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

Reduced baroreflex sensitivity and pulmonary dysfunction in alcoholic cirrhosis: effect of hyperoxia

Patients with cirrhosis exhibit impaired regulation of the arterial blood pressure, reduced baroreflex sensitivity (BRS), and prolonged QT interval. In addition, a considerable number of patients have a pulmonary dysfunction with hypoxemia, impaired lung diffusing capacity (Dl(CO)), and presence of hepatopulmonary syndrome (HPS). BRS is reduced at exposure to chronic hypoxia such as during sojourn in high altitudes. In this study, we assessed the relation of BRS to pulmonary dysfunction and cardiovascular characteristics and the effects of hyperoxia. Forty-three patients with cirrhosis and 12 healthy matched controls underwent hemodynamic and pulmonary investigations. BRS was assessed by cross-spectral analysis of variabilities between blood pressure and heart rate time series. A 100% oxygen test was performed with the assessment of arterial oxygen tensions (Pa(O(2))) and alveolar-arterial oxygen gradient. Baseline BRS was significantly reduced in the cirrhotic patients compared with the controls (4.7 +/- 0.8 vs. 10.3 +/- 2.0 ms/mmHg; P < 0.001). The frequency-corrected QT interval was significantly prolonged in the cirrhotic patients (P < 0.05). There was no significant difference in BRS according to presence of HPS, Pa(O(2)), Dl(CO), or Child-Turcotte score, but BRS correlated with metabolic and hemodynamic characteristics. After 100% oxygen inhalation, BRS and the QT interval remained unchanged in the cirrhotic patients. In conclusion, BRS is significantly reduced in patients with cirrhosis compared with controls, but it is unrelated to the degree of pulmonary dysfunction and portal hypertension. Acute hyperoxia does not significantly revert the low BRS or the prolonged QT interval in cirrhosis.

Balancing volume resuscitation and ascites management in cirrhosis

PURPOSE OF REVIEW

Patients with cirrhosis have total extracellular fluid overload but central effective circulating hypovolaemia. The resulting neurohumoral compensatory response favours the accumulation of fluids into the peritoneal cavity (ascites) and may hinder renal perfusion (hepatorenal syndrome). Their deranged systemic haemodynamics (hyperdynamic circulatory syndrome) is characterized by elevated cardiac output with decreased systemic vascular resistance and low blood pressure.

RECENT FINDINGS

Molecular and biological mechanisms determining cirrhosis-induced haemodynamic alterations are progressively being elucidated. The need for a goal-directed assessment of volume resuscitation (especially with volumetric techniques) in patients with cirrhosis is becoming more and more evident. The role of fluid expansion with albumin and the use of splanchnic vasopressors in a variety of cirrhosis-related conditions has recently been investigated.

SUMMARY

The response to fluid loading in patients with advanced cirrhosis is abnormal, primarily resulting in expansion of their noncentral blood volume compartment. Colloid solutions, in particular albumin, are best used in these patients. Albumin may be effective in preventing the haemodynamic derangements associated with large-volume paracentesis (paracentesis-induced circulatory dysfunction), in preventing renal failure during spontaneous bacterial peritonitis and, in association with splanchnic vasopressors, in caring for patients with the hepatorenal syndrome.

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.

Cardiovascular changes in cirrhosis: pathogenesis and clinical implications

Liver cirrhosis is associated with a wide range of cardiovascular abnormalities including hyperdynamic circulation, cirrhotic cardiomyopathy, and pulmonary vascular abnormalities. The pathogenic mechanisms of these cardiovascular changes are multifactorial and include neurohumoral and vascular dysregulations. Accumulating evidence suggests that cirrhosis-related cardiovascular abnormalities play a major role in the pathogenesis of multiple life-threatening complications including hepatorenal syndrome, ascites, spontaneous bacterial peritonitis, gastroesophageal varices, and hepatopulmonary syndrome. Treatment targeting the circulatory dysfunction in these patients may improve the short-term prognosis while awaiting liver transplantation. Careful fluid management in the immediate post-transplant period is extremely important to avoid cardiac-related complications. Liver transplantation results in correction of portal hypertension and reversal of all the pathophysiological mechanisms that lead to the cardiovascular abnormalities, resulting in restoration of a normal circulation. The following is a review of the pathogenesis and clinical implications of the cardiovascular changes in cirrhosis.

Impaired cardiovascular function in primary biliary cirrhosis

Cardiovascular system dysregulation in the form of autonomic dysfunction is common at all stages of the disease process in the autoimmune liver disease primary biliary cirrhosis (PBC) and associates with the symptom of fatigue. The mechanisms underpinning autonomic dysfunction in PBC are, however, at present unclear. In this study we set out to explore, for the first time, cardiac structure and function in PBC using impedance cardiography (ICG) and magnetic resonance methodologies. ICG was assessed beat to beat in response to orthostasis (by head-up tilt) in age and sex case-matched high-fatigue and low-fatigue PBC groups (assessed by Fatigue Impact Scale), normal control subjects (n = 15 each group) and a liver disease control cohort (primary sclerosing cholangitis). Cardiac structure and bioenergetics were examined in 15 of the PBC subjects and 8 of the normal control subjects by magnetic resonance spectroscopy and cine imaging. Capacity of the left ventricle to respond to orthostasis [left ventricular ejection time (LVET)] was impaired in PBC compared with matched normal control subjects (P = 0.05). This was a PBC-specific phenomenon unrelated to fatigue status. PBC patients exhibited significantly lower cardiac muscle phosphocreatine-to-ATP ratio (PCr/ATP ratio; measure of cardiac bioenergetic integrity) compared with control subjects (P < 0.01). PCr/ATP <1.6 (indicative of increased risk of death in cardiomyopathy) was present in 6/15 (40%) PBC patients (0/8 control subjects; P < 0.05). Cardiac structure and function were similar in all measures of left ventricular morphology between control subjects and PBC. The close relationship between PCr/ATP and LVET seen in normal subjects (r(2) = 0.6; P < 0.05) was lost in PBC patients, a finding compatible with myocardial dysfunction. Significant correlation was seen between fatigue severity in PBC and fall in cardiac output on orthostasis (r(2) = 0.25; P = 0.005). Our findings suggest the presence of altered myocardial function in PBC. Autonomic "dysfunction" may, rather than being an abnormal process, represent a compensatory mechanism to increase cardiac return to mitigate these effects.

Hemodynamics in the immediate post-transplantation period in alcoholic and viral cirrhosis

AIM: To study the hemodynamics in the immediate post transplant period and compare patients with alcoholic vs viral cirrhosis.

METHODS: Between 2000-2003, 38 patients were transplanted for alcoholic cirrhosis and 28 for postviral cirrhosis. Heart rate (HR), central venous pressure (CVP), mean arterial pressure (MAP), pulmonary capillary wedge pressure (PCWP), cardiac index (CI), systemic vascular resistance index (SVRI), pulmonary artery pressure (PAP), and pulmonary vascular resistance index (PVRI) were measured immediately and 24 h post transplantation.

RESULTS: Hyperdynamic circulation persisted at 24 h following transplantation with an elevated CI of 5.4 ± 1.3 L/(min × m²) and 4.9 ± 1.0 L/(min × m²) in the viral and alcoholic groups, respectively, and was associated with a decreased SVRI. Within the first 24 h, there was a significant decrease in HR and increase in MAP; the extent of the change was similar in both groups. The CVP, PCWP, and SVRI increased, and CI decreased in the viral patients, but not the alcoholic patients. Alcoholics showed a lower PVRI (119 ± 52 dynes/(cm⁵× m²) vs 166 ± 110 dynes/(cm⁵× m²), P < 0.05) and PAP (20 ± 7 mmHg vs 24 ± 7 mmHg, P < 0.05) compared to the viral group at 24 h.

CONCLUSION: Hyperdynamic circulation persists in the immediate post-transplant period with a faster improvement in the viral group. Alcoholic patients have a more pronounced pulmonary vasodilatation.

Baroreceptor sensitivity and baroreceptor effectiveness index in cirrhosis: the relevance of hepatic venous pressure gradient

BACKGROUND

Autonomic dysfunction has been reported as one of the complications of cirrhosis.

AIMS

The aim of this study was to test autonomic dysfunction in cirrhotic patients by analysing the baroreflex sensitivity and the baroreceptor effectiveness index (BEI), in order to determine its correlation with the severity and the aetiology of liver disease. Moreover, we explored the relationship between baroreceptor function and mortality in our cohort of patients.

METHODS

Clinical and laboratory evaluation, hepatic venous pressure gradient (HVPG) and haemodynamic setting and baroreceptor function were assessed in 45 cirrhotic patients (median age 55, range 38-72 years) divided in groups according to the severity of their disease (26 patients Child A, 13 patients Child B and six patients Child C).

RESULTS

Baroreceptor sensitivity and BEI were impaired in more advanced cirrhotic patients compared with subjects with milder disease (P<0.001). HVPG was significantly, independently and inversely correlated with baroreceptor sensitivity (P=0.003). More severe impairment of baroreceptor function was associated with a higher mortality (P=0.04) and subjects with alcohol-related cirrhosis presented worse baroreceptor function (P=0.032) and poorer survival (P=0.003) compared with subjects with post-viral liver disease.

CONCLUSIONS

These data support the hypothesis that liver disease severity and particularly portal hypertension have an important role in the derangement of baroreceptor function. The aetiology of cirrhosis seems to be related to baroreceptor impairment as well. Mortality rate is higher in subjects with a more damaged autonomic system, strengthening the idea of a worse prognosis in cirrhotic patients with autonomic neuropathy.

Is the immediate reversal of diastolic dysfunction of cirrhotic cardiomyopathy after liver transplantation a sign of the metabolic etiology?

Cirrhotic cardiomyopathy currently is believed to be a multifactorial entity. This communication describes a case of immediate intraoperative recovery of diastolic function following liver transplantation. This suggests that an underlying metabolic inhibition of myocardial metabolism is an important factor in the development of cardiomyopathy in end-stage liver disease. Liver Transpl 15:1417-1419, 2009. (c) 2009 AASLD.

Cardiac and systemic haemodynamic complications of liver cirrhosis

Cardiovascular complications of liver cirrhosis include cardiac dysfunction and abnormalities in the central-, splanchnic,- and peripheral circulation. Vasodilatation prevails, but vascular beds with various degrees of reduced and increased haemodynamic resistance are the results of massive activation of powerful homeostatic, regulatory systems. Cirrhotic cardiomyopathy implies systolic and diastolic dysfunction and electrophysiological abnormalities, an entity that is different from alcoholic heart muscle disease. Being often clinical latent, cirrhotic cardiomyopathy can be unmasked by physical and pharmacological strain. Cardiac failure is an important cause of mortality after liver transplantation and stressful procedures as insertions of transjugular intrahepatic portal systemic shunt (TIPS), peritoneal venous shunting, and other types of surgery. Improvement of liver function has been shown to reverse the cardiovascular complications. The clinical significance is an important topic for future research. At present, no specific treatment can be recommended, and the cardiac failure in cirrhosis should be treated as in non-cirrhotic patients with sodium restriction, diuretics, and beta-adrenergic blocking agents. Special care should be taken with the use of ACE-inhibitors and angiotensin antagonist in these patients.

Severe left-sided heart failure early after liver transplantation

Left-sided heart failure (LHF) after liver transplantation (LT) is rare and poorly understood. We performed a case-control study. We reviewed the data of all patients with LHF after LT at our center from November 2000 to July 2007. Each case was matched to 1 LT control without LHF for age, sex, date of transplantation, and liver disease. Twenty of 599 patients developed LHF (3.3%). Pretransplant cardiovascular characteristics and risk factors were similar in cases and controls, except for the prevalence of left ventricular enlargement, which was greater in controls. At the time of diagnosis, the median left ventricular ejection fraction was 25% in cases, and increased afterload was documented by markedly elevated vascular resistances. The prevalence of infection at the time of LHF in cases was higher (55%) than in controls (10%, P = 0.02). The reported causes of LHF were infection [bacterial (n = 1) or viral (n = 7)], intraoperative cardiac arrest (n = 2), and unknown (n = 10). In comparison with their controls, cases with immediate postoperative LHF (day 0) did not have a higher Model for End-Stage Liver Disease (MELD) score (15 versus 21.5) or infection prevalence rate (17% versus 34%), whereas those with later onset LHF had a significantly higher MELD score (25.5 versus 17, P = 0.01) and infection prevalence rate (71% versus 0%, P = 0.002). Mortality was 45% in cases versus 0% in controls (P = 0.004), and the 11 cases who survived recovered from LHF. In conclusion, LHF after LT carries a high mortality risk and may have different causes. Except for immediate postoperative cases, an infection and an elevated MELD score appear to be determinant.

The use of E/A ratio as a predictor of outcome in cirrhotic patients treated with transjugular intrahepatic portosystemic shunt

OBJECTIVES

The clinical significance of diastolic dysfunction in cirrhosis, a feature of cirrhotic cardiomyopathy, is unclear. The aim of this study was to assess the utility of E/A ratio, an indicator of diastolic dysfunction, to predict ascites clearance and mortality after transjugular intrahepatic portosystemic stent shunt (TIPS) insertion.

METHODS

A total of 101 cirrhotic patients who received TIPS had pre-TIPS assessments of demographics, severity of liver dysfunction (Child-Pugh and Model for End-Stage Liver Disease (MELD) scores), renal function, hemodynamics, and cardiac function (two-dimensional echocardiography). An E/A ratio of < or =1 was used to indicate diastolic dysfunction. Patients were followed-up for a mean period of 24.6+/-2.4 months post TIPS.

RESULTS

A total of 41 patients with an E/A ratio of < or =1 (group A), and 60 patients with an E/A ratio of >1 (group B) were studied. Group A had significantly higher MELD scores (14.0+/-1.0 vs. 11.4+/-0.8; P=0.03), because of higher serum creatinine levels (107+/-5 vs. 86+/-6 micromol/l; P<0.01). There was no difference in pre-TIPS systemic hemodynamics, systolic function, or portal pressure between the two groups. After TIPS, more patients in group B had ascites clearance (log rank, P=0.038), and the same patients had a higher probability of survival (log rank, P=0.046). There were three post-TIPS cardiac deaths in group A only. A multivariate analysis showed that an E/A of ratio < or =1 was predictive of slow ascites clearance (hazard ratio=7.3, 95% confidence interval=1.3-40.7, P=0.021) and death after TIPS (hazard ratio=4.7, 95% confidence interval=1.1-20.2, P=0.035).

CONCLUSIONS

Diastolic dysfunction, indicated by reduced E/A ratio, is prevalent in advanced cirrhosis and is associated with reduced ascites clearance and increased mortality post TIPS, possibly related to worsening of hemodynamic dysfunction in the post-TIPS period.

Preoperative risk assessment for patients with liver disease

Patients with underlying liver disease often present for non-liver-related surgery and are at risk for postoperative decompensation. Several predictive models exist to determine the risk of morbidity and mortality after surgery in such patients, but the risk depends on the severity of liver disease and also the type and urgency of the surgery. Clinicians should be cognizant of the various risk assessment tools and incorporate them into their practice when encountering patients with liver disease undergoing surgery.

Prediction of cardiac complications after liver transplantation

BACKGROUND

Orthotopic liver transplantation (OLT) stresses the cardiovascular system, and cardiac complications after OLT are common.

METHODS

Hundred ninety-seven patients (>or=40 years) who had OLT from 2002 to 2007 were reviewed to identify predictors of cardiac complications within 6 months after transplantation.

RESULTS

Median age was 56 years (40-75 years); 69% men. Reasons for OLT were hepatitis C virus (HCV) 45.5%, alcohol 22%, hepatocellular carcinoma (HCC) 8%, primary biliary cirrhosis 10%, and others 14.5%. Eighty-two patients suffered one or more cardiac complications within 6 months after OLT (pulmonary edema=61 [overt heart failure=7], arrhythmia=13, pulmonary hypertension=7, pericardial effusion=2, and right atrial thrombus=1). Cardiac causes were the leading cause of death (n=5; 23.8% of all mortality). By multivariate analysis, after adjusting for age and sex, independent predictors were adverse intraoperative cardiovascular events (adjusted odds ratio; 95% confidence interval: 5.89, 1.82-19.14), history of cardiac disease (2.42, 0.89-6.6), and i-MELD (integrated model for end-stage liver disease) score (1.08, 1.02-1.14), whereas adverse intraoperative cardiovascular events (5.73, 1.96-16.78) and i-MELD (1.07, 1.01-1.13) predicted pulmonary edema. None of the following variables predicted complications: age, sex, OLT indication, body mass index, blood pressure, alcohol and smoking history, pre-OLT investigations (chest X-ray, electrocardiogram, echocardiography, coronary angiography, pulmonary arterial pressure, and 2-methoxy isobutyl isonitrile scan), immunosuppressive treatment, or intraoperative variables (transfusion amount, cadaveric vs. living graft or cold ischemia and rewarming times).

CONCLUSIONS

Cardiac complications after OLT are common and were the leading cause of death after surgery. Adverse intraoperative cardiovascular events, previous cardiac disease, and advanced liver disease as quantified by i-MELD score predicted postoperative cardiac complications.

Impact of liver transplantation on rate-corrected QT interval and myocardial function in children with chronic liver disease*

Prolonged QTc interval (>440 ms) is a common abnormality in adult patients with CLD and has been reported to predict patient survival. In this study, 88 children who underwent evaluation for LT, including a 12-lead electrocardiogram and echocardiogram included to determine the frequency of QTc prolongation and related factors in children with CLD and the effect of LT on these factors. Sixty-nine healthy, age- and sex-matched children served as controls. QTc interval was prolonged in 40 CLD patients (45.4%). It was found to be related to PELD score and presence of portal hypertension. Mean QTc was higher in patients who died prior to LT than in the survivors without LT. Mortality risk was increased 3.66-fold in patients with prolonged QTc (p = 0.001, 95% CI: 2-7.2). Cox regression analysis showed that only PELD score was an independent predictor of survival (p = 0.001, beta = -0.41, 95% CI: 5.58-1.82). Five of 48 transplanted children died within three months post-transplant; QTc was not related to post-transplant survival (p = 0.27). QTc normalized in 63.8% patients after LT. After LT, LAD, LVEF, and LVPWT decreased. In conclusion, QTc prolongation is common in children with CLD and associated with high mortality. It may be useful for assessment of the severity of CLD and for the timing for transplantation.

Saline contrast echocardiography in patients with hepatopulmonary syndrome awaiting liver transplantation

BACKGROUND

Patients with hepatopulmonary syndrome (HPS) with end-stage liver disease (ESLD) have higher cardiorespiratory mortality than those without. The aims of this study were to determine whether echocardiography could distinguish patients with ESLD with and without HPS and whether the diagnosis of HPS by contrast echocardiography (CE) was altered by the performance of the test in a supine or standing position.

METHODS

Subjects were recruited prospectively from patients with end-stage liver disease undergoing assessment for liver transplantation. Hepatopulmonary syndrome was diagnosed on the basis of arterial blood gas analysis, lung function testing and agitated saline contrast echocardiography in the absence of primary cardiac or pulmonary disease. Bubble contrast injections were performed supine or standing in a randomised order and read by a blinded observer.

RESULTS

CE showed late right-to-left shunting in 13 of 50 consecutive patients with cirrhosis (26%). Eight patients (16%) had definite diagnoses of HPS. CE in the standing position consistently increased both the number and the size of shunts compared with supine injection. CE detected intrapulmonary shunting before a change in arterial blood gases. Standard echocardiographic parameters did not distinguish between those with and without HPS.

CONCLUSION

This study suggests that screening for HPS in patients with advanced cirrhosis should be done using CE with patients in the upright position.

N-terminal pro B-type natriuretic peptide and the evaluation of cardiac dysfunction and severity of disease in cirrhotic patients

PURPOSE

Cardiac dysfunction and hyperdynamic systemic circulation may be present in patients with cirrhosis. The purpose of this study was to identify relations between plasma levels of N-terminal-proBNP (NT-proBNP), reflecting early ventricular dysfunction, and the severity of liver disease and cardiac dysfunction in cirrhotic patients.

MATERIALS AND METHODS

Sixty-three cirrhotic patients and 15 controls (group 1) were enrolled in this study. Plasma levels of NT-proBNP were determined in echocardiographically examined patients, which were allocated to 1 of 3 groups according to Child-Pugh classification or into 2 groups, i.e., a compensated group without ascites (group 2) and decompensated group with ascites (group 3).

RESULTS

Plasma NT-proBNP levels were significantly higher in cirrhotic patients (groups 2 and 3) than in age-matched controls (155.9 and 198.3 vs. 40.3 pg/mL, respectively, p < 0.05). NT-proBNP levels were significantly increased in Child class C patients than in classes B and A (250.0 vs. 168.6 and 119.6 pg/mL, respectively, p < 0.05). Left atrial dimension, wall thickness of left ventricle, and EF or E/E' were significantly increased, and EDT was prolonged in cirrhotic patients than in controls. Increased LVMI and decreased E/A ratio were noted in the group of patients with ascites as compared with the other groups.

CONCLUSION

Plasma NT-proBNP levels were high in cirrhotic patients and are likely to be related to the severity of disease. Advanced cirrhosis is associated with advanced cardiac dysfunction, and NT-proBNP levels has predictive value for concomitant cardiac dysfunction and cirrhosis progression.

Clinical significance of prolonged QTc interval in patients with liver cirrhosis

AIM: To invesigate the change and clinical significance of the rate-corrected Q-T (QTc) interval in patients with liver cirrhosis.

METHODS: A cohort of 67 liver cirrhotic patients with complete data were retrospectively studied and followed up. The relationship between QTc interval and Child-Turcotte-Pugh (CTP) scores was analyzed. The area under the receiver operating characteristic (ROC) curve was used to compare QTc with CTP scores in predicting the accuracy of mortality risk. The optimal cut-off values of QTc to discriminate between deceased and surviving patients were calculated using ROC curves.

RESULTS: In liver cirrhosis patients, the QTc interval was prolonged and positvely correlated with CTP scores (r = 0.406, P = 0.001), while the abnormal rate of QTc interval was higher than that in the normal controls; the prognosis was markedly differently between patients with normal and abnormal QTc interval (χ² = 6.976, P = 0.008). In predicting the accuracy of 6-mo, 12-mo and 24-mo mortality risk , the areas under the ROC curve of the QTc interval were 0.843, 0.860 and 0.749, respectively, which were larger than that of CTP scores, but the difference was not significant. The optimal cut-off values of the QTc interval for predicting prognosis were 0.440, 0.440 and 0.430 s respectively, while those of CTP scores were 9, 9 and 7 respectively.

CONCLUSION: The change of electrocardiogram exists in patients with liver cirrhosis. The QTc interval is valuable in evaluating the severity if liver cirrhosis, predicting prognosis and guiding clinical practice.

Liver protection in the perioperative setting

With recent advances in surgical and anaesthetic management, clinical medicine has responded to societal expectations and the number of operations in patients with a high-risk of perioperative liver failure has increased over the last decades. This review will outline important pathophysiological alterations common in patients with pre-existing liver impairment and thus highlight the anaesthetic challenge to minimise perioperative liver insults. It will focus on the intraoperative balancing act to reduce blood loss while maintaining adequate liver perfusion, the various anaesthetic agents used and their specific effects on hepatic function, perfusion and toxicity. Furthermore, it will discuss advances in pharmacological and ischaemic preconditioning and summarise the results of recent clinical trials.

The liver transplant recipient with cardiac disease

Liver transplantation is a stressful condition for the cardiovascular system of patients with advanced hepatic disease. The underlying hemodynamic and cardiac status of patients with cirrhosis is crucial to determine which patients should became recipients. Generally preoperative cardiovascular testing is performed on potential candidates who are more than 45 years old, or have diabetes mellitus, or peripheral vascular disease, or more than two standard cardiac risk factors. Recent data suggest that the prevalence of coronary artery disease among patients with cirrhosis is much greater than previously believed; it likely mirrors or exceeds the prevalence rate in the healthy population. The morbidity and mortality of patients with coronary artery disease who undergo orthotopic liver transplantation (OLT) without treatment are unacceptably high. In conclusion, accurate preoperative cardiac evaluation according to the new American Heart Association & American College of Cardiology should lead to detect and treat coronary artery disease before liver transplantation. In case of alcohol-related cardiomyopathy, portopulmonary hypertension, and hypertrophic cardiomyopathy, there should be a case-by-case discussion by the hepatologist and cardiologist to consider the patient for liver transplantation. No robust data are available on the impact of decompensated dilated heart failure in this setting. If a recipient with cardiac disease is scheduled for OLT, we strongly suggest advanced intra- and postoperative hemodynamic monitoring plus transesophageal echocardiography.

2-Arachidonoylglycerol, an endogenous cannabinoid receptor agonist, in various rat tissues during the evolution of experimental cholestatic liver disease

BACKGROUND/AIM

Changes in tissue levels of 2-arachidonoylglycerol (2-AG), an endocannabinoid, during the evolution of bile duct ligation (BDL) may indicate that endocannabinoids have a role in the hemodynamic changes that occur in this condition.

METHODS

2-AG levels, in various organs and vascular beds of BDL rats, 2 and 4 weeks post surgery, were determined. Untouched and sham-operated (SO) rats were used as controls.

RESULTS

2-AG content of a specific organ was not a static finding and depended on the rat's age, the time from the surgical procedure and the type of procedure. The most pronounced changes were observed in BDL rats 4 weeks post surgery. In these rats, hepatic, pulmonary, cardiac and renal medullary and papillary 2-AG levels were highest observed. No changes in splenic, aortic and renal cortical 2-AG levels were observed. In addition a stepwise increase in 2-AG levels from the cortex to the papilla was detected and was followed by a decrease in creatinine clearance.

CONCLUSIONS

2-AG probably has a role in the pathophysiologic changes in the liver, heart, lung and kidney that follows BDL.

Predictive value of dobutamine stress echocardiography for coronary artery disease detection in liver transplant candidates

Patients with obstructive coronary artery disease (CAD) undergoing orthotopic liver transplantation (OLT) are at increased risk of poor outcomes. The accuracy of dobutamine stress echocardiography (DSE) to detect obstructive CAD is not well established in this population. We retrospectively identified patients with end-stage liver disease who underwent both DSE and coronary angiography as part of risk stratification prior to OLT. One hundred and five patients had both DSE and angiography, of whom 14 had known CAD and 27 failed to reach target heart rate during DSE. Among the remaining 64 patients (45 men; average age 61 +/- 8 years) DSE had a low sensitivity (13%), high specificity (85%), low positive predictive value (PPV) (22%) and intermediate negative predictive value (NPV) (75%) for obstructive CAD. DSE as a screening test for obstructive CAD in OLT candidates has a poor sensitivity. The frequent chronotropic incompetence and low sensitivity in patients who achieve target heart rate, even in those with multiple cardiovascular disease risk factors, suggest that alternative or additional methods of risk stratification are necessary.

Nitric oxide levels in chronic liver disease patients with and without oesophageal varices

Introduction Patients with chronic liver disease ultimately progress to develop cirrhosis and portal hypertension. Recently it seems well established that nitric oxide disturbances play a key role in the pathogenesis of chronic liver disease and portal hypertension. The aim of this work was to clarify the correlation between chronic liver disease stages, liver function status, esophageal varices presence and nitric oxide disturbances. Subjects and methods All subjects (n = 120) in the present study were classified into; group I which included 15 age and sex matched healthy volunteers (taken as control), group II which included 20 patients with chronic active hepatitis, and group III which included 85 patients with hepatic cirrhosis. All subjects included were subjected to full clinical assessment, routine laboratory investigations, serum nitrate level determination using colorimetric method, abdominal ultrasonography and upper endoscopy. Results Increased serum nitrate level could not be detected in patients with chronic active hepatitis as well as those with early cirrhosis (Child’s class A). Progressive and significant increase of serum nitrate levels were detected in more advanced stages of cirrhosis (Child’s class B & C). The best non-invasive predictor for the presence of oesophageal varices was a combination of platelet count <150.000/mm³, splenomegaly >18 cm, Child’s class B or C and serum nitrate ≥38 μmol/l, with 93.3% sensitivity and 100% specificity. Conclusion Serum nitrate level can be used as a non-invasive predictor for progression of chronic liver disease as well as for the presence of oesophageal varices.

Increased left ventricular mass in pre-liver transplantation cirrhotic patients

OBJECTIVE

Severe liver disease is associated with abnormalities in cardiac geometry and function. We aimed to assess the prevalence of these abnormalities and to determine if they represent an adaptation of the heart to the haemodynamic overload associated with liver dysfunction.

METHODS

Seventy cirrhotic patients underwent standard Doppler echocardiography, as a screening evaluation for liver transplantation, and were compared with 70 normal subjects matched for age and sex. The values of echocardiographically measured left ventricular mass (LVM) were compared with those predicted from individual haemodynamic load, sex and height, which represent the compensatory values. LVM was considered inappropriately high when the observed/predicted LVM ratio was >128%.

RESULTS

Cirrhotic patients had higher LVM index (40.6 +/- 11.2 vs. 36.3 +/- 7.7 g/m; P = 0.009)), similar values of ejection fraction, but lower intrinsic wall mechanics (P < 0.01) compared to controls. The observed/predicted LVM ratio was also significantly increased (117.7 +/- 30.2 vs. 106.5 +/- 16.8%; P < 0.01) and prevalence of inappropriate LVM was almost three-fold higher in cirrhotic patients (27.7 vs. 10.0%; P < 0.05) than in controls. Cirrhotic patients also presented mild impairment of left ventricular systolic function, documented by lower values of midwall shortening.

CONCLUSIONS

Patients with severe liver disease have LVM values exceeding the compensatory needs to sustain haemodynamic overload, associated with subclinical systolic dysfunction.

Effect of chronic beta-blockade on QT interval in patients with liver cirrhosis

BACKGROUND/AIMS

QT interval prolongation is frequent in cirrhosis, predicts a poor prognosis and may trigger severe ventricular arrhythmias. Our aim was to evaluate the effect of chronic beta-blockade on QT prolongation.

METHODS

Clinical and laboratory evaluation, ECG and hepatic vein pressure gradient (HVPG) measurement were performed in 30 cirrhotic patients before and 1-3 months after prophylactic nadolol. QT was corrected for heart rate by the cirrhosis-specific formula and other formulas.

RESULTS

QT(cirrhosis) was prolonged in 10 patients (33%); HVPG was increased in all cases. QT(cirrhosis) was correlated with the Child-Pugh score (r=0.40; p=0.027). Nadolol shortened QT interval only with the Bazett formula (p=0.01), remaining unchanged with the other formulas. The QT interval shortened only if prolonged at baseline (from 473.3+/-5.5 to 458.4+/-6.5 ms; p=0.007), while it lengthened when normal (from 429.8+/-3.1 to 439.3+/-2.9 ms; p=0.01). QTc changes were directly related to the baseline value (p<0.001). HVPG decreased from 19.4+/-0.8 to 15.6+/-1.3 mmHg (p=0.004). The HVPG changes did not correlate with QTc changes.

CONCLUSIONS

Chronic beta-blockade shortens the QT interval only in patients with prolonged baseline values, and this is likely due to a direct cardiac effect.

Q-T interval (QT(C)) in patients with cirrhosis: relation to vasoactive peptides and heart rate

OBJECTIVE

Prolonged Q-T interval (QT) has been reported in patients with cirrhosis who also exhibit profound abnormalities in vasoactive peptides and often present with elevated heart rate (HR). The aim of this study was to relate QT to the circulating level of endothelins (ET-1 and ET-3) and calcitonin gene-related peptide (CGRP) in patients with cirrhosis. In addition, we studied problems with HR correction of QT.

MATERIAL AND METHODS

Forty-eight patients with cirrhosis and portal hypertension were studied during a haemodynamic investigation. Circulating levels of ETs and CGRP were determined by radioimmunoassays. Correction of QT for HR above 60 beats per min was performed using the methods described by Bazett (QT(C)) and Fridericia (QT(F)).

RESULTS

Prolonged QT(C) (above 440 ms), found in 56% of the patients, was related to the presence of significant portal hypertension and liver dysfunction (p < 0.05 to 0.001), but not to elevated ET-1, ET-3 or CGRP. When corrected according to Bazett, QT(C) showed no significant relation to differences in HR between patients (r = 0.07, ns). QTF showed some undercorrection of HR (r = -0.36; p < 0.02). During HR variation in the individual patient, QT(C) revealed a small but significant overcorrection (2.6 ms per heartbeat per min; p < 0.001). This value was significantly (p < 0.02) smaller with QTF (1.2 ms per heartbeat per min).

CONCLUSIONS

The prolonged QT(C) in cirrhosis is related to liver dysfunction and the presence of portal hypertension, but not to the elevated powerful vasoconstrictor (ET-1) or vasodilator (CGRP, ET-3) peptides. The problems with correction of the QT for elevated HR in cirrhosis are complex, and the lowest HR should be applied for determination of the QT.

Acute renal dysfunction in liver diseases

Renal dysfunction is common in liver diseases, either as part of multiorgan involvement in acute illness or secondary to advanced liver disease. The presence of renal impairment in both groups is a poor prognostic indicator. Renal failure is often multifactorial and can present as pre-renal or intrinsic renal dysfunction. Obstructive or post renal dysfunction only rarely complicates liver disease. Hepatorenal syndrome (HRS) is a unique form of renal failure associated with advanced liver disease or cirrhosis, and is characterized by functional renal impairment without significant changes in renal histology. Irrespective of the type of renal failure, renal hypoperfusion is the central pathogenetic mechanism, due either to reduced perfusion pressure or increased renal vascular resistance. Volume expansion, avoidance of precipitating factors and treatment of underlying liver disease constitute the mainstay of therapy to prevent and reverse renal impairment. Splanchnic vasoconstrictor agents, such as terlipressin, along with volume expansion, and early placement of transjugular intrahepatic portosystemic shunt (TIPS) may be effective in improving renal function in HRS. Continuous renal replacement therapy (CRRT) and molecular absorbent recirculating system (MARS) in selected patients may be life saving while awaiting liver transplantation.

Pre- and postoperative systemic hemodynamic evaluation in patients subjected to esophagogastric devascularization plus splenectomy and distal splenorenal shunt: A comparative study in schistomomal portal hypertension

AIM: To investigate the systemic hemodynamic effects of two surgical procedures largely employed for treatment of schistosomal portal hypertension.

METHODS: Thirty-six patients undergoing elective surgical treatment of portal hypertension due to hepatosplenic mansonic schistosomiasis were prospectively evaluated. All patients were subjected to preoperative pulmonary artery catheterization; 17 were submitted to esophagogastric devascularization and splenectomy (EGDS) and 19 to distal splenorenal shunt (DSRS). The systemic hemodynamic assessment was repeated 4 d after the surgical procedure.

RESULTS: Preoperative evaluation revealed (mean ± SD) an increased cardiac index (4.78 ± 1.13 L/min per m²), associated with a reduction in systemic vascular resistance index (1457 ± 380.7 dynes.s/cm⁵.m²). The mean pulmonary artery pressure (18 ± 5.1 mmHg) as well as the right atrial pressure (7.9 ± 2.5 mmHg) were increased, while the pulmonary vascular resistance index (133 ± 62 dynes.s/cm⁵.m²) was decreased. Four days after EGDS, a significant reduction in cardiac index (3.80 ± 0.4 L/min per m², P < 0.001) and increase in systemic vascular resistance index (1901.4 ± 330.2 dynes.s/cm⁵.m², P < 0.001) toward normal levels were observed. There was also a significant reduction in pulmonary artery pressure (12.65 ± 4.7 mmHg, P < 0.001) and no significant changes in the pulmonary vascular resistance index (141.6 ± 102.9 dynes.s/cm⁵.m²). Four days after DSRS, a non-significant increase in cardiac index (5.2 ± 0.76 L/min per m²) and systemic vascular resistance index (1389 ± 311 dynes.s/cm⁵.m²) was observed. There was also a non-significant increase in pulmonary artery pressure (19.84 ± 5.2 mmHg), right cardiac work index (1.38 ± 0.4 kg.m/m²) and right ventricular systolic work index (16.3 ± 6.3 g.m/m²), without significant changes in the pulmonary vascular resistance index (139.7 ± 67.8 dynes.s/cm⁵.m²).

CONCLUSION: The hyperdynamic circulatory state observed in mansonic schistosomiasis was corrected by EGDS, but was maintained in patients who underwent DSRS. Similarly, the elevated mean pulmonary artery pressure was corrected after EGDS and maintained after DSRS. EGDS seems to be the most physiologic surgery for patients with schistosomal portal hypertension.

Hemodynamic evaluation before liver transplantation: insights into the portal hypertensive syndrome

The cardiac hemodynamics of patients awaiting liver transplantation is complex. Coronary atherosclerosis, a hyperdynamic circulatory state and cirrhotic cardiomyopathy are present to a variable degree in this population. In this contribution to the Symposium on Portal Hypertension, we expand on our published experience with coronary angiography and cardiac hemodynamics at the time of evaluation of candidacy for liver transplantation in a cohort of 161 patients. Although we confirmed the relation of systemic hemodynamics with the degree of liver failure, we noted a higher prevalence of high output heart failure, defined as an increased left ventricular end-diastolic pressure in the setting of an elevated cardiac output, most notably in patients classified as Child C. Most patients with high pulmonary artery pressure also exhibited evidence of elevated left ventricle filling pressures. A low systemic vascular resistance, a marker of arterial vasodilatation, was similar in the presence of atherosclerosis, a condition where impaired vasorelaxation occurs as a result of endothelial dysfunction. The high prevalence of coronary artery disease in this series supports the observations that atherosclerosis is a major issue in the current population with cirrhosis awaiting liver transplantation. A lower sensitivity of noninvasive screening tools for the detection of coronary atherosclerosis is likely the result of the interaction of the hyperdynamic circulation with the performance of these tests.

Diurnal variation and dispersion in QT interval in cirrhosis: relation to haemodynamic changes

BACKGROUND/AIMS

A long QT(C) interval has been described in a substantial fraction of patients with cirrhosis, but information on QT variation and dispersion is sparse. The aim was to determine QT variation with time and QT dispersion (QT(disp)).

METHODS

The study population comprised 23 patients with cirrhosis, undergoing a haemodynamic investigation. 24-h 12 lead Holter monitoring provided information on QT and heart rate variability.

RESULTS

Mean QT(C) was above upper normal limit (440 ms(1/2)) in eleven patients (47%) and significantly higher than in controls (441 vs 400 ms(1/2), p<0.01). The minimum value of QT(C) (but not the maximum value) showed a significant diurnal variation both in cirrhosis and controls. QT(disp) in cirrhosis and controls was similar (33 vs 36 ms, ns), but related to indicators of liver dysfunction, central circulation time, and arterial blood pressure (r=0.44-0.58, p=0.03-0.001). No diurnal variation of QT(disp) was found in cirrhosis. Heart rate variability was reduced with a significant relation to central hypovolaemia (r=0.55, p=0.01).

CONCLUSIONS

Twenty-four hours QT(C) is prolonged in a substantial fraction of patients with cirrhosis, but with normal diurnal variation. The combination of long QT(C) and normal QT(disp) suggests delayed myocyte repolarisation on the cellular level, rather than temporal and spatial heterogeneity in the myocardial wall.

Endocannabinoids acting at CB1 receptors mediate the cardiac contractile dysfunction in vivo in cirrhotic rats

Advanced liver cirrhosis is associated with hyperdynamic circulation consisting of systemic hypotension, decreased peripheral resistance, and cardiac dysfunction, termed cirrhotic cardiomyopathy. Previous studies have revealed the role of endocannabinoids and vascular CB(1) receptors in the development of generalized hypotension and mesenteric vasodilation in animal models of liver cirrhosis, and CB(1) receptors have also been implicated in the decreased beta-adrenergic responsiveness of isolated heart tissue from cirrhotic rats. Here we document the cardiac contractile dysfunction in vivo in liver cirrhosis and explore the role of the endocannabinoid system in its development. Rats with CCl(4)-induced cirrhosis developed decreased cardiac contractility, as documented through the use of the Millar pressure-volume microcatheter system, low blood pressure, and tachycardia. Bolus intravenous injection of the CB(1) antagonist AM251 (3 mg/kg) acutely increased mean blood pressure, as well as both load-dependent and -independent indexes of systolic function, whereas no such changes were elicited by AM251 in control rats. Furthermore, tissue levels of the endocannabinoid anandamide increased 2.7-fold in the heart of cirrhotic compared with control rats, without any change in 2-arachidonoylglycerol levels, whereas, in the cirrhotic liver, both 2-arachidonoylglycerol (6-fold) and anandamide (3.5-fold) were markedly increased. CB(1)-receptor expression in the heart was unaffected by cirrhosis, as verified by Western blotting. Activation of cardiac CB(1) receptors by endogenous anandamide contributes to the reduced cardiac contractility in liver cirrhosis, and CB(1)-receptor antagonists may be used to improve contractile function in cirrhotic cardiomyopathy and, possibly, in other forms of heart failure.

Cardiovascular determinants of survival in cirrhosis

Diastolic response as the strongest determinant of mortality after TIPS

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.

Preoperative evaluation of patients with liver disease

Patients with end-stage liver disease often undergo surgery for indications other than liver transplantation. These patients have an increased risk of morbidity and mortality that is related to their underlying liver disease. Assessments of surgical risk provide a basis for discussion of risks and benefits, treatment decision making, and for optimal management of patients for whom surgery is planned. The most useful indicators of surgical risk are indices that predict advanced disease, such as the Child-Turcotte-Pugh score, or those that predict prognosis, such as the Model for End-stage Liver Disease score. Careful preoperative risk assessment, patient selection, and management of various manifestations of advanced disease might decrease morbidity and mortality from nontransplant surgery in patients with liver disease.

Cirrhotic cardiomyopathy

Cirrhotic cardiomyopathy is the term used to describe a constellation of features indicative of abnormal heart structure and function in patients with cirrhosis. These include systolic and diastolic dysfunction, electrophysiological changes, and macroscopic and microscopic structural changes. The prevalence of cirrhotic cardiomyopathy remains unknown at present, mostly because the disease is generally latent and shows itself when the patient is subjected to stress such as exercise, drugs, hemorrhage and surgery. The main clinical features of cirrhotic cardiomyopathy include baseline increased cardiac output, attenuated systolic contraction or diastolic relaxation in response to physiologic, pharmacologic and surgical stress, and electrical conductance abnormalities (prolonged QT interval). In the majority of cases, diastolic dysfunction precedes systolic dysfunction, which tends to manifest only under conditions of stress. Generally, cirrhotic cardiomyopathy with overt severe heart failure is rare. Major stresses on the cardiovascular system such as liver transplantation, infections and insertion of transjugular intrahepatic portosystemic stent-shunts (TIPS) can unmask the presence of cirrhotic cardiomyopathy and thereby convert latent to overt heart failure. Cirrhotic cardiomyopathy may also contribute to the pathogenesis of hepatorenal syndrome. Pathogenic mechanisms of cirrhotic cardiomyopathy are multiple and include abnormal membrane biophysical characteristics, impaired β-adrenergic receptor signal transduction and increased activity of negative-inotropic pathways mediated by cGMP. Diagnosis and differential diagnosis require a careful assessment of patient history probing for excessive alcohol, physical examination for signs of hypertension such as retinal vascular changes, and appropriate diagnostic tests such as exercise stress electrocardiography, nuclear heart scans and coronary angiography. Current management recommendations include empirical, nonspecific and mainly supportive measures. The exact prognosis remains unclear. The extent of cirrhotic cardiomyopathy generally correlates to the degree of liver insufficiency. Reversibility is possible (either pharmacological or after liver transplantation), but further studies are needed.

Cirrhotic cardiomyopathy: Indian scenario

BACKGROUND

Cirrhotic cardiomyopathy has been reported to be a major cause of morbidity and mortality in liver transplant recipients. However, there is scant data from Asia. With liver transplantation programs gradually being established in the region, Asian hepatologists are bound to face this entity.

METHODS

Thirty patients with alcoholic cirrhosis and 30 with cirrhosis of nonalcoholic etiology were enrolled, after excluding those with recent bleeding, gross ascites, severe anemia and other conditions which could alter cardiovascular status. Thirty healthy subjects without cardiovascular risk factors were enrolled as controls. Hepatic function status was assessed by biochemical tests and prothrombin time. Cardiac structural and functional assessment was performed non-invasively using transthoracic echocardiography.

RESULTS

Deceleration time was significantly (P < 0.05) prolonged in both the cirrhotic groups (235.03 +/- 44.23 ms and 255.87 +/- 46.16 ms) compared to controls (185.83 +/- 25.04 ms), indicative of diastolic dysfunction in cirrhotic patients. Other parameters, viz. ejection fraction, E : A ratio, left ventricular relative wall thickness, interventricular septal thickness and left ventricular systolic as well as diastolic chamber dimensions did not show statistically significant difference between any of the groups. Cardiac structural and functional parameters were not correlated with the severity of liver dysfunction. There was no statistically significant difference between the alcoholic and nonalcoholic groups.

CONCLUSIONS

Asian patients with cirrhosis do have evidence of diastolic dysfunction. Cardiac structural and functional parameters did not correlate with the severity of liver dysfunction. Cardiac dysfunction seemed to be the consequence of cirrhosis itself, rather than of alcohol.

Cardiac dysfunction in cirrhosis

Cirrhosis is known to be associated with numerous cardiovascular abnormalities. These include increased cardiac output and decreased arterial pressure and total peripheral resistance. Despite this increased baseline cardiac output, patients with cirrhosis show an attenuated systolic and diastolic function in the face of pharmacological, physiological and surgical stresses, as well as cardiac electrical abnormalities such as QT prolongation. These abnormalities have been termed cirrhotic cardiomyopathy. The pathogenic mechanisms that underlie this syndrome include impairment of the beta-adrenergic receptor signalling, cardiomyocyte plasma membrane function, intracellular calcium kinetics, and humoral factors such as endogenous cannabinoids, nitric oxide and carbon monoxide. Cirrhotic cardiomyopathy is believed to contribute to the cardiac dysfunction that can be observed in patients with transjugular intrahepatic portosystemic stent-shunt insertion and liver transplantation. Insufficient cardiac contractile function may also play a role in the pathogenesis of hepatorenal syndrome precipitated by spontaneous bacterial peritonitis. In this review, the clinical features, pathogenic mechanisms, clinical consequences and management options for cirrhotic cardiomyopathy are discussed.

Monitoring Hepatic and Renal Function

Liver disease represents a serious risk factor for patients requiring anesthesia and surgery. Even subclinical liver disease increases perioperative morbidity and mortality. Perioperative renal dysfunction and failure have similar implications. Thus, detection of early hepatic and renal dysfunction and monitoring of their progress is essential. This article discusses methods for monitoring hepatic and renal function in patients who have high risk for liver or renal injury in the perioperative period.

Pulmonary blood volume and transit time in cirrhosis: relation to lung function

BACKGROUND/AIMS

In cirrhosis a systemic vasodilatation leads to an abnormal distribution of the blood volume with a contracted central blood volume. In addition, the patients have a ventilation/perfusion imbalance with a low diffusing capacity. As the size of the pulmonary blood volume (PBV) has not been determined separately we assessed PBV and pulmonary transit time (PTT) in relation to lung function in patients with cirrhosis and in controls.

METHODS

Pulmonary and cardiac haemodynamics and transit times were determined by radionuclide techniques in 22 patients with alcoholic cirrhosis and in 12 controls. The lung function including diffusing capacity for carbon monoxide (DL, CO) was determined by conventional single breath technique.

RESULTS

In the patients, PTT was shorter, 3.9+/-1.2 vs 5.7+/-1.0 s in the controls, P<0.001, and the PBV was lower, 362+/-151 vs 587+/-263 ml, in the controls, P<0.005. Both PTT and PBV were lowest in patients with advanced disease. DL, CO was reduced in the patients and correlated significantly with PTT (r=0.58, P=0.007) and PBV (r=0.49, P<0.03).

CONCLUSIONS

The results suggest that the reduced PBV contributes to the reduced effective blood volume in cirrhosis. The relation between PBV and PTT and the low diffusing capacity suggests the pulmonary vascular compartment as an important element in the pathophysiology of the lung dysfunction in cirrhosis.

Therapy insight: Cirrhotic cardiomyopathy

Liver cirrhosis is associated with several cardiovascular disturbances. These disturbances include hyperdynamic systemic circulation, manifested by an increased cardiac output and decreased peripheral vascular resistance and arterial pressure. Despite the baseline increase in cardiac output, cardiac function in patients with cirrhosis is abnormal in several respects. Patients show attenuated systolic and diastolic contractile responses to stress stimuli, electrophysiological repolarization changes, including prolonged QT interval, and enlargement or hypertrophy of cardiac chambers. This constellation of cardiac abnormalities is termed cirrhotic cardiomyopathy. It has been suggested that cirrhotic cardiomyopathy has a role in the pathogenesis of cardiac dysfunction and even overt heart failure after transjugular intrahepatic portosystemic shunt placement, major surgery and liver transplantation. Cardiac dysfunction contributes to morbidity and mortality after liver transplantation, even in many patients who have no prior history of cardiac disease. Depressed cardiac contractility contributes to the pathogenesis of hepatorenal syndrome, especially in patients with spontaneous bacterial peritonitis. Pathogenic mechanisms underlying cirrhotic cardiomyopathy include cardiomyocyte-membrane biophysical changes, attenuation of the stimulatory beta-adrenergic system and overactivity of negative inotropic systems mediated via cyclic GMP. The clinical features, general diagnostic criteria, pathogenesis and treatment of cirrhotic cardiomyopathy are discussed in this review.

Functional status of beta-2-adrenoceptor in isolated membranes of mature erythrocytes from patients with cirrhosis and oesophageal varices

Propranolol is a widely used drug for prophylaxis of variceal bleeding in patients with cirrhosis, but not all patients show an adequate clinical response. This variability may be in relation to beta adrenoceptor activity, but no information is available in this setting. Thirty-nine patients with advanced cirrhosis and presence of oesophageal varices were sequentially included. We studied the function of beta-2-adrenoceptor in isolated membranes of mature erythrocytes obtained from patients by measuring cyclic AMP (cAMP) production before and after isoproterenol. Blood samples obtained from 11 healthy volunteers were used as control. Patients showed a six-fold increase in the mean basal cAMP production as compared to healthy volunteers. Isoproterenol produced a small, non-significantly and highly variable increase in the AC activity in patients compared with controls. cAMP values remain stable after three months of continuous treatment with oral beta-blockers in both groups. Patients without antecedent of variceal bleeding or with an active alcohol intake showed a significantly higher isoproterenol effect. In conclusion, beta-receptor function in human erythrocytes membranes is altered in patients with cirrhosis and oesophageal varices.

The use of vasoconstrictors in patients with cirrhosis: type 1 HRS and beyond

In patients with cirrhosis and type 1 hepatorenal syndrome (HRS), systemic vasodilation, which is mainly attributable to splanchnic vasodilation, plays a critical role in the activation of endogenous vasoconstrictor systems, resulting in renal vasoconstriction and functional renal failure. It has been suggested that the use of splanchnic (and systemic) vasoconstrictors such as terlipressin (a vasopressin analog) or alpha-1-adrenoceptor agonists (midodrine or noradrenaline) may improve renal function in patients with type 1 HRS. Six studies (with only one randomized study in a small series of patients) have shown that terlipressin improves renal function in these patients. However, there is evidence that terlipressin alone may be less effective than terlipressin combined with intravenous albumin in improving renal function. Future randomized studies should confirm this difference and evaluate the impact of terlipressin therapy (with or without intravenous albumin) on survival. Interestingly, in nonrandomized studies, the use of alpha-1 agonists combined with other therapies (octreotide and albumin for midodrine; furosemide and albumin for noradrenaline) has been shown to improve renal function in patients with type 1 HRS. The efficacy and safety of combined therapies including alpha-1 agonists should be confirmed in randomized studies. Finally, preliminary evidence suggests that vasoconstrictor administration may be a novel therapeutic approach targeting vasodilation involved in the mechanism of: (1) renal failure in type 2 HRS; (2) paracentesis-induced circulatory dysfunction; and (3) arterial hypotension induced by byproducts of gram-negative bacteria. Further studies are needed in all these fields.

Arterial hypertension in cirrhosis: arterial compliance, volume distribution, and central haemodynamics

BACKGROUND AND AIMS

Arterial hypertension is a common disorder. Hyperkinetic circulation and reduced effective volaemia are central elements in the haemodynamic dysfunction in cirrhosis. The aim of the present study was to investigate whether cirrhotic patients with arterial hypertension are normokinetic and normovolaemic or whether they reveal the same circulatory dysfunction as their normotensive counterparts.

MATERIAL AND METHODS

Thirty three patients with arterial hypertension were identified among 648 patients with cirrhosis: 14 in Child class A, 12 in class B, and seven in class C. Controls were 130 normotensive cirrhotic patients, 19 controls with normal arterial blood pressure and without liver disease, and 16 patients with essential arterial hypertension. All groups underwent haemodynamic investigation with determination of cardiac output (CO), plasma volume (PV), central blood volume (CBV), hepatic venous pressure gradient (HVPG), hepatic blood flow (HBF), arterial compliance (AC), and systemic vascular resistance (SVR) in the supine position.

RESULTS

Liver function, as evaluated by galactose elimination capacity, indocyanine green clearance, HBF, and Child score, was significantly better in hypertensive cirrhotics than in their normotensive counterparts (p<0.05-0.01) but portal pressure was similar (HVPG 13 v 15 mm Hg; NS). AC was significantly lower and normal in the arterial hypertensive cirrhotic group (1.07 v 1.39 mm Hg/ml; p<0.02) and SVR was significantly higher and normal (1475 v 1020 dynxs/cm5; p<0.01). Arterial hypertensive cirrhotic patients were hyperdynamic (CO 6.80 v 7.14 l/min; NS) and central hypovolaemic (CBV 19.8 v 20.6 ml/kg; NS), as were normotensive patients, but differences were found in relation to arterial blood pressure. Whereas arterial pressure was inversely correlated with CO, PV, and Child score in the normotensive group (p< 0.01), the same correlations were either direct or insignificant in arterial hypertensive cirrhotics.

CONCLUSION

Arterial hypertensive cirrhotic patients are hyperkinetic and central hypovolaemic, in common with their normotensive counterparts, but vasodilatation is reduced and regulation of arterial blood pressure may be less deranged.

"Hepar divisum"--as a rare donor complication after intraoperative mortality of the recipient of an intended living donor liver transplantation

In this study, we present our experience with 4 healthy donors having the rare condition of "hepar divisum" after the intraoperative death of the recipient of an intended right adult living donor liver transplantation (LDLT). The study included 4 donors and 4 intended right LDLT recipients affected by neuroendocrine tumor (n = 2), hepatocellular carcinoma (n = 1), and cryptogenic cirrhosis (n = 1). All 4 recipients died intraoperatively. At the time of recipient death, the dissection of the donor liver parenchyma was complete, the vessels intact, and the hepatic duct(s) already divided. In each case, reconstruction of the donor biliary tract was performed: hepaticojejunostomy (HJ) in 2 cases, each with 3 ducts, and duct-to-duct anastomosis in 2. Of the donors receiving the HJ, 1 had a cut surface bile leak and the other experienced an anastomotic leak, treated by percutaneous drainage and reoperation, respectively. The latter patient experienced recurrent HJ stenosis at 44 months and 50 months after the operation and was treated by percutaneous balloon dilatation. One duct-to-duct reconstruction was complicated by early stenosis (postoperative day 6) and treated with endoscopic stenting. In conclusion, in the case of intraoperative death of the recipient of an intended LDLT, when the parenchyma and the hepatic duct of the donor have already been divided, the options are completion of the donor hepatectomy or the status of "fegatum divisum" with reconstruction of biliary tract. The high incidence of biliary complication, however, is of concern. When more than 1 hepatic duct is present, the donor hepatectomy should be completed and the graft reallocated according to the policy of the transplant institution.

Cardiac and vascular changes in cirrhosis: Pathogenic mechanisms

Cardiovascular abnormalities accompany both portal hypertension and cirrhosis. These consist of hyperdynamic circulation, defined as reduced mean arterial pressure and systemic vascular resistance, and increased cardiac output. Despite the baseline increased cardiac output, ventricular inotropic and chronotropic responses to stimuli are blunted, a condition known as cirrhotic cardiomyopathy. Both conditions may play an initiating or aggravating pathogenic role in many of the complications of liver failure or portal hypertension including ascites, variceal bleeding, hepatorenal syndrome and increased postoperative mortality after major surgery or liver transplantation. This review briefly examines the major mechanisms that may underlie these cardiovascular abnormalities, concentrating on nitric oxide, endogenous cannabinoids, central neural activation and adrenergic receptor changes. Future work should address the complex interrelationships between these systems.

Liver cirrhosis and arterial hypertension

Characteristic findings in patients with cirrhosis are vasodilatation with low overall systemic vascular resistance, high arterial compliance, increased cardiac output, secondary activation of counter-regulatory systems (renin-angiotensin-aldosterone system, sympathetic nervous system, release of vasopressin), and resistance to vasopressors. The vasodilatory state is mediated through adrenomedullin, calcitonin gene-related peptide, nitric oxide, and other vasodilators, and is most pronounced in the splanchnic area. This constitutes an effective (although relative) counterbalance to increased arterial blood pressure. This review considers the alterations in systemic hemodynamics in patients with cirrhosis in relation to essential hypertension and arterial hypertension of the renal origin. Subjects with arterial hypertension (essential, secondary) may become normotensive during the development of cirrhosis, and arterial hypertension is rarely manifested in patients with cirrhosis, even in cases with renovascular disease and high circulating renin activity. There is much dispute as to the understanding of homoeostatic regulation in cirrhotic patients with manifest arterial hypertension. This most likely includes the combination of vasodilatation and vasoconstriction in parallel.