Reduced baroreflex sensitivity in alcoholic cirrhosis: relations to hemodynamics and humoral systems

Association of echocardiography-related parameters with the prognosis of decompensated cirrhosis: a retrospective cohort study

BACKGROUND

Cardiac morphology and function, which are conventionally evaluated by echocardiography, are often abnormal in decompensated cirrhosis. We aimed to evaluate the association of echocardiography-related parameters with prognosis in cirrhosis.

METHODS

This retrospective study included 104 decompensated cirrhotic patients, in whom cardiac structure and function were measured by echocardiography, including mitral inflow early diastolic velocity/mitral inflow late diastolic velocity (E/A), left atrium diameter, left ventricular end-diastolic dimension, interventricular septal thickness, left ventricular posterior wall thickness, right atrial transverse diameter, right atrial longitudinal diameter, right ventricular dimension (RVD), stroke volume, cardiac output, left ventricular ejection fraction, and fractional shortening. Cox regression and competing risk analyses and Kaplan-Meier and Nelson-Aalen cumulative risk curves were used to evaluate their associations with further decompensation and death in cirrhotic patients, if appropriate.

RESULTS

Lower RVD was a predictor of further decompensation in Cox regression (adjusted by Child-Pugh score: p = 0.138; adjusted by MELD score: p = 0.034) and competing risk analyses (p = 0.003), and RVD ≤17 mm was significantly associated with higher cumulative incidence of further decompensation in Kaplan-Meier (p = 0.002) and Nelson-Aalen cumulative risk curves (p = 0.002). E/A ≤ 0.8 was a significant predictor of death in Cox regression (adjusted by Child-Pugh score: p = 0.041; adjusted by MELD score: p = 0.045) and competing risk analyses (p = 0.024), and E/A ≤ 0.8 was significantly associated with higher cumulative incidence of death in Kaplan-Meier (p = 0.023) and Nelson-Aalen cumulative risk curves (p = 0.024). Other echocardiography-related parameters were not significantly associated with further decompensation or death.

CONCLUSION

RVD and E/A may be considered for the prognostic assessment of decompensated cirrhosis.

How non-alcoholic fatty liver disease and cirrhosis affect the heart

Liver diseases affect the heart and the vascular system. Cardiovascular complications appear to be a leading cause of death in patients with non-alcoholic fatty liver disease (NAFLD) and cirrhosis. The predominant histological changes in the liver range from steatosis to fibrosis to cirrhosis, which can each affect the cardiovascular system differently. Patients with cirrhotic cardiomyopathy (CCM) and NAFLD are at increased risk of impaired systolic and diastolic dysfunction and for suffering major cardiovascular events. However, the pathophysiological mechanisms behind these risks differ depending on the nature of the liver disease. Accurate assessment of symptoms by contemporary diagnostic modalities is essential for identifying patients at risk, for evaluating candidates for treatment, and prior to any invasive procedures. This review explores current perspectives within this field.

COVID-19 and hepatorenal syndrome

Coronavirus disease 2019 (COVID-19) is a highly infectious disease which emerged into a global pandemic. Although it primarily causes respiratory symptoms for affected patients, COVID-19 was shown to have multi-organ manifestations. Elevated liver enzymes appear to be commonly observed during the course of COVID-19, and there have been numerous reports of liver injury secondary to COVID-19 infection. It has been established that patients with pre-existing chronic liver disease (CLD) are more likely to have poorer outcomes following COVID-19 infection compared to those without CLD. Co-morbidities such as diabetes, hypertension, obesity, cardiovascular and chronic kidney disease frequently co-exist in individuals living with CLD, and a substantial population may also live with some degree of frailty. The mechanisms of how COVID-19 induces liver injury have been postulated. Hepatorenal syndrome (HRS) is the occurrence of kidney dysfunction in patients with severe CLD/fulminant liver failure in the absence of another identifiable cause, and is usually a marker of severe decompensated liver disease. Select reports of HRS following acute COVID-19 infection have been presented, although the risk factors and pathophysiological mechanisms leading to HRS in COVID-19 infection or following COVID-19 treatment remain largely unestablished due to the relative lack and novelty of published data. Evidence discussing the management of HRS in high-dependency care and intensive care contexts is only emerging. In this article, we provide an overview on the speculative pathophysiological mechanisms of COVID-19 induced HRS and propose strategies for clinical diagnosis and management to optimize outcomes in this scenario.

The effect of acute alcohol ingestion on systemic hemodynamics and sleep architecture in young, healthy men

Objective Heightened nocturnal blood pressure (BP) may be attributed to the disruption of sleep, a condition worsened by alcohol ingestion. This study investigated the effects of acute alcohol ingestion on hemodynamics and sleep architecture in a young, healthy cohort of male. METHODS: Subjects (n = 17) underwent acute alcohol ingestion reaching a breath alcohol content of 0.08. Each subject endured a battery of hemodynamic tests and had their sleep architecture and nocturnal blood pressure monitored pre- and post-ingestion. Results: Systolic blood pressure (SBP) increased both 30 minutes and 12 hours after alcohol. Ambulatory nocturnal SBP significantly increased after alcohol compared to baseline measures. Minutes of total, rapid eye movement, and light sleep all increased after alcohol ingestion, while a decrease was observed for sleep latency. Conclusions: An acute bout of heavy alcohol consumption may attenuate nocturnal BP dipping that, in turn, may hasten the progression of hypertension-related cardiovascular disease.

A Prospective Study of Prevalence and Predictors of Cirrhotic Cardiomyopathy and Its Role in Development of Hepatorenal Syndrome

BACKGROUND AND AIMS

Cirrhotic cardiomyopathy (CCM) is a term used to collectively describe abnormal structural and functional changes in heart of patients with cirrhosis. The present study was undertaken to find the prevalence of CCM in patients with liver cirrhosis and its predictors. We also followed these patients to evaluate the role of CCM in the development of hepatorenal syndrome (HRS).

MATERIALS & METHODS

This was a prospective study carried out in department of Gastroenterology, Sir Ganga Ram hospital, New Delhi. A total of 104 patients with liver cirrhosis were included. Liver cirrhosis was diagnosed on basis of clinical, biochemical, and imaging features. CCM was defined based on echocardiography. Dobutamine stress echocardiography and hepatic venous pressure gradient (HVPG) were performed in patients who gave consent. HRS was defined as per standard criteria. Patients with CCM were followed for development of HRS.

RESULTS

Fifty (48%) patients were diagnosed with CCM. All patients had diastolic dysfunction, and none had systolic dysfunction. Median age of patients with CCM was significantly higher (59 [31-78 y] vs. 52 [24-70 y], P < 0.05). Severity of liver disease (Child Turcotte Pugh score and model for end-stage liver disease score) and portal pressures (HVPG) did not differ in patients with or without CCM. Patients with CCM did not have increased incidence of HRS at the end of 6-month follow-up study.

CONCLUSION

The presence of CCM was not related with the severity of liver dysfunction or portal pressures. Age was a significant determinant of CCM. Diastolic cardiac dysfunction does not influence the occurrence of HRS.

Autonomic dysfunction is common in liver cirrhosis and is associated with cardiac dysfunction and mortality: prospective observational study

BACKGROUND

Although autonomic dysfunction has been shown to be associated with liver cirrhosis, the prevalence and prognostic implications are unclear. Abnormal heart rate variability (HRV), a measure of autonomic function, has not been well investigated in cirrhosis.

OBJECTIVE

To evaluate the prevalence of high-risk HRV parameters in a cohort of cirrhotic patients and their association with cardiac dysfunction and mortality.

DESIGN AND SETTING

Prospective observational study conducted in the Federal University of São Paulo.

METHOD

A cohort of 120 patients, comprising 17 healthy controls and 103 cirrhotic outpatients, was evaluated and followed for 10 months. HRV analysis was based on 24-hour Holter monitoring and defined using time-domain and frequency-domain parameters.

RESULTS

The HRV parameters were statistically lower in cirrhotic patients than in healthy subjects. High-risk HRV parameters were prevalent, such that 64% had at least one high-risk parameter. Time-domain parameters correlated with Child scores (P < 0.0001). In regression models, HRV parameters were independent predictors of diastolic dysfunction and mortality. During 10 months of follow-up, there were 11 deaths, all of patients with at least one high-risk HRV parameter. Kaplan-Meier analysis estimated low survival rates among patients with standard deviation of normal-to-normal RR intervals (SDNN) < 100.

CONCLUSION

Reduced HRV is prevalent in liver cirrhosis and is related to cardiac dysfunction, severity of liver disease and mortality. Abnormal high-risk HRV parameters are prevalent among cirrhotic patients and are also predictors of mortality. Our findings highlight the need for a more careful cardiac evaluation of cirrhotic patients.

What's New in Cirrhotic Cardiomyopathy?-Review Article

Cirrhotic cardiomyopathy (CCM) is a relatively new medical term. The constant development of novel diagnostic and clinical tools continuously delivers new data and findings about this broad disorder. The purpose of this review is to summarize current facts about CCM, identify gaps of knowledge, and indicate the direction in which to prepare an updated definition of CCM. We performed a review of the literature using scientific data sources with an emphasis on the latest findings. CCM is a clinical manifestation of disorders in the circulatory system in the course of portal hypertension. It is characterized by impaired left ventricular systolic and diastolic dysfunction, and electrophysiological abnormalities, especially QT interval prolongation. However, signs and symptoms reported by patients are non-specific and include reduced exercise tolerance, fatigue, peripheral oedema, and ascites. The disease usually remains asymptomatic with almost normal heart function, unless patients are exposed to stress or exertion. Unfortunately, due to the subclinical course, CCM is rarely recognized. Orthotopic liver transplantation (OLTx) seems to improve circulatory function although there is no consensus about its positive effect, with reported cases of heart failure onset after transplantation. Researchers indicate a careful pre-, peri-, and post-transplant cardiac assessment as a crucial point in detecting CCM and improving patients’ prognosis. There is also an urgent need to update the CCM definition and establish a diagnostic algorithm for early diagnosis of CCM as well as a specific treatment of this condition.

A Review for the Practicing Clinician: Hepatorenal Syndrome, a Form of Acute Kidney Injury, in Patients with Cirrhosis

The hepatorenal syndrome type of acute kidney injury (HRS-AKI), formerly known as type 1 hepatorenal syndrome, is a rapidly progressing renal failure that occurs in many patients with advanced cirrhosis and ascites. Accumulating evidence has led to a recent evolution of diagnostic criteria for this serious complication of end-stage liver disease. The aim of this review is to provide an overview of disease-related characteristics and therapeutic management of patients with HRS-AKI. Relevant literature was compiled to support discussion of the pathophysiology, diagnosis, prognosis, associated conditions, prevention, treatment, and management of HRS-AKI. Onset of HRS-AKI is characterized by sudden severe renal vasoconstriction, leading to an acute reduction in glomerular filtration rate and rapid, potentially life-threatening, renal deterioration. Although our understanding of disease pathophysiology continues to evolve, etiology of HRS-AKI likely involves systemic hemodynamic changes caused by liver disease, inflammation, and damage to renal parenchyma. There is currently no gold standard for diagnosis, which typically involves a clinical workup, abdominal imaging, and laboratory assessments. The current consensus definition of HRS-AKI includes proposed diagnostic criteria based on changes in serum creatinine levels tailored for high sensitivity, and rapid detection to accelerate diagnosis and treatment initiation. The only potential cure for HRS-AKI is liver transplantation; however, vasoconstrictive agents and other supportive measures are used as needed to help maintain survival for patients who are awaiting or are ineligible for transplantation. The severity of HRS-AKI, complex pathology, limited treatment options, and range of associated conditions pose significant challenges for both patients and care providers.

Heart rate variability in patients with cirrhosis: a systematic review and meta-analysis

Background. Cirrhosis is associated with abnormal autonomic function and regulation of cardiac rhythm. Measurement of heart rate variability (HRV) provides an accurate and non-invasive measurement of autonomic function as well as liver disease severity currently calculated using the MELD, UKELD, or Child-Pugh scores. This review assesses the methods employed for the measurement of HRV, and evaluates the alteration of HRV indices in cirrhosis, as well as their value in prognosis.Method.We undertook a systematic review using Medline, Embase and Pubmed databases in July 2020. Data were extracted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The risk of bias of the included studies was assessed by a modified version of the Newcastle-Ottawa Scale. The descriptive studies were analysed and the standardized mean differences of HRV indices were pooled.Results.Of the 247 studies generated from our search, 14 studies were included. One of the 14 studies was excluded from meta-analysis because it reported only the median of HRV indices. The studies included have a low risk of bias and include 583 patients with cirrhosis and 349 healthy controls. The HRV time and frequency domains were significantly lower in cirrhotic patients. Between-studies heterogeneity was high in most of the pooled studies (P < 0.05). Further, HRV indices predict survival independent of the severity of liver disease as assessed by MELD.Conclusion.HRV is decreased in patients with cirrhosis compared with healthy matched controls. HRV correlated with severity of liver disease and independently predicted survival. There was considerable variation in the methods used for HRV analysis, and this impedes interpretation and clinical applicability. Based on the data analysed, the standard deviation of inter-beat intervals (SDNN) and SDNN corrected for basal heart rate (cSDNN) are the most suitable indices for prognosis in patients with cirrhosis.

Cardiac baroreflex function and vascular reactivity recovery after aerobic exercise in patients with early cirrhosis

OBJECTIVE

To investigate the effects of aerobic exercise on the cardiac baroreflex function and vascular reactivity in patients with cirrhosis.

METHODS

Thirteen patients with cirrhosis were submitted to exercise and control intervention. At baseline and at 30 and 60 min following intervention, we evaluated cardiac baroreflex sensitivity (cBRS) and the baroreflex effectiveness index (BEI) using sequence technique. Vascular reactivity was assessed inducing reactive hyperemia before and 60 min after intervention.

RESULTS

At baseline, there was no difference (P interaction = 0.848) between exercise (from 3.0 ± 0.34 to 14.60 ± 1.06 ml/100ml/min) and control sessions (from 2.38 ± 0.10 to 13.73 ± 1.05 ml/100ml/min) regarding the increase in forearm blood flow during reactive hyperemia. However, this response was higher postexercise (from 3.38 ± 0.31 to 16.58 ± 1.58 ml/100ml/min) than postcontrol intervention (from 2.04 ± 0.23 to 11.98 ± 1.16 ml/100ml/min, P interaction < 0.001). BEI increased at 30- and 60-min postexercise (from 32 ± 7 to 42 ± 7 and 46 ± 7%), but not after control intervention (from 33 ± 6 to 31 ± 5 and 33 ± 7%, P interaction = 0.014). In contrast, cBRS decreased at 30-min postexercise (from 10.3 ± 1.9 to 8.2 ± 1.4 and 10.3 ± 2.1 ms/mmHg) and increased postcontrol intervention (from 7.9 ± 0.9 to 10.5 ± 1.5 and 10.3 ± 1.3 ms/mmHg, P interaction = 0.012).

CONCLUSION

The results suggest that a single bout of aerobic exercise improved cardiac baroreflex function and increased vascular reactivity in patients with early-stage cirrhosis.

Pathophysiological-based treatments of complications of cirrhosis

Detailed knowledge and understanding of the pathophysiological mechanisms and changes in hepatic and splanchnic function leading to the development of haemodynamic changes and portal hypertension in patients with cirrhosis are essential since it guides the search for targets to ameliorate liver-related abnormalities. Recent research has focused on the gut-liver axis, changes in intestinal permeability, translocation of bacterial products, and inflammation as important drivers of haemodynamic alterations and thereby targets for treatment. Additionally, treatment strategies should focus on microbiotic modulation, antiangiogenics, anti-inflammatory strategies, and modulation of bile acid metabolism. This paper aims to review contemporary pathophysiological-based treatment principles of the major complications of cirrhosis and portal hypertension and future targets for treatment.

Mechanisms in fluid retention - towards a mutual concept

Fluid retention is a common and challenging condition in daily clinical practice. The normal fluid homoeostasis in the human body is based on accurately counter-balanced physiological mechanisms. When compromised fluid retention occurs and is seen in pathophysiologically different conditions such as liver cirrhosis, heart and kidney failure, and in preeclampsia. These conditions may share pathophysiological mechanisms such as functional arterial underfilling, which seems to be a mutual element in cirrhosis, cardiac failure, cardiorenal and hepatorenal syndromes, and in pregnancy. However, there are also distinct differences and it is still unclear whether kidney dysfunction or arterial underfilling is the initiating factor of fluid retention or if they happen simultaneously. This review focuses on similarities and differences in water retaining conditions and points to areas where important knowledge is still needed.

Reappraising the spectrum of AKI and hepatorenal syndrome in patients with cirrhosis

The occurrence of acute kidney injury (AKI) in patients with end-stage liver disease constitutes one of the most challenging clinical scenarios in in-hospital and critical care medicine. Hepatorenal syndrome type 1 (HRS-1), which is a specific type of AKI that occurs in the context of advanced cirrhosis and portal hypertension, is associated with particularly high mortality. The pathogenesis of HRS-1 is largely viewed as a functional derangement that ultimately affects renal vasculature tone. However, new insights suggest that non-haemodynamic tubulo-toxic factors, such as endotoxins and bile acids, might mediate parenchymal renal injury in patients with cirrhosis, suggesting that concurrent mechanisms, including those traditionally associated with HRS-1 and non-traditional factors, might contribute to the development of AKI in patients with cirrhosis. Moreover, histological evidence of morphological abnormalities in the kidneys of patients with cirrhosis and renal dysfunction has prompted the functional nature of HRS-1 to be re-examined. From a clinical perspective, a diagnosis of HRS-1 guides utilization of vasoconstrictive therapy and decisions regarding renal replacement therapy. Patients with cirrhosis are at risk of AKI owing to a wide range of factors. However, the tools currently available to ascertain the diagnosis of HRS-1 and guide therapy are suboptimal. Short of liver transplantation, goal-directed haemodynamically targeted pharmacotherapy remains the cornerstone of treatment for this condition; improved understanding of the underlying pathogenic mechanisms might lead to better clinical outcomes. Here, we examine our current understanding of the pathophysiology of HRS-1 and existing challenges in its diagnosis and treatment.

Significant reduction in heart rate variability is a feature of acute decompensation of cirrhosis and predicts 90-day mortality

BACKGROUND

Heart rate variability (HRV) is reduced in cirrhosis and in conditions of systemic inflammation. Whether HRV is associated with cirrhosis decompensation and development of acute-on-chronic liver failure (ACLF) is unknown.

AIMS

To (a) validate wireless remote HRV monitoring in cirrhosis decompensation; (b) determine if severely reduced HRV is a surrogate for inflammation and progression of cirrhosis decompensation; (c) assess if measuring HRV determines prognosis in cirrhosis decompensation.

METHODS

One hundred and eleven patients at risk of cirrhosis decompensation at two clinical sites were monitored for HRV. Standard deviation of all normal beat-beat intervals (SDNN) reflecting HRV was assessed using remote monitoring (Isansys Lifetouch) and/or Holter ECG recording. Clinical outcomes and major prognostic scores were recorded during 90-day follow-up.

RESULTS

Reduced HRV denoted by lower baseline SDNN, correlated with severity of decompensation (median 14 (IQR 11-23) vs 33 (25-42); P < 0.001, decompensated patients vs stable outpatient cirrhosis). Furthermore, SDNN was significantly lower in patients developing ACLF compared to those with only decompensation (median 10 (IQR9-12) vs 16 (11-24); P = 0.02), and correlated inversely with MELD and Child-Pugh scores, and C-reactive protein (all P < 0.0001) and white cell count (P < 0.001). SDNN predicted disease progression on repeat measures and appeared an independent predictor of 90-day mortality (12 patients). An SDNN cut-off of 13.25 ms had a 98% negative predictive value.

CONCLUSIONS

This study demonstrates that remote wireless HRV monitoring identifies cirrhosis patients at high risk of developing ACLF and death, and suggests such monitoring might guide the need for early intervention in such patients. Clinical Trial number: NIHR clinical research network CPMS ID 4949.

Promising utilization areas of therapeutic plasmapheresis in cardiovascular surgery practice

OBJECTIVE

Apheresis is performed for treatment of numerous diseases by removing auto-antibodies, antigen-antibody complexes, allo-antibodies, paraproteins, non-Ig proteins, toxins, exogenous poisons. In current study, we present our experience of using therapeutic plasma exchange (TPE) in patients with different types of clinical scenarios.

METHODS

Between January 2013 and May 2016, we retrospectively presented the results of 64 patients in whom postoperative TPE was performed in ICU setting after cardiac surgery. Patients were grouped into four as; 1-sepsis (n = 26), 2-hepatorenal syndrome(n = 24), 3-antibody mediated rejection(AMR) following heart transplantation(n = 4) and 4-right heart failure(RHF) after left ventricular asist device(LVAD)(n = 10). Hemodynamic parameters were monitored constantly, pre- and post-procedure peripheral blood tests including renal and liver functions and daily complete blood count (CBC), sedimentation, C-reactive protein and procalcitonin (ng/ml) levels were studied.

RESULTS

The mean age was 61 ± 17.67 years old and 56.25% (n = 36) were male. Mean Pre TPE left ventricular ejection fraction (LVEF) (%), central venous pressure (CVP)(mmHg) pulmonary capillary wedge pressure (PCWP)(mmHg) and pulmonary arterial pressure (PAP)(mmHg) were measured as 41.8 ± 8.1, 15.5 ± 4.4, 17.3 ± 3.24 and 39.9 ± 5.4, respectively. Procalcitonin (ng/ml) level of patients undergoing TPE due to sepsis was significantly reduced from 873 ± 401 ng/ml to 248 ± 132 ng/ml. Seventeen (26.5%) patients died in hospital during treatment, mean length of intensive care unit (ICU) stay(days) was 13.2 ± 5.1.

CONCLUSION

This study shows that TEP is a safe and feasible treatment modality in patients with different types of complications after cardiac surgery and hopefully this study will lead to new utilization areas.

Severe abnormal Heart Rate Turbulence Onset is associated with deterioration of liver cirrhosis

Background

In patients with liver cirrhosis, cardiac dysfunction is frequent and is associated with increased morbidity and mortality. Cardiac dysfunction in cirrhosis seems to be linked to autonomic dysfunction. This study investigates the role of autonomic dysfunction assessed by Heart Rate Turbulence (HRT) analyses in patients with liver cirrhosis.

Methods and patients

Inclusion criteria was (1) diagnosis of cirrhosis by clinical, imaging or biopsy and (2) evaluation by standard 12-lead-ECG and 24h holter monitoring and (3) at least 3 premature ventricular contractions. The exclusion criterion was presence of cardiac diseases, independent of liver cirrhosis. Biochemical parameters were analysed using standard methods. HRT was assessed using Turbulence onset (TO) and slope (TS). The endpoint was deterioration of liver cirrhosis defined as increased MELD and readmission for complications of liver cirrhosis.

Results

Out of 122 cirrhotic patients, 82 patients (63% male) with median Child score of 6 (range 5–12) and median MELD score of 10 (range 6–32) were included. Increasing Child score, INR and decreasing albumin were correlated with TO. In addition, decompensated patients with ascites showed more abnormal TO and TS. During the observation period, patients with more abnormal TO showed significantly higher rate of rising MELD Score at 6 months (p = 0.03). Nevertheless, at least in our collective HRT-parameters were not independent predictors of deterioration of cirrhosis.

Conclusion

Parameters of HRT are closely associated with deterioration of cirrhosis and might be helpful in its prediction.

Cardiovascular dysfunction and liver transplantation

Cardiovascular complications have emerged as the leading cause of death after liver transplantation, particularly among those with advanced liver cirrhosis. Therefore, a thorough and accurate cardiovascular evaluation with clear comprehension of cirrhotic cardiomyopathy is recommended for optimal anesthetic management. However, cirrhotic patients manifest cardiac dysfunction concomitant with pronounced systemic hemodynamic changes, characterized by hyperdynamic circulation such as increased cardiac output, high heart rate, and decreased systemic vascular resistance. These unique features mask significant manifestations of cardiac dysfunction at rest, which makes it difficult to accurately evaluate cardiovascular status. In this review, we have summarized the current knowledge of heart and liver interactions, focusing on the usefulness and limitations of cardiac evaluation tools for identifying high-risk patients.

The pathophysiology of arterial vasodilatation and hyperdynamic circulation in cirrhosis

Patients with cirrhosis and portal hypertension often develop complications from a variety of organ systems leading to a multiple organ failure. The combination of liver failure and portal hypertension results in a hyperdynamic circulatory state partly owing to simultaneous splanchnic and peripheral arterial vasodilatation. Increases in circulatory vasodilators are believed to be due to portosystemic shunting and bacterial translocation leading to redistribution of the blood volume with central hypovolemia. Portal hypertension per se and increased splanchnic blood flow are mainly responsible for the development and perpetuation of the hyperdynamic circulation and the associated changes in cardiovascular function with development of cirrhotic cardiomyopathy, autonomic dysfunction and renal dysfunction as part of a cardiorenal syndrome. Several of the cardiovascular changes are reversible after liver transplantation and point to the pathophysiological significance of portal hypertension. In this paper, we aimed to review current knowledge on the pathophysiology of arterial vasodilatation and the hyperdynamic circulation in cirrhosis.

Reduced neural baroreflex sensitivity is related to enhanced endothelial function in patients with end-stage liver disease

OBJECTIVES

Reduced baroreflex sensitivity (BRS) is a frequent complication in end-stage liver disease, but the underlying mechanism is unknown. We investigated the mechanical and neural components of BRS. Increased nitric oxide (NO) production has been reported in end-stage liver failure. Based on earlier experiments, we hypothesised that enhanced endothelial function might affect baroreflex function. Therefore, we explored the relation between endothelial function and the components of BRS.

MATERIALS AND METHODS

We enrolled 24 patients and 23 controls. BRS was determined by the spontaneous sequence method. Mechanical component was characterised by the distensibility coefficient (DC) of common carotid artery. Neural component was estimated as the ratio of integrated BRS and DC. Endothelial function was quantified by flow-mediated dilation (FMD) of the brachial artery.

RESULTS

Integrated BRS was reduced in patients [7.00 (5.80-9.25) vs. 11.1 (8.50-14.80) ms/mmHg]. The mechanical component was not different in the two groups, whereas neural component showed significant reduction in patients (3.54 ± 1.20 vs. 4.48 ± 1.43 ms/10^-3). FMD was higher in patients (9.81 ± 3.77 vs. 5.59 ± 1.36%). FMD and neural BRS were directly related in controls (r = 0.62), but inversely related in patients (r = -0.49).

CONCLUSIONS

Baroreflex impairment in end-stage liver disease might be explained by deterioration of the neural component, while the mechanical component appears to be preserved. Endothelial NO may enhance BRS in health; however, central endothelial overproduction of NO likely contributes to the reduction of neural component of BRS in patients awaiting liver transplantation.

Expression of classical mediators in hearts of rats with hepatic dysfunction

Liver cirrhosis is associated with impairment of cardiovascular function including alterations of the heart innervation, humoral and nervous dysregulation, changes in systemic circulation and electrophysiological abnormalities. Choline acetyltransferase (ChAT), enzyme forming acetylcholine, tyrosine hydroxylase (TH), and dopamine-β-hydroxylase (DBH), enzymes participating in noradrenaline synthesis, are responsible for the production of classical neurotransmitters, and atrial natriuretic peptide (ANP) is produced by cardiomyocytes. The aim of this study was to evaluate the influence of experimentally induced hepatic dysfunction on the expression of proANP, ChAT, TH, and DBH in the heart. Hepatic dysfunction was induced by application of thioacetamide (TAA) or by ligation of bile duct. Biochemical parameters of hepatic injury and levels of peroxidation in the liver and heart were measured. Liver enzymes measured in the plasma were significantly elevated. Cardiac level of peroxidation was increased in operated but not TAA group animals. In the left atrium of operated rats, the expression of TH and DBH was lower, while expression of ChAT remained unchanged. In TAA group, no significant differences in the expression of the genes compared to controls were observed. Liver injury induced by ligation leads to an imbalance in the intracardiac innervation, which might impair nervous control of the heart.

Nitrosative Stress-Induced Disruption of Baroreflex Neural Circuits in a Rat Model of Hepatic Encephalopathy: A DTI Study

The onset of hepatic encephalopathy (HE) in liver failure is associated with high mortality; the underlying mechanism is undecided. Here we report that in an acute liver failure model employing intraperitoneal administration of thioacetamide in Sprague-Dawley rats, diffusion weighted imaging revealed a progressive reduction in apparent diffusion coefficient in the brain stem. Diffusion tensor imaging further showed that the connectivity between nucleus tractus solitarii (NTS), the terminal site of baroreceptor afferents in brain stem and rostral ventrolateral medulla (RVLM), the origin of sympathetic innervation of blood vessels, was progressively disrupted until its disappearance, coincidental with the irreversible cessation of baroreflex-mediated sympathetic vasomotor tone signifying clinically the occurrence of brain death. In addition, superoxide, nitric oxide, peroxynitrite and ammonia levels in the NTS or RVLM were elevated, alongside swelling of astroctytes. A scavenger of peroxynitrite, but not an antioxidant, delivered intracisternally reversed all these events. We conclude that nitrosative stress because of augmented peroxynitrite related to accumulation of ammonia and swelling of astrocytes in the NTS or RVLM, leading to cytotoxic edema in the brain stem and severance of the NTS-RVLM connectivity, underpins the defunct baroreflex-mediated sympathetic vasomotor tone that accounts for the high mortality associated with HE.

The role of autonomic dysfunction in cirrhotic patients before and after liver transplantation. Review of the literature

In patients affected by hepatic cirrhosis, autonomic dysfunction is a common finding; usually it is asymptomatic but it may correlate with increased mortality and morbidity before, during and after liver transplant, due to hemodynamic instability in the course of stressful events like sepsis, gastrointestinal bleeding and reperfusion after transplantation surgery. Hyperdynamic circulation and hepatic dysfunction seem to play a role in the pathogenesis of autonomic dysfunction, even if pathophysiological mechanisms are not completely known. We present a revision of previous literature about prevalence, pathophysiological mechanisms, clinical features, and mortality and morbidity of autonomic dysfunction secondary to hepatic cirrhosis.

Decreased excitability and voltage-gated sodium currents in aortic baroreceptor neurons contribute to the impairment of arterial baroreflex in cirrhotic rats

Cardiovascular autonomic dysfunction, which is manifested by an impairment of the arterial baroreflex, is prevalent irrespective of etiology and contributes to the increased morbidity and mortality in cirrhotic patients. However, the cellular mechanisms that underlie the cirrhosis-impaired arterial baroreflex remain unknown. In the present study, we examined whether the cirrhosis-impaired arterial baroreflex is attributable to the dysfunction of aortic baroreceptor (AB) neurons. Biliary and nonbiliary cirrhotic rats were generated via common bile duct ligation (CBDL) and intraperitoneal injections of thioacetamide (TAA), respectively. Histological and molecular biological examinations confirmed the development of fibrosis in the livers of both cirrhotic rat models. The heart rate changes during phenylephrine-induced baroreceptor activation indicated that baroreflex sensitivity was blunted in the CBDL and TAA rats. Under the current-clamp mode of the patch-clamp technique, cell excitability was recorded in DiI-labeled AB neurons. The number of action potential discharges in the A- and C-type AB neurons was significantly decreased because of the increased rheobase and threshold potential in the CBDL and TAA rats compared with sham-operated rats. Real-time PCR and Western blotting indicated that the NaV1.7, NaV1.8, and NaV1.9 transcripts and proteins were significantly downregulated in the nodose ganglion neurons from the CBDL and TAA rats compared with the sham-operated rats. Consistent with these molecular data, the tetrodotoxin-sensitive NaV currents and the tetrodotoxin-resistant NaV currents were significantly decreased in A- and C-type AB neurons, respectively, from the CBDL and TAA rats compared with the sham-operated rats. Taken together, these findings implicate a key cellular mechanism in the cirrhosis-impaired arterial baroreflex.

Differential Sympathetic Vasomotor Activation Induced by Liver Cirrhosis in Rats

We tested the hypothesis that there is a topographical sympathetic activation in rats submitted to experimental cirrhosis. Baseline renal (rSNA) and splanchnic (sSNA) sympathetic nerve activities were evaluated in anesthetized rats. In addition, we evaluated main arterial pressure (MAP), heart rate (HR), and baroreceptor reflex sensitivity (BRS). Cirrhotic Wistar rats were obtained by bile duct ligation (BDL). MAP and HR were measured in conscious rats, and cardiac BRS was assessed by changes in blood pressure induced by increasing doses of phenylephrine or sodium nitroprusside. The BRS and baseline for the control of sSNA and rSNA were also evaluated in urethane-anesthetized rats. Cirrhotic rats had increased baseline sSNA (BDL, 102 vs control, 58 spikes/s; p<0.05), but no baseline changes in the rSNA compared to controls. These data were accompanied by increased splanchnic BRS (p<0.05) and decreased cardiac (p<0.05) and renal BRS (p<0.05). Furthermore, BDL rats had reduced basal MAP (BDL, 93 vs control, 101 mmHg; p<0.05) accompanied by increased HR (BDL, 378 vs control, 356; p<0.05). Our data have shown topographical sympathetic activation in rats submitted to experimental cirrhosis. The BDL group had increased baseline sSNA, independent of dysfunction in the BRS and no changes in baseline rSNA. However, an impairment of rSNA and HR control by arterial baroreceptor was noted. We suggest that arterial baroreceptor impairment of rSNA and HR is an early marker of cardiovascular dysfunction related to liver cirrhosis and probably a major mechanism leading to sympathoexcitation in decompensated phase.

The heart matters when the liver shatters! Cirrhotic cardiomyopathy: frequency, comparison, and correlation with severity of disease

Introduction

Cirrhotic cardiomyopathy is a visor complication among patients with cirrhosis of the liver, manifesting during stress, exertion, transjuglar intrahepatic portosystemic shunt (TIPS), or liver transplantation. Cirrhotic cardiomyopathy is reported to be most common cause of post transplant mortality after rejection of 7% to 21%.

Aim

To determine the frequency of cirrhotic cardiomyopathy and was further designed to compare parameters of cardiac dysfunction in patients with or without cirrhotic cardiomyopathy.

Material and methods

All confirmed cases of cirrhosis with various aetiologies were enrolled. Resting ejection fraction (EF) was determined in all patients. Patients were grouped with resting EF < 55% (suspected cardiomyopathy) or > 55% (without cardiomyopathy). Stress echocardiography with dobutamine infusion in both groups yielded an increase of less than 10% in left ventricular (LV) EF at peak dobutamine infusion confirming systolic dysfunction. The diastolic dysfunction (E/A ratio), electrocardiographic parameter (prolong QT interval), and cardiac biomarker (NT-proBNP) were also determined in both the groups to confirm cirrhotic cardiomyopathy.

Results

Among 89 patients with cirrhosis, 35 (39.32%) had cirrhotic cardiomyopathy. All components of cirrhotic cardiomyopathy, like systolic dysfunction, diastolic dysfunction, prolong QT interval, and cardiac biomarkers, were found to be statistically significant (p = 0.001) when compared with patients without cardiomyopathy. Cirrhotic cardiomyopathy parameters were positively correlated with advancing liver disease.

Conclusions

Cirrhotic cardiomyopathy is a frequent but unmasked complication in cirrhosis of the liver. All components of cardiac dysfunction, such as systolic, diastolic, and electrocardiographic changes, are present in patients with cirrhotic cardiomyopathy. Cirrhotic cardiomyopathy is positively correlated to severity of liver disease.

Diastolic dysfunction diagnosed by tissue Doppler imaging in cirrhotic patients: Prevalence and its possible relationship with clinical outcome

BACKGROUND

Cirrhotic cardiomyopathy has been characterized by impaired contractile response to stress and/or altered diastolic relaxation, with electrophysiological abnormalities in the absence of known cardiac disease. However, the clinical significance of diastolic dysfunction (DDF) in cirrhotic patients has not been clarified.

METHODS

We studied 84 cirrhotic patients with normal systolic function to evaluate the prevalence of DDF using tissue Doppler imaging, and to investigate the possible correlation of DDF with outcomes (hospitalization, death) and with the specific causes of death.

RESULTS

The mean follow-up was 10±8months. DDF was diagnosed in 22 patients (26.2%). Patients with DDF more frequently had ascites (90.9% vs. 64.5 %; p=0.026), lower levels of albumin (OR: 5.39; p=0.004), higher NT-proBNP levels, and longer QTc interval (464±23ms vs. 452±30ms; p=0.039). At follow-up, patients with DDF did not have a higher incidence of adverse events in terms of hospitalization and death.

CONCLUSIONS

The presence of diastolic dysfunction has not been found to be clearly associated with outcome, and prognosis has been determined primarily by the severity of liver disease.

Cardiac imaging in patients with chronic liver disease

Cirrhotic cardiomyopathy (CCM) is characterized by an impaired contractile response to stress, diastolic dysfunction and the presence of electrophysiological abnormalities, and it may be diagnosed at rest in some patients or demasked by physiological or pharmacological stress. CCM seems to be involved in the development of hepatic nephropathy and is associated with an impaired survival. In the field of cardiac imaging, CCM is not yet a well-characterized entity, hence various modalities of cardiac imaging have been applied. Stress testing with either physiologically or pharmacologically induced circulatory stress has been used to assess systolic dysfunction. Whereas echocardiography with tissue Doppler is by far the most preferred method to detect diastolic dysfunction with measurement of E/A- and E/E'-ratio. In addition, echocardiography may also possess the potential to evaluate systolic dysfunction at rest by application of new myocardial strain techniques. Experience with other modalities such as cardiac magnetic resonance imaging and cardiac computed tomography is limited. Future studies exploring these imaging modalities are necessary to characterize and monitor the cardiac changes in cirrhotic patients.

Cirrhotic Multiorgan Syndrome

Patients with cirrhosis and portal hypertension are at an increased risk of the development of circulatory dysfunction that may potentially result in multiple organ failure. Apart from the liver, this may involve the heart, lungs, kidneys, the immune system, the adrenal glands, and other organ systems. As the disease progresses, the circulation becomes hyperdynamic, and signs of cardiac, pulmonary, and renal dysfunction are observed, in addition to reduced survival. Infections and an altered cardiac function known as cirrhotic cardiomyopathy may be precipitators for the development of other complications such as hepatorenal syndrome. In patients with chronic organ dysfunction, various precipitating events may induce an acute-on-chronic renal failure and acute-on-chronic liver failure that negatively affect the prognosis. Future research on the pathophysiologic mechanisms of the complications and the precipitating factors is essential to understand the basics of the treatment of these challenging conditions. The aim of the present review is to focus on the development and precipitating factors of various organ failures in patients with decompensated cirrhosis.

Complications of cirrhosis. A 50 years flashback

In patients with cirrhosis and portal hypertension, it is largely the frequency and severity of complications relating to the diseased liver, degree of portal hypertension and hemodynamic derangement that determine the prognosis. It can be considered as a multiple organ failure that apart from the liver involves the heart, lungs, kidneys, the immune systems and other organ systems. Progressive fibrosis of the liver and subsequent metabolic impairment leads to a systemic and splanchnic arteriolar vasodilatation. With the progression of the disease development of portal hypertension leads to formation of esophageal varices and ascites. The circulation becomes hyperdynamic with cardiac, pulmonary as well as renal consequences for dysfunction and reduced survival. Infections and a changed cardiac function known as cirrhotic cardiomyopathy may be involved in further aggravation of other complications such as renal failure precipitating the hepatorenal syndrome. Patients with end-stage liver disease and related complications as for example the hepatopulmonary syndrome can only radically be treated by liver transplantation.

Cirrhotic cardiomyopathy: Implications for the perioperative management of liver transplant patients

Cirrhotic cardiomyopathy is a disease that has only recently been recognised as a definitive clinical entity. In the setting of liver cirrhosis, it is characterized by a blunted inotropic and chronotropic response to stress, impaired diastolic relaxation of the myocardium and prolongation of the QT interval in the absence of other known cardiac disease. A key pathological feature is the persistent over-activation of the sympathetic nervous system in cirrhosis, which leads to down-regulation and dysfunction of the β-adrenergic receptor. Diagnosis can be made using a combination of echocardiography (resting and stress), tissue Doppler imaging, cardiac magnetic resonance imaging, 12-lead electrocardiogram and measurement of biomarkers. There are significant implications of cirrhotic cardiomyopathy in a number of clinical situations in which there is an increased physiological demand, which can lead to acute cardiac decompensation and heart failure. Prior to transplantation there is an increased risk of hepatorenal syndrome, cardiac failure following transjugular intrahepatic portosystemic shunt insertion and increased risk of arrhythmias during acute gastrointestinal bleeding. Liver transplantation presents the greatest physiological challenge with a further risk of acute cardiac decompensation. Peri-operative management should involve appropriate choice of graft and minimization of large fluctuations in preload and afterload. The avoidance of cardiac failure during this period has important prognostic implications, as there is evidence to suggest a long-term resolution of the abnormalities in cirrhotic cardiomyopathy.

Stroke volume response to liver graft reperfusion stress in cirrhotic patients

INTRODUCTION

In patients with advanced cirrhosis, stressful stimuli may reveal a silent reduced cardiac performance. During liver transplantation (LT), graft reperfusion strongly stresses the heart and may unmask latent myocardial dysfunction.

AIM

The objective of this study was to assess heart response to acutely increased preload after liver graft reperfusion and correlate this response with preoperative data and outcome.

METHODS

Preoperative clinical, echocardiographic, and hemodynamic data, and patient outcome were retrospectively recorded for 235 liver recipients who had no known cardiac disease. Myocardial dysfunction was defined as less than 10 % increase of stroke volume after graft reperfusion (non-responder).

RESULTS

We found 84 (35.7 %) non-responder patients. The non-responders showed higher Model for end-stage liver disease scores (p = 0.046), left atrial diameter (LAD) (p = 0.040), hepatic vein pressure gradient (p = 0.055), and hyperdynamic state than responders. The percentages of patients with hyponatremia (p = 0.048) and alcohol etiology (p = 0.025) were also higher among non-responders. Independent predictors of inadequate cardiac response in the multivariate analysis were low preoperative systemic vascular resistance (SVRI) [odds ratio (OR) 3.09, 95 % CI 1.15-4.82; p = 0.027] and enlargement of LAD (OR 2.08, 95 % CI 1.49-2.74; p = 0.044). Non-response was associated with higher rates of early cardiovascular events [hazard ratio (HR) 2.84, 95 % CI 1.09-4.22; p = 0.039] and higher length of intensive care unit stay (p = 0.038). No differences were found in 1-year survival rates.

CONCLUSIONS

Latent cardiac dysfunction among LT recipients, considered to be abnormal stroke volume response to unclamping of portal vein, is very prevalent. SVRI and LAD were independent predictors of inadequate responses. This condition deserves special attention since it may aggravate the early postoperative course of LT.

Kidney injury in cirrhosis: pathophysiological and therapeutic aspects of hepatorenal syndromes

Acute kidney injury (AKI) is frequent in patients with cirrhosis. AKI and hyponatraemia are major determinants of the poor prognosis in advanced cirrhosis. The hepatorenal syndrome (HRS) denotes a functional and potential reversible impairment of renal function. Type 1 HRS, a special type of AKI, is a rapidly progressive AKI, whereas the renal function in type 2 HRS decreases more slowly. HRS is precipitated by factors such as sepsis that aggravate the effective hypovolaemia in decompensated cirrhosis, by lowering arterial pressure and cardiac output and enhanced sympathetic nervous activity. Therefore, attempts to prevent and treat HRS should seek to improve liver function and to ameliorate arterial hypotension, central hypovolaemia and cardiac output, and to reduce renal vasoconstriction. Ample treatment of HRS is important to prevent further progression and death, but as medical treatment only modestly improves long-term survival, these patients should always be considered for liver transplantation. Hyponatraemia, defined as serum sodium <130 mmol/L, is common in patients with decompensated cirrhosis. From a pathophysiological point of view, hyponatraemia is related to an impairment of renal solute-free water excretion most likely caused by an increased vasopressin secretion. Patients with cirrhosis mainly develop hypervolaemic hyponatraemia. Current evidence does not support routine use of vaptans in the management of hyponatraemia in cirrhosis.

Diastolic and autonomic dysfunction in early cirrhosis: a dobutamine stress study

OBJECTIVE. Presence of cardiac dysfunction in patients with advanced cirrhosis is widely accepted, but data in early stages of cirrhosis are limited. Systolic and diastolic functions, dynamics of QT-interval, and pro-atrial natriuretic peptide (pro-ANP) are investigated in patients with early stage cirrhosis during maximal β-adrenergic drive. MATERIAL AND METHODS. Nineteen patients with Child A (n = 12) and Child B cirrhosis (n = 7) and seven matched controls were studied during cardiac stress induced by increasing dosages of dobutamine and atropine. RESULTS. Pharmacological responsiveness was similar in cirrhosis and controls and the heart rate (HR) increased by 66 ± 15 versus 67 ± 8 min(-1). HR-blood pressure product increased equally by 115% in both cirrhotic patients and controls. However, time to resume HR of 100 beats/min was significantly longer in cirrhosis, p < 0.01. The QTc interval increased after dobutamine infusion in cirrhosis (0.41 ± 0.02 vs. 0.43 ± 0.02 s, p = 0.001) but similar electrophysiological changes were seen in controls. Cardiac volumes increased with the severity of disease. The increased cardiac output was primarily attributed to increased stroke volume. The ejection fraction was similar in patients and controls. Peak filling rate was longer in cirrhosis compared to controls (1.8 ± 0.4 and 1.4 ± 0.2 end-diastolic volume/s, p < 0.01). Pro-ANP was higher in cirrhosis and increased during stress by 13% compared to 0% in controls, p < 0.01. CONCLUSIONS. These findings indicate that patients with early stage cirrhosis exhibit early diastolic and autonomic dysfunction as well as elevated pro-ANP. However, the cardiac chronotropic and inotropic responses to dobutamine stress were normal. The dynamics of ventricular repolarization appears normal in patients with early stage cirrhosis.

Cirrhotic cardiomyopathy: pathogenesis and clinical relevance

Cirrhosis is known to cause alterations in the systemic haemodynamic system. Cirrhotic cardiomyopathy designates a cardiac dysfunction that includes impaired cardiac contractility with systolic and diastolic dysfunction, as well as electromechanical abnormalities in the absence of other known causes of cardiac disease. This condition is primarily revealed by inducing physical or pharmacological stress, but echocardiography is excellent at revealing diastolic dysfunction and might also be used to detect systolic dysfunction at rest. Furthermore, measurement of circulating levels of cardiac biomarkers could improve the diagnostic assessm+ent. Cirrhotic cardiomyopathy contributes to various complications in cirrhosis, especially as an important factor in the development of hepatic nephropathy. Additionally, cirrhotic cardiomyopathy seems to be associated with the development of heart failure in relation to invasive procedures such as shunt insertion and liver transplantation. Current pharmacological treatment is nonspecific and directed towards left ventricular failure, and liver transplantation is currently the only proven treatment with specific effect on cirrhotic cardiomyopathy.

Liver in cardiopulmonary disease

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

Cardiac sympathetic imaging with mIBG in cirrhosis and portal hypertension: relation to autonomic and cardiac function

Autonomic and cardiac dysfunction is frequent in cirrhosis and includes increased sympathetic nervous activity, impaired heart rate variability (HRV), and baroreflex sensitivity (BRS). Quantified (123)I-metaiodobenzylguanidine (mIBG) scintigraphy reflects cardiac noradrenaline uptake, and in patients with cardiac failure it predicts outcome. In this study, we aimed to investigate cardiac sympathetic neuronal function in cirrhosis by mIBG scintigraphy in relation to cardiovascular function. Ten patients with alcoholic cirrhosis and 10 age- and sex-matched healthy controls participated in the study. Heart/mediastinum (H/M) ratios of mIBG uptake were calculated 15 and 230 min after intravenous injection of mIBG. Furthermore, washout rate (WOR) of mIBG was calculated. The patients underwent a liver vein catheterization with determination of splanchnic and systemic hemodynamics and measurement of HRV and BRS. mIBG-scintigraphy revealed significantly increased WOR in patients with cirrhosis compared with controls (P < 0.005), whereas H/M uptakes were equal in the groups. Forty percent of the patients had reduced uptake of mIBG in the infero-lateral segment of the left ventricle. WOR correlated significantly with central circulation time, an estimate of central hypovolemia (r = -0.64, P < 0.05) and frequency-corrected QT(F) interval (r = 0.71, P = 0.01). Patients with cirrhosis had significantly decreased HRV and BRS correlating with indicators of abnormal cathecholamine uptake by mIBG although the catecholamine level was normal in the patients. In conclusion, in alcoholic cirrhosis, mIBG scintigraphy reveals autonomic dysfunction and impaired myocardial distribution of sympathetic nervous activity. It is associated to indicators of central hypovolemia, QT interval, and decreased HRV and BRS. Measurement of myocardial catecholamine uptake by mIBG may add important information on autonomic and cardiac dysfunction in cirrhosis.

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.

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.

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.

Pulmonary dysfunction and hepatopulmonary syndrome in cirrhosis and portal hypertension

BACKGROUND

Pulmonary dysfunction including the hepatopulmonary syndrome (HPS) is an important complication to cirrhosis and portal hypertension. However, the precise relation to liver dysfunction and the prevalence of HPS are unclear.

AIMS

We therefore aimed to assess (i) the prevalence of HPS in consecutive alcoholic cirrhotic patients, (ii) the degree of pulmonary dysfunction in relation to liver function and (iii) the response of a 100% oxygen test on cardiopulmonary and peripheral oxygenation.

METHODS

Fifty patients with cirrhosis and 12 matched healthy controls were entered in this study. All underwent haemodynamic and pulmonary investigations [lung diffusing capacity for carbon monoxide (DLCO), contrast-enhanced echocardiography and detection of extrapulmonary shunt fraction]. A 100% oxygen test was performed with the assessment of arterial oxygen tension (PaO(2)), the alveolar-arterial oxygen gradient (AaPO(2)) and peripheral transcutaneous oxygen tension (tcPO(2)).

RESULTS

The prevalence of HPS was 10%. PaO(2) and DLCO were reduced in 32 and 72% and AaPO(2), was increased in 60% of the patients respectively. DLCO correlated with indicators of liver dysfunction (galactose elimination capacity, P<0.01, indocyanine green clearance, P<0.001), portal hypertension (post-sinusoidal resistance, P<0.01) and central hypovolaemia (central and arterial blood volume, P<0.01). After 100% oxygen inhalation, the changes in PaO(2), AaPO(2), tcPO(2) and heart rate were abnormal in the patients compared with controls (P<0.02).

CONCLUSIONS

Pulmonary dysfunction in alcoholic cirrhosis is common and relates to different aspects of liver dysfunction, whereas the prevalence of HPS is low. The haemodynamic response to oxygen inhalation is clearly impaired and HPS and pulmonary dysfunction seem to be caused by different pathophysiological mechanisms.

Investigation of autonomic function and orocecal transit time in patients with nonalcoholic cirrhosis and the potential influence of these factors on disease outcome

BACKGROUND

The presence of autonomic dysfunction in nonalcoholic cirrhosis and its influence on intestinal transit and disease outcome still need clarification.

GOALS

To investigate the function of the autonomic nervous system in patients with nonalcoholic cirrhosis and the possible associations among autonomic dysfunction, severity of liver disease, disturbed intestinal transit, and the development of complications during follow-up.

STUDY

Measurements of heart rate variability obtained by analysis of 24-hour ambulatory electrocardiographic recordings to assess autonomic function and lactulose breath hydrogen test to determine orocecal transit time were performed in 32 patients with nonalcoholic cirrhosis divided into Child A and B.

RESULTS

Child B patients showed significantly lower values (P<0.05) of those parameters reflecting parasympathetic (high frequency, log-transformed high frequency, pNN50) and sympathetic function (low frequency, log-transformed low frequency) in comparison with controls and Child A patients. Orocecal transit time values were significantly (P=0.02) higher in Child B patients than in controls, but no relationship was found between delayed orocecal transit time and autonomic dysfunction. During follow-up, 42% of Child B patients developed encephalopathy. This complication was significantly associated with autonomic dysfunction. In addition, in the 4 patients who died the parameters reflecting parasympathetic function were significantly reduced in comparison with those of survivors.

CONCLUSIONS

Autonomic dysfunction and delayed intestinal transit are related to the severity of disease in nonalcoholic cirrhosis. Autonomic dysfunction seems to predispose cirrhotic patients to the development of encephalopathy and may be associated with a poor prognosis of these patients.

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.