Atrial volume in cirrhosis: relationship to blood volume and plasma concentration of atrial natriuretic factor

Cardiovascular manifestation of end-stage liver disease and perioperative echocardiography for liver transplantation: anesthesiologist’s view

Liver transplantation (LT) is the curative therapy for decompensated cirrhosis. However, anesthesiologists can find it challenging to manage patients undergoing LT due to the underlying pathologic conditions of patients with end-stage liver disease and the high invasiveness of the procedure, which is frequently accompanied by massive blood loss. Echocardiography is a non-invasive or semi-invasive imaging tool that provides real-time information about the structural and functional status of the heart and is considered to be able to improve outcomes by enabling accurate and detailed assessments. This article reviews the pathophysiologic changes of the heart accompanied by cirrhosis that mainly affect hemodynamics. We also present a comparative review of the diagnostic criteria for cirrhotic cardiomyopathy published by the World Congress of Gastroenterology in 2005 and the Cirrhotic Cardiomyopathy Consortium in 2019. This article discusses the conditions that could affect hemodynamic stability and postoperative outcomes, such as coronary artery disease, left ventricular outflow tract obstruction, portopulmonary hypertension, hepatopulmonary syndrome, pericardial effusion, cardiac tamponade, patent foramen ovale, and ascites. Finally, we cover a number of intraoperative factors that should be considered, including intraoperative blood loss, rapid reaccumulation of ascites, manipulation of the inferior vena cava, post-reperfusion syndrome, and adverse effects of excessive fluid infusion and transfusion. This article aimed to summarize the cardiovascular manifestations of cirrhosis that can affect hemodynamics and can be evaluated using perioperative echocardiography. We hope that this article will provide information about the hemodynamic characteristics of LT recipients and stimulate more active use of perioperative echocardiography.

Management of refractory cirrhotic ascites: challenges and solutions

Among the various risky complications of liver cirrhosis, refractory ascites is associated with poor survival of cirrhotics and persistently worsens their quality of life (QOL). Major clinical guidelines worldwide define refractory ascites as ascites that cannot be managed by medical therapy either because of a lack of response to maximum doses of diuretics or because patients develop complications related to diuretic therapy that preclude the use of an effective dose of diuretics. Due to the difficulty in receiving a liver transplantation (LT), the ultimate solution for refractory ascites, most cirrhotic patients have selected the palliative therapy such as repeated serial paracentesis, transjugular intrahepatic portosystemic shunt, or peritoneovenous shunt to improve their QOL. During the past several decades, new interventions and methodologies, such as indwelling peritoneal catheter, peritoneal-urinary drainage, and cell-free and concentrated ascites reinfusion therapy, have been introduced. In addition, new medical treatments with vasoconstrictors or vasopressin V2 receptor antagonists have been proposed. Both the benefits and risks of these old and new modalities have been extensively studied in relation to the pathophysiological changes in ascites formation. Although the best solution for refractory ascites is to eliminate hepatic failure either by LT or by causal treatment, the selection of the best palliative therapy for individual patients is of utmost importance, aiming at achieving the longest possible, comfortable life. This review briefly summarizes the changing landscape of variable treatment modalities for cirrhotic patients with refractory ascites, aiming at clarifying their possibilities and limitations. Evolving issues with regard to the impact of gut-derived systemic and local infection on the clinical course of cirrhotic patients have paved the way for the development of a new gut microbiome-based therapeutics. Thus, it should be further investigated whether the early therapeutic approach to gut dysbiosis provides a better solution for the management of cirrhotic ascites.

Morphologic and Functional Changes in Right-Sided Cardiac Chambers in Patients With Chronic Liver Disease and Normal Pulmonary Artery Pressure

OBJECTIVES

To investigate the effects of chronic liver disease (CLD) on the structural and functional characteristics of right-sided heart chambers in patients with normal pulmonary artery pressure.

METHODS

Fifty-one patients with known CLD but without pulmonary hypertension or other cardiovascular conditions were consecutively enrolled, along with 25 age- and sex-matched participants. Patients with CLD were classified according to the Model of End-Stage Liver Disease score and Child-Pugh classification. Right ventricular (RV) and right atrial (RA) dimensions, indices of RV systolic/diastolic function, and myocardial strain were measured by standard echocardiographic methods.

RESULTS

Patients in the study group had similar RV end-diastolic, end-systolic, and RA dimensions compared to controls. Similarly, neither the conventional indices of RV systolic/diastolic function nor the strain imaging findings were different between groups (P > .05). Only RV free wall thickness was significantly higher in the study group (mean ± SD, 4.15 ± 0.64 versus 3.75 ± 0.37 mm; P < .001). Right ventricular end-diastolic diameter (P = .018; r = 0.334) and RA area (P = .017; r = 0.335) had a significant correlation with RV free wall thickness in patients with CLD. Patients treated with beta blockers were found to have a significant reduction in mean RV free wall strain compared to patients who did not receive beta blocker treatment (-20.37 ± 6.6 versus -24.07 ± 6.52; P = .04).

CONCLUSIONS

Patients with CLD had increased RV free wall thickness despite normal systolic pulmonary pressure, presumably secondary to cirrhotic cardiomyopathy. In the absence of pulmonary hypertension, however, cirrhotic cardiomyopathy did not cause impaired RV systolic or diastolic function.

Immune-Inflammatory and Metabolic Effects of High Dose Furosemide plus Hypertonic Saline Solution (HSS) Treatment in Cirrhotic Subjects with Refractory Ascites

Introduction

Patients with chronic liver diseases are usually thin as a result of hypermetabolism and malnutrition expressed by reduced levels of leptin and impairment of other adyponectins such as visfatin.

Aims

We evaluated the metabolic and inflammatory effects of intravenous high-dose furosemide plus hypertonic saline solutions (HSS) compared with repeated paracentesis and a standard oral diuretic schedule, in patients with cirrhosis and refractory ascites.

Methods

59 consecutive cirrhotic patients with refractory ascites unresponsive to outpatient treatment. Enrolled subjects were randomized to treatment with intravenous infusion of furosemide (125–250mg⁄bid) plus small volumes of HSS from the first day after admission until 3 days before discharge (Group A, n:38), or repeated paracentesis from the first day after admission until 3 days before discharge (Group B, n: 21). Plasma levels of ANP, BNP, Leptin, visfatin, IL-1β, TNF-a, IL-6 were measured before and after the two type of treatment.

Results

Subjects in group A were observed to have a significant reduction of serum levels of TNF-α, IL-1β, IL-6, ANP, BNP, and visfatin, thus regarding primary efficacy endpoints, in Group A vs. Group B we observed higher Δ-TNF-α, Δ-IL-1β, Δ-IL-6, Δ-ANP, Δ-BNP, Δ-visfatin, Δ-Leptin at discharge.

Discussion

Our findings underline the possible inflammatory and metabolic effect of saline overload correction in treatment of cirrhosis complications such as refractory ascites, suggesting a possible role of inflammatory and metabolic-nutritional variables as severity markers in these patients.

The end-organ impairment in liver cirrhosis: appointments for critical care

Liver cirrhosis (LC) can lead to a clinical state of liver failure, which can exacerbate through the course of the disease. New therapies aimed to control the diverse etiologies are now more effective, although the disease may result in advanced stages of liver failure, where liver transplantation (LT) remains the most effective treatment. The extended lifespan of these patients and the extended possibilities of liver support devices make their admission to an intensive care unit (ICU) more probable. In this paper the LC is approached from the point of view of the pathophysiological alterations present in LC patients previous to ICU admission, particularly cardiovascular, but also renal, coagulopathic, and encephalopathic. Infections and available liver detoxifications devices also deserve mentioning. We intend to contribute towards ICU physician readiness to the care for this particular type of patients, possibly in dedicated ICUs.

Cirrhotic cardiomyopathy

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.

The heart and the liver

Cardiac failure affects the liver and liver dysfunction affects the heart. Chronic and acute heart failure can lead to cardiac cirrhosis and cardiogenic ischemic hepatitis. These conditions may impair liver function and treatment should be directed towards the primary heart disease and seek to secure perfusion of vital organs. In patients with advanced cirrhosis, physical and/or pharmacological stress may reveal a reduced cardiac performance with systolic and diastolic dysfunction and electrophysical abnormalities, termed cirrhotic cardiomyopathy. Pathophysiological mechanisms include reduced beta-adrenergic receptor signal transduction and defective cardiac electromechanical coupling. However, the QT interval is prolonged in approximately half of patients with cirrhosis and it may be improved by beta-blockers. No specific therapy can be recommended but it should be supportive and directed against the heart failure. Transjugular intrahepatic portosystemic shunt insertion and liver transplantation affect cardiac function in portal hypertensive patients and cause stress to the cirrhotic heart, with a risk of perioperative heart failure. The risk and prevalence of coronary artery disease are increasing in cirrhotic patients and since perioperative mortality is high, careful evaluation of such patients with dobutamine stress echocardiography, coronary angiography and myocardial perfusion imaging is required prior to liver transplantation. Future research should focus on beneficial effects of treatment on cardiac function and mortality.

Cirrhotic cardiomyopathy

Decompensated liver cirrhosis is characterized by a peripheral vasodilation with a low-resistance hyperdynamic circulation. The sustained increase of cardiac work load associated with such a condition may result in an inconstant and often subclinical series of heart abnormalities, constituting a new clinical entity known as "cirrhotic cardiomyopathy". Cirrhotic cardiomyopathy is variably associated with baseline increase in cardiac output, defective myocardial contractility and lowered systo-diastolic response to inotropic and chronotropic stimuli, down-regulated beta-adrenergic function, slight histo-morphological changes, and impaired electric "recovery" ability of ventricular myocardium. Cirrhotic cardiomyopathy is usually clinically latent or mild, likely because the peripheral vasodilation significantly reduces the left ventricle after-load, thus actually "auto-treating" the patient and masking any severe manifestation of heart failure. In cirrhotic patients, the presence of cirrhotic cardiomyopathy may become unmasked and clinically evident by certain treatment interventions that increase the effective blood volume and cardiac pre-load, including surgical or transjugular intrahepatic porto-systemic shunts, peritoneo-venous shunts (LeVeen) and orthotopic liver transplantation. Under these circumstances, an often transient overt congestive heart failure may develop, with increased cardiac output as well as right atrial, pulmonary artery and capillary wedge pressures.

Evaluation of cardiac function by tissue Doppler imaging in children with chronic hepatitis

OBJECTIVES

Pathoanatomic changes in cirrhosis result in impaired ventricular filling and diastolic dysfunction and were named as cirrhotic cardiomyopathy. However, cardiac functions have not been studied in patients with chronic hepatitis. We hypothesized that such patients might have subclinical ventricular dysfunction, detectable by tissue Doppler echocardiography and related to the severity of hepatic inflammation and fibrosis.

METHODS

We studied 63 clinically stable patients, 27 patients with mild chronic hepatitis (group 1), 22 patients with moderate chronic hepatitis (group 2) and 14 patients with severe chronic hepatitis (group 3) according to the scoring system of Knodell, and 36 age-matched healthy subjects.

RESULTS

Patients with severe chronic hepatitis had impaired right ventricular diastolic function. The early diastolic velocity of the tricuspid valve annulus was lower in patients from group 3 than in healthy subjects (P < 0.001). Patients in group 3 had a greater isovolumic relaxation time (P < 0.001), indicating right ventricular diastolic dysfunction. Comparing group 3 with the healthy subjects, the ratio of peak early myocardial tissue velocity and peak late (or atrial) myocardial tissue velocity was significantly decreased (P < 0.001), at 1.4 (0.7) and 1.9 (0.7), respectively. There was also a slightly lower peak early myocardial tissue velocity and peak late (or atrial) myocardial tissue velocity ratio and a slightly longer isovolumic relaxation time in patients from group 2 than in healthy subjects (P < 0.05).

CONCLUSIONS

We detected subclinical dysfunction of the right ventricle in children with chronic hepatitis in whom hepatic inflammation and fibrosis is prominent. Tissue Doppler echocardiography provides a quantifiable indicator useful for detection and monitoring of disease progression.

Overexpression of kidney neutral endopeptidase (EC 3.4.24.11) and renal function in experimental cirrhosis

Neutral endopeptidase degrades atrial natriuretic peptide (ANP) and bradykinin and may generate endothelin-1 from big-endothelin. In advanced cirrhosis, sodium retention is accompanied by elevated plasma ANP levels, and infusion of ANP causes hypotension, but in normal humans increasing the concentration of ANP through the inhibition of neutral endopeptidase, localized in renal proximal tubule cells, causes natriuresis without any arterial pressure drop. The purpose of this study was the assessment of kidney neutral endopeptidase expression and responses to candoxatrilat (a specific inhibitor of this enzyme) in rats with CCl4-induced cirrhosis. Two groups of control rats ( n = 5) were injected with vehicle or 3 mg/kg candoxatrilat. Three groups of cirrhotic rats with ascites ( n = 10) received vehicle alone or 3 or 10 mg/kg candoxatrilat. In cirrhotic rats, Western blot analysis revealed a 170% increase in renal neutral endopeptidase protein content ( P < 0.03), mainly in the proximal nephron and macula densa, and both candoxatrilat dosages increased plasma ANP levels, urinary volume, and urinary excretion of sodium, ANP, and cGMP compared with vehicle alone (all P < 0.03). Candoxatrilat (10 mg/kg) also reduced tubular solute-free water reabsorption ( P < 0.03) in cirrhotic rats, but renal blood flow, arterial pressure, and plasma renin activity were unaffected. Neutral endopeptidase inhibition has natriuretic and aquaretic actions in cirrhosis without any effect on blood pressure and kidney perfusion due to a significant overexpression of this enzyme in renal cortex.

Loss of tubuloglomerular feedback in decompensated liver cirrhosis: physiopathological implications

In healthy subjects, arterial pressure reduction or renal ischemia produces renal artery dilatation through autoregulation and tubuloglomerular feedback (TuGF). Patients with decompensated cirrhosis have reduced kidney perfusion pressure but show renal vasoconstriction instead of autoregulation-mediated vasodilation. This study investigates the consequences of kidney autoregulation loss on renal perfusion, glomerular filtration rate, and tubular handling of electrolytes in both compensated and ascitic nonazotemic cirrhotic patients. Forty-two consecutive patients with diuretic-free liver cirrhosis (32 with preascitic and 10 with ascitic disease) and 10 controls were submitted to the following determinations: (a) basal plasma renin activity and aldosterone levels; (b) endogenous dopaminergic activity measured as incremental aldosterone responses during metoclopramide administration; and (c) renal clearances of sodium, potassium, inulin, para-aminohippurate and lithium. Compared with the other groups, ascitic patients showed lower renal plasma flow (P < 0.01) and lithium clearance (P < 0.05), a higher filtration fraction (P < 0.01), and secondary aldosteronism. Controls and preascitic patients displayed tubuloglomerular feedback (the mechanism increasing the glomerular filtration rate when a reduced sodium load reaches the distal tubule), as demonstrated by negative correlations between fractional excretion of lithium (an expression of fractional delivery of sodium to the distal nephron) and glomerular filtration rate (respectively, r = -0.73, P < 0.03, and r = -0.48, P < 0.01). Conversely, patients with ascites showed a positive correlation between lithium fractional excretion and glomerular filtration rate (r = 0.64, P < 0.05). Reduction in renal perfusion, increased filtration fraction, and TuGF derangement, as found in decompensated patients, are indicative of prevalent postglomerular arteriolar vasoconstriction, with ensuing stimulation of proximal tubular sodium reabsorption.

Evidence of a dynamic aldosterone-independent distal tubular control of renal sodium excretion in compensated liver cirrhosis

BACKGROUND AND AIM

In preascitic cirrhosis increased sodium retention occurs in kidney distal tubule in spite of normal aldosterone plasma levels. No clearance technique can dissect the respective contribution to sodium retention exerted by Henle's loop, distal convoluted tubule and collecting duct, so we evaluated proximal and distal tubular sodium handling in preascites during two manoeuvres that temporarily increase aldosterone secretion.

METHODS

Ten patients with compensated cirrhosis and nine controls were studied in recumbency, during standing and after dopamine receptor blockade with metoclopramide through: 4 h renal clearances of sodium, potassium, lithium and creatinine; plasma levels of active renin and aldosterone.

RESULTS

Whilst comparable in recumbency, aldosterone levels significantly rose during standing and after metoclopramide in both groups. In patients, dopaminergic blockade caused a fall of distal sodium delivery (P < 0.01) but urinary sodium excretion was unchanged because the reabsorbed fraction of distal sodium delivery also fell (P < 0.03). Cirrhotic patients showed the same findings in the passage from recumbency to standing.

CONCLUSIONS

In preascitic cirrhosis, the distal tubular segments of the nephron are able to cope with decreases in tubular flow by reducing reabsorption at an aldosterone-independent site (possibly the loop of Henle).

Cardiac morbidity and mortality related to orthotopic liver transplantation

This article briefly discusses the cardiac status of liver transplant recipients and their preoperative cardiac evaluation. It describes in detail perioperative and early and late postoperative complications as well as the cardiac problems associated with immunosuppression. The preoperative cardiovascular status of patients is important in determining how they cope with the stresses imposed by liver transplantation. Minor early cardiac events are common and may influence longer term cardiac morbidity. Immunosuppressive therapy may have short term effects but is likely to adversely affect long term cardiac risk.

Effects of tilting on central hemodynamics and homeostatic mechanisms in cirrhosis

Patients with cirrhosis have a hyperdynamic circulation and an abnormal blood volume distribution with central hypovolemia, an activated sympathetic nervous system (SNS) as well as the renin-angiotensin-aldosterone system (RAAS). As the hyperdynamic circulation in cirrhosis may be present only in the supine patient, we studied the humoral and central hemodynamic responses to changes with posture. Twenty-three patients with alcoholic cirrhosis (Child-Turcotte-Pugh classes A/B/C: 2/13/8) and 14 healthy controls were entered. Measurements of central hemodynamics and activation of SNS and RAAS were taken in the supine position, after 30 degrees head-down tilting, and after 60 degrees passive head-up tilting for a maximum of 20 minutes. After the head-up tilting, the central blood volume (CBV) decreased in both groups, but the decrease was significantly smaller in patients than in controls (-19% vs. -36%, P <.01). Central circulation time increased only in the patients (+30% vs. -1%, P <.01). The absolute increases in circulating norepinephrine and renin after head-up tilting were significantly higher in the patients than in the controls (P <.05 and P <.01, respectively). In patients with cirrhosis, changes in SNS and RAAS were related to changes in arterial blood pressure, systemic vascular resistance, heart rate, non-CBV, plasma volume, and arterial compliance. In conclusion, cardiovascular and humoral responses to changes in posture are clearly abnormal in patients with cirrhosis. Head-up tilting decreases the CBV less in patients with cirrhosis, and the results suggest a differential regulation of central hemodynamics in patients with cirrhosis.

Effects of tilting on central hemodynamics and homeostatic mechanisms in cirrhosis

Patients with cirrhosis have a hyperdynamic circulation and an abnormal blood volume distribution with central hypovolemia, an activated sympathetic nervous system (SNS) as well as the renin-angiotensin-aldosterone system (RAAS). As the hyperdynamic circulation in cirrhosis may be present only in the supine patient, we studied the humoral and central hemodynamic responses to changes with posture. Twenty-three patients with alcoholic cirrhosis (Child-Turcotte-Pugh classes A/B/C: 2/13/8) and 14 healthy controls were entered. Measurements of central hemodynamics and activation of SNS and RAAS were taken in the supine position, after 30 degrees head-down tilting, and after 60 degrees passive head-up tilting for a maximum of 20 minutes. After the head-up tilting, the central blood volume (CBV) decreased in both groups, but the decrease was significantly smaller in patients than in controls (-19% vs. -36%, P <.01). Central circulation time increased only in the patients (+30% vs. -1%, P <.01). The absolute increases in circulating norepinephrine and renin after head-up tilting were significantly higher in the patients than in the controls (P <.05 and P <.01, respectively). In patients with cirrhosis, changes in SNS and RAAS were related to changes in arterial blood pressure, systemic vascular resistance, heart rate, non-CBV, plasma volume, and arterial compliance. In conclusion, cardiovascular and humoral responses to changes in posture are clearly abnormal in patients with cirrhosis. Head-up tilting decreases the CBV less in patients with cirrhosis, and the results suggest a differential regulation of central hemodynamics in patients with cirrhosis.

Cardiac dysfunction in portal hypertension among patients with cirrhosis and non-cirrhotic portal fibrosis

BACKGROUND/AIMS

In cirrhosis, diastolic dysfunction of heart is well documented. Contribution of portal hypertension towards cardiac changes in cirrhosis is difficult to assess. We examined the patients of non-cirrhotic portal fibrosis who have portal hypertension without liver insufficiency to understand the contribution of portal hypertension in causing cardiac changes.

METHODS

Cardiac function was studied in four groups of patients: normal controls, patients with non-cirrhotic portal fibrosis (having portal hypertension without liver dysfunction) and cirrhotics with and without ascites. Cardiac function was evaluated by echocardiography. Additional measurements of plasma renin activity and aldosterone levels were performed.

RESULTS

Diastolic function as assessed by the ratio between E wave and A wave (E/A ratio), was significantly lower in patients with non-cirrhotic portal fibrosis (median 1.3) compared to normal controls (median 1.52). However, even lower values were observed in cirrhotics without ascites (median 1.05) and with ascites (median 0.94). There was a significant correlation (r=-0.75) between plasma aldosterone levels and the E/A ratio in cirrhotics.

CONCLUSIONS

Diastolic dysfunction is not only present in cirrhosis but also in non-cirrhotic portal fibrosis. It indicates that portal hypertension is an important factor in the genesis of cardiac dysfunction.

Cirrhotic cardiomyopathy: a pathophysiological review of circulatory dysfunction in liver disease

The systemic circulation in patients with cirrhosis is hyperdynamic with an increased cardiac output and heart rate and a reduced systemic vascular resistance as the most pronounced alterations. The concomitant cardiac dysfunction has recently been termed "cirrhotic cardiomyopathy", 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.

Modifications of cardiac function in cirrhotic patients treated with transjugular intrahepatic portosystemic shunt (TIPS)

OBJECTIVES

The implantation of a transjugular intrahepatic portosystemic shunt (TIPS) has been shown to exacerbate the hyperdynamic circulation and might induce a significant cardiac overload. We investigated cardiac function before and 1, 3, 6, and 12 months after the TIPS procedure in cirrhotic patients.

METHODS

Eleven patients with nonalcoholic cirrhosis were evaluated. Cardiovascular parameters were assessed by two-dimensional Doppler echocardiography.

RESULTS

After TIPS, the left ventricular diastolic diameter increased from 26.5 +/- 1.8 mm (basal) to 30.0 +/- 2.8 mm (6 months) (p < 0.05), whereas the ejection fraction showed a slight increase (basal, 64.5 +/- 3.3; 6 months, 68.1 +/- 3.2). The left ventricular pre-ejection period and the isovolumetric relaxation time decreased transiently at 1 month (p < 0.05). An increased velocity in all of the components of pulmonary venous flow (systolic, diastolic, and atrial) documented the accelerated fluxes induced by the procedure. The estimated pulmonary systolic arterial pressure also increased at 1 month (29.5 +/- 1.4 vs 44.1 +/- 1.4 mm Hg, p < 0.05). All of these modifications reverted after 6 months.

CONCLUSIONS

Our study demonstrates that nonalcoholic cirrhotic patients, without cardiovascular pathologies, show transient modifications in cardiac dimension and function for 3-6 months after TIPS caused by the increased volume load shunted to the heart.

Hyperdynamic circulation in portal hypertension: a comparative model of arterio-venous fistula

Complications of portal hypertension remain perplexing physiologic phenomena in the understanding of shunt hemodynamics with multiple theories. Hyperdynamic circulation was also found in sepsis, chronic anemia and arterio-venous (A-V) fistula which relate to an increase in nitric oxide. We hypothesize that portosystemic collaterals may mimic an A-V fistula in which the high-pressure portal blood connects with the lower pressure systemic venous circulation. Although these collaterals decompress the portal circulation, a number of secondary hemodynamic phenomena occur which increase portal blood flow and tend to counteract the portal hypotensive effect of the portosystemic shunt. The consequent increases in cardiac output and portal blood flow perfuse the compromised liver. As portal blood flow increases, collateral flow increases and is nearly totally shunted in the systemic circulation. This shunt may eventually introduce a vicious cycle of hyperdynamic circulation into a compromised host. Ultimately, high-output cardiac failure occurs, leading to cirrhotic cardiomyopathy.

High plasma cardiac natriuretic peptides associated with enhanced cyclic guanosine monophosphate production in preascitic cirrhosis

BACKGROUND/AIMS

The initial abnormalities of renal sodium handling in cirrhosis remain unclear. The aim of this study was to characterize sodium metabolism in preascitic cirrhosis.

METHODS

Ten patients with preascitic cirrhosis and ten controls were studied. All subjects ate a diet providing 120 mmol sodium during an equilibration period lasting 5 days and the study day. On the study day, after remaining in bed, plasma levels of atrial natriuretic peptide, brain natriuretic peptide, renin activity, aldosterone, noradrenaline, and cyclic guanosine monophosphate were measured at 7 am. Thereafter, they were instructed to maintain an upright posture until dinner and the measurements were repeated at 9 am and 6 pm. After having dinner, all subjects were asked to remain in bed and the measurements were repeated at 11 pm. To measure renal sodium and cyclic guanosine monophosphate excretion, 24-h urine collections were performed, starting from 7 pm on the day before the experimental day.

RESULTS

Plasma levels of atrial natriuretic peptide, brain natriuretic peptide and cyclic guanosine monophosphate in patients with preascitic cirrhosis were significantly elevated compared with those in controls at every sampling time (p=0.03 or less, p= 0.04 or less, and p=0.01 or less). In contrast, plasma renin activities at every sampling time were significantly lower in patients than in controls (p= 0.04 or less). Plasma aldosterone and noradrenaline levels were not significantly different at every sampling time in the two groups. No significant differences in daily renal sodium excretion were found. However, urinary cyclic guanosine monophosphate excretion was significantly higher in patients than in controls (p<0.01).

CONCLUSIONS

The initial abnormalities of sodium metabolism in cirrhosis might be characterized by blunted renal responsiveness to natriuretic peptides. The results of the study also provide indirect evidence that the impairment is mainly located at postreceptor levels of signal transduction pathway to the peptides, if the activation of antinatriuretic factors other than renin-angiotensin or sympathoadrenergic systems does not play a role.

Endogenous dopaminergic activity in Child-Pugh A cirrhosis: potential role in renal sodium handling and in the maintenance of clinical compensation

BACKGROUND

We studied the main determinants of aldosterone secretion in a group of 20 patients with biopsy-proven Child-Pugh A cirrhosis without previous ascites or diuretic consumption.

METHODS

We evaluated the plasma levels of adrenocorticotrophic hormone (ACTH), active renin and aldosterone (both supine at 07.00 h and after 30 min of upright posture),and active renin and aldosterone responses 30 min and 60 min after the administration of metoclopramide, a dopamine DA2 antagonist (10 mg e.v.). Nine normal subjects were also submitted to the metoclopramide stimulation test.

RESULTS

Compared with control subjects, the patients showed significantly greater incremental aldosterone responses both 30 min and 60 min after metoclopramide (+30 min: 157.5+/-73.3 vs. 83.5+/-32.2 pg mL(-1), P< 0003; +60 min: 142.1+/-87.2 vs. 36.8+/-39.0 pg mL(-1), P < 0-001). We found significant positive correlations between amplitude of aldosterone response 30 min after metoclopramide and 24-h urinary fractional excretion of sodium (r=0.61, P < 0.01) and basal morning aldosterone levels (r=0.69, P < 0.001).

CONCLUSIONS

The higher incremental aldosterone responses observed after metoclopramide in cirrhotic patients are expressions of increased dopaminergic activity in these patients compared with control subjects. Moreover, the correlation we found between the degree of dopaminergic activity and 24-h urinary fractional excretion of sodium suggests a role for endogenous dopamine as a relevant mediator of natriuresis in cirrhosis, at least in patients with compensated disease.

Protein profiling in cardiac tissue in response to the chronic effects of alcohol

An investigation was made into cardiac protein levels after chronic ethanol consumption to examine whether specific proteins are affected by alcohol. Ethanol was administered for six weeks to male Wistar rats which were fed a nutritionally complete liquid diet containing 35% of total calories as ethanol. Controls were pair-fed identical amounts of the same diet in which ethanol was replaced by isocaloric glucose; thus both groups had identical nutritional intakes, albeit differences in ethanol or carbohydrate. After six weeks' feeding, cardiac tissue was removed and analyzed by two-dimensional electrophoresis, where equal amounts of proteins were studied. Protein patterns were analyzed by computerized densitometry and characterized by comparison with a database of known cardiac proteins. Chronic alcohol feeding caused significant decreases in the relative amounts of various proteins, including several tentatively identified as heat shock protein (HSP) 60, HSP70, and desmin. The relative proportions of actin, vimentin, myosin light chain 1, myosin light chain 2, and albumin, remained unchanged. Examination of antibodies raised against HSP65 showed no overt differences in plasma levels following chronic alcohol consumption, and liver changes as assessed by histology were mild. In conclusion, chronic alcohol appears to have selective effects on particular proteins, and the effects were not directly ascribed to overt liver dysfunction or malnutrition. This may explain some of the functional and morphological characteristics observed in alcohol-induced heart muscle disease, including reduced contractility.

Effect of posture-induced blood volume expansion on systemic and regional hemodynamics in patients with cirrhosis

BACKGROUND/AIMS

This study aimed to investigate the effects of posture-induced blood volume expansion on systemic and regional hemodynamics in patients with cirrhosis.

METHODS

The mean arterial pressure, cardiac index, peripheral vascular resistance index, and flow volume index of the superior mesenteric artery (SMA) and femoral artery (FA) were measured in 10 patients with cirrhosis and portal hypertension and 10 controls after they had been standing for 2 h. Plasma atrial natriuretic peptide, plasma renin activity, and plasma glucagon levels were also determined. These measurements were repeated after 30 min and 60 min when the patients were recumbent.

RESULTS

In the upright posture, systemic hemodynamics, FA blood flow index, plasma atrial natriuretic peptide level, and plasma renin activity level were similar in patients and controls. However, SMA blood flow index and plasma glucagon level were significantly higher in patients than in controls. On the assumption of the supine position, cardiac index and plasma atrial natriuretic peptide level significantly increased in the two groups, but the changes were greater in patients than in controls. Mean arterial pressure remained unchanged. The reduction in peripheral vascular resistance index was therefore greater in patients in controls. SMA and FA blood flow index increased significantly in the two groups, but the changes were greater in patients than in controls. Furthermore, SMA blood flow fraction (SMA blood flow index/cardiac index) was steady in controls, whereas it increased significantly in patients. In contrast, FA blood flow fraction (FA blood flow index/cardiac index) remained unchanged in the two groups. In patients, the change in peripheral vascular resistance index was correlated inversely with that of SMA blood flow index, but not with that of FA blood flow index. Plasma renin activity level dropped significantly, but the decline was similar in the two groups. Plasma glucagon level was not modified in either group.

CONCLUSIONS

In patients with cirrhosis, splanchnic vasodilation appears to be present, even in the upright position, and further abnormal vasodilation occurs on recumbency-induced blood volume expansion. This abnormal shear-stress phenomenon observed in the splanchnic circulation seems to be mediated by a local vasodilator rather than a general vasodilator.

Effects of endoscopic variceal sclerotherapy on azygos vein blood flow and systemic haemodynamics

The present study was designed to determine the systemic haemodynamic effects of obliterating oesophageal varices by endoscopic sclerotherapy. We evaluated systemic and splanchnic haemodynamics before and after the first course of sclerotherapy in cirrhotic patients. The baseline cardiac index was significantly correlated with baseline azygos vein blood flow (r = 0.64; P < 0.01) and the azygos vein blood flow and cardiac index significantly decreased (-33% and -16%, respectively; P < 0.01) following sclerotherapy. The systemic vascular resistance index was also increased significantly (+ 20%; P < 0.01) in these patients. Moreover, the per cent change in azygos vein blood flow was directly correlated with that of the cardiac index (r = 0.51; P < 0.03). We conclude from these findings that the obliteration of portosystemic collaterals by sclerotherapy significantly reverses hyperdynamic circulation in such patients via a decrease in cardiac preload. The blood flow of the portosystemic shunt per se is a leading contributor to the hyperdynamic circulation observed in patients with well-developed portal systemic collateral vessels.

Decreased right heart blood volume determined by magnetic resonance imaging: evidence of central underfilling in cirrhosis

Whether the central blood volume is reduced or expanded in cirrhosis is still under debate. Accordingly, the current study was undertaken to assess the volume of the heart cavities. Ten cirrhotic patients and matched controls had their right and left ventricular end-diastolic volumes (RVDV and LVDV), and end-systolic volumes (RVSV and LVSV) determined by magnetic resonance imaging (MRI). RVDV (122 vs. control 166 mL, P < .02), RVSV (41 vs. 80 mL, P < .02) and right atrial volume (47 vs. 64 mL, P < .05) were significantly reduced in the patients. In contrast, LVDV (134 vs. 129 mL, NS), LVSV (54 vs. 40 mL, NS), and left atrial volume (70 vs. 57 mL, P = .08) were normal or slightly increased. The right ejection fraction (68% vs. 53%, P < .05) was significantly increased, but the left ejection fraction was slightly reduced (61% vs. 69%, NS). The central and arterial blood volume (CBV), assessed as the cardiac output (CO) multiplied by the central circulation time, was significantly decreased (1.47 vs. 1.81 L, P < .05). The noncentral blood volume (4.43 vs. 3.64 L, P < .02), plasma volume (4.05 vs. 3.27 L, P < .02), and CO (7.11 vs. control 5.22 L/min, P < .01) were significantly increased in the patients. CCT (13.1 vs. 20.0 sec, P < .005) and the right ventricular transit time (0.79 vs. 1.35 sec, P < .005) were significantly reduced, but the left ventricular transit time was normal (0.91 vs. 0.88 sec, NS). Systemic vascular resistance was reduced (991 vs. 1,490 dyn.sec/cm5, P < .01).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of upright posture and physical exercise on endogenous neurohormonal systems in cirrhotic patients with sodium retention and normal supine plasma renin, aldosterone, and norepinephrine levels

It is well known that sodium retention occurs in a significant proportion of patients with cirrhosis despite normal supine plasma levels of renin, aldosterone (ALDO), and norepinephrine (NE). The current study was performed to assess whether this subset of patients also present normal activity of the renin-aldosterone and sympathetic nervous systems during upright posture in sitting position and moderate physical exercise. Nine healthy controls, 14 patients with compensated cirrhosis and 10 patients with cirrhosis, ascites, sodium retention, and normal supine plasma renin activity (PRA) and ALDO and NE concentration were sequentially studied after 60 minutes in supine rest, 30 minutes in sitting position, and 30 minutes of cycloergometric exercise (3-METs). Sitting position and exercise were associated with similar stimulation of the renin-aldosterone and sympathetic nervous systems in the three groups of subjects. Consequently, cirrhotic patients with ascites showed values of PRA and plasma concentration of ALDO and NE similar to healthy subjects and patients with compensated cirrhosis during supine rest (renin: 1.4 +/- 0.3, 0.8 +/- 0.2, and 0.8 +/- 0.3 ng/mL; aldosterone: 24.3 +/- 4.7, 20.2 +/- 3.9 and 21.4 +/- 3.4 ng/dL; norepinephrine: 252 +/- 23, 250 +/- 16, and 255 +/- 23 pg/mL), sitting position (renin: 2.1 +/- 0.5, 1.1 +/- 0.3, and 1.6 +/- 0.4; aldosterone: 32.2 +/- 7.3, 23.7 +/- 5.3, and 26.2 +/- 4.5; norepinephrine: 356 +/- 38, 401 +/- 63, and 420 +/- 35), and exercise (renin: 2.9 +/- 0.8, 1.6 +/- 0.4, and 2.2 +/- 0.5; aldosterone: 43 +/- 6.4, 34.9 +/- 8.5, and 38.2 +/- 5.3; norepinephrine: 481 +/- 35, 499 +/- 54, and 534 +/- 48).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of high dose atrial natriuretic peptide on renal haemodynamics, sodium handling and hormones in cirrhotic patients with and without ascites

To elucidate and to try to reverse the antinatriuretic mechanisms in liver cirrhosis, atrial natriuretic peptide (ANP) was given as a pharmacological bolus dose (2 micrograms per kg body weight) to 14 cirrhotic patients, and as a control to 14 healthy subjects. The nine patients with ascites had baseline values of glomerular filtration rate (GFR), effective renal plasma flow (ERPF) and blood pressure (BP) similar to controls. Their distal tubular fractional reabsorption of sodium (DFRNa), estimated by the lithium clearance technique, was higher than in controls, and so were plasma values of aldosterone (564 vs. 119 pmol l-1 medians), endothelin (1.23 vs. 0.63 pmol l-1), ANP (7.5 vs. 3.6 pmol l-1) and cyclic GMP (8.8 vs. 4.6 nmol l-1); p < 0.01 for all. The five patients without ascites had higher GFR and ERPF, and lower plasma angiotensin II than controls. After ANP injection, similar plasma levels of ANP and cyclic GMP were reached in all groups. Urinary sodium excretion rate increased in controls (0.23 to 0.52 mmol min-1, p < 0.01), while GFR increased (108 to 117 ml min-1, p < 0.05), and DFRNa decreased (93 to 89%, p < 0.01). In cirrhotics with ascites sodium excretion was unaltered (0.12 to 0.11 mmol min-1), and so was GFR (84 to 83 ml min-1). Proximal tubular fractional reabsorption of sodium increased after 90 min, whereas DFRNa decreased immediately (97 to 96%, p < 0.01) though less markedly than in controls. Sodium excretion increased in four of five patients without ascites (0.23 to 0.27 mmol min-1, medians). In patients with ascites, endothelin in plasma decreased after ANP (p < 0.05). Plasma levels of angiotensin II, aldosterone and vasopressin were unchanged in all groups. In conclusion, although hyper-reabsorption of sodium occurred in the distal rather than the proximal part of the nephron in cirrhotic patients with ascites, ANP had no natriuretic effect. This was most probably due primarily to the lack of increase of GFR and blunted inhibition of DFRNa, attributed to high aldosterone. The effect of ANP in suppressing the high endothelin did not seem to improve sodium excretion.

Pattern of sodium handling and its consequences in patients with preascitic cirrhosis

BACKGROUND/AIMS

The initial abnormalities in the renal sodium handling in patients with cirrhosis before developing ascites remain unknown. The aim of this study is to further characterize sodium metabolism and the effects of sodium loading in preascitic cirrhosis.

METHODS

Eight male, preascitic patients with cirrhosis and 6 volunteers had their daily urinary sodium excretion level measured while on a strictly metabolically controlled diet, first consisting of 20 mmol then of 200 mmol sodium per day each for 7 days. Central blood volume, plasma norepinephrine, and atrial natriuretic factor levels were measured during each diet.

RESULTS

Preascitic patients with cirrhosis had significantly less daily urinary sodium excretion on both diets. Volume expansion in the patients with cirrhosis was indicated by significantly greater weight gain and higher atrial natriuretic factor levels for each diet. Patients with cirrhosis had central blood volume expansion (1725 +/- 54 mL/m2) compared with controls (1495 +/- 81 mL/m2; P = 0.03) on a low-sodium diet. This increased significantly in the controls (1864 +/- 164 mL/m2; P = 0.04) on a high-sodium diet, associated with suppression of plasma norepinephrine, but not in the patients with cirrhosis (1679 +/- 107 mL/m2; P > 0.05).

CONCLUSIONS

Failure of further central blood volume expansion in the patients with cirrhosis on high-sodium diet in the presence of significant weight gain suggests maldistribution away from the effective arterial blood volume. This study provides further reasons why preascitic patients with cirrhosis might benefit from sodium restriction.

Hyperdynamic circulation of advanced cirrhosis: a re-appraisal based on posture-induced changes in hemodynamics

Little is known about the effect of posture on the circulatory abnormalities of advanced cirrhosis. We evaluated the systemic hemodynamics, measured by Doppler-echocardiography, atrial natriuretic factor, plasma renin activity and plasma norepinephrine, in 10 patients with cirrhosis and ascites and 10 healthy controls, after 2 h of standing and during lying down for a further 2 h. Standing hemodynamic patterns of controls and patients with cirrhosis did not differ significantly. The latter, however, showed higher plasma renin activity, norepinephrine and atrial natriuretic factor. The assumption of the supine position led to greater increases in cardiac index and atrial natriuretic factor, and reduction in systemic vascular resistance in patients with cirrhosis. Norepinephrine and plasma renin activity declined in both groups to a similar extent, while heart rate only slowed in controls. Thus, after 2 h in the supine position, patients with cirrhosis showed hyperdynamic circulation with increased cardiac index and heart rate and reduced systemic vascular resistance. Norepinephrine, plasma renin activity and atrial natriuretic factor were also elevated. The hyperdynamic circulation in advanced cirrhosis appears during or is enhanced by lying down. This finding suggests that this syndrome is, at least in part, attributable to excessive blood volume translocation towards the central area. However, the persistent activation of renin-angiotensin and sympathoadrenergic systems suggests that a concomitant reduced vascular sensitivity to vasoconstrictors concurs in its development.

Atrial natriuretic factor in cirrhosis: relationship to renal function and hemodynamic changes

Plasma atrial natriuretic factor concentrations and different hemodynamic parameters, including the evaluation of femoral arteriovenous shunting by measuring the arteriovenous difference of oxygen content (Ca-vO2), were determined in eight healthy subjects and 24 patients with cirrhosis without renal failure (group I: seven patients without ascites, group II: nine patients with ascites and UNaV > 10 mEq/24 h and group III: eight patients with ascites and UNaV < or = 10 mEq/24 h). Atrial natriuretic factor was 34 +/- 4.7 pg/ml in the control group and 44.28 +/- 5.4, 67.89 +/- 8.8 and 84 +/- 10.8 pg/ml in groups I, II and III respectively (p < 0.001. group III vs. I and control and II vs. control). Atrial natriuretic factor directly correlated with cardiac index (p < 0.01), blood volume (p: 0.01), femoral blood flow (p < 0.01) and inversely with systemic and femoral vascular resistances (p < 0.02), Ca-vO2 (p < 0.01), serum albumin (r: -0.61; p < 0.01) and prothrombin index (r: -0.63; p < 0.02). These results indicate that plasma atrial natriuretic factor is increased in patients with cirrhosis, especially in those with advanced disease and marked renal sodium retention. This suggests that in cirrhosis, arteriolar vasodilation and peripheral arteriovenous shunting influence renal function while inducing a state of overflow at the central venous compartment leading to increased atrial natriuretic factor secretion. Increased production of this vasodilatory hormone may thus contribute to the hyperkinetic circulation of cirrhosis.

Volume-dependent echocardiographic parameters are not useful for estimating baseline blood volume but are useful for detecting acute changes in vascular filling state

To assess the hypothesis that echocardiographic variables vary as a function of baseline blood volume and change in response to changes in vascular filling state, we evaluated the relationship between the atrial and ventricular dimensions and left ventricular function, as measured by combined Doppler and M-mode echocardiography on the one hand, and blood volume as measured by a standard radioactive isotope technique on the other. Furthermore, we determined the effect of an increment in vascular filling state induced by plasma volume expansion. Test subjects were ten male and six female volunteers. Blood volume/kg was the only factor not different between male and female subjects and therefore suitable for our study. None of the echocardiographic variables correlated with blood volume/kg. Volume loading increased stroke volume, left atrial diameter, right atrial area, left ventricular end-diastolic dimension, mean velocity of circumferential fiber shortening and left ventricular ejection time. It is concluded that echocardiographic variables are unsuitable for estimating blood volume. Serial measurements of atrial dimensions and left ventricular dimensions are useful for detecting rapid changes in vascular filling state.

Early pregnancy changes in hemodynamics and volume homeostasis are consecutive adjustments triggered by a primary fall in systemic vascular tone

OBJECTIVE

The purpose of this study was to test the hypothesis that early pregnancy changes in volume homeostasis develop as a consequence of preceding changes in maternal hemodynamics.

STUDY DESIGN

Maternal cardiovascular function of 10 pregnant women was followed up by Doppler echocardiography. Vascular filling state and volume homeostasis were evaluated by echocardiographic index values, glomerular filtration rate, serum osmolality, and volume-regulating hormones. Studies were performed weekly in early pregnancy, in the second and third trimesters, and post partum. Changes relative to the fifth week and the consistency of changes between weeks 5 and 8 were evaluated by nonparametric statistics.

RESULTS

In early pregnancy cardiac output increased and afterload decreased. Concomitant increases in ultrasonic preload index values and glomerular filtration rate were accompanied by decreases in serum renin, Na+, and osmolality.

CONCLUSION

These data support the concept that maternal hemodynamic adaptation to pregnancy is most likely triggered by a primary fall in systemic vascular tone. The resulting rapid fall in preload and afterload leads to a compensatory increase in heart rate and activation of the volume-restoring mechanisms. Subsequently cardiac output increases because of a rise in stroke volume, which develops because the vascular filling state normalizes, whereas the reduced afterload reduction is maintained.

The role of atrial natriuretic peptide (ANP) in chronic liver disease

The role of atrial natriuretic peptide (ANP) and potential defects of ANP in liver disease are reviewed. Patients with cirrhosis of the liver show no decrease of ANP plasma concentrations nor changes in the pattern of ANP immunoreactivity nor changes of splanchnic ANP clearance. The renal effects of exogenously administered as well as endogenously released ANP are blunted in cirrhosis, in particular in patients with ascites. This seems due to increased activity of sodium-retaining hormonal systems and changes of the renal ANP receptor status. Pharmacological inhibition of ANP-degradation or clearance may yield therapeutic potential.

Variability of atrial natriuretic peptide plasma levels in ascitic cirrhotics: pathophysiological and clinical implications

Ascitic cirrhotic patients are a heterogenous population with respect to factors that may affect plasma human atrial natriuretic peptide levels (such as degree of plasma volume and plasma levels of angiotensin II, vasopressin and norepinephrine). Thus the proven variability of plasma human atrial natriuretic peptide values in ascitic cirrhotic patients may be due also to the selection of patients, not only to the study conditions. The response to standardized stepped-care medical treatment of ascites makes it possible to characterize ascitic cirrhotic patients with different patterns of renal sodium excretion, intrarenal sodium handling, plasma renin activity, plasma aldosterone and thus, probably, effective circulating volume. Consequently, we evaluated human atrial natriuretic peptide plasma levels in controls (n = 23), in ascitic cirrhotic patients who underwent spontaneous diuresis (group A, n = 7) and in cirrhotic patients who required diuretic treatment (group B, n = 44). The last group was then divided into two subgroups. Subgroup B-R (n = 25) included patients who responded to spironolactone alone, whereas subgroup B-NR (n = 19) included patients who did not respond to 500 mg/day spironolactone. All patients were maintained on identical normocaloric restricted sodium intake (80 mEq/day) throughout the study. Ascitic cirrhotic patients, as a whole, had higher values of human atrial natriuretic peptide than did controls (70.8 +/- 46.6 pg/ml vs. 41.7 +/- 16.3 pg/ml, p < 0.025). No difference was found in human atrial natriuretic peptide/plasma renin activity between the two groups (87 +/- 160 pg/ng/hr vs. 44 +/- 73 pg/ng/hr, p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Estimated central blood volume in cirrhosis: relationship to sympathetic nervous activity, beta-adrenergic blockade and atrial natriuretic factor

The estimated central blood volume (i.e., blood volume in the heart cavities, lungs and central arterial tree) was determined by multiplying cardiac output by circulatory mean transit time in 19 patients with cirrhosis and compared with sympathetic nervous activity and circulating level of atrial natriuretic factor. Arterial norepinephrine level, an index of overall sympathetic nervous activity (3.08 nmol/L in patients vs. 1.36 nmol/L in controls; p < 0.01) was negatively correlated (r = -0.54, p < 0.01) with estimated central blood volume (mean = 23 ml/kg in patients vs. 27 ml/kg in controls; p < 0.05). Similarly, renal venous norepinephrine level (an index of renal sympathetic tone; 4.26 nmol/L in patients vs. 1.78 nmol/L in controls; p < 0.01) was inversely correlated with estimated central blood volume (r = -0.53, n = 18, p < 0.02). No significant correlation could be established between arterial atrial natriuretic factor level (8.9 pmol/L in patients vs. 9.6 pmol/L in controls; not significant) and estimated central blood volume. Hemodynamic values were subsequently modified with oral propranolol (80 mg). During beta-adrenergic blockade, the mean estimated central blood volume was not altered significantly, except in six patients who exhibited decreases in mean arterial blood pressure (85 to 69 mm Hg; n = 6) and decreases in mean estimated central blood volume (23.2 to 20.6 ml/kg; n = 6, p < 0.05). Slight increases were observed in mean right atrial pressure (2.2 to 3.7 mm Hg; n = 14, p < 0.05); this change was positively correlated with the change in estimated central blood volume (r = 0.44, n = 14, p = 0.06).(ABSTRACT TRUNCATED AT 250 WORDS)

Bed-rest-induced hypernatriuresis in cirrhotic patients without ascites: does it contribute to maintain 'compensation'?

Renal function, plasma renin activity, plasma aldosterone concentration and urine excretion of free norepinephrine were evaluated in 13 cirrhotics without previous or ongoing ascites and in 13 healthy subjects, after 6 days of controlled electrolyte intake (40 mmol of Na and 70 mmol of K per day) and during 24 h of recumbency. Plasma concentrations of the atrial natriuretic peptide (ANP) were also measured in 8 patients and 8 controls. Despite a low-normal filtered load of sodium (14.6 +/- 1.2 vs. 17.1 +/- 1.2 mmol/min), cirrhotic patients showed supernormal natriuresis (141.5 +/- 14.1 vs. 78.8 +/- 8.6 mmol/day; p < 0.001). Whereas the fractional excretion of sodium in these patients was twice that of controls (0.70 +/- 0.05 vs. 0.36 +/- 0.04%; p < 0.001), potassium excretion (42.5 +/- 2.7 vs. 43.1 +/- 2.7 mmol/day) and urine volume (1270 +/- 98 vs. 1452 +/- 148 ml/day) did not differ. In cirrhotics, plasma renin activity was reduced (0.50 +/- 0.12 vs. 1.39 +/- 0.33 ng/ml/h; p < 0.02), and plasma aldosterone concentration tended to be lower (66 +/- 10 vs. 86 +/- 9 pg/ml; p = 0.09), while urine norepinephrine excretion did not significantly differ from controls (961 +/- 120 vs. 782 +/- 43 ng/h). ANP was higher in patients than in controls (92 +/- 17 vs. 48 +/- 9 pg/ml; p < 0.05). Natriuresis was directly correlated with ANP (r = 0.69, p < 0.005) and ANP/plasma aldosterone ratio (r = 0.63; p < 0.01) in patients and healthy subjects taken together.(ABSTRACT TRUNCATED AT 250 WORDS)

The hemodynamic status of preascitic cirrhosis: an evaluation under steady-state conditions and after postural change

To assess the hemodynamic status of patients with compensated cirrhosis, mean arterial pressure, cardiac index and peripheral vascular resistance and markers of central (plasma concentrations of atrial natriuretic factor) and arterial volemia (plasma norepinephrine concentration, plasma renin activity) were studied in 10 patients and 10 healthy control subjects under steady-state conditions (after 2 hr of standing) and after assumption of the supine position (30, 60, and 120 min). After standing, neither hemodynamics nor markers of effective volemia differed significantly between controls and patients. By evaluating the areas under the curve during the 2 hr of supine posture, the increase in cardiac output and plasma natriuretic factor and the decrease in peripheral vascular resistance were greater in patients (2.59 +/- 0.43 [S.E.M.] L/min/hr; 32.8 +/- 7.2 pg/ml/hr -1,103 +/- 248.4 dyn.sec/cm5/hr, respectively) than in controls (0.53 +/- 0.24 L/min/hr, p = 0.005; 17.4 +/- 4.7 pg/ml/hr, p = 0.005; -265.5 +/- 206.2 dyn.sec/cm5/hr, p = 0.02). The declines in heart rate, plasma norepinephrine concentration and plasma renin activity did not differ significantly. Mean arterial pressure did not significantly change. Our results suggest that during periods of upright posture, cirrhotic patients in the preascitic stage, who are known to have expanded blood volume, compensate for dilatation of the splanchnic vascular bed through total hypervolemia. The latter becomes excessive during recumbency, leading to supernormal increases in venous return, central volemia and cardiac index. The decline in peripheral vascular resistance appears to be a compensatory mechanism to maintain steady arterial blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Segmental mean transit times of 99mtechnetium within central vascular space in liver cirrhosis

Mean transit time (MTT) through a given vascular space is closely related to the effective blood volume in this compartment. Central vascular blood volume in liver cirrhosis is believed to be reduced, but more precise data on the location of the underfilled vascular area are lacking. 99mTechnetium first-pass angiography was performed in 15 cirrhotic patients and in 10 age-matched normals. The method of segmental analysis of MTT was validated by performing an analog study in a plastic tubing/chamber system. The mean tracer sojourn in the central circulation was described in cirrhotic patients (10.25 +/- 2.17 s vs 12.92 +/- 2.88 s; p less than 0.05); however, this finding was not observed beyond cardiopulmonary circulation (MTT between right and left heart chambers). Segmental comparative analysis between cirrhotics and normals revealed significant MTT differences in two vascular subcompartments, i.e. right chamber-pulmonary artery, and within the lung vascular bed. Analysis of time activity lung curves in patients with cirrhosis disclosed a shorter time to peak and more rapid washout of the tracer from this area, without any change in curve symmetry as compared to normals. Ascites had no apparent impact on MTT rate, and cirrhotics with most advanced disease (grade C Child-Pugh) had longer MTT through the cardiopulmonary circulation as compared to combined groups A & B (7.32 +/- 0.13 s vs 6.03 +/- 1.23 s; p less than 0.05). Our data provide further evidence for contraction of the cardiopulmonary vascular space in liver cirrhosis.

Plasma renin activity in alcoholic liver disease

PURPOSE AND PATIENTS AND METHODS

The relationship of plasma renin activity (PRA) to indices of circulatory filling and other possible determinants of renin secretion was studied in 31 men with alcoholic liver disease. Characteristics of patients with normal and increased PRA values were examined. Significant differences guided subsequent simple and multiple regression analysis.

RESULTS

Supine PRA was increased (greater than 2.4 ng/mL/h on a 200 mEq/d intake of sodium, ranging as high as 33 ng/mL/h) in 14 of 57 studies. Nonascitic patients with elevated PRA values were significantly younger than those with normal PRA values. Among patients without ascites, the plasma atrial natriuretic factor concentration correlated inversely with PRA. Ascitic patients with elevated PRA values had a significantly reduced serum sodium concentration, urinary sodium excretion, creatinine clearance, and arterial pressure. Systemic vascular resistance, plasma norepinephrine and caffeine concentrations, and left atrial volume were similar in patients with and without increased PRA values. Univariate followed by multiple regression analysis identified age and plasma atrial natriuretic factor concentration as significant independent correlates of PRA in patients without ascites (R2 = 0.54). Serum sodium concentration and urinary sodium excretion were significant correlates of PRA in patients with ascites (R2 = 0.80).

CONCLUSION

The associates of PRA in alcoholic liver disease are diverse and potentially complex. Age and plasma atrial natriuretic factor concentration are important in patients without ascites. In patients with ascites, tubular delivery of sodium to the macula densa, as modified by the filtered load and proximal reabsorption, appeared to be a principal association of PRA. Indices of circulatory filling did not emerge as clearly independent associations of PRA. Increased PRA values in patients with ascites may be an effect of sodium retention rather than part of its cause.

Arterial vasodilation is not the cause of increased cardiac output in cirrhosis

A pathological state of arterial vasodilation has been postulated to cause the increased cardiac output commonly observed in cirrhosis. Further, subsequent arterial underfilling has been proposed as the stimulus to sodium retention and ascites formation. Left ventricular size during the cycle of a cardiac contraction is predictably altered by a decrease in afterload. Specifically, increased systolic emptying should be observed. The relationship of left ventricular size during the cardiac cycle to systemic hemodynamic indices and urinary sodium retention was investigated in patients with alcoholic cirrhosis to test these hypotheses. Echocardiographic studies were performed on 24 male patients with alcoholic cirrhosis and compared with the results obtained in 10 age-matched male controls. Patients with cirrhosis had increased cardiac output and heart rate and decreased arterial pressure compared with normal subjects, confirming the presence of a hyperdynamic circulation. Patients with cirrhosis had enlarged left ventricular diameter at both end diastole (0.08 +/- 0.01 vs. 0.07 +/- 0.007 cm/kg dry body wt; P less than 0.001) and end systole (0.06 +/- 0.01 vs. 0.05 +/- 0.005 cm/kg; P less than 0.05). Left ventricular end-diastolic diameter was directly related to blood volume (r = 0.56, P less than 0.005). No significant differences in cardiac output, arterial pressure, or systemic resistance were found between patients with and patients without ascites. Increased cardiac output in cirrhosis occurs in conjunction with an enlarged ventricle throughout the cardiac cycle. The increase in left ventricular end-systolic diameter indicates that diminished afterload is not responsible for the increase in cardiac output. As the diameter of the ventricle during diastolic filling correlates with vascular volume, cardiac output in cirrhosis may be primarily determined by an increase in vascular volume.