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PubMed1989

[Noninvasive imaging methods and angiography in the diagnosis of chronic viscero-visceral arterial collateral circulation in stenosis of the celiac trunk].

Stenosis or even occlusion of truncus coeliacus represents the most frequent cause in the development of collateral blood circulation with caudiocranial flow through extended pancreatic-duodenal arcades. In a group of 32 patients with such mesenteric-coeliacal collateral circulation their arteriographic picture was evaluated. The authors evaluated differences and specific diagnostic contribution of individual visualization methods for demonstration of arteries. The non-invasive visualization methods are of exceptional contribution in the examination of abdominoretroperitoneal region by considerably decreasing the needs of invasive angiographic examination of catheterization technique. This leads to a decrease in the number of diagnosed chronically developed viscerovisceral arterial collateral circulations of various etiologies. Ultrasonography and computer tomography well depicts morphological changes in the aorta diameter as well as unpaired visceral arteries in the segment of their branching. The viscerovisceral arterial collateral circulations, however, may not be detected or at least not to a sufficient degree. They are represented in detail in the whole course only by selective arteriography. The authors draw attention to supplementary role of arteriography within the framework of non-invasive visualization methods.

Adult↗
PubMed1989

Altering local soft-tissue circulation fails to halt venous drainage from the femur.

It has been suggested that tourniquet application proximal to bone biopsy in an extremity can reduce the number of tumor cells spread through circulation. This study investigates the anatomical pathway through which rapid cell spread could occur. Radioactively labeled 15-mu microspheres were injected into the medullary canal of rat femurs. The ratio of injected particles found in the femur was compared among groups that received application of a tourniquet prior to injection, no tourniquet, or transection of all soft tissue proximal to the injection site. Obliteration of circulation in the soft tissue surrounding the femur with a tourniquet or tissue transection did not alter the spread of particles from the femur. The pulmonary circulation trapped approximately 95% of particles reaching the lungs, limiting their access to peripheral arterial circulation. If the number of particles injected into the femur was increased, the number of particles leaving the femur increased at an even greater rate. These data suggest that (1) a particle can exit the femur without traveling through the soft tissue surrounding the femur; (2) most particles that reach the lung are retained; and (3) the injected bone acts as a sponge, retaining some particles and permitting the rest to enter the venous drainage.

Animals↗
PubMed1987

[Doppler examination of the umbilical and cerebral arterial circulation of the fetus].

Umbilical circulation can be explored by Doppler ultrasound methods very easily. The umbilical arteries spectrum provides information on the placental circulation. The diastolic flow is directly related to the vascular resistances of the placenta (Rp). In cases of pathological pregnancies with hypertension the decrease in the diastolic flow and the increase in the resistance index Rp have been correlated with intra-uterine fetal growth retardation. The specificity of this index Rp is of 95% but the sensitivity much more lower (approximately 70%). For that reason Doppler assessment of the fetal circulation in other areas has been recently carried out. Fetal cerebral arteries have been explored during normal pregnancies. The index of cerebral resistances as defined by Pourcelot Rc = S-D divided by S (with S systolic amplitude and D diastolic amplitude) show similar variations to the placental index but later in the pregnancy. During the pregnancy the cerebral index is higher than the placental one and the cerebro placental ratio (CPR) superior to 1. During pathological pregnancy (hypertension) with fetal growth retardation one of the index Rc or Rp may be out of the normal range but the cerebro placental ratio CPR is always lower than 1. The follow up of both the umbilical and cerebral circulation increases notably the accuracy of the Doppler method for the detection of intra-uterine fetal growth retardation.

Cerebrovascular Circulation↗
PubMed1986

The effects of +Gz on the coronary circulation: a review.

The exposure of the human body to +Gz acceleration produces dramatic effects on the cardiovascular system. For example, during +Gz stress, heart rate has been reported to increase in excess of 200 b . min-1 and left ventricular pressure has been estimated to reach 300 mm Hg. Several reviews have dealt with the overall effects of +Gz stress on the cardiovascular system. However, none of these reviews has dealt specifically with the effects of +Gz on the coronary circulation and on the ability of the coronary circulation to maintain adequate perfusion of the heart. A common misconception exists within the aeromedical community that coronary blood flow must be compromised during +Gz due to the high heart rates and stress levels encountered during +Gz exposures. The purpose of this review is to deal with this issue by reviewing available information about basic coronary physiology, acceleration physiology, and their interaction. The current state of our understanding of basic coronary function will first be summarized. Serious students of coronary physiology are referred to other reviews for more detailed discussion. The current understanding of normal coronary function will then be integrated with the available information about the effects of +Gz on the heart and coronary circulation. Finally, potential chronic effects of +Gz and its interrelationships with cardiac and cardiovascular pathology in relation to the coronary circulation will be briefly considered.

Acceleration↗
PubMed1986

[Clinical study of serum enzyme and metabolic changes after extracorporeal circulation--comparison with the surgery of aortic aneurysm].

The changes of serum enzyme and metabolism were studied by comparing the serial change among three groups. The first group consisted of twenty seven patients treated by surgery under extracorporeal circulation. The second group of ten patients of thoracic aortic aneurysm treated under temporary bypass and the third group of nineteen patients of abdominal aortic aneurysm under aortic cross clamp. The following results were obtained: The enzyme of serum GOT, LDH and CPK increased postoperatively in the all groups, the changes after surgery being greater in the group 1 than the other groups. The metabolism of lactic acid and glycolipid was depressed in the group 1 higher than the other groups. The tissue injury of total body after surgery with extracorporeal circulation was greater than the other groups without extracorporeal circulation. And these results suggest the necessary of improvement of circuit and perfusion technique of extracorporeal circulation.

Alanine Transaminase↗
PubMed1985

[Role of pulmonary air embolism in the etiology of cerebral, cardiac and pulmonary complications after operations with artificial blood circulation].

Possible penetration of a considerable volume of air into the lesser circulation when opening the right auricle of the working heart was shown in experiments in 21 dogs. It resulted in blockade of the blood flow along the lesser circulation with a pronounced hemodynamic disturbance, pulmonary edema and penetration of air into the greater circulation vessels and possible embolisation of the latter. The experimental data have confirmed the role of air embolism of lungs in genesis of some cerebral, cardiac and pulmonary complications after operations on the open heart with the artificial blood circulation.

Animals↗
PubMed1979

[Morphogenesis of experimental emphysema induced by different circulation disorders in the lungs].

Pulmonary emphysema was reproduced in 126 rabbits by disorders of circulation in the pulmonary artery system with the development of pre- and postcapillary hypertension and hypovolemia of pulmonary circulation. Under conditions of pulmonary circulation hypertension changes in the lungs initially are of the compensatory-hypertrophic nature: hyperplasia and distention of capillaries, myoelastosis of respiratory bronchioles and closing plates of alveoli, hypertrophy of the muscle wall of arteries and veins. At later intervals (4--12 months), processes of atrophy, sclerosis and inflation develop in the lungs; changes in the lungs acquire the nature of emphysema. Anemia, parenchymal atrophy, sclerosis and inflation develop in the lungs due to a considerable reduction of circulation.

Animals↗
PubMed1970

Ascaris suum infection in calves. II. Circulating and marrow eosinophil responses.

An increment in the number of circulating eosinophils occurred between the 11th and 14th days after infection with Ascaris suum and this increase was generally greater after a challenge infection. Continual infection with small numbers of A. suum eggs over prolonged periods resulted in circulating eosinophil levels which fluctuated and were dose-dependent. The per cent marrow eosinophils always increased after a primary infection and a greater increase usually followed a challenge infection. The maximum increment of marrow eosinophils occurred between the tenth and 12th days and preceded the rise in circulating eosinophils by 36 hours. Antihistamine therapy did not alter eosinophil responses to A. suum. Circulating eosinophilia was not usually reflected by drastic changes in differential white cell counts. However, an increase in total white cell count often followed infection with A. suum and frequently parallelled changes in eosinophil counts. Hemoglobin and P.C.V. values remained within normal limits in A. summ infected calves.

Age Factors↗
PubMed1980

[Physiological basis of fetal and neonatal circulation].

The extremely reduced nature of the pulmonary circulation, the parallel arrangement of the right and left sides of the heart, and the mixture of oxygenated umbilical blood with the rest of the venous return in the right atrium endow the foetal circulation with its "relatively protected" nature. Thus the majority of cardiac and pulmonary malformations have no effect or cause only minor circulatory disturbances. The transfer of respiratory function from the placenta to the lungs which becomes necessary as soon as the cord is clamped is a highly disturbing event. The pulmonary circulation must be established, the communications of foetal life close (Botal's foramen, ductus arteriosus), and the right and left heart function in series. Such adaptations, certain of which are essential to immediate survival, may require several weeks before completion. Any disease in the newborn, congenital or acquired, respiratory, circulatory, metabolic or other, is accompanied by numerous interwoven consequences. In particular, return to a foetal type circulation by increase or absence of pulmonary resistances could induce a right-left shunt through a fossa ovale which is only asking to open, or even through a ductus arteriosus which is only asking to reopen. Congenital diaphragmatic hernia is no exception is no exception to this rule.

Blood Circulation↗
PubMed1984

[Indicators of spiroveloergometry and the sympathetic-adrenal system in patients with exertion-induced angina pectoris with different types of circulation].

The response of the cardiorespiratory and sympathoadrenal (SA) systems to exercise in coronary heart disease patients was found to depend on the hemodynamic type of circulation and the initial activity of the SA system. In patients with the hyperkinetic type of the circulation showing a high initial activity of the SA system and the absence of its response to exercise, the authors observed an increased consumption of oxygen both at rest and during mild exercise which indicated that oxygen expenditure in these patients was ineffective, and subsequently led to a reduction in their capacity to do physical work. Patients with the hypokinetic circulation type and an initially low activity of the SA system exhibited a considerable elevation in the activity of the hormonal component of the SA system during exercise. The maximum oxygen consumption during exercise in these patients was significantly lower than in patients with other types of the blood circulation.

Adrenal Glands↗
PubMed1983

Use of a subpulmonary ventricular chamber in the Fontan circulation.

In order to study the usefulness of incorporating a subpulmonary ventricular chamber (SPVC) in the Fontan circulation, we compared the hemodynamics of 18 patients who underwent an atriopulmonary connection with those of 17 patients with an atrioventricular connection. Early postoperatively, regardless of whether an SPVC was incorporated or not, the mean pulmonary artery pressure was not higher than the mean right atrial pressure in any of our patients. The stroke work of the right heart was at best zero, and pressure tracings showed an a wave in the pulmonary artery (right atrium-dependent circulation). If an additional gradient was interposed between the right atrium and pulmonary artery, the effective stroke work of the right heart might be negative and the work curve have a negative slope. This can occur irrespective of the use of an SPVC. In the long term, if it grows sufficiently, an SPVC can sometimes provide a right ventricle-dependent pulmonary circulation with a more normal hemodynamic pattern (mean right atrial pressure less than mean pulmonary artery pressure). We concluded that an SPVC should be used in Fontan's circulation, provided that an obstruction-free atrioventricular connection can be established.

Adolescent↗
PubMed1983

[Hemodynamic relations between systemic and pulmonary circulation in hypertension].

Central and pulmonary circulation was studied in 111 patients with essential hypertension, stages I, IIa, IIb, using radio- and polycardiographic techniques. Pulmonary circulation changes associated with output hypertension were manifested in increased systolic pressure in the pulmonary artery and vascular volume of the lungs with increased venous return, and high blood flow rate combined with relatively normal pulmonary vascular resistance (total pulmonary resistance). Decreased cardiac output in vasoconstrictive pressor mechanism results from high total pulmonary resistance and reduced venous return, in addition to high peripheral resistance. Pulmonary hemodynamic changes were particularly pronounced in patients with normokinetic circulation. A quantitative assessment of relationships between major parameters of systemic and pulmonary circulation brought out close functional bonds within one circulatory variant. The findings obtained revealed similar patterns in the mechanisms of systemic and regional pressure formation in essential hypertension.

Adolescent↗
PubMedDate not supplied

[Feasibility of increasing the high-speed response of the electromechanical drive in assisted circulation devices].

The conditions in assisted circulation, especially with ballooned aorta, place high demands on the speed of the intraortal pump-balloon response. The salient feature of the described assisted circulation unit consists in that the intraortal pump-balloon is connected to the pneumotract via a commutative air-operated valve. A block diagram of the assisted circulation unit "Biopulso-4" based on the use of the electric drive, designed at the All-Union Scientific-Research Institute of Medical Equipment and Instruments, stress diagrams and a scheme explaining the operation of the apparatus, are described. The results obtained show the possibility of the balloon's resetting and opening in 70 ms, with the triggering synchronous pulse delay of 10 ms prior to response (with air use as power gas). These results are not any worse than those obtained with the pneumatic drive-based assisted circulation apparatus.

Assisted Circulation↗
PubMed1981

Assisted circulation by phasic external lower body compression.

Assistance to the systemic venous circulation after experimental acute bypass of the right heart was provided by phasic external compression of the body. Pressure to 60 mm Hg administered to the body below the costal margin at 6--8 cycles/min augmented the circulation by translocation of blood volume from the peripheral to the central circulation, which increased right atrial pressure by 44%, mean cardiac index (61 to 74 m/kg/min) and mean arterial pressure (79 to 100 mm Hg) by 21%. The experimental study was followed by clinical trial of this method of circulatory support after anastomosis of the right atrium to the pulmonary artery (Fontan operations) in nine patients. One-minute cycles of phasic external compression of 45--50 mm Hg for 45 seconds followed by decompression for 15 seconds in patients increased right atrial pressure by 44% (mean increase 7 mm Hg) and systolic arterial pressure by 30% (average 20 mm Hg, range 13--28 mm Hg). Only two patients required inotropic medications; the others received either no medications or nitroprusside during the first 24 hours after surgery. Phasic external compression of the lower body is a simple and effective means of assisting the circulation after the Fontan operation.

Adolescent↗
PubMed1981

[The behaviour of the granular alveocytes in chronic pulmonary congestion, pulmonary fibrosis and after extracorporeal circulation (author's transl)].

The granular alveocytes, known to be the site of the production of the surfactant, undergo characteristic changes following chronic pulmonary congestion and the succeeding fibrosis, and after extracorporeal circulation. Congestion is accompanied by cell edema and the breakdown of the lamellar bodies. With fibrosis the cells are shrunken and present with little if any lysosomes. The nuclei are pyknotic or demonstrate karyolysis. Vacuolar degeneration of the lamellar bodies and progressive degeneration of the mitochondria are observed. The extracorporeal circulation damages many granular alveocytes. The degree of damage correlates with the duration of the cardiopulmonary bypass and with the degree of the prepump pathological changes present in the lungs. On the other and the extracorporeal circulation induces in the intact cells enhanced surfactant production, during which the different developmental stages of the lamellar body increasingly accumulate within the cell. In conclusion, pulmonary congestion and fibrosis reduce the activity of the granular alveocytes. The extracorporeal circulation enhances structurally favourable conditions in the granular alveocytes for the increased release of the surfactant in the immediate post-operative phase - a process which could be regarded as an autoregulatory mechanism.

Adult↗
PubMed1981

Quantitative 99mTechnetium cerebral circulation time in brain infarction. Its relation to clinical findings, electroencephalograms and conventional radionuclide studies.

Four circulation time parameters were measured by intravenously injected 99mTechnetium and a gamma camera in 183 patients displaying a unilateral supratentorial brain infarction. The mean values of all the calculated circulation time parameters in the infarcted hemisphere were significantly slower than those of the contralateral hemispheres. The difference between the hemispheres proved a more sensitive parameter than absolute values. Both the quantitative circulation time differences between the hemispheres and the absolute circulation time values showed significant correlations with several clinical findings, e.g. severity of infarction, recovery from infarction, and patient's age. However, quantification gave only a minor addition to the number of the patients with abnormalities detected by routine static and dynamic brain scintigrams. Though the value of the quantitative intravenous 99mTechnetium method in routine clinical work is limited, it provides valuable information on the haemodynamics in brain infarction, e.g. the persistence of measurable asymmetry suggesting decreased function even of non-infarcted parts of the affected hemisphere ("deafferentiation").

Adult↗
PubMed1980

[Noninvasive method of determining the cerebral blood flow circulation rate and its correlations with cardiac minute volume].

A method is suggested for noninvasive determination of the cerebral circulation rate and its correlations with the cardiac output. It is based on the metrological possibilities of tetrapolar rheoencephalography in correlation with chest (transthoracic) rheography. The percentage of cerebral circulation rate in relation to the cardiac output measured by this method (Ic/o) characterizes the direction and value of compensatory blood redistribution in various hemodynamic situations, while the absolute values of cerebral circulation rate (Cm, in millilitres per minute) and their relation to the proper values (Cm. in % of proper values) make it possible to appraise the afficacy of the compensatory shifts in each individual case. The method may gain wide use in the clinic for indirect appraisal of the condition of the cerebral circulation.

Adult↗
PubMed1980

Enterohepatic circulation of l-alpha-acetylmethadol in the rat.

The enterohepatic circulation of the biliary metabolites of l-alpha[3H]acetylmethadol ([3H]LAAM) was studied in rats. Bile was collected for 48 hr from a biliary-cannulated donor rat after s.c. administration of [3H]LAAM. This bile containing tritium-labeled LAAM metabolites was then infused into the small intestine of a recipient rat for 48 hr and the appearance of radioactivity in bile formed in the liver of the recipient rat was monitored. Forty-eight hours after the start of infusion, 40% of the infused radioactivity had been excreted into the bile of the recipient rat, indicating extensive enterohepatic circulation of the biliary metabolites of LAAM. The data indicated that only a small percentage of the infused [3H]LAAM metabolites were present in the systemic circulation at any one time. This was further investigated by comparing the plasma levels of tritium with time and the tissue concentrations at 24 and 48 h after s.c. [3H]LAAM administration in biliary-cannulated and sham-operated control rats. Complete diversion of the bile did not significantly decrease the levels of [3H]LAAM or its metabolites in the systemic pool. These findings tend to minimize the contribution of enterohepatic circulation in the recirculation of active metabolites of LAAM and ultimately in its long duration of opiate-like action.

Animals↗