Features of the Left Ventricular Functional Geometry in Patients with Myocardial Diseases with Varying Degrees of Systolic Dysfunction.

We revealed some features of the left ventricular functional geometry in patients with myocardial diseases with different degrees of left ventricular systolic dysfunction. A negative correlation was found between the spatio-temporal heterogeneity of the kinetics of the left ventricular wall during systole and ejection fraction in normal heart and in systolic dysfunction. The differences in the quantitative characteristics of the functional geometry between patients and normal subjects and between different groups of patients depended on the severityof left-ventricular systolic dysfunction. In particular, spatial heterogeneity index that characterizes heterogeneity of systolic movement of the wall segments and end-systolic Fourier shape-power index characterizing complexity of the left ventricle shape during systole differed significantly in the examined groups of patients and have the greatest diagnostic power.

[Ultrasound markers of the genetic pathology and early hemodynamic changes in human embryo].

First trimester nuchal translucency (NT) and ductus venosus reverse blood flow (DVRBF) are used as ultrasound markers (UM) to determine the risk of fetal aneuploidy, heart defects and subsequent maternal preeclampsia. One pathophysiological explanation for these UM, encompassing both normal and pathological outcomes, is the development of transient heart failure due to increased vascular resistance (afterload). Left ventricular isovolumic relaxation time (LV IRT) was demonstrated as sensitive index of afterload increase in the second and third trimester fetus. The objective of study was to determine LV IRT in normally developing embryos and embryos with early UM of chromosomal and cardiac abnormalities and to test the hypothesis of embryonic hypertension as a cause of transient heart failure. An ultrasound study in 122 normally developing and 27 human embryos with increased NT (>3 mm) and DVRBF at gestational ages 11-14 weeks was perfomed. Mean LV IRT (41 +/- 3 ms) was 36.6 percent longer in embryos with UM as compared to the normal subset (30 +/- 2 ms) (p < 0.001).

[Perinantal programming of arterial hypertension in child].

There is a growing number of evidence linking fetal intrauterine malnutrition, other adverse events or exposures and arterial hypertension during the following life. After important epidemiological studiesfrom many countries, research now focuses on mechanisms of organ dysfunction and on refining the understanding of the interaction between common elements ofadverse perinatal conditions and normal development. This review focused on advances in comprehension of the influence of intrauterine malnutrition on developmental programming of hypertension. Significant decrease in nephrons number was demonstrated as a result of fetal asymmetrical growth restriction syndrome both in human and experimental animal model. The role of malnutrition and dexametasone induced rennin-angiotensin system inhibition in fetal and newborn nephrogenesis is discussed. Recent studies have revealed important mechanisms of altered vascular function and structure as well as sympathetic regulation of the cardiovascular system in perinatal hypertension models. Some of adverse effects on nephrogenesis and blood pressure regulation could be reversed by special diet and treatment during first two years of life. While the complexity of the interactions between antenatal and postnatal influences on blood pressure is increasingly recognized, the importance of early postnatal life in modulating developmental programming offers the hope of a critical 1000 days window of opportunity to reverse programming and prevent or reduce child hypertension.

[The intrauterine programming of adult and children's disesases].

The intrauterine programming hypothesis proposed that cardiovascular and metabolic disease originate through developmental plasticity and fetal adaptation arising from failure of the materno-placental supply of nutrients. The hypothesis is supported by experimental data in animals indicating that maternal nutrition can program long term effects on the offspring. The intrauterine conditions in which the fetus develops have an important role in regulating the function of its physiological systems later in life. Intrauterine programming of physiological systems occurs at the gene, cell, tissue, organ, and system levels and causes permanent structural and functional changes, which can lead to overt disease, particularly with increasing age. The physiological prevention of disease programming is discussing.

[Experimental-theoretical study of the force-interval relationship in the developing chicken myocardium]. / Eksperimental'no-teoreticheskoe issledovanie sviazi interval-sila v razvivaiushchemsia miokarde tsyplenka.

The force-interval relationship was studied on myocardium preparations from chick embryos and hatched chickens. It is shown that the force-interval relationships of myocardium change during ontogenesis. A negative staircase (a decrease in the isometric force with increasing stimulation rate) in the chick embryo myocardium and a positive steady-state relationship in hatched stage myocardium were revealed. Changes in the force after switching from one stimulation frequency to another, the effects of poststimulation potentiation, as well as responses to the introduction of pauses and extrasystols at a constant stimulation rate were recorded. All the effects observed in the transient processes in preparations from hatched stage myocardium were more pronounced than in embryo myocardium. Our previous mathematical model of calcium recirculation in cardiomyocytes was adapted for simulating the main features of force-interval relationships in embryonal and relatively developed myocardium. The main source of regulatory calcium in the model of hatched stage myocardium is sarcoplasmic reticulum. In the model of embryo myocardium, it was postulated, based on data available in literature, that the main regulator of contractile response of the muscle is calcium that enters cardiomyocytes from extracellular medium. To describe force-interval relationships, by this model, the decreasing dependence of the entry of extracellular calcium on the intervals between stimuli was introduced.

[Effect of paired stimulation on the electrical and mechanical activity of myocardial cells in congenital and acquired heart defects]. / Vliianie parnoi stimuliatsii na élektricheskuiu i mekhanicheskuiu aktivnost' kletok miokarda bol'nykh vrozhdennymi i priobretennymi porokami serdtsa.

Thin myocardial strips were dissected from the papillary muscles of patients undergoing mitral valve replacement (group I) and atrial tissue of patients undergoing the correction of congenital septal defects (group II) and mitral stenosis (group III). Electrical activity and isometric tension were measured. Paired stimulation (PS) with time intervals of 250-350 ms and 380-440 ms activated two action potentials (AP) for each potentiated contraction (80 and 70% of force increase, respectively) in bundles of groups I and III. Strips of group III had depressed level of resting potential (RP) and different types of AP including AP with additional spike activity in the plateau phase. The inotropic effect of PS depends on the level of the resting potential. If RP was more than 45 mv PS activated two AP or one doubled AP for each potentiated contraction (80-120% of force increase). If RP was less than 35 mv PS was not able to initiate doubled AP and to initiate the increase of contractility. Epinephrine (10(-6) g/ml) increased the depressed RP and AP in group III bundles and potentiated the inotropic effect of PS in groups I and III. Verapamil (2 X 10(-6) g/ml) inactivated the doubled AP and abolished the inotropic effect of PS in group III strips. It is supposed that additional inflow of Ca during excitation produces the inotropic effect of paired stimulation in human myocardium.

[Evaluation of ontogenetic changes in the chrono- and inotropic functions of the rat myocardium under a random stimulation regimen]. / Otsenka ontogeneticheskikh izmenenii khronoinotropnoi funktsii miokarda krysy pri sluchainom rezhime stimuliatsii.

The relationships between isometric contractions and duration of interstimulus intervals, which were changed randomly, were assessed in myocardial strips of adult (AR) and newborn rats (NR). The highest coefficients of variation of contractions amplitude were seen in AR and lowest those in preparations of 1-3 day of life NR. The "force-interval" autoregression coefficients were estimated in different Ca2+ concentrations, their differences being due, probably, to ontogenetic changes.

[Myocardial contractility in newborn kittens under a physiologic loading regimen]. / Sokratimost' miokarda novorozhdennykh kotiat v rezhime fiziologicheskogo nagruzheniia.

The angles of ramp of normalized dependences: "strength-velocity" and "terminal systolic length--terminal systolic strength" proved to be lesser under physiological loads in isolated papillary muscles of newborn kitten as compared with adult cats. Adrenaline increased the slope of these dependences up to the values characteristics of the adult cat's myocardium in saline. The data obtained suggest a low level of the calcium activation and ATPase activity of contractile proteins of the myocardium in newborn kitten.

[Mechanism of postextrasystolic potentiation of the myocardium]. / K mekhanizmu postékstrasistolicheskoi potentsiatsii v serdechnoi myshtse.

Combined effects of poststimulation and postextrasystolic potentiation (PESP) were studied in the rat papillary muscles. The constant PESP augmentation of isometric force triggered by extrasystolic stimulus was shown for 2-8 poststimulatory potentiated contractions. The PESP was not dependent upon the Ca2+ concentration within the 0.5-1.2 mM range. The findings corroborate the postulate that the PESP in cardiomyocytes is associated with special Ca2+ store which is triggered by two APs: regular and extrasystolic ones.

[Non-invasive evaluation of systolic and diastolic functions of the left ventricle in newborn infants]. / Neinvazivnaia otsenka sistolicheskoi diastolicheskoi funktsii levogo zheludochka u novorozhdennykh detei, perenesshikh gipoksiiu.

To assess possible changes in myocardial contractile function and relaxation occurring after mild perinatal asphyxia, maximal blood pressure and M-mode echocardiograms should be registered simultaneously in 32 normal term newborns (group 1) and in 22 term asphyxiated newborns (group II). The slope of end-systolic pressure-dimension relation (ESPDR) was used as a reliable index for evaluation of the myocardial contractility. The slope of ESPDR and some indices of ventricular relaxation decreased in newborns from group II. It is suggested that ESPDR and parameters of left ventricular relaxation and filling can serve as early and sensitive indices of hypoxic myocardial damage.

[A spectral analysis of the periodic components in the heart rhythm structure of newborn infants]. / Spektral'nyi analiz periodicheskikh sostavliaiushchikh v strukture serdechnogo ritma novorozhdennykh detei.

Spectral analysis of spontaneous heart rate fluctuations were assessed in 12 healthy newborn infants and in 14 low birth weight newborns. The orthostatic test was performed by the change of newborns posture. High-frequency fluctuations at the respiratory rate were detected in healthy infants and orthostatic reactions of heart rate resembled the same reactions in healthy adults. High-frequency (respiratory) fluctuations were diminished in low-birth weight infants. It is supposed that respiratory fluctuations can be used as a sign of newborn infants well-being and maturation.

[Anesthetics and the developing heart]. / Anestetiki i razvivaiushcheesia serdtse.

Effects of various anesthetics on the myocardium of developing heart are reviewed. Anesthetics suppress myocardial contractility in a fetus and newborn more intensively than in an adult. This is due to immature cell mechanisms regulating cardiomyocyte contractile activity and specific effect of the autonomic nervous system on the heart. It is obvious that the problem of interactions between anesthetics and developing cardiovascular system remains important because of constant introduction of new drugs with new cell and organ effects into practical anesthesiology.

[Hemodynamic status of the mother and fetus in pregnant women with gestosis during abdominal delivery under different anesthesia methods]. / Gemodinamicheskii status materi i ploda u beremennykh s gestozom pri abdominal'nom rodorazreshenii v usloviiakh razlichnykh vidov anesteziologicheskogo posobiia.

Pregnants in the third trimester with medium- and severe gestosis were divided into 3 groups according to types of maternal and fetal hemodynamics: 1) controls (n = 58 pts); 2) eukinetic type (n = 54 pts); and 3) hypokinetic type (n = 55 pts). Each group was subdivided into 3 subgroups according to administered types of anesthesia for cesarean section (epidural, spinal, and general). Central hemodynamics of the mother, fetus, and fetoplacental complex was studied. Use of different anesthesias in woman with normal pregnancy did not affect the hemodynamics, and therefore any type of anesthesia can be used in cesarean section. In pregnants with gestosis, the eukinetic hemodynamic and compensated or subcompensated placental insufficiency the optimal anesthesia was epidural and spinal. For pregnant with hypokinetic circulation and subcompensated or decompensated placental insufficiency epidural anesthesia is preferable.