteriovenous gradient of pressure in the coronary system by decreasing the pressure in the coronary sinus which leads to an increase in the orthograde myocardial circulation and systemic pressure as well as to improved cardio-mechanics.

Improvement in intra-aortic balloon pumping and evaluation of its efficacy by electrode methods of control.

A basically new design for the reversing balloon pump has been proposed for increasing the efficacy of intra-aortic balloon pumping (IABP). The device not only causes a significant increase in discharge, but also permits control of the central and peripheral circulation within the desired limits owing to back-and-forth movements (like a piston) of the balloon pump. Standard one- and two-chamber balloon pumps were compared.