[The right heart ventricle during hemodynamic overload of the left ventricle]. / Pravyi zheludochek serdtsa pri gemodinamicheskoi peregruzke levogo.

Two types of hemodynamic overload were simulated in rabbits: renovascular arterial hypertension by the Goldblatt method and the half coarctation of the ascending aorta versus the baseline diameter. The functional indices and ultrastructure of the left and right ventricles were studied in different periods of these processes. If the left ventricle is hemodynamically overloaded, the right one immediately takes part in the process and then largely governs the performance dynamics of the whole heart.

[Defining the concept "cardiac insufficiency"]. / Ob opredelenii poniatiia "serdechnaia nedostatochnost'".

The paper analyzes various definitions of the concept "heart failure" and shows disadvantages of these definitions. Based on the analysis of the time course of myocardial functional and structural changes during various pathological processes, heart failure is defined as a condition characterized by lower cardiac reserve potentialities. A process of cardiac desynchronization is analyzed as a predisposition to heart failure.

[An assessment of the differences in the reaction of the left and right heart ventricles to a long-term rise in systemic arterial pressure in experimental renoprival arterial hypertension in rabbits]. / Otsenka razlichii v reaktsii levogo i pravogo zheludochkov serdtsa na dlitel'noe povyshenie sistemnogo arterial'nogo davleniia pri éksperimental'noi renoprivnoi arterial'noi gipertenzii u krolikov.

Different parameters of the function of the left and right heart ventricles were investigated in rabbits with renoprival arterial hypertension during a period of 52 weeks from the moment of modelling the process. As a result, this process was divided into 3 stages: 1. The establishment of compensation (1-4 weeks); 2. Compensation (6-10 weeks); 3. Decompensation (22-52 weeks). In mathematical prognosis of the time-course changes in the parameters associated with different stages of the process, the prognostic data were shown to be close to the experimental ones during prognosis for the left ventricle in the second stage, and for the right ventricle in the first stage. While prognosing for the left ventricle in the first stage and for the right ventricle in the second stage, the data obtained were significantly different from the experimental ones. These results suggest a conclusion that the right ventricle adapts itself to cardiac overload quicker than the left ventricle, but it also gets "worn out" quicker than the latter due to the conditions of "rigid" functioning in the second stage of the process when the adaptive potentials of the heart are limited.

[Effect of verapamil on arterial pressure and various parameters of heart contractile function in rabbits with prerenal artery hypertension when administered at various times of day]. / Vliianie verapamila na arterial'noe davlenie i nekotorye pokazateli sokratitel'noi funktsii serdtsa u krolikov s renoprivnoi arterial'noi gipertenziei pri ego vvedenii vraznoe vremia sutok.

The dynamics of arterial blood pressure and some data of cardiac contractility in rabbits with vasorenal hypertension were investigated in 4 seasons of the year. Simultaneously, the effects of verapamil on the said data were studied in rabbits with vasorenal hypertension (verapamil was administered at 12 and 18 h during last 2 weeks of experiment). In different seasons the definite differences in therapeutic effect of verapamil depending on the time of its administration were revealed.

[Relationship between left and right ventricular function in experimental acute focal ischemia]. / O vzaimosviazi funktsii levogo i pravogo zheludochkov serdtsa pri ostroi ochagovoi ishemii v éksperimente.

Experiments were conducted on rats to record the parameters characterizing the real and maximally accessible function of the left and right ventricles in acute focal ischemia of the myocardium of these parts 5, 20, 40, and 60 minutes after ligation of the corresponding coronary artery. It was established that disorders of synchronism in heart activity are greater in injury to the right than in those to the left ventricle.

[Seasonal changes in blood pressure and certain indicators of cardiac contractile function in intact rabbits]. / Sezonnye izmeneniia urovnia arterial'nogo davleniia i nekotorykh pokazatelei sokratitel'noi funktsii serdtsa u intaktnykh krolikov.

Some data of intact rabbits' cardiovascular system (arterial blood pressure, data of real and maximum function of heart ventricles) were investigated in different seasons of the year. It was revealed, that in winter the cardiovascular system functions with definite degree of overstrain, and in summer these data are on the lower level of the norm. Correlative analysis showed that in summer the degree of synchronization of the function of cardiovascular system drops and this can open wide possibilities for it's adaptation to variable conditions.

[Changes in the activity of lysosomal enzymes and in the indices of cardiac contractile function in experimental diphtheria poisoning in rabbits]. / Izmenenie aktivnosti fermentov lizosom i nekotorykh pokazatelei sokratitel'noi funktsii serdtsa pri éksperimental'noi difteriinoi intoksikatsii u krolikov.

Contractility of the heart ventricles and the activity of N-acetyl-beta-D-galactosaminiidase in fraction of lysosomes of this part of the heart were studied in rabbits with experimental diphtheritic intoxication. Three days after the onset of the process changes in the activity of the enzyme reached maximum and were expressed in increase of values indicating increased transfer of enzymes from the particles into the cytosol. At the same time, values which were evidence of fixation of the enzyme in the lysosomes reduced. Correlation analysis showed that intensified escape of enzymes into the cytoplasm led to weakening of heart contractile function.

[Dynamic changes in arylsulfatase activity in the initial period of acute focal myocardial ischemia in an experiment]. / Dinamika izmeneniia aktivnosti arilsul'fatazy v nachal'nom periode ostroi ochagovoi ishemii miokarda v éksperimente.

The increase in arylsulphatase activity in the ischemic zone has been shown by histochemical method in progressing acute myocardial ischemia. The increase in the enzyme activity in a so-called "intact" zone was less marked.

[Effect of geomagnetic storms on the state of heart mitochondria and their role in providing energy for myocardial contraction]. / Vliianie geomagnitnoi buri na sostoianie mitokhondrii miokarda i ikh rol' v énergeticheskom obespechenii sokratitel'noi funktsii serdtsa.

The experiments on intact rabbits have shown that geomagnetic storm breaks the relationship between the size of myocardial mitochondria and the degree of cardiac contractility, causes swelling and further destruction of mitochondria. Geomagnetic storm leads to a decline in the left ventricular contractility. The development of geomagnetic storm is associated with a significant strong positive correlation between the size of mitochondria and the blood level of free fatty acids.

[Changes in the myocardial mitochondria in the dynamics of ventricular fibrillation (based on scanning electron microscopic data)]. / Izmeneniia mitokhondrii miokarda v dinamike fibrilliatsii zheludochkov serdtsa (po dannym rastrovoi élektronnoi mikroskopii).

Left ventricle of the rabbit heart was studied in the scanning electron microscope 1,2 and 5 minutes after the heart fibrillation induced by an impulse electrical current. It is found that as long as the fibrillation developed the degree of the structural heterogeneity of the heart muscle increased, the swelling of mitochondria and rough damage of their membranes occurred.

[Nature of the relation between contractile activity indices of the left and right heart ventricles in normal and pathological conditions]. / O kharaktere sviazei mezhdu pokazateliami sokratitel'noi aktivnosti levogo i pravogo zheludochkov serdtsa v norme i pri nekotorykh patologicheskikh sostoianiiakh.

Positive correlations were established between contractile activity of left and right rabbit ventricles in normal conditions, reflecting synchronous activity of both heart ventricles. These correlations could be broken in case of pathology due to disturbances of adaptation mechanisms resulting in the impairment of heart functioning.

[Change in the mitochondria of the left heart ventricle in the intact rabbit during the course of the day (based on scanning electron microscopic data)]. / Izmenenie mitokhondrii levogo zheludochka serdtsa intaktnogo krolika na protiazhenii sutok (po dannym rastrovoi élektronnoi mikroskopii).

The myocardium of the left ventricle of intact rabbit was investigated by scanning electron microscopy during 24 hours, namely at 0, 6 a.m., noon and 6 p.m. It was discovered that the mitochondria reach the maximal volume at 6 p.m. and the minimal at 6 a.m. The qualitative differences in the mitochondria at different periods of the day are described. A correlation was established between the swelling of the mitochondria and some indices of heart function.

[Changes in the contractile activity of the left heart ventricle and blood content of free fatty acids during acute focal myocardial ischemia in rabbits at different times of the day]. / Izmenenie sokratitel'noi aktivnosti levogo zheludochka serdtsa i soderzhaniia svobodnykh zhirnykh kislot v krovi pri ostroi ochagovoi ishemii miokarda u krolikov v raznoe vremia sutok.

Left-ventricular contractility and arterial blood levels of free fatty acids were studied experimentally in rabbits with acute focal myocardial ischemia at different hours of the day (12 a. m., 6 p. m., 12 p. m.). All parameters were measured before a myocardial acute-ischemia focus was created, and 15, 20 and 40 minutes after coronary artery ligation. Heart contractility and blood free fatty acid levels were shown to vary throughout the day. In acute focal myocardial ischemia, these parameters also show different patterns of variation. A relationship was demonstrated between the pattern of changes in some contractility indices under acute focal ischemia and blood baseline levels of free fatty acids, which was particularly manifest at 12 p. m., and grew very weak at 12 a. m.