Parts Of Cardiovascular System Research Articles

PARAMETERS OF CENTRAL AND INTRACARDIAC HAEMODYNAMICS IN WOMEN WITH THYROID HYPERPLASIA AND ACALCULOUS CHOLECYSTITIS.

Aim: The study aimed to investigate some parameters of functional status of central and intracardiac haemodynamics in women with thyroid hyperplasia and acalculous cholecystitis. Materials and Methods: Functional changes of haemodynamic status in women with thyroid hyperplasia and acalculous cholecystitis were investigated. All data are obtained through general and special clinical methods, standard and special laboratory methods of examination, physiological, biochemical and statistical methods. Parameters of central and intracardiac haemodynamics have been recorded by the method of two-dimensional M-mode echocardiography in the echo chamber "Toshiba-140" (Japan) at the resting state. Results: An increase in heart rate (by 45.6%) was observed in patients, which led to decreased duration of cardiac cycle and ejection time. Statistically significant (p<0.05, 11.7% on average) increase in total peripheral vascular resistance was indicated. Dynamics of changes of parameters of central and intracardiac haemodynamics indicates different parallel existing pathways of secondary disturbances in the part of cardiovascular system. A significant increase in peripheral vascular resistance associated with decreased elasticity (increased vascular rigidity) of the arteries is the element of concentric type of left ventricular hypertrophy. The increase in volume in the absence of vasospastic reactions and increasing venous tone is an element of eccentric hypertrophy. Conclusions: It is possible to talk about the presence of systolic dysfunction in patients, which, however, is predominantly of functional character. The revealed specific changes in homeostatic haemodynamic characteristics in the women's body with thyroid hyperplasia and acalculous cholecystitis require the development of new, more effective and preferably drug-free (due to liver pathology and detoxification dysfunction) approaches to medical treatment of such patients.

Spatially averaged haemodynamic models for different parts of cardiovascular system

AbstractThis paper revisits the usage of spatially averaged haemodynamic models such as non-stationary 1D/0D in space and stationary 0D in space models. Conditions of equivalence between different 1D model formulations are considered. The impact of circular and elliptic shapes of the tube cross-section on the friction term and the tube law is analyzed. Finally, the relationship between 0D lumped and 1D models is revealed.

Physical principles of venous hemodynamics and its mathematical modeling

In physiological conditions, the cardiovascular system (CVS) is a closed circulatory system comprising a pump (the heart), a conduit system (vasculature), and a continuum media (blood) moving through the system. The heart is a major source of energy in this system. It pumps the blood through the two connected loops. From the mechanical point of view, CVS can be represented as a network of flexible tubes filled with a viscous incompressible fluid driven by a periodic energy source. The fluid dynamics are described by Navier-Stokes's equations, representing the fundamental physical principles of mass and momentum conservation. These equations allow computation of the blood velocity field and pressure depending on the forces exerted to the fluid's surface (surface forces) and to a unit portion of the fluid (mass forces). Equations of structural dynamics describe the motion of the vascular wall. The state-of-the-art models incorporate fluid and structure interaction (FSI). The blood flow in various parts of CVS has different features that must be considered during computational simulations. Elastic properties of the veins and arteries are different. The structural features of veins (valves) limit the backward flow. The geometry of venous cross-sections may be circular, elliptic, and dumbbell-shaped. It changes the flow characteristics. Blood rheology plays a significant role in venous flows. According to the mass conservation law, the work of the heart pump provides energy for the arterial flow and determines venous return to the heart atria. Venous hemodynamics comprises a lot of various processes with different physical and biological origins. Complex analysis of a patient requires computational simulations, which provide medical experts with a basis for prognosis and optimal surgical treatment. In this work, we review basic physical principles and modern mathematical models of venous hemodynamics. In conclusion, the blood flow in veins can be considered as a mechanical process. It obeys the fundamental physical principles and can be described by the well-known mathematical models of continuum mechanics. Thus, the flow characteristics can be simulated and predicted in various healthy and pathological conditions basing on the boundary conditions and material properties of the blood and veins.

Cardiac Compression Devices: Alternative Technology and Innovative Concept

: Heart failure is a leading cause of death around the world. Heart transplantation is the only reliable therapy for improving functional capacity, quality of life, life expectancy, and limiting the options for heart failure patients. In fact, a large number of patients with severe heart failure in need of heart transplantation are unable to receive therapy with up to 30% mortality before a heart is donated. In recent decades, cardiac replacement and assisting therapies have presented promising outcomes to treat these end-stage patients as alternative solutions. These devices are capable of providing temporary to permanent, partial or full assistance. Such devices can be divided into two categories based on location and mechanism of augmentation: 1) devices exposed directly to blood including ventricular assistive devices (VADs) and total artificial hearts (TAHs) and 2) devices that augment cardiac output through compression of ventricles or another part of circulatory system with no direct contact to blood such as extra-cardiac compression devices (ECCDs). In recent years, novel ECCDs which compress tissue and muscles to indirectly assist blood pumping have been developed to circumscribe problems associated with blood-contacting devices and the risks involved with piercing arterial and ventricular walls. Not only do ECCDs aim to reduce risks from the patient and surgeon perspective, the complexity of engineering an intra-corporeal extra-cardiac device is also reduced.

New Physiological Vessel’s Quality: Biomechanical Study—Brain Veins

The study of biomechanical characters of vessels a them modeling cause the new information about behavior this anatomical structures. Recently discovered vessel quality, angiosynizesis, and self-excitation wall vessel vibration have an influence on behavior understand part of cardiovascular system. Recently discovered biomechanical vessel duality have an influence on physiology and pathophysiology vessel system in different anatomical systems of body, for example, central nervous system area. We study physiological aspects in hemodynamic regulation, pathophysiological problems. Very small exchange of length (∼1%) about bridging brain veins can go to angiosynizesis, vibration of vessel wall during physiological state, facility beginning of angiosynizesis by propagation pulsing pressure wave, structural stability of bridging veins can be restore by adequate rise in pressure in given moment. The function of flow in thin wall venous system of brain is combination of angiosynizesis and “pulsing venous pump” of cavernous sinus, which follow into venous system pulsing flow.

A. facialis in ground squirrel (Citellus itellus)

A ground squirrel is a hibernator, which hibernation lasts, depending on the age and sex, since the end of the summer until the spring. During this period in the body of ground squirrel, as well as in other hibernators, starts lowering of all vital functions, what has been proven by numerous physiological, biochemical and histological examinations of some organ systems of this animal. The objective of our work was to investigate a part of cardiovascular system of ground squirrel so in that way to contribute to a better knowledge of this animal body structure and accordingly to comparative anatomy in general. The investigation included 6 ground squirrels, of both gender, body weight 200-300 grams. For obtaining head and neck arterial vascularization, after exsanguination of the animal, contrast mass of gelatin coloured with tempera was injected into thoracic aorta (Aorta thoracica). After injecting, the blood vessels were prepared and photographed. For obtaining the corrosive preparations of head and neck arterial blood vessels, after exsanguination of the animal, Biocryl (a mixture of liquid biocryl - methil - methacrylate monomer and biocryl in powder - methil - methacrylate polymer) was injected into thoracic aorta (Aorta thoracica). After injecting the preparations were placed into 5% NaOH, for 96 hours or into 10% NaOH for 48 hours. After that they were rinsed in hot water and photographed. A. facialis in ground squirrel is an extension of A. maxillaris. The branches of A. facialis are: A. labialis inferior, A. bursae buccalis dorsalis, A. labialis superior, A. dorsalis nasi and A. angularis oculi. The obtained results regarding A. facialis in ground squirrel (Citellus citellus) were compared to the same ones in rats. In rats, A. facialis is the biggest branch separating from A. carotis externa. The branches of A. facialis in rats are: Ramus glandularis, A. submentalis, A. masseterica ventralis, A. labialis inferior, A. angularis oris, A. labialis superior, Rami musculares, A. lateralis nasi and A. angularis oculi. Based on the above mentioned results, it can be concluded that both in ground squirrel and rat A. facialis branches into A. labialis inferior, A. labialis superior and A. angularis oculi. In ground squirrel the branches of A. facialis are also A. bursae buccalis dorsalis and A. dorsalis nasi, and in rat those are Ramus glandularis, A. submentalis, A. masseterica ventralis, A. angularis oris, Rami musculares and A. lateralis nasi.

A. Hepatica in European ground squirrel (Citellus Citellus) compared to other experimental animals

European ground squirrel is the only representative of its genus in Serbia. It is used as experimental animal in microbioogy, parasitology, pharmacology and immunology. The objective of this work was to investigate a part of cardiovascular system of ground squirrel so in that way to contribute to a better knowledge of this animal body structure and accordingly to comparative anatomy in general. The investigation included 6 ground squirrels, of both gender, body weight 200-300 grams. For obtaining the liver arterial vascularization, after exsanguination of the animal, contrast mass of gelatin coloured with tempera was injected into abdominal aorta (Aorta abdominalis). After injecting, the blood vessels were prepared and photographed. In ground squirrel A. celiaca is odd, larger vessel that exits the abdominal aorta. It is divided into three branches: A. lienalis, A. gastrica sinistra and A. hepatica. A. hepatica is divided into A. hepatica propria and A. gastroduodenalis. A. hepatica propria further gives A. cystica, Rami cardiaci and small branches for Lnn. portales. A. gastroduodenalis is divided into A. pancreaticoduodenalis and A. gastroepiploica dextra. A. celiaca in nutria and rat is an odd artery, divided into A. lienalis, A. gastrica sinistra and A. hepatica. In rabbits, celiac artery (A. celiaca) is divided into A. lienalis and short trunk from which A. gastrica sinistra and A. Hepatica emerge. A. celiaca in golden hamster does not exist in the form of tripus coeliacus (A. lienalis, A. gastrica sinistra and A. hepatica), but from A. celiaca it is firstly separated A. hepatica, and then short trunk from which A. gastrica sinistra and A. Lienalis emerge. In guinea-pig, from abdominal aorta a joint tree branches off into A. celiaca and A. mesenterica cranialis (Truncus celiacomesentericus). Based on the above mentioned results, it can be concluded that A. celiaca in European ground squirrel, nutria and rat branches from abdominal aorta as a separate blood vessel. In these animals A. celiaca branches are: A. lienalis, A. gastrica sinistra and A. hepatica. &lt;br&gt;&lt;br&gt;&lt;font color="red"&gt;&lt;b&gt; This article has been corrected. Link to the correction &lt;u&gt;&lt;a href="http://dx.doi.org/10.2298/VETGL1702141E"&gt;10.2298/VETGL1702141E&lt;/a&gt;&lt;u&gt;&lt;/b&gt;&lt;/font&gt;

Label-free optical imaging of lymphatic vessels within tissue beds in vivo.

Lymphatic vessels are a part of circulatory system in vertebrates that maintain tissue fluid homeostasis and drain excess fluid and large cells that cannot easily find their way back into venous system. Due to the lack of non-invasive monitoring tools, lymphatic vessels are known as forgotten circulation. However, lymphatic system plays an important role in diseases such as cancer and inflammatory conditions. In this paper, we start to briefly review the current existing methods for imaging lymphatic vessels, mostly involving dye/targeting cell injection. We then show the capability of optical coherence tomography (OCT) for label-free non-invasive in vivo imaging of lymph vessels and nodes. One of the advantages of using OCT over other imaging modalities is its ability to assess label-free blood flow perfusion that can be simultaneously observed along with lymphatic vessels for imaging the microcirculatory system within tissue beds. Imaging the microcirculatory system including blood and lymphatic vessels can be utilized for imaging and better understanding pathologic mechanisms and treatment technique development in some critical diseases such as inflammation, malignant cancer angiogenesis and metastasis.

Are Primo Vessels (PVs) on the Surface of Gastrointestine Involved in Regulation of Gastric Motility Induced by Stimulating Acupoints ST36 or CV12?

Previous studies showed primo vessels (PVs), which were referred to as Bonhan ducts (BHDs) and a part of circulatory system by Kim, located in different places of the body. The BHDs system was once considered as the anatomical basis of classical acupuncture meridian but not clearly identified by other investigators. In the present study, we tried to address the relationship between PVs and meridians through detecting the modulation of gastric motility by stimulating the PVs on the surface of stomach or intestine, as well as acupoints Zusanli (ST36) and Zhongwan (CV12). The results showed electric stimulation of the PVs had no effect on the gastric motility. While stimulating CV12 inhibited gastric motility significantly in PVs-intact and PVs-cut rats, there is no significant difference between the inhibition rate of the PVS-intact and the PVS-cut rats. Stimulating at ST36 increased gastric motility significantly in both the PVs-intact and the PVs-cut rats, yet there was no significant difference between the facilitation rate of the both groups. Taken together, the PVs on the surface of stomach or intestine did not mediate the regulation of gastric motility induced by stimulating at the acupoints ST36 or CV12.

Science Review: Vasopressin and the cardiovascular system part 2 – clinical physiology

Vasopressin is emerging as a rational therapy for vasodilatory shock states. In part 1 of the review we discussed the structure and function of the various vasopressin receptors. In part 2 we discuss vascular smooth muscle contraction pathways with an emphasis on the effects of vasopressin on ATP-sensitive K+ channels, nitric oxide pathways, and interaction with adrenergic agents. We explore the complex and contradictory studies of vasopressin on cardiac inotropy and coronary vascular tone. Finally, we summarize the clinical studies of vasopressin in shock states, which to date have been relatively small and have focused on physiologic outcomes. Because of potential adverse effects of vasopressin, clinical use of vasopressin in vasodilatory shock should await a randomized controlled trial of the effect of vasopressin's effect on outcomes such as organ failure and mortality.

Science review: Vasopressin and the cardiovascular system part 1--receptor physiology.

Vasopressin is emerging as a rational therapy for vasodilatory shock states. Unlike other vasoconstrictor agents, vasopressin also has vasodilatory properties. The goal of the present review is to explore the vascular actions of vasopressin. In part 1 of the review we discuss structure, signaling pathways, and tissue distributions of the classic vasopressin receptors, namely V1 vascular, V2 renal, V3 pituitary and oxytocin receptors, and the P2 class of purinoreceptors. Knowledge of the function and distribution of vasopressin receptors is key to understanding the seemingly contradictory actions of vasopressin on the vascular system. In part 2 of the review we discuss the effects of vasopressin on vascular smooth muscle and the heart, and we summarize clinical studies of vasopressin in shock states.

Mental stress and the cardiovascular system part V. Chrome mental stress and cardiovascular disease: Job stress

Parameters of job stress include degree of job control and magnitude of psychological stress. These occupational characteristics may be multiplicative when low job control coexists with high psychological stress. Cardiovascular entities adversely affected by these two occupational characteristics (either alone or in combination) include hypertension, diastolic blood pressure, and coronary artery disease. Some studies challenge these hypotheses. Organism behavior may depend on both stimulus and individual capacity. Individual differences in emotional reactivity and defensiveness may relate to tension arousal and cardiovascular response to work. Enhanced tension arousal and adverse cardiovascular response may contribute to the origin and/or course of coronary artery disease. Definitive description of the relationship between job stress and cardiovascular disease awaits further large-scale studies. The influence of socioeconomic status may need to be considered to reach final resolution of this controversy. Clinicians need not wait until investigators have resolved all the controversies surrounding the relationship between job control and coronary heart disease before intervening. Behavioral strategies offer more long-term promise than simple pharmacotherapy.

Mental Stress and the Cardiovascular System Part IV. Chronic Mental Stress and Cardiovascular Disease: Depression and Anxiety

In this portion of our series on mental stress and the cardiovascular system, we review the roles that depression and anxiety play in the development, progression, and outcome of coronary artery disease. Depression, in the immediate post-myocardial infarction period, is an important risk factor for subsequent unfavorable cardiac events during the 1- or 2-year period following infarction. In long-term follow-up, preliminary findings suggest that depressive symptoms identify subjects at increased risk for coronary heart disease. Epidemiologic evidence is lacking to demonstrate that patients with anxiety-related psychiatric illness have a higher prevalence of cardiovascular disease than their less anxious counterparts. Depression and anxiety, of course, warrant treatment independent of their impact on coronary artery disease. Also, aspects of these psychiatric illnesses may mimic clinical features of coronary artery disease or may develop following the clinical manifestations of coronary artery disease.

Mental stress and the cardiovascular system part III. chronic mental stress and cardiovascular disease: personality and behavior

In this portion of our review of mental stress and the cardiovascular system, we focus on type A behavior and hostility as a component of that behavior. For more than 30 years, clinicians and investigators have studied the relationship between behavior and cardiovascular disease. Despite these efforts, evidence remains divided on whether specific behavioral patterns adversely impact on the development, progression, and outcome of cardiovascular disease. The cardiovascular response to earthquakes in subjects with preexisting coronary artery disease provides a particularly useful model with which to study stress-induced cardiovascular changes in vulnerable patients. Even though no preponderance of evidence links behavioral patterns with cardiovascular disease, we hope that medical professionals will provide their patients with general guidelines to reduce mental stress derived from adverse behavioral patterns and personality trait hostility. Stress reduction usually promotes mental health, yields a greater capacity to live a healthy life, and helps patients comply with somatic and nonsomatic treatments of their cardiovascular illnesses.

Mental stress and the cardiovascular system part II: Acute mental stress and cardiovascular disease

As in normal subjects, acute mental stress increases blood pressure measurements (sometimes to hypertensive levels) in subjects with cardiovascular disease. We found examples in the literature of acute mental stress increasing peripheral vascular resistance (as in isometric exercise) in patients with cardiovascular disease. We did not, however, find examples of acute mental stress decreasing peripheral vascular resistance (as in isotonic exercise) in subjects with cardiovascular disease. Acute mental stress commonly increases heart rate in subjects with cardiovascular disease. Angina pectoris or other evidence of ischemia may accompany this increase in heart rate. Acute mental stress may alter cardiac electrical stability and lead to arrhythmias—some life-threatening. Acute mental stress may provoke coronary artery vasoconstriction, reduce left ventricular ejection fraction, or induce or exacerbate left ventricular wall motion abnormalities in subjects with cardiovascular disease. In particular, anger among subjects with cardiovascular disease may leave them vulnerable to cardiac complications.

Mental stress and the cardiovascular system part I: Cardiovascular response to acute mental stress in normal subjects

In normal subjects, acute mental stress may alter baseline cardiovascular parameters. During this stimulation, blood pressure and heart rate commonly increase. Changes in peripheral vascular resistance are variable. Parameter responses during acute mental stress may be incorporated in the model of isotonic (dynamic or volume) exercise with increased blood pressure and decreased peripheral vascular resistance or in the model of isometric (static or pressure) exercise with increased blood pressure and increased peripheral vascular resistance. Sustained isotonic exercise such as jogging or swimming is generally considered healthful. In contrast, sustained isometric exercise such as weight lifting or snow shoveling is generally not considered healthful. Measuring peripheral vascular resistance may be important in distinguishing between healthful and unhealthful activities. In normal subjects, acute mental stress may also alter heart rate, double product (blood pressure × heart rate), cardiac output, stroke volume, forearm blood flow, left ventricular ejection fraction, and cardiac microcirculation. Studies in normal subjects have identified relationships between hostility and increased arousal, and blood pressure and heart rate increases. Failure to measure peripheral vascular resistance in these studies confounds full interpretation of the findings.

Pattern of distribution of dopamine-.BETA.-hydroxylase activity in normal subjects and in patients with mitral stenosis or left to right shunts.

Eighteen patients with mitral stenosis and twelve patients with left-to-right shunts heart disease and six normal subjects were catheterized and plasma dopamine-β-hydroxylase (DBH) activities in various parts of cardiovascular system were measured in order to assess the role of sympathetic activity in pulmonary hypertension. Arteriovenous differences of DBH activities were positive in normal subjects and patients with normal pulmonary artery pressure. A negative difference was found in patients with pulmonary hypertension. DBH activity in patients with pulmonary hypertension was significantly elevated compared with that of normal subjects. There was a weak correlation between mean pulmonary artery pressure and DBH activity in pulmonary artery. There were significant differences between normal, mitral stenosis with pulmonary hypertension and left-to-right shunts heart diseases about the pattern of distribution of DBH activity among these groups. A significant difference of the distribution between mitral stenosis with normal pulmonary artery pressure and that with pulmonary hypertension was also found. These findings suggested that a prolonged, increased level of sympathetic nervous system activity among patients with mitral stenosis and left-to-right shunt heart disease developed pulmonary hypertension. Thus, a significant contribution of sympathetic nervous activity to the establishment of pulmonary hypertension was suggested.