[Differential neural influences on the heart rate and contractile force in different reflex reactions].

Chronotropic and inotropic responses of the cat heart to cooling of the nn. vagi, raising of arterial pressure, stimulation of central ends of the nn. vagi, were different under different actions but stable in their character.

[Neural regulatory effects on the contractility of heart ventricles].

As a result of acute experiments on cats we revealed the approaches to choosing the best indices of the contractility of the left and the right cardiac ventricles in the concrete conditions of the experiment on the basis of the original criterion of optimality. For revealing neural inotropy influences we suggest the index based on the combined changes of optimum indices. A new approach to revealing reflex influences on contractility in the conditions of intact blood circulation is worked out, which is based on the comparison of these influences with the control changes of haemodynamic parameters.

[Organization of reflex sympathetic influence on rate and force of cardiac contraction].

In acute experiments on 21 cats it was proved that the change of afferent impulse on vagus nerves by means of either freeze-block or electrostimulation of their central ends results in differential reflex influences on rhythm and force of the cardiac contractions caused by sympathetic nervous system. The cut of the lower cardiac nerves may cause 'break-up' of the observed reflex, removing or inverting its ino- or chronotropy component. The given phenomenon was revealed in the experiments with high arterial pressure and with absence of tonic chronotropy influences of the left lower cardiac nerve.

[Myocardial contractile indices as a means for studying the inotropic reactions of the different heart chambers in a computerized experiment].

Artifacts which can distort the heart chambers contractility indices and the ways of its prevention are discussed. Changes in the heart pre- and afterload causing an inotropic effects, are analysed. Recommendations on the computer systems for recording and processing of blood pressure parameters in physiological experiment, are given.

[Selection of an optimal system for measurement of blood pressure].

The "pop-test" method was used to design an optimal system for precise measurement of fast arterial pressure oscillations by means of selecting optimal parameters of cardiovascular catheters and pressure transducers.