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We propose that the circulatory impairments produced, in both portal hypertension and liver cirrhosis, to a certain degree resemble those characterizing prenatal life in the fetus. In fact, the left-right circulatory syndrome is common in cirrhotic patients and in the fetus. Thus, in patients with portal hypertension and chronic liver failure, the re-expression of a blood circulation comparable to fetal circulation is associated with the development of similar amniotic functions, i.e., ascites production and placenta functions, and portal vascular enteropathy. Therefore, these re-expressed embryonic functions are extra-embryonic and responsible for prenatal trophism and development.

Evidence suggests that the renin angiotensin system (RAS) may play a role in the pathological splanchnic vasodilatation that leads to a hyperdynamic circulation in cirrhosis. An impaired contractile response to the angiotensin II peptide of the classical RAS system has been described in animal models of cirrhosis and in vivo in cirrhotic subjects. Furthermore, in experimental cirrhosis, the so-called alternate arm of the RAS was found to be upregulated and its effector peptide, angiotensin-(1-7) was shown to attenuate splanchnic vascular tone. The aim of this study was to explore the relevance of these findings to human disease. Omental arteries from cirrhotic and controls subjects were studied in isolation using a wire myograph. Varied protocols to evaluate the vasoactivity of RAS mediators were enacted. The contractile response to angiotensin II was comparable in cirrhotic vs control splanchnic arteries (61 ± 9 vs 68 ± 11% KPSS, respectively). Despite this, however, arterial contractility of the cirrhotic vessels correlated negatively with Child Pugh score (p = 0.0003, r=-0.83) and there was evidence that angiotensin II-induced contractility was increased in early cirrhosis. Angiotensin II-induced contractility was attenuated by angiotensin-(1-7) in cirrhotic and control arteries, however, adrenergic responses were not affected by angiotensin-(1-7). Contractile responses to angiotensin II are preserved in narrow lumen human cirrhotic splanchnic arteries and are comparatively augmented in early disease. Angiotensin-(1-7) had no vasodilatory effect on adrenergic tone, however, attenuated angiotensin II-induced contractility, possibly through an Ang-(1-7)-AT1R interaction, and thus may contribute to pathological vasodilatation in human cirrhosis.

Objective We compared the intraoperative hemodynamic profiles and outcomes of liver transplant (LT) patients receiving preoperative beta-blockers for portal hypertension with those of patients not receiving beta-blockers. Methods Beat-to-beat hemodynamic data were recorded with the use of a lithium dilution cardiac output monitor, including heart rate (HR), cardiac output (CO), cardiac index (CI), systemic vascular resistance (SVR), SVR index, mean arterial pressure, stroke volume (SV), and SV index. Perioperative data included age, sex, etiology of cirrhosis, Model of End-Stage Liver Disease score, warm and cold ischemia times, and intraoperative blood and blood products replacement. Postoperative data included Acute Physiology and Chronic Health Evaluation II score, Intensive Care National Audit and Research Centre (ICNARC) score, length of intensive care unit stay, renal replacement treatment, and mortality. Results After exclusion, 215 patients not receiving and 93 patients receiving beta-blockers for portal hypertension were included. There was no significant difference between groups in demographic data. HR, CO, and CI were significantly lower in the beta-blocker group (P = .0001). Regarding outcomes, the ICNARC score was significantly higher in the beta-blocker group (P Conclusions Preoperative administration of beta-blockers attenuates the hyperdynamic circulation in LT patients; this is clearly seen through a reduction in intraoperative CO, CI, and HR. This decreased hyperdynamic state was not shown to relate to outcomes in any of the variables except for a higher ICNARC score reported in the group treated with beta-blockers.

Pulmonary hypertension is a relatively common phenomenon in patients with hepatic cirrhosis and can appear through various mechanisms. The most characteristic scenario that binds portal and pulmonary hypertension is portopulmonary syndrome. However, hyperdynamic circulation, TIPS placement and heart failure can raise the mean pulmonary artery pressure without increasing the resistances. These conditions are not candidates for treatment with pulmonary vasodilators and require a specific therapy. A correct assessment of hemodynamic, ultrasound and clinical variables enables the differential diagnosis of each situation that produces pulmonary hypertension in patients with cirrhosis.

Acute or chronic insults to the liver are usually followed by a tissue repairing process. Unfortunately, this action, in most cases, is not effective enough to restore the normal hepatic structure and function. Instead, fibrogenesis and regenerative nodules formation ensue, which are relatively nonfunctioning. The common final stage of the process is liver cirrhosis with increased intrahepatic resistance to portal venous blood flow. Throughout the entire course, the extrahepatic circulatory dysfunction, including increased splanchnic blood flow, elevated portal venous blood flow and pressure, decreased splanchnic and peripheral vascular resistance, tachycardia, and increased cardiac output, are noted and denoted as portal hypertension with hyperdynamic circulatory dysfunction. When such a condition is established, patients may suffer from fatal complications such as gastroesophageal variceal hemorrhage, hepatic encephalopathy, or hepatorenal syndrome. The cause of such a circulatory dysfunction is not fully elucidated. Nevertheless, clarification of the pathophysiology definitely contributes to the control of portal hypertension-related complications. Herein, the molecular mechanism of this intriguing disaster is reviewed and discussed.

Portal hypertension is a common clinical syndrome associated with chronic liver diseases, and is characterized by a pathological increase in portal pressure that leads to the formation of portosystemic collaterals resulting in shunting of portal blood into the systemic circulation. The increase in portal pressure is due to an increase in vascular resistance and an elevated portal blood flow. The site of increased resistance is variable, and dependent upon the disease process. The site of relative obstruction may be prehepatic, hepatic, or posthepatic. There are several intrahepatic lesions that lead to increased resistance. Some of these lesions are irreversible, like fibrosis, regenerating nodules, and capillarization of the space of Disse; however, there is a functional component, increased vascular tone, which contributes to increased intrahepatic resistance and is potentially reversible. Another important factor contributing to the increased portal pressure is elevated portal blood flow. Peripheral vasodilatation initiates the classical profile of decreased systemic resistance, expanded plasma volume, elevated splanchnic blood flow, and elevated cardiac index, which characterize the hyperdynamic circulatory state. This hyperdynamic circulation is responsible for various complications of portal hypertension.

Patients with liver disease have multisystem organ dysfunction that leads to physiological perturbations ranging from hyperbilirubinaemia of no clinical consequence to severe coagulopathy and metabolic disarray. Patient-specific risk factors, clinical scoring systems, and surgical procedures stratify perioperative risk for these patients. The anaesthetic management of patients with hepatic dysfunction involves consideration of impaired drug metabolism, hyperdynamic circulation, perioperative hypoxaemia, bleeding, thrombosis, and hepatic encephalopathy.

Cirrhotic cardiomyopathy designates a cardiac dysfunction, which includes reduced cardiac contractility with systolic and diastolic dysfunction, and presence of electrophysiological abnormalities in particular prolongation of the QT interval. Several pathophysiological mechanisms including reduced beta-receptor function seem involved in the autonomic and cardiac dysfunction. Cirrhotic cardiomyopathy can be revealed by tissue Doppler imaging but is best demasked by physical or pharmacological stress. Liver transplantation may revert cardiac dysfunction but surgery and shunt insertion may also aggravate the condition. Moreover, cirrhotic cardiomyopathy may contribute to heart failure after invasive procedures and to development of hepatic nephropathy as part of a cardiorenal syndrome. Whether beta-blockers have a deleterious effect in this clinical situation remains to be settled.

Hepatopulmonary syndrome (HPS) and portopulmonary hypertension (PoPH) are two fascinating and incompletely understood pulmonary vascular conditions seen in the setting of cirrhotic patients. Of the two HPS is more common and is primarily caused by pulmonary vasodilatation resulting in hypoxaemia and hyperdynamic circulation. PoPH is less common and conversely, pulmonary vasoconstriction and vascular remodelling occurs resulting in increased pulmonary vascular resistance. However, both conditions can co-exist and it is usually PoPH which develops in a patient with pre-existing HPS. Although these two pulmonary conditions are not common complications of chronic liver diseases, the treatment options are mainly limited to liver transplantation. Cirrhotic cardiomyopathy is closely related to haemodynamic changes in portal hypertension. The key features are normal cardiac pressures at rest, with reduced ability to compensate for physiological or iatrogenic stresses such as drug therapy or TIPSS. There is no effective therapy and outcomes after liver transplantation are variable.

In patients with liver cirrhosis, albumin is given to improve relative hypovolemia caused by marked splanchnic arteriolar vasodilatation. However, the volume effect of albumin is not predictable and depends also on capillary permeability, hydrostatic pressure and lymphatic ability to re-circulate albumin from interstitium to plasma. In patients with decompensated cirrhosis, the capillary permeability is increased, hydrostatic pressure is higher, and the lymphatics functions are deficient. Hence the albumin molecules are more likely to be extravasated rapidly into the interstitium and are subsequently less likely to be re-circulated back into the plasma. This would not only fail to correct circulating hypovolemia, the purpose for which it is given, but also would favor development of reverse colloid oncotic pressure and fluid movement out of the capillaries leading to development of edema. Thus, anything else which could further increase capillary permeability or hydrostatic pressure in cirrhotic patients might create more problems with albumin infusion. An increased capillary permeability is the hallmark of diabetes mellitus. Furthermore, diabetes mellitus may worsen immunodepression in cirrhotic patients thus increasing the incidence of severe infections which may further have a deleterious effect on hemodynamics and capillary permeability. A diabetic patient with advanced cirrhosis and sepsis usually has markedly increased capillary permeability, high hydrostatic pressure due to hyperdynamic circulation, and compromised lymphatic drainage capacity. Hence, using albumin infusion in them would not only fail to improve relative hypovolemia, but also would deleteriously promote extravascular accumulation of fluid, which might impair the functions of many vital organs. However, the efficacy and safety of albumin infusion in diabetic patients with advanced cirrhosis and sepsis is not known. Such data can have a great clinical implication and would necessitate search of a suitable alternative. Because albumin has relatively smaller molecular weight, synthetic colloids with a higher molecular weight might be effective in conditions of increased capillary permeability.

Cirrhosis is associated with hyperdynamic circulation, which consists of peripheral vasodilatation and increased cardiac output. Peripheral vasodilatation is central to hyperdynamic circulation and portal hypertension in cirrhosis. However, those mechanisms underlying hyperdynamic circulation remain elusive, and are not fully understood. Most of the earlier research and attention have been focused on humoral factor abnormalities. Various gut-derived or locally produced humoral factors such as nitric oxide, endotoxin, endocannabinoids, and others have been implicated as possible mediators of hyperdynamic circulation development in cirrhosis. The associated cardiac dysfunction had been termed “cirrhotic cardiomyopathy (CCM),” which is an entity different from that seen in alcoholic heart muscle disease. Clinically, these patients present with sodium fluid retention, and strain often unmasks the presence of latent heart failure. No specific treatment can yet be recommended, but caution should be used with respect to procedures that may stress the heart such as shunt implantation and liver transplantation. Ultimately, additional research will be necessary to more accurately describe the prevalence, impact, and morbidity and survival rates for CCM, and to identify potential treatments.

The hyperdynamic circulation of cirrhosis participates in the pathophysiology of portal hypertension. P450-dependent epoxyeicosatrienoic acids (EET) are potent vasodilators. We evaluated plasma levels of EETs in cirrhotic patients and the effect of epoxygenase and nitric oxide synthase (NOS) inhibition on skin blood flow, measured by laser Doppler flowmetry, in normal subjects and cirrhotic patients with and without ascites. Free plasma EETs were increased in cirrhotic patients compared to normal subjects, while the ratio between 8,9-, 11,12-, and 14-15-EET was the same. In cirrhotic patients without ascites, skin blood flow was significantly increased compared to normal subjects. In patients with ascites skin blood flow was significantly reduced compared to control subjects and patients without ascites. Inhibition of epoxygenase with miconazole and of NOS with l -NG-Nitroarginine methyl ester ( l -NAME) decreased basal skin flow in normal subjects and in cirrhotic patients, the effect being higher in cirrhotic patients. Miconazole caused a further decrease in flow when administered with l -NAME, both in normal subjects and in cirrhotic patients. In conclusion, EETs participate in the control of peripheral circulation of normal subjects and in the pathophysiology of peripheral vasodilatation of cirrhotic patients with ascites.

BACKGROUND & AIMS: Circulating levels of endotoxin, interleukin (IL)-6, and tumor necrosis factor (TNF)-alpha increase with intestinal bacterial overgrowth and translocation, and are believed to be involved in the pathogenesis of hyperdynamic circulatory syndrome and functional renal failure in patients with advanced cirrhosis. METHODS: We investigated the effects of the antibiotic rifaximin on systemic hemodynamics and renal function in patients with alcohol-related cirrhosis and ascites. We measured mean arterial pressure, cardiac output (CO) by Doppler ultrasound, systemic vascular resistance (as the ratio of mean arterial pressure:CO), plasma rennin activity, levels of plasma aldosterone, the glomerular filtration rate by plasma clearance of technetium-99m-DTPA, natriuresis, levels of plasma endotoxin, and serum levels of IL-6 and TNF-alpha in 13 patients at baseline and after 4 weeks of treatment with rifaximin. RESULTS: Rifaximin treatment significantly reduced CO and significantly increased systemic vascular resistance, in association with a significant decrease in plasma rennin activity. The therapy also significantly increased the glomerular filtration rate and natriuresis while reducing levels of endotoxin, IL-6, and TNF-alpha. CONCLUSIONS: Intestinal decontamination with rifaximin improved systemic hemodynamics and renal function in patients with advanced cirrhosis. Clin Gastroenterol Hepatol

Cirrhosis is a frequent and severe condition, which is the late stage of numerous chronic liver diseases. It is associated with major hemodynamic alterations characteristic of hyperdynamic circulation and with a series of structural, functional, electrophysiological and biological heart abnormalities termed cirrhotic cardiomyopathy. The pathogenesis of this syndrome is multifactorial. It is usually clinically latent or mild, likely because the peripheral vasodilatation significantly reduces the left ventricle afterload. However, sudden changes of hemodynamic state (vascular filling, surgical or transjugular intrahepatic porto-systemic shunts, peritoneo-venous shunts and orthotopic liver transplantation) or myocardial contractility (introduction of beta-blocker therapy) can unmask its presence, and sometimes convert latent to overt heart failure. Cirrhotic cardiomyopathy may also contribute to the pathogenesis of hepatorenal syndrome. This entity has been described recently, and its diagnostic criteria are still under debate. To date, current management recommendations are empirical, nonspecific measures. Recognition of cirrhotic cardiomyopathy depends on a high level of awareness for the presence of this syndrome, particularly in patients with advanced cirrhosis who undergo significant surgical, pharmacological or physiological stresses.

Summary Cirrhotic patients are prone to develop life-threatening complications that require emergency care and ICU admission. They can present specific decompensations related to cirrhosis such as variceal bleeding and hepatorenal syndrome (HRS) or other critical events also observed in the general population such as severe sepsis or septic shock. Clinical management of all these entities requires a specific approach in cirrhosis. Cirrhotic patients have a hyperdynamic circulation with high cardiac output and low systemic vascular resistance in the absence of infection [1,2]. Circulatory dysfunction increases the susceptibility of critically-ill cirrhotic patients to develop multiple organ failure and attenuates vascular reactivity to vasopressor drugs [3]. HRS, a severe functional renal failure occurring in patients with advanced cirrhosis and ascites, is also secondary to this circulatory dysfunction that leads to an extreme renal vasoconstriction [2]. Moreover, hypotensive cirrhotic patients require a carefully balanced replacement of volemia, since overtransfusion increases portal hypertension and the risk of variceal bleeding and undertransfusion causes tissue hypoperfusion which increases the risk of multiple organ failure [4,5]. Cirrhotic patients are also at a high risk for development of other bleeding complications and are more susceptible to nosocomial infections [6,7]. This extreme complexity of critically-ill cirrhotic patients requires a specific medical approach that should be known by general intensivists since it has a negative impact on patient prognosis. This review will focus on the diagnostic approach and treatment strategies currently recommended in the critical care management of patients with cirrhosis.

Ascites is a common complication of liver cirrhosis, occurring in more than 50–60% of the patients within 10 years of the diagnosis. In 5–10% of patients, ascites cannot be mobilized, or its early recurrence cannot be prevented by medical treatment. This condition is known as “refractory ascites”. The use of terlipressin in cirrhotic patients with refractory ascites and normal renal function has not been evaluated. This prospective study was aimed at evaluating whether terlipressin in addition to standard therapy (diuretics plus albumin) might improve the outcome of refractory ascites in cirrhotic patients without HRS. Patients 26 cirrhotic patients with refractory ascites were prospectively enrolled in this study. All the patients had tense (grade 3) ascites, and 10/26 showed also massive peripheral edema. Patients received maximum diuretic treatment plus albumin and terlipressin. Results Complete response was seen in 16/26 patients. The higher response to therapy was seen during the 2nd week of treatment. 6 patients showed a decrease of at least two points in the ascites score. No differences in clinical response to treatment were seen according to the etiology of the disease. Conclusions In conclusion, our study shows a synergistic effect of terlipressin vs treatment with albumin plus diuretics in patients with refractory ascites. One could speculate that albumin might enhance the vasoconstrictive response to terlipressin, thus contributing to counterbalance the negative effects of systemic vasodilation, which characterizes the hyperdynamic circulation of cirrhotic patients.

This review describes the pathogenic mechanisms of blood pressure (BP) regulation and long-term control in thyroid disorders. Variations from the euthyroid status affect virtually all physiological systems but the effects on the cardiovascular system are particularly pronounced. Thyroid disorders induce several hemodynamic changes leading to elevated BP as a consequence of their interaction with endothelial function, vascular reactivity, renal hemodynamic and renin-angiotensin system. However, in thyroid disorders, the regulation of BP and the development and maintenance of variable forms of arterial hypertension (HT) are different. Hyperthyroidism results in an increased endothelium-dependent responsiveness secondary to the shear stress induced by the hyperdynamic circulation, and contributes to reduce vascular resistance. Conversely, hypothyroidism is accompanied by a marked decrease in sensitivity to sympathetic agonists with an increase of peripheral vascular resistance and arterial stiffness. Furthermore in animal models, hypothyroidism reduces the endothelium-dependent and nitric oxide-dependent vasodilatation. HT due to thyroid disorders is usually reversible with achievement of euthyroidism, but in some cases pharmacological treatment for BP control is required. In hyperthyroidism, β-blockers are the first-choice treatment to control BP but when they are contraindicated or not tolerated, ACE-inhibitors or calcium-channel blockers (CCB) are recommended. Hypothyroidism is a typical low rennin HT form showing a better antihypertensive response to CCB and diuretics; indeed in hypothyroidism a low-sodium diet seems further to improve BP control. Randomized clinical trials to compare the efficacy on BP control of the antihypertensive treatment in thyroid disorders are needed.

This prospective, randomized, controlled experimental study examined the effects of the peroxynitrite decomposition catalyst WW-85 on global hemodynamics and regional microvascular blood flow (RMBF) in an established ovine model of septic shock following severe smoke inhalation injury. Twenty-one sheep were randomized into a sham group (no injury), a control group (smoke/sepsis), and a treatment group (smoke/sepsis/WW-85; n = 7 each). WW-85 was administered 1 h after injury as a bolus (0.1 mg/kg), followed by a continuous infusion of 0.02 mg/kg/h RMBF was analyzed using colored microspheres. All control animals developed a hypotensive, hyperdynamic circulation and increased plasma levels of nitrate/-nitrite (NOx). All hemodynamic variables and NOx levels were significantly improved in the treatment group. In visceral organs of controls, blood flow to trachea, ileum, and spleen significantly increased (p < 0.05). Blood flow to kidneys and pancreas significantly decreased (p < 0.05). Treatment with WW-85 stabilized blood flow to ileum, spleen, and kidneys on baseline levels and was significantly improved compared to controls (p < 0.05). Cerebral blood flow deteriorated in controls, but was significantly improved in cerebral cortex, cerebellum, pons, medulla oblongata, and thalamus (p < 0.05) by WW-85. These results provide evidence that WW-85 blocks NO production, thereby improving cardiovascular function and microcirculation.

The hypermetabolic response to severe burn injury is characterized by hyperdynamic circulation, profound metabolic, physiologic, catabolic and immune system derangements. Failure to satisfy overwhelming energy and protein requirements after, and during severe burn injury, results in multi-organ dysfunction, increased susceptibility to infection, and death. Attenuation of the hypermetabolic response by various pharmacologic modalities is emerging as an essential component of the management of severe burn patients. This review focuses on the more recent advances in therapeutic strategies to attenuate the hypermetabolic response and its post-burn associated insulin resistance. Modulation of the response by early excision and grafting of burn wounds, environmental thermoregulation, early and continuous enteral feeding with high protein-high carbohydrate feedings and pharmacologic treatments that stimulate anabolism and oppose catabolism have markedly decreased morbidity in the acute phase post severe burn injury.

Background: The hyperdynamic circulation of hepatic cirrhosis is related to decreased systemic vascular resistance due to arterial vasodilation. Urotensin II plasma levels are increased in cirrhotic patients, and have been suggested to play a role in the pathogenesis of systemic haemodynamic alterations. Aim: To evaluate the relationships between systemic haemodynamics and urotensin II plasma levels. Methods: Thirty-six consecutive in-patients with cirrhosis and no alteration of plasma creatinine, and 20 age- and gender-matched healthy volunteers underwent noninvasive assessment of systemic haemodynamics and measurement of urotensin II plasma levels. Results: In comparison to healthy controls, cirrhotic patients had signs of hyperdynamic circulation and higher plasma urotensin II levels. Plasma urotensin II was neither significantly different amongst patients with different severity of cirrhosis nor between patients with or without ascites. Both in controls and cirrhotic patients no significant correlations were found between parameters of systemic haemodynamics and plasma urotensin II levels. Conclusions: In patients with cirrhosis and hyperdynamic circulation, but with normal serum creatinine, urotensin II is higher than in healthy subjects. However, no correlation with cardiac index or other haemodynamic parameters was observed, indicating that other mechanisms prevail.

Fetal echocardiography was initially used to diagnose structural heart disease, but recent interest has focused on functional assessment. Effects of extracardiac conditions on the cardiac function such as volume overload (in the recipient in twin-twin transfusion syndrome), a hyperdynamic circulation (arterio-venous malformation), cardiac compression (diaphragmatic hernia, lung tumours) and increased placental resistance (intrauterine growth restriction and placental insufficiency) can be studied by ultrasound and may guide decisions for intervention or delivery. A variety of functional tests can be used, but there is no single clinical standard. For some specific conditions, however, certain tests have shown diagnostic value.

Increased cardiac output was first described in patients with cirrhosis more than fifty years ago. Later, various observations have indicated the presence of a latent cardiac dysfunction, which includes a combination of reduced cardiac contractility with systolic and diastolic dysfunction and electrophysiological abnormalities. This syndrome is termed cirrhotic cardiomyopathy. Results of experimental studies indicate the involvement of several mechanisms in the pathophysiology, such as reduced beta-adrenergic receptor signal transduction, altered transmembrane currents and electromechanical coupling, nitric oxide overproduction, and cannabinoid receptor activation. Systolic incompetence in patients can be revealed by pharmacological or physical strain and during stressful procedures, such as transjugular intrahepatic portosystemic shunt insertion and liver transplantation. Systolic dysfunction has recently been implicated in development of renal failure in advanced disease. Diastolic dysfunction reflects delayed left ventricular filling and is partly attributed to ventricular hypertrophy, subendocardial oedema, and altered collagen structure. The QT interval is prolonged in about half of the cirrhotic patients and it may be normalised by beta-blockers. No specific therapy for cirrhotic cardiomyopathy can be recommended, but treatment should be supportive and directed against the cardiac dysfunction. Future research should better describe the prevalence, impact on morbidity and survival, and look for potential treatments.

Acute liver failure is often accompanied by hyperdynamic circulation, which is also a characteristic of septic shock. Pre-existing acute liver failure may worsen the hemodynamic impairment and prognosis in sepsis.To evaluate the hemodynamic and metabolic characteristics and clinical outcomes of septic shock in patients with acute liver failure.Twenty patients with acute liver failure and 19 patients without preexisting liver disease were evaluated. Systemic hemodynamics, arterial and mixed vein blood gases, arterial lactate levels, plasma renin activity, and plasma aldosterone levels were checked during the early phase of septic shock.In acute liver failure group, cardiac index (4.92 +/- 1.13 vs 3.69 +/- 1.06 L/min per square meter, P.001) and oxygen delivery (604.7 +/- 139.7 vs 485.4 +/- 137.3 mL/min per square meter, P = .011) were significantly higher than those without preexisting liver diseases, while systemic vascular resistance index (1041.2 +/- 503.3 vs 1409 +/- 505.25 dyne.s/cm(5).m(2)), oxygen consumption (119.1 +/- 29.2 vs 162.4 +/- 49.4 mL/min per square meter) and oxygen extraction ratio (20% +/- 6% vs. 32% +/- 8%) were significantly higher in the latter group. Furthermore, the patients with acute liver failure had higher arterial lactate (P = .026), plasma renin activity (P = .03), plasma aldosterone levels (P.001), and intensive care unit as well as hospital mortality rates (P = .005, and 0.02 respectively).In patients with acute liver failure, septic shock was characterized by an accentuated hyperdynamic circulation, hyperlactatemia and an augmented renin-angiotensin-aldosterone system activity. Pre-existing liver failure has a significant impact on the disease severity of septic shock and portends a grave prognosis.

Background. Patients with acute liver failure (ALF) show an aggravated hyperdynamic circulation. We evaluated potential changes in systemic hemodynamics and improved kidney function induced by the molecular adsorbent recirculating system (MARS) in a group of patients with primary nonfunction (PNF). Patients and Methods. In the intensive care unit we treated 18 patients with PNF (6 females and 12 males) after orthotopic liver transplantation (OLT) of overall mean age 47.8 years (range, 28-60 years). Continuous MARS treatment was performed on all patients with a kit change every 8 hours during a mean of 10 days (range, 1-20 days). Double-lumen catheter type veno-venous access was used for the blood supply. The blood flow rate was 150 to 250 mL/min, depending on the hemodynamic situation of the patient. Blood passed through an albumin nonpermeable, high flux dialysis membrane. During MARS treatment we monitored the hemodynamic condition, using a series of parameters: heart rate (HR), mean arterial pressure (MAP), cardiac index (CI), systemic vascular resistance index (SVRI), and pulmonary vascular resistance index (PVRI) before (baseline value) as well as after 1 hour (T1), 3 hours (T2), and the end of treatment (T3). Results. There was a progressive decrease in positive inotropic support (dobutamine, norepinephrine) and significant improvement in hemodynamic parameters, such as MAP (P

Animal models allow detailed study of the hemodynamic alterations in portal hypertension syndrome and of the molecular mechanisms involved in the abnormalities in splenic and systemic circulation associated with this syndrome. Models of prehepatic portal hypertension can be used to study alterations in the splenic circulation and the physiopathology of hyperdynamic circulation. Moreover, models of cirrhosis allow the alterations in intrahepatic microcirculation that lead to increased resistance to portal flow to be studied. The present review summarizes currently available animal models of portal hypertension and analyzes their relative utility in investigating the distinct disorders associated with this entity. The criteria for the choice of a particular model, depending on the specific objectives of the study, are also discussed.

The presence of a hyperdynamic circulation in cirrhotic liver is currently a well established concept. The first studies of cardiac function in patients with cirrhosis suggested the existence of an alcoholic cardiomyopathy. More recently, altered left ventricular response to physiological and/or pharmacological stimuli in patients with post-viral liver cirrhosis has been established, and clinically insignificant diastolic cardiac function has also been observed. Neurohumoral hyperactivity and hyperdynamic circulation, which are associated with chronic exposure to the cardiodepressant substances present in advanced liver disease, play a decisive role in the genesis of this process. The lack of relaxation of the left ventricle and alteration in the pattern of transmitral flow, both of which are characteristics of this clinical entity, are easily detected by echocardiography. The growing evidence of diastolic dysfunction in liver cirrhosis, particularly in decompensated cirrhosis, suggests the clinical importance of the problem, thus introducing the concept of "cirrhotic cardiomyopathy". Greater insight into this phenomenon could help to decrease cardiovascular risk, especially during maneuvers commonly used in the treatment of the complications of liver cirrhosis, such as paracentesis, transjugular intrahepatic portosystemic shunt stent implantation, and liver transplantation.

Objective: To evaluate the efficacy of a novel lipopolysaccharide (LPS) antagonist, E5531, in blocking LPS-induced cardiac responses including myocardial depression (as assessed by relatively load-independent echocardiographic indices of contractility) in a human model of experimental endotoxemia. Design: Randomized, prospective, placebo-controlled, double-blind trial. Setting: ICU procedure room. Participants: Thirty-two healthy, male volunteers. Interventions: Administration of LPS (4 ng/kg) and either a placebo or one of four sequential doses of E5531 (100 μg, 250 μg, 500 μg, or 1,000 μg) followed by volumetric echocardiography before and during 4-L saline solution infusion (3 L over 3 h, followed by 1 L over 2 h). Results: In addition to the generation of a hyperdynamic circulation throughout the study period, administration of LPS resulted in a biphasic contractility response. Ejection fraction (EF), rate-corrected mean velocity of circumferential fiber shortening (Vcfc), peak systolic BP (SBP)/end-systolic volume index (ESVI) ratio, and end-systolic pressure (Pes)/ESVI ratio increased at the 3-h post-LPS assessment, compared to a control group of subjects receiving only similar amounts of saline solution (minimum p Conclusions: Endotoxin generates significant myocardial depression when measured using highly load-independent indices of cardiac contractility. E5531 is a potent inhibitor of the early hyperdynamic cardiovascular and later myocardial depression response seen in experimental human endotoxemia.

The gut flora plays an important role in the pathogenesis of the complications of cirrhosis. Cirrhotic patients are prone to develop bacterial infections, mainly the 'spontaneous' infection of ascites or spontaneous bacterial peritonitis. Other complications of cirrhosis, such as variceal haemorrhage and ascites, occur mostly or solely as a consequence of portal hypertension. Portal pressure increases initially as a consequence of an increased intrahepatic resistance but, once collaterals have formed, high portal pressure is maintained by an increased splanchnic blood inflow secondary to vasodilatation. Splanchnic vasodilatation is the initiating event in the hyperdynamic circulatory state that aggravates the complications of cirrhosis. The gut flora plays a role in both the development of infections and in the hyperdynamic circulatory state of cirrhosis and, although less prominently, it also plays a role in the pathogenesis of hepatic encephalopathy. This chapter presents evidence regarding gut flora and its modification in the pathogenesis and management of these complications of cirrhosis.

Earlier studies have shown a prolonged frequency-adjusted Q-T interval (QTc0.440 s(1/2)) in a substantial fraction of patients with cirrhosis. The effect of beta-blockade on QTc is unknown, and its determination was the aim of the study.Seventeen patients with cirrhosis received 80 mg propranolol orally during a haemodynamic investigation with measurements at baseline and 90 min after propranolol ingestion.Beta-blockade reduced cardiac output (-21%, P0.001), heart rate (-20%, P0.001), and the hepatic venous pressure gradient (HVPG, -17%, P0.02). The mean QTc=0.460 s(1/2) was prolonged compared to 0.410 s(1/2) in age-matched controls (P0.01). Whereas QTc decreased during beta-blockade in the cirrhotic patients (from 0.460 to 0.440 s(1/2), P0.01), no effect was found in the subgroup with normal QTc (0.429 vs. 0.422 s(1/2), ns), and a reduction was seen in the patients with prolonged QTc (from 0.488 to 0.456 s(1/2), P0.01). The percentage decrease in QTc was related to the reduction in HVPG (r=0.48, P=0.03) and cardiac output (r=0.56, P=0.02).Acute non-selective beta-blockade reduces prolonged QTc towards normal values in patients with cirrhosis. The clinical significance of QTc reduction in arrhythmia is a topic for future research.

Liver cirrhosis is complicated by a hyperdynamic circulation characterized by a generalized arterial vasodilatation. This vasodilatation occurs despite high plasma concentration of several potent vasoconstrictive substances like angiotensin, vasopressin, endothelin and norepinephrine. The experimental evidence available shows that compensatory adrenergic and vasoconstrictive signals are not normally transmitted intracellularly. G protein-coupled receptor kinases phosporylate plasma membrane receptors and block the transmission of the signal intracellularly. We hypothesize that these kinases are responsible for the desensitization to vasoconstrictors observed in patients with liver cirrhosis. Pharmacological intervention at this level might be beneficial to treat complications like ascites and variceal bleeding.

In cirrhosis, cardiac symptoms and physical signs occur as the liver functions worsen. Cirrhosis is associated with hyperdynamic circulation and beta-adrenergic system activation responsible for the cardiovascular changes. The purpose of the present study was to explore the cardiovascular response to exercise in cirrhotic patients. A total of 20 patients (16 men, four women) with cirrhosis of hepatitis B or C without any cardiac dysfunction were included in the study. Ten people (eight men, two women) were enrolled in the control group. Plasma noradrenaline and adrenaline concentrations, blood pressures in supine and standing positions, exercise echocardiography and exercise radionuclide ventriculography were carried out. In cirrhotics, the exercise capacity was lower and also there was an impaired cardiovascular response to exercise with lower than expected peak heart rate without any cardiac dysfunction, which may have important clinical implications for the ability of these patients to withstand cardiovascular stress.

Increased vascular nitric oxide (NO) production has been implicated in the pathogenesis of the hyperdynamic circulation in liver cirrhosis. This study investigated the expression of three isoforms of NO synthase (NOS) in rat cirrhotic livers. Cirrhosis was induced by chronic bile duct ligation (BDL). NOS enzyme activity was assessed by L-citrulline generation. Competitive RT-PCR was performed to detect the mRNA levels of NOS. In situ hybridization was done to localize NOS mRNA. Protein expression of NOS was evaluated by Western blotting and immunohistochemistry. The L-citrulline assay showed that constitutive NOS (cNOS) enzymatic activity was decreased, while inducible NOS (iNOS) activity was increased in BDL livers. Both endothelial NOS (eNOS) and neuronal NOS (nNOS) mRNA were detected in BDL and sham rats, but with enhanced expression in BDL rats. eNOS protein was redistributed with less expression in sinusoidal endothelial cells, but the total levels in liver were not changed. nNOS was induced in hepatocytes of BDL rats, in contrast to only a weak signal observed around some blood vessels in sham livers. Intense mRNA and protein expression of iNOS was induced in livers of BDL rats and was localized in hepatocytes, with no or a negligible amount in control livers. In conclusion, iNOS was induced in cirrhotic liver with its activity increased. In contrast, cNOS activity was impaired, regardless of unchanged eNOS protein levels and enhanced nNOS expression. These results suggest that all three types of NOS have a role in cirrhosis, but their expression and regulation are different.

Adrenomedullin (AM) is a vasodilatory peptide hormone, playing a key role in the regulation of cardiovascular homeostasis. In view of the circulatory failure in sepsis, it is still debated as to whether the occurrence of vascular hyporeactivity against AM plays a causative or protective role. This study was designed as a prospective, controlled trial to elucidate the hemodynamic response following a titrating infusion of human AM in healthy and endotoxemic sheep. ANOVA demonstrated that AM infusion produced hypotension and tachycardia, and increased cardiac index in a dose-dependent manner, both in healthy and endotoxemic sheep. In addition, AM application reduced pulmonary vascular resistance index in ovine endotoxemia (P=0.02). These findings confirm that AM produces a hyperdynamic circulation, in the presence and absence of systemic inflammation. Further, exogenous AM could possibly be a useful adjunct in the common setting of sepsis-associated pulmonary hypertension.

Direct hemoperfusion (DHP) with an adsorbent column using polymyxin B-immobilized fiber (PMX-F) has been shown to improve the state of shock in patients with septic shock. However, no evidence has been presented for a direct link between endotoxin removal by DHP with PMX-F and improvement in septic shock. We retrospectively analyzed clinical profiles of 24 patients with septic shock (16 patients, gram-negative; 8 patients, non-gram-negative septic shock) who underwent DHP with PMX-F. Patients with gram-negative septic shock were characterized by hyperdynamic circulation. DHP with PMX-F reduced blood endotoxin concentrations and ameliorated shock, with an improvement in hyperdynamic circulation in patients with gram-negative septic shock. Mean arterial pressure also was elevated after therapy in patients with non-gram-negative septic shock, but systemic hemodynamics were unaffected. Regardless of the causative microorganism, patients with endotoxemia (blood endotoxin level > 10 pg/mL) showed hyperdynamic shock, and DHP with PMX-F reduced blood endotoxin levels and ameliorated hyperdynamic circulation, whereas patients without endotoxemia showed features of shock without hyperdynamic circulation, and DHP with PMX-F ameliorated shock without affecting cardiac performance. In patients with gram-negative septic shock, blood endotoxin concentration correlated positively with cardiac output and negatively with systemic vascular resistance before DHP therapy. Reduction in blood endotoxin concentration by DHP therapy positively correlated with the reduction in cardiac output. Our findings indicate that the improvement in hyperdynamic circulation was related directly to endotoxin removal by the PMX-F column, and endotoxin has an important role in the development of hyperdynamic circulation in patients with gram-negative septic shock.

It has been demonstrated that an overproduction of nitric oxide plays an important role in the pathogenesis of the hyperdynamic circulation exhibited by cirrhotic patients. Nevertheless, evidence is supported by studies performed in experimental models or by indirect measurements in humans. The purpose of this study has been to evaluate nitric oxide production in splanchnic vasculature of patients with cirrhosis and to investigate its possible relationship with systemic and splanchnic hemodynamics.Nitric oxide synthase (NOS) activity was measured in hepatic artery and portal vein tissues of nine cirrhotic patients. Samples were obtained during liver transplantation. Control samples were obtained simultaneously from the corresponding tissues of the liver donors. Hemodynamic parameters were determined with Doppler ultrasonography.NOS activity was significantly higher in hepatic artery of cirrhotic patients than in controls (8.17 +/- 1.30 vs 4.57 +/- 0.61 pmoles/g of tissue/min, P0.05). Patients with ascites showed a higher hepatic artery NOS activity than patients without ascites. Highly significant correlation was observed between cardiac output and hepatic artery NOS activity as well as between portal blood flow and hepatic artery NOS activity.The present study demonstrates an enhanced production of nitric oxide in the splanchnic vasculature of patients with cirrhosis.

The hyperdynamic circulation begins in the portal venous bed as a consequence of portal hypertension due to the increased resistance to flow from altered hepatic vascular morphology of chronic liver disease. Dilatation of the portal vein is associated with increased blood flow, as well as the opening up or formation of veno-venous shunts and splenomegaly. At the same time, portal hypertension leads to subclinical sodium retention resulting in expansion of all body fluid compartments, including the systemic and central blood volumes. This blood volume expansion is associated with vasorelaxation, as manifested by suppression of the renin--angiotensin--aldosterone system, initially only when the patient is in the supine position. Acute volume depletion in such patients results in normalisation of the hyperdynamic circulation, whilst acute volume expansion results in exaggerated natriuresis. As liver disease progresses and liver function deteriorates, the systemic hyperdynamic circulation becomes more manifest with activation of the renin--angiotensin--aldosterone system. The presence of vasodilatation in the presence of highly elevated levels of circulating vasoconstrictors may be explained by vascular hyporesponsiveness due to increased levels of vasodilators such as nitric oxide, as well as the development of an autonomic neuropathy. However, vasodilatation is not generalised, but confined to certain vascular beds, such as the splanchnic and pulmonary beds. Even here, the status may change with the natural history of the disease, since even portal blood flow may decrease and become reversed with advanced disease. The failure of these changes to reverse following liver transplantation may be due to remodelling and angiogenesis.

The hepatopulmonary syndrome is a triad of liver disease, increased alveolar-arterial oxygen gradient and intrapulmonary vascular dilatations. Manifestations include orthodeoxia, platypnoea and hyperdynamic circulation. Intrapulmonary vascular abnormalities, perhaps mediated by nitric oxide, cause hypoxaemia by shunting, a perfusion-diffusion defect, and ventilation-perfusion mismatching. Contrast-enhanced echocardiography is the method of choice for demonstrating pulmonary vascular abnormalities, although perfusion lung scanning is a more specific and sensitive test. Angiography is best reserved for patients with poor response to 100% oxygen and defines whether vascular dilatations are of the diffuse 'spongy' type or, less commonly, discrete arteriovenous communications amenable to embolization. About 80% of patients with the hepatopulmonary syndrome eventually have improved oxygenation after liver transplantation, thereby making worsening hypoxaemia the primary indication for transplantation in many instances. Nevertheless, severe hypoxaemia carries a peri-operative mortality of 30% and reliable predictors of successful outcome after transplantation remain to be determined.

Background/Aims: The aim of this study was to evaluate cardiovascular and renal function in patients with compensated cirrhosis and essential hypertension in the supine position and in response to standing up. Methods: Twenty-four patients with compensated cirrhosis (12 with elevated arterial pressure) and 20 healthy volunteers underwent echocardiographic evaluation of left ventricular end-diastolic and stroke volumes, ejection fraction, cardiac index, arterial pressure, peripheral resistance, creatinine clearance and sodium excretion in both the supine and the standing position. Results: When supine, only normotensive patients had a hyperdynamic circulation, with increased left ventricular end-diastolic and stroke volumes, cardiac index, and ejection fraction, and reduced peripheral resistance. Creatinine clearance and sodium excretion were comparable in patients and controls. Standing induced a decrease in end-diastolic volume in all subjects. Healthy volunteers maintained cardiovascular homeostasis by increasing ejection fraction and heart rate, while both normotensive and hypertensive cirrhotic patients experienced a fall in stroke volume and cardiac index, despite a marked activation of the renin-aldosterone and sympathetic nervous system. Creatinine clearance decreased only in normotensive patients, who experienced the greatest reduction in sodium excretion. Conclusions: Compensated cirrhotic patients with arterial hypertension had no evidence of hyperdynamic circulation. Like their normotensive counterparts, hypertensive patients had an impaired cardiovascular response to the postural challenge, but a lesser degree of renal dysfunction during standing.

OBJECTIVES: Our hypothesis was that during pregnancy nitric oxide acts as mediator in the hemodynamic response to volume expansion. STUDY DESIGN: The study was performed on 12 rats on days 19 to 20 of pregnancy. Six rats were injected intravenously with hexamethonium bromide plus the inhibitor of nitric oxide synthase l-nitro-arginine methyl ester. For a control group, six rats were injected with hexamethonium bromide plus the l-nitro-arginine methyl ester vehicle. A volume expansion (1.2% body weight) was performed in both groups by intravenous infusion of bovine albumin (6%) solution. RESULTS: In the control group volume expansion induced a hyperdynamic circulation characterized by increased cardiac output, decreased total vascular resistance, and no change in arterial pressure; however, in the study group volume expansion induced a pressor response without hyperdynamic circulation. CONCLUSION: During pregnancy volume expansion induces a hyperdynamic circulatory state possibly mediated by nitric oxide release. A defect in the release of nitric oxide may be responsible for an inadequate hemodynamic response to volume expansion. (Am J Obstet Gynecol 1998;178:823-9.)

Backgrouond/Aims: Due to structural and functional similarities between platelets and vascular smooth muscle cells, platelet cytosolic calcium concentration ([Ca 2+ ] 1 ) has been suggested to be a useful tool to study regulatory mechanisms of peripheral vascular tone. The aim of the present study was to investigate platelet [Ca 2+ ] i in patients with cirrhosis and whether this parameter is related with the systemic and splanchnic vasodilation found in these patients. Methods: Seventeen patients with cirrhosis and eight age- and sex-matched controls were studied. Mean arterial pressure, cardiac output, femoral blood flow and basal and thrombin-stimulated platelet [Ca 2+ ] i were measured. Cardiac output (thermal dilution), azygos blood flow, hepatic venous pressure gradient and hepatic blood flow were also measured in patients with cirrhosis. Results: Patients with cirrhosis had severe portal hypertension and a significantly higher cardiac output and femoral blood flow and a significantly lower systemic and femoral vascular resistance than controls. Patients with cirrhosis had a lower basal platelet [Ca 2+ ] i than normal subjects. However, there was no relationship between platelet [Ca 2+ ] i and any of the hemodynamic parameters that evaluate systemic or splanchnic vasodilatation. Conclusions: This study shows that cirrhotic patients with portal hypertension have a significant reduction in platelet basal [Ca 2+ ] i . The lack of correlation between platelet [Ca 2+ ] i and hepatic and systemic hemodynamics does not support the use of platelet [Ca 2+ ] i as a model to study mechanisms involved in the pathophysiology of the hyperdynamic circulation associated to portal hypertension.

This study was designed to assess the contribution of splanchnic and extrasplanchnic vascular hemodynamics to the hyperdynamic circulation in patients with cirrhosis.Cardiac index and flow volume index and pulsatility index (PI) of superior mesenteric artery (SMA) and femoral artery (FA) were measured with Doppler ultrasonography in 40 controls and 86 patients with cirrhosis (Child-Pugh grade A=41, grade B=30, and grade C=15). Mean arterial pressure was also recorded to calculate systemic vascular resistance index.Systemic vascular resistance index was significantly lower in each Child-Pugh group than in controls. SMA blood flow index was significantly higher in each Child-Pugh group than in controls and the increase in SMA blood flow index paralleled the degree of liver dysfunction. SMA-PI was significantly lower in each Child-Pugh group than in controls and the decrease in SMA-PI paralleled the degree of liver dysfunction. FA blood flow index was slightly higher in Child-Pugh grade A patients and significantly higher in grade B patients than in controls, whereas grade C patients had normal FA blood flow index. FA-PI was significantly lower in grade A and grade B patients than in controls, whereas grade C patients had normal FA-PI. When all patients were examined together, SMA-PI significantly correlated with systemic vascular resistance index (r=0.69, p0.01). In contrast, FA-PI did not significantly correlate with systemic vascular resistance index (r=0.15, p=0.18).Splanchnic arterial vasodilatation plays an important role in the pathogenesis of decreased systemic vascular resistance seen in patients with cirrhosis.

Background/Aims: Low arterial blood pressure is recognised as a distinctive factor in the hyperdynamic circulation in cirrhosis. 24-hour monitoring of the blood pressure and heart rate has recently revealed a reduced circadian variation with relation to liver function. However, associations with other clinical and haemodynamic characteristics have not been investigated and the aim of the present study was to identify splanchnic and systemic determinants of the 24-h blood pressure and heart rate in cirrhosis. Methods: The variables were measured by an automatic ambulant device for monitoring blood pressure and related to the results of an invasive haemodynamic investigation, including measurements of intra-arterial blood pressure (9.00–11.00 h) in 37 patients with cirrhosis. Results: The 24-h blood pressures were significantly lower and the heart rate was significantly higher in patients with cirrhosis than in matched controls ( p Conclusions: Although the 24-h blood pressure and the intra-arterial blood pressure were determined by different variables, the overall results indicate that abnormalities in both splanchnic and central haemodynamics and sodium-water retention are important in the pathophysiology of arterial hypotension in patients with portal hypertension.

Chronically instrumented awake healthy sheep (n = 6) received the synthetic catecholamine, dopexamine, during or without a background infusion of the nitric oxide synthase inhibitor. L-nitro-arginine-methylester (L-NAME). Three days later, hypotensive-hyperdynamic circulation was induced and maintained by continuous infusion of Salmonella typhosa endotoxin (10 ng/kg per min). After 24 h of continuous endotoxin infusion, the dopexamine L-NAME protocol was repeated. In healthy and endotoxaemic animals with and without nitric oxide synthase inhibition dopexamine caused the same haemodynamic changes: heart rate and cardiac output increased, mean arterial pressure and systemic vascular resistance decreased. L-NAME infusion induced normalisation of the hypotonic-hyperdynamic circulation in endotoxaemic animals. Dopexamine reduced some adverse effects of L-NAME treatment, like increased pulmonary vascular resistance and decreased oxygen delivery. In conclusion the haemodynamic effects of dopexamine are independent of the amount of nitric oxide production. Dopexamine may attenuate some of the adverse effects of nitric oxide synthase inhibition.

Calcitonin gene-related peptide (CGRP), a potent vasodilator; plays an important role in modulating vascular tone, acting as a noncholinergic nonadrenergic neurotransmitter. The aim of this study was to assess the role of CGRP, present in the vascular system, in the development of the hyperdynamic circulation observed in liver cirrhosis.Two doses of human alpha-CGRP [8-37], a specific antagonist of CGRP, were administered to cirrhotic and controls rats. Hemodynamics were evaluated using radioactive microspheres in conscious animals. To investigate the arterial depressor effect of exogenous CGRP, we constructed a dose-response curve for mean arterial pressure in cirrhotic and control rats by administering human alpha-CGRP.The administration of high-dose human alpha-CGRP [8-37] (300 nmol.kg body weight-1.min-1) significantly increased both the mean arterial pressure (21 +/- 2 vs. 13 +/- 1%, p0.01) and total vascular resistance (76 +/- 5 vs. 54 +/- 5%, p0.01) in cirrhotic rats, compared to control rats. The splanchnic hemodynamic effects induced by human alpha-CGRP [8-37] were a significant decrease in percent change of portal venous inflow -42 +/- 3 vs. -33 +/- 3%, p0.05) and a significant increase in percent change of splanchnic arterial resistance (110 +/- 9 vs. 76 +/- 5%, p0.01) in cirrhotic rats, compared to control rats. Low-dose human alpha-CGRP [8-37] (60 nmol.kg body weight-1. min-1) caused similar hemodynamic changes, but the degree of change was much less than for the high-dose administration. The vascular response to human alpha-CGRP was significantly reduced in cirrhotic rats as compared to controls (ANOVA, p0.01). Plasma concentrations of CGRP were significantly elevated in cirrhotic rats.CGRP in the vascular system was involved in the modulation of vasodilatation in rats with liver cirrhosis, as demonstrated by the administration of a selective CGRP antagonist and exogenous CGRP.

Portal hypertension and hyperdynamic circulation (i.e. generalized vasodilation and increased cardiac output and regional organ blood flows) may play an important role in the development of portal hypertensive gastropathy. This study investigated the effect of chronic administration of aminoguanidine, a selective inducible nitric oxide synthase inhibitor, to portal hypertensive rats on hemodynamics and the development of portal hypertensive gastropathy.Partial portal vein-ligated or sham-operated rats were randomly assigned to receive either placebo (distilled water) or aminoguanidine (approximately 100 mg/kg per day subcutaneously) for 2 days prior to and 14 days. Hemodynamic studies with a thermodilution technique and gastric morphometric analysis were performed at 14 days after the operation.In rats given placebo, portal vein-ligated rats had a significantly lower mean arterial pressure and systemic vascular resistance associated with a significantly higher cardiac index and portal pressure than sham-operated rats (p0.05). In portal vein-ligated rats aminoguanidine induced a significant increase in mean arterial pressure and systemic vascular resistance accompanied by a significant decrease in cardiac index (p0.05) without changes in portal pressure (p0.05). Despite persistence of portal hypertension, the aminoguanidine-treated portal vein-ligated rats had similar mean arterial pressure, cardiac index, and systemic vascular resistance as seen in placebo-treated sham-operated rats. The mean cross-sectional area of gastric mucosal vessels was significantly higher in placebo-treated portal vein-ligated than in placebo-treated sham-operated rats (p0.05). Treatment with aminoguanidine did not induce changes in the mean cross-sectional area of gastric mucosal vessels in either portal vein-ligated or sham-operated rats (p0.05).The results show that in portal hypertensive rats long-term aminoguanidine therapy corrects the hyperdynamic circulation without inducing changes in portal pressure and ameliorating the development of portal hypertensive gastropathy. This study suggests that, instead of correcting hyperdynamic circulation, treatment of portal hypertensive gastropathy should be aimed at reducing portal pressure.

Background/Aims: Liver cirrhosis and portal hypertension are associated with hyperdynamic circulation. Portacaval shunts are widely used to prevent recurrent hemorrhage, but the hemodynamic effects caused by these procedures have not been well characterized in cirrhosis. We therefore compared the hemodynamic effects of both end-to-side and side-to-side portacaval shunts in normal and cirrhotic rats. Methods: Sprague-Dawley rats were divided into six groups according to the operations they underwent. End-to-side or side-to-side portacaval shunts were performed in both rats with cirrhosis induced by bile duct ligation and sham-operated rats. Systemic and regional blood flows were measured by the radioactive microsphere method. Results: Portal pressures in the shunted rats decreased significantly. Cardiac index in cirrhotic rats (557±27 ml·min −1 ·kg −1 ) was significantly higher than controls (455±21 ml·min −1 ·kg −1 ), but the two types of shunts did not further increase cardiac index in either the cirrhotic or the sham-operated rats. After shunting, hepatic arterial flows approximately doubled. Portal tributary blood flows in the end-to-side shunted sham (108±13 ml·min −1 ·kg −1 ) and cirrhotic (139±19 ml·min −1 ·kg −1 groups were significantly higher than their respective controls (62±8 and 76±5 ml·min −1 ·kg −1 ). Portosystemic shunting indices were >99% in both the end-to-side and side-to-side shunted groups in cirrhotic and sham-operated rats. Conclusions: The hyperdynamic circulation in cirrhotic rats was not augmented by portacaval shunting operations (either end-to-side or side-to-side), despite essentially total portosystemic blood diversion. Compensatory increase in the hepatic arterial blood flow to the liver remained intact even in cirrhotic rats. A selective redistribution of cardiac output to the mesenteric vascular bed was observed after the shunting procedure. However, there were no significant differences in hemodynamics between the end-to-side and side-to-side shunted groups.

formed. The arterial splanchnic circulation was normal but there was complete thrombosis of all veins in the mesentery of the small intestine including the central splanchnic veins. The entire small intestine was cyanotic, consistent with severe ischaemia, but no part of the intestine was necrotic and no resection was performed. In the IC-unit a hyperdynamic circulation was pursued with fluid challenge and dobutamine inotropic support guided by pulmonary artery pressure monitoring (cardiac index > 4.0 1/min/m2). Vasodilatation was achieved with ketanserin (4 rag/ h). Oxygen delivery (DO2) and oxygen consumption (VO2) were calculated using the standard formulae. In addition the patient was heparinised (APTT 60-90 s). Total parenteral feeding was started. Second and third look laparotomies were performed after 16 and 48 h. The severely compromised venous circulation of the small intestine appeared to be significantly improved.

To evaluate the effect of a hypothyroid state, induced by chronic propylthiouracil administration, on splanchnic and systemic hemodynamic parameters in rats with portal hypertension due to portal vein ligation.Portal hypertension was induced by surgical stenosis of the portal vein. Cardiac index and portal blood flow were measured using radioactive microspheres. Measurements were performed after treatment with propylthiouracil (1 mg/ml in drinking water) for 5 days.Propylthiouracil-treated portal hypertensive rats had a lower portal pressure (12.4 +/- 1.9 versus 16.3 +/- 0.7 mmHg; p0.05) and portal blood flow (11.6 +/- 0.7 versus 13.2 +/- 1.3 ml/min/100 g; p0.05) than non-treated animals. Splanchnic vasoconstriction in treated animals was associated with a higher peripheral vascular resistance (2.3 +/- 0.4 versus 1.8 +/- 0.3 mmHg/ml/min/100 g; p0.05) than controls.These results suggest that portal pressure can be lowered by inducing a hypothyroid state by chronic administration of propylthiouracil.

The relationship between nitric oxide production, endotoxemia, renal function and hyperdynamic circulatory syndrome has not been yet investigated in patients with cirrhosis.Serum and urine nitrate, endotoxemia and cardiac index were measured in 59 patients with cirrhosis.Patients with a tense ascites had higher serum nitrate levels than healthy control subjects (39 +/- 7 vs 19 +/- 4 mumol/l, p0.01). Patients with mild ascites and without ascites had normal values of nitrate levels. In the group of patients not treated with diuretics (n = 38), creatinine and nitrate clearances were lower in ascitic patients than in nonascitic patients (respectively 0.82 +/- 0.12 vs 1.48 +/- 0.32 ml/s, p0.02 and 0.30 +/- 0.07 vs 2.89 +/- 2.04 ml/s, p0.05). Endotoxin levels were higher in patients with cirrhosis than in control subjects and paralleled the severity of liver failure (Child A/B/C vs control subjects: 0.056 +/- 0.014/0.064 +/- 0.005/ 0.090 +/- 0.008 vs 0.027 +/- 0.005 Endotoxin Units/ml, p0.001). Serum nitrate levels did not correlate with endotoxemia (r = -0.110). On the other hand, levels of orosomucoid, a protein synthesized by the liver in response to a stimulation by cytokines correlated with those of nitrate (respectively r = 0.343, p0.01). Hemoglobin levels were negatively correlated with serum nitrate levels (r = -0.328 p0.02). Cardiac index was higher in patients than in control subjects and paralleled the degree of liver failure (Child A/B/C vs control subjects: 3.60 +/- 0.25/ 4.10 +/- 0.19/4.47 +/- 0.25 vs 3.15 +/- 0.12 l.min.m2, p0.001). Cardiac index did not correlate with serum nitrate levels, urine nitrate excretion and endotoxemia.Renal impairment accounts for the increased levels of serum nitrate in ascitic patients. A stimulation of nitric oxide production by cytokines may occur but endotoxemia is not involved in such a mechanism. Anemia has a role in nitric oxide activity. Nitric oxide generation assessed by nitrate in serum and urine does not seem to participate in the hyperdynamic circulatory syndrome in patients with cirrhosis.