The relationship of heart rate variability with severity and prognosis of cirrhosis

Recovery of cardiac electrophysiological alterations by heart rate complexity based on multiscale entropy following liver transplantation

Autonomic nervous dysfunction is a known cardiac sequalae in patients with end-stage liver disease and is associated with a poor prognosis. Heart rate analysis using nonlinear models such as multiscale entropy (MSE) or complexity may identify marked changes in these patients where conventional heart rate variability (HRV) measurements do not. To investigate the application of heart rate complexity (HRC) based on MSE in liver transplantation settings. Thirty adult recipients of elective living donor liver transplantation were enrolled. HRV parameters using conventional HRV analysis and HRC analysis were obtained at the following time points: (1) 1 day before surgery, (2) postoperative day (POD) 7, (3) POD 14, (4) POD 90, and (5) POD 180. Preoperatively, patients with MELD score ≥ 25 had significantly lower HRC compared to patients with lower MELD scores. This difference in HRC disappeared by POD 7 following liver transplantation and subsequent analyses at POD 90 and 180 continued to show no significant difference. Our results indicated a significant negative correlation between HRC based on MSE analysis and liver disease severity preoperatively, which may be more sensitive than conventional linear HRV analysis. HRC in patients with MELD score ≧ 25 improved over time and became comparable to those with MELD < 25 as early as in 7 days.

Evaluation of Electrocardiogram Parameters and Heart Rate Variability During Blood Pressure Elevation by Phenylephrine in Cirrhotic Rats

Cirrhotic cardiomyopathy is a myocardial disease that may go undetected in the early stages due to peripheral vasodilatation. The aim of the study was to evaluate the electrocardiogram (ECG) and heart rate variability (HRV) after raising blood pressure by phenylephrine injection in rats with liver cirrhosis. Twenty male Sprague-Dawley rats were divided into the Sham and common bile duct ligation (CBDL) groups. After 44 days, animals were anesthetized and the right femoral artery and vein catheterized. After a steady-state period, a bolus injection of phenylephrine (PHE, 10 μg/μl/IV, baroreflex maneuver) was followed by a slow injection of PHE (100 μg/ml/5 min/IV, sustained maneuver). Rapid and slow injections of PHE resulted in a greater increase in mean arterial pressure (MAP) and a weaker bradycardia response in the CBDL group than in the Sham group. ECG analysis showed increased QT, QTc, JT, and T peak to T end in the CBDL group, which remained unchanged after PHE injection. On the other hand, the parasympathetic indices of the HF band and RMSSD, and the sympathetic index of the LF band after PHE injection were lower in the CBDL group than in the Sham group.ECG data indicated prolonged ventricular depolarization and repolarization, independent of blood pressure levels in cirrhosis. On the other hand, after PHE injection, the parasympathetic and sympathetic components of HRV decreased, regardless of the duration of elevated blood pressure. We suggest that HRV analysis can provide a useful approach to assess cardiac dysfunction associated with elevated blood pressure in cirrhosis.

Heart rate variability is associated with disease severity and portal hypertension in cirrhosis

INTRODUCTION

Autonomic nervous system activity in cirrhotic portal hypertension is linked to hyperdynamic circulation. Heart rate variability (HRV) is a validated noninvasive method to assess the sympathovagal balance. To investigate the correlation between HRV parameters and degree of portal hypertension, we studied a cohort of patients with cirrhosis accounting for etiology and treatments.

PATIENTS AND METHODS

In this cross-sectional, observational cohort study, 157 outpatients of both sex with nonalcoholic cirrhosis were assessed by upper gastrointestinal endoscopy to search for esophagogastric varices. Twenty-four-hour electrocardiogram Holter monitoring with 3 HRV parameters measurement [SD of the NN intervals, root mean square successive difference of NN intervals, and SD of the averages of NN intervals (SDANN)] according to time-domain analysis were performed in all patients. Sixteen patients with large esophagogastric varices underwent measurements of the HVPG and assessment of HRV parameters at baseline and after 45 days on carvedilol.

RESULTS

The liver dysfunction, expressed by Child-Pugh class or MELD score, was directly related to root mean square successive difference of NN intervals and inversely related to SDANN. Presence of ascites was inversely related to SDANN and to SD of the NN intervals. Treatment with carvedilol had an inverse relation with SDANN. Presence and size of esophagogastric varices had an inverse relation to SDANN and SD of the NN intervals. Upon multivariate analysis the associations between SDANN and Child-Pugh class, size of varices and ascites were confirmed. In the subgroup of 16 patients undergoing HVPG measurement, pressure gradient was unrelated to heart rate and HRV parameters.

CONCLUSIONS

Time-domain HRV parameters in patients with cirrhosis, confirm the autonomic nervous system alteration, and their correlation to the degree of portal hypertension suggesting a role of the ANS in hepatic decompensation.

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

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

Cardiac autonomic modulation in children with severe liver disease, before and after liver transplantation

BACKGROUND

The cardiovascular system is directly influenced by the autonomic nervous system (ANS); its changes affect heart rate variability (HRV) and are sensitive indicators of physiological changes. Autonomic dysfunction (AD) is manifested in up to 60% of patients with cirrhosis. Therefore, we aim to analyze the indexes of HRV pre- and post-surgery of children submitted for liver transplantation (LT).

METHODS

HRV, in children of both genders from 6 months of age to 10 years, that attended at the pediatric surgery clinic in the queue for LT at the Children's Institute were analyzed. To access HRV we analyzed indexes such as standard deviation of the RR intervals (SDNN), root-mean-square of the successive normal sinus RR interval difference (RMSSD), low frequency (LF), high frequency (HF), and LF/HF.

RESULTS

The analysis of the behavior of cardiac autonomic modulation, in the period prior to LT and after surgery, showed an increase in HRV linear parameters SDNN, TINN (triangular interpolation of NN interval histogram), HFms². In the time domain, there was also an increase in the HFms² index.

CONCLUSIONS

The analysis of the period preceding LT and two months after surgery showed an increase in the HRV linear parameters representing a global HRV improvement. In the time domain, there was also an increase in the HFms² index, parasympathetic tone of the HRV.

The mechanistic and prognostic implications of heart rate variability analysis in patients with cirrhosis

Chronic liver damage leads to scarring of the liver tissue and ultimately a systemic illness known as cirrhosis. Patients with cirrhosis exhibit multi-organ dysfunction and high mortality. Reduced heart rate variability (HRV) is a hallmark of cirrhosis, reflecting a state of defective cardiovascular control and physiological network disruption. Several lines of evidence have revealed that decreased HRV holds prognostic information and can predict survival of patients independent of the severity of liver disease. Thus, the aim of this review is to shed light on the mechanistic and prognostic implications of HRV analysis in patients with cirrhosis. Notably, several studies have extensively highlighted the critical role systemic inflammation elicits in conferring the reduction in patients' HRV. It appears that IL-6 is likely to play a central mechanistic role, whereby its levels also correlate with manifestations, such as autonomic neuropathy and hence the partial uncoupling of the cardiac pacemaker from autonomic control. Reduced HRV has also been reported to be highly correlated with the severity of hepatic encephalopathy, potentially through systemic inflammation affecting specific brain regions, involved in both cognitive function and autonomic regulation. In general, the prognostic ability of HRV analysis holds immense potential in improving survival rates for patients with cirrhosis, as it may indeed be added to current prognostic indicators, to ultimately increase the accuracy of selecting the recipient most in need of liver transplantation. However, a network physiology approach in the future is critical to delineate the exact mechanistic basis by which decreased HRV confers poor prognosis.

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.

Heart Rate Variability and Its Associations with Organ Complications in Adults after Fontan Operation

Reduction of heart rate variability (HRV) parameters may be a risk factor and precede the occurrence of arrhythmias or the development of heart failure and complications in people with postinfarct left ventricular dysfunction and after coronary artery bypass grafting. Data on this issue in adults after a Fontan operation (FO) are scarce. This study assessed the association between HRV, exercise capacity, and multiorgan complications in adults after FO. Data were obtained from 30 FO patients (mean age 24 ± 5.4 years) and 30 healthy controls matched for age and sex. HRV was investigated in all patients by clinical examination, laboratory tests, echocardiography, a cardiopulmonary exercise test, and 24-h electrocardiogram. The HRV parameters were reduced in the FO group. Reduced HRV parameters were associated with patients’ age at the time of FO, time since surgery, impaired exercise capacity, chronotropic incompetence parameters, and multiorgan complications. Univariate analysis showed that saturated O₂ at rest, percentage difference between adjacent NN intervals of >50 ms duration, and peak heart rate were associated with chronotropic index. Multivariable analysis revealed that all three variables were independent predictors of the chronotropic index. The results of this study suggest novel pathophysiological mechanisms that link HRV, physical performance, and organ damage in patients after FO.

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.

Autonomic Nervous System Profiling In Response to Liver Transplantation: Prognostic Evaluation and Preliminary Study

BACKGROUND

Liver cirrhosis leads to autonomic dysfunction (AD). We present a pilot study and review of published literature to investigate the long-term changes in the Autonomic Nervous System (ANS) of patients who underwent liver transplant. We propose Autonomic Function Tests (AFT) can be used as a predictor of liver transplant outcome.

METHODS

Twenty-eight patients (19 men and 9 women; mean age 45 years) with cirrhosis due to different etiologies underwent a noninvasive ANS evaluation test, pre- and post-liver transplant at 3 to 6 months, 8 to 12 months, and 14 to 24 months. Data were compared with 45 age-matched controls (14 men and 31 women). We investigated changes in the following 3 adrenergic measures: percentage of cutaneous vasoconstriction in the hand and foot in response to cold stress test and cutaneous blood flow adjustment ratio; and 3 cardiovagal measures: change in heart rate in relation to deep respiration, forced respiration represented as Valsalva Ratio, and head-up tilting (30/15 ratio).

RESULTS

A total of 23 of 28 patients (82%) had impairment in AFT before transplant, 16 of 28 (57%) in the sympathetic adrenergic measures, and 15 of 28 (54%) in the parasympathetic cardiovagal measures. There was a gradual improvement in ANS function posttransplant, with a significant improvement in the cardiovagal measure of Valsalva Ratio (P < .05 from baseline). These data suggest some temporary decline in ANS functions within the first 6 months posttransplant.

CONCLUSIONS

To optimize outcomes in liver transplant patients with autonomic dysfunction, autonomic testing perhaps combined with frailty testing can be used as objective measures of mortality in the pre-liver transplant stage.

Wearables, Physical Activity, and Exercise Testing in Liver Disease

Physical inactivity is a major cause of deterioration in all forms of advanced liver disease. It is especially important as a driver of the components of the metabolic syndrome, with nonalcoholic fatty liver disease rapidly becoming the dominant cause of liver-related death worldwide. Growing realization of the health benefits of moderate-to-vigorous physical activity has captured the interest of persons who desire to improve their health, including those at risk for chronic liver injury. They are increasingly adopting wearable activity trackers to measure the activity that they seek to improve. Improved physical activity is the key lifestyle behavior that can improve cardiorespiratory fitness, which is most accurately measured with cardiopulmonary exercise testing (CPET). CPET is showing promise to identify risk and predict outcomes in transplant hepatology. Team effort among engaged patients, social support networks, and clinicians supported by web-based connectivity is needed to fully exploit the benefits of physical activity tracking.

Heart Rate Turbulence Predicts Survival Independently From Severity of Liver Dysfunction in Patients With Cirrhosis

Background

Reduced heart rate variability (HRV) is an independent predictor of mortality in patients with cirrhosis. However, conventional HRV indices can only be interpreted in individuals with normal sinus rhythm. In patients with recurrent premature ventricular complexes (PVCs), the predictive capacity of conventional HRV indices is compromised. Heart Rate Turbulence (HRT) represents the biphasic change of the heart rate after PVCs. This study was aimed to define whether HRT parameters could predict mortality in cirrhotic patients.

Materials and Methods

24 h electrocardiogram recordings were collected from 40 cirrhotic patients. Turbulence Onset was calculated as HRT indices. The enrolled patients were followed up for 12 months after the recruitment in relation to survival and/or transplantation.

Results

During the follow-up period, 21 patients (52.5%) survived, 12 patients (30%) died and 7 patients (17.5%) had liver transplantation. Turbulence Onset was found to be strongly linked with mortality on Cox regression (Hazard ratio = 1.351, p < 0.05). Moreover, Turbulence Onset predicted mortality independently of MELD and Child-Pugh's Score.

Conclusion

This study provides further evidence of autonomic dysfunction in cirrhosis and suggests that HRT is reliable alternative to HRV in patients with PVCs.

Cardiovascular Acute Effects of Traditional vs. Paired Set Resistance Training in Patients With Liver Cirrhosis

Purpose: This study compared the acute effects of two different resistance training methods on heart rate variability, blood pressure, and rating of perceived exertion in patients with liver cirrhosis. Methods: Ten patients with Child-Pugh A (seven women and three men) participated in two experimental sessions, in random order: The traditional set condition consisted of three sets of six exercises performed in a sequential manner, while the paired set condition consisted of alternating sets between two exercises (three pairs of exercises). Ten repetitions were performed for each set with 70% of a 10 repetition maximum load and with 2 min rest between sets. Blood pressure and heart rate variability were assessed pre-workout and for 60 min post-workout. The rating of perceived exertion was assessed at the end of the third set for each exercise. Results: Significant alterations in heart rate variability were observed when considering the lowest value obtained during recovery, in which the SDNN was reduced in both the traditional set and paired set conditions, as well as the root mean square of standard deviation for the traditional set condition (p < .05). Additionally, for the paired set condition, there was a significant reduction in the HFnu band and a significant increase in the LFnu band (p < .05). Effect size showed reductions in diastolic and mean blood pressure until 30 min in a small magnitude for traditional sets. Conclusion: Similar cardiovascular responses were observed between methods eliciting normal physiological responses within safe limits for patients with liver cirrhosis.

Obesity-Induced Heart Rate Variability Impairment and Decreased Systolic Function in Obese Male Dogs

Simple Summary

Obesity in dogs can induce many adverse health effects including musculoskeletal problems, respiratory distress, metabolic syndrome, and cardiovascular diseases. In humans with obesity, heart rate variability (HRV) is used to identify and predict the risk of cardiovascular diseases. However, this predictive tool has never been used in veterinary medicine, and the relationship between obesity and HRV has rarely been investigated. In this study, we investigated HRV, plasma oxidative stress (MDA), and cardiac function in obese male dogs. We hypothesized that obese male dogs have decreased cardiac function and impaired HRV compared to non-obese dogs. Our study found that obese dogs have decreased cardiac systolic function and impaired HRV, as indicated by reduced percentages of cardiac contraction and impaired cardiac autonomic activity compared to non-obese dogs. We concluded that obesity can decrease systolic function and cause HRV impairment, which might increase the risk of cardiovascular disease in dogs. In addition, HRV might be used as a predictive or prognostic tool in the prevention of cardiovascular disease in obese dogs.

Abstract

Obesity can induce cardiovascular diseases in both humans and animals. Heart rate variability (HRV) is an indicator of sympathovagal balance and is used to identify cardiovascular diseases in humans. However, HRV and cardiac function have rarely been investigated in obese dogs. This study investigated the effect of obesity on oxidative stress, HRV, and cardiac function in obese and non-obese dogs. The nine-scale body condition score (BCS) system was used to determine obesity. Thirty small breed dogs were divided into a normal weight group (n = 15) and an obese group (n = 15). All dogs underwent physical examination, plasma malondialdehyde (MDA) measurement, electrocardiography, echocardiography, and two hours of Holter monitoring. This study found that obese dogs had increased plasma MDA and sympathovagal imbalance, which was indicated by impaired time and frequency domains compared to normal weight dogs. Although cardiac function was within normal limits, the echocardiographic study found that the obese dogs had reduced cardiac wall thickness and lower systolic function, as indicated by a reduction in %ejection fraction, %fractional shortening, increased left ventricular (LV) internal diameter during systole, and LV end-systolic volume compared to normal weight dogs. This study concluded that obesity in dogs can induce increased plasma oxidative stress, impaired HRV, and reduced cardiac systolic function compared to non-obese dogs.

Non-Alcoholic Cirrhosis and Heart Rate Variability: A Systematic Mini-Review

Background and Objectives: Cirrhosis is a liver disease that causes about one million deaths annually worldwide. The estimated cirrhosis prevalence ranges from 4.5–9.5% in the general population. Up to 40% of cirrhotic patients are asymptomatic and may be diagnosed late. Studies have described the importance of the functions of the liver and autonomic nervous system (ANS) and their relationship. There is limited information available on non-alcoholic cirrhosis and heart rate variability (HRV), which is a measure of the ANS. This study aimed to evaluate cardiac autonomic modulation through HRV in non-alcoholic cirrhosis individuals reported in previous observational and clinical trial studies. Materials and Methods: We performed a systematic review according to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) statement using the Medline, Scopus, and Web of Science electronic databases. Five studies were identified and reviewed. Results: HRV was decreased in patients with non-alcoholic cirrhosis, even in the first stage. Conclusions: HRV could be used as a complementary method to improve both the diagnosis and prognosis of non-alcoholic cirrhosis.

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.

Which heart rate variability index is an independent predictor of mortality in cirrhosis?

BACKGROUND

Liver cirrhosis is associated with reduced heart rate variability (HRV), which indicates impaired integrity of cardiovascular control in this patient population. There are several different indices for HRV quantification. The present study was designed to: 1) determine which of the HRV indices is best at predicting mortality in patients with cirrhosis; 2) verify if such ability to predict mortality is independent of the severity of hepatic failure.

METHODS

Ten minutes electrocardiogram was recorded in 74 patients with cirrhosis. Heart rate fluctuations were quantified using statistical, geometrical and non-linear analysis. The patients were followed-up for 18months and information was collected on the occurrence of death/liver transplantation.

RESULTS

During the follow-up period, 24 patients (32%) died or were transplanted for hepatic decompensation. Cox's regression analysis showed that SDNN (total HRV), cSDNN (corrected SDNN), SD1 (short-term HRV), SD2 (long-terms HRV) and spectral indices could predict survival in these patients. However, only SD2 and cSDNN were shown to be independent of MELD in predicting survival. The prognostic value of HRV indices was independent of age, gender, use of beta blockers, and the aetiology of liver disease.

CONCLUSION

Two HRV indices were identified that could predict mortality in patients with cirrhosis, independently of MELD. These indices are potentially useful tools for survival prediction.

Q-T Interval Prolongation in Patients with Liver Cirrhosis

Liver cirrhosis (LC) is the end stage of chronic liver disease characterized by the appearance of extensive fibrosis and regeneration nodes associated with hepatocyte necrosis in liver but also by the reshuffling of hepatic architecture. The triad consisting of hepatic parenchymal necrosis, regeneration and scarring is always present regardless of the type of clinical manifestation. The Child-Pugh-Turcotte classification dates back more than 30 years and has been widely used in diagnosing and assessing the severity of liver cirrhosis. This is preferred due to a low degree of complexity and a good predictive value. Prolongation of the QT interval on the electrocardiogram is common, with a prevalence exceeding 60% in patients with advanced stage of cirrhosis. In these cases, beta blockers and antiarrhythmics should be avoided or used with caution and with close QT interval monitoring. Changes in heart rate and Q-T interval are new entities in cirrhosis complications. A prolonged Q-T interval in chronic liver disease could lead to ventricular arrhythmias and sudden death. There is no report on heart rate and Q-T interval disorders in our area.

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.

Liver cirrhosis-effect on QT interval and cardiac autonomic nervous system activity

AIM

To examine the impact of liver cirrhosis on QT interval and cardiac autonomic neuropathy (CAN).

METHODS

A total of 51 patients with cirrhosis and 51 controls were examined. Standard 12-lead electrocardiogram recordings were obtained and QT as well as corrected QT interval (QTc) and their dispersions (dQT, dQTc) were measured and calculated using a computer-based program. The diagnosis of CAN was based upon the battery of the tests proposed by Ewing and Clarke and the consensus statements of the American Diabetes Association. CAN was diagnosed when two out of the four classical Ewing tests were abnormal.

RESULTS

QT, QTc and their dispersions were significantly longer (P < 0.01) in patients with cirrhosis than in controls. No significant differences in QT interval were found among the subgroups according to the etiology of cirrhosis. Multivariate regression analysis after controlling for age, gender and duration of cirrhosis demonstrated significant association between QT and presence of diabetes mellitus [standardized regression coefficient (beta) = 0.45, P = 0.02] and treatment with diuretics (beta = 0.55, P = 0.03), but not with the Child-Pugh score (P = 0.54). Prevalence of CAN was common (54.9%) among patients with cirrhosis and its severity was associated with the Child-Pugh score (r = 0.33, P = 0.02). Moreover, patients with decompensated cirrhosis had more severe CAN that those with compensated cirrhosis (P = 0.03). No significant association was found between severity of CAN and QT interval duration.

CONCLUSION

Patients with cirrhosis have QT prolongation. Treatment with diuretics is associated with longer QT. CAN is common in patients with cirrhosis and its severity is associated with severity of the disease.

Cholinergic Anti-Inflammatory Pathway and the Liver

The hepatic vagus branches innervate the liver and serve an important role in liver-brain connection. It appears that brain modulates inflammatory responses by activation of vagal efferent fibers. This activation and subsequent acetylcholine releases from vagus nerve terminals leads to inhibition of inflammatory cytokines through α7 nicotinic acetylcholine receptors (α7nAChRs) which located on the surface of different cell types such as liver Kupffer cells. This protective role of vagus-α7nAChR axis in liver diseases has been shown in several experimental studies. On the other hand, accumulated evidence clearly demonstrate that, autonomic dysfunction which is reduced functioning of both vagal and sympathetic nervous system, occurs during chronic liver disease and is well-known complication of patients suffering from cirrhosis. This review describes the impact and significance of cholinergic anti-inflammatory pathway in the liver and discusses about its disease-related dysfunction on the progression of cirrhosis. Considering the fact that sepsis is major cause of death in cirrhotic patients, convergence of these findings, may lead to designing novel therapeutic strategies in the field of chronic liver diseases management involving selective drug targeting and electrical nerve stimulation.

Cardiac dysfunction as an early predictor of portal hypertension in chronic hepatitis C

Background:

Cirrhotic cardiomyopathy is characterized by a set of cardiovascular modifications observed in advanced chronic liver disease. The aim of this study was to investigate cardiovascular alterations in chronic liver disease with different stages of fibrosis and to correlate cardiac involvement with endoscopic complications of portal hypertension.

Methods:

Seventy patients with chronic hepatitis C-related chronic liver disease and 20 sex- and age-matched controls underwent clinical evaluation, hepatic transient elastography, and echocardiography. Forty-nine of the 70 patients underwent an esophagogastroduodenoscopy for screening of esophageal and gastric varices.

Results:

According to the value of liver stiffness (LS), patients were divided in 2 groups: non-cirrhotics (LS<12.5 kPa; n=30; median LS=8.1 kPa, 95% confidence interval [CI] 6.4-9.2 kPa) and cirrhotics (LS>12.5 kPa; n=40; median LS=19.4 kPa, 95%CI 17-22 kPa). Compared to non-cirrhotics, cirrhotics showed a significant dilatation of the left atrium (P=0.007 and P=0.003 for area and volume index, respectively). In patients with chronic liver disease, peak systolic wave velocity (S¢) measured by tissue Doppler imaging (TDI) was lower (P=0.004), but ejection fraction was not reduced. Left atrial volume, left ventricular mass index and TDI S¢-wave velocity, but not liver stiffness, correlated with endoscopic signs of portal hypertension.

Conclusions:

Left atrial enlargement and peak S¢-wave systolic velocities are echocardiographic markers of diastolic and systolic dysfunction in liver cirrhosis. Cardiac alterations closely correlate to endoscopic portal hypertension; further studies could elucidate the potential role of echocardiography in the early identification of cirrhotic patients at higher risk for endoscopic complications of portal hypertension.

The role of autonomic dysfunction in predicting 1-year mortality after liver transplantation

BACKGROUND & AIMS

Model for end-stage liver disease (MELD) score has been extensively used to prioritize patients for liver transplantation and determine their prognosis, but with limited predictive value. Autonomic dysfunction may correlate with increased mortality after liver transplant. In this study, two autonomic biomarkers, complexity and deceleration capacity, were added to the predicting model for 1-year mortality after liver transplantation.

METHODS

In all, 30 patients with end-stage liver diseases awaiting liver transplantation were included. Complexity and deceleration capacity were calculated by multi-scale entropy and phase-rectified signal averaging, respectively. Different combinations of autonomic factors and MELD score were used to predict mortality rate of liver transplant after 1-year follow-up. Receiver-operating characteristics curve analysis was performed to determine clinical predictability. Area under the receiver-operating characteristics curve represents the overall accuracy.

RESULTS

The 1-year mortality rate was 16.7% (5/30). The overall accuracy of MELD score used for predicting mortality after liver transplantation was 0.752. By adding complexity and deceleration capacity into the predicting model, the accuracy increased to 0.912. Notably, the accuracy of the prediction using complexity and deceleration capacity alone was 0.912.

CONCLUSION

Complexity and deceleration capacity, which represent different dynamical properties of a human autonomic system, are critical factors for predicting mortality rate of liver transplantation. We recommend that these pre-operative autonomic factors may be helpful as critical adjuncts to predicting model of mortality rate in prioritizing organ allocation.

Autonomic Nervous System Pretransplant Malfunction Is a Powerful Predictor of Survival After Allogeneic Hematopoietic Cell Transplantation

BACKGROUND

Autonomic nervous system function indexed by heart rate variability (HRV) has shown prognostic value for mortality in various cardiovascular and noncardiovascular diseases including cancer. The purpose of this study was to evaluate an association between HRV and outcomes of allogeneic hematopoietic cell transplantation (allo-HCT).

METHODS

We prospectively measured HRV as a surrogate pretransplant marker of autonomic nervous system activity in consecutive allo-HCTs with hematological diseases.

RESULTS

We analyzed 112 allo-HCTs performed between July 2011 and July 2013 in our center. Univariate analysis showed that increased values of HRV components (low-frequency [LF] and high-frequency [HF] spectral component), SD of normal-to-normal RR interval (SDNN), and squares of the differences between adjacent normal-to-normal RR intervals (r-MSSD) were significantly associated with decreased probability of overall mortality (hazard ratio = 0.3 for LF, P < 0.001; hazard ratio = 0.3 for HF, P = 0.001; hazard ratio = 0.6 for SDNN, P = 0.004; and hazard ratio = 0.5 for r-MSSD, P = 0.014). Among these 4 indicators, the LF-added pretransplantation assessment of mortality, hematopoietic cell transplantation-comorbidity index, and disease risk index models showed the highest values of ΔAkaike information criterion (16.5, 22.2, and 11.4, respectively). When stratified into quartiles of LF groups, 2-year overall survival was 92.9, 84.5, 59.7, and 33.2%, respectively (P < 0.001). LF alone represented a better discriminating variable for the prediction of mortality when compared with pretransplantation assessment of mortality, hematopoietic cell transplantation-comorbidity index, and disease risk index. In addition, from bivariate analyses, decreased LF was an independent and significant factor for higher overall mortality in all models.

CONCLUSIONS

Indicators reflective of autonomic nervous system function might be a powerful predictor of survival after allo-HCT.

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.

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.

Cardiohepatic syndrome

Accumulating evidence shows that acute as well as chronic heart disease can directly contribute to an acute or chronic worsening of liver function and vice versa. Description and definition of cardiohepatic syndrome (CHS) in this review are based on the cardiorenal syndrome (CRS) concept. The eye-catching analogy between CHS and CRS is applied to facilitate an understanding of the pathophysiology and overall burden of disease for each of the proposed CHS subtypes, their natural course, and associated morbidity and mortality.

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.

Management of Complications of End-Stage Liver Disease in the Intensive Care Unit

The management of critically ill patients with end-stage liver disease can be challenging due to the vulnerability of this population and the wide-ranging complications of the disease. This review proposes an approach based on the major organ systems affected, to provide a framework for managing the most common complications. Although considerable practice variation exists, a focus on the evidence behind the most common practices will ensure the development of the optimal skillset to appropriately manage this disease.

Chronotropic incompetence on dobutamine stress echocardiography in candidates for a liver transplant

OBJECTIVES

We evaluated dobutamine stress echocardiography as an initial screening test for a cardiac evaluation before a liver transplant.

MATERIALS AND METHODS

We retrospectively examined 111 liver transplant candidates who had undergone previous cardiac evaluation; 30 of whom had undergone a liver transplant.

RESULTS

Eighty patients (72.1%) completed a dobutamine stress echocardiography (41 chronotropically competent, 39 incompetent), while 31 patients (27.9%) required us to terminate early. Overall, 68 patients (61%) were on β-blockers (21 required early dobutamine stress echocardiography termination, 30 chronotropically incompetent, and 17 competent). Patient results were normal. Thirty patients underwent a liver transplant. Among candidates requiring termination of early dobutamine stress echocardiography, posttransplant cardiac events included 1 fatal acute myocardial infarction, 1 nonfatal acute myocardial infarction, and 1 idiopathic cardiomyopathy. Among chronotropically incompetent patients, 2 patients had transient bradycardia, and among those who were chronotropically competent, 1 had refractory atrial fibrillation, and 1 had transient bradycardia.

CONCLUSIONS

Nearly 50% of patients with end-stage liver disease may not reach the target heart rate. Early termination of dobutamine stress echocardiography because of cardiac symptoms or significant echocardiographic changes have more effect in predicting postoperative cardiac events, but further evaluation is required even if their target heart rate is close to that desired. Lower target heart rate may be acceptable in chronotropically incompetent individuals provided they are asymptomatic, have no echocardiographic changes, or cardiovascular risk factors, especially if they are on β-blockers.

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.

Hepato-cardiac disorders

Understanding the mutual relationship between the liver and the heart is important for both hepatologists and cardiologists. Hepato-cardiac diseases can be classified into heart diseases affecting the liver, liver diseases affecting the heart, and conditions affecting the heart and the liver at the same time. Differential diagnoses of liver injury are extremely important in a cardiologist’s clinical practice calling for collaboration between cardiologists and hepatologists due to the many other diseases that can affect the liver and mimic haemodynamic injury. Acute and chronic heart failure may lead to acute ischemic hepatitis or chronic congestive hepatopathy. Treatment in these cases should be directed to the primary heart disease. In patients with advanced liver disease, cirrhotic cardiomyopathy may develop including hemodynamic changes, diastolic and systolic dysfunctions, reduced cardiac performance and electrophysiological abnormalities. Cardiac evaluation is important for patients with liver diseases especially before and after liver transplantation. Liver transplantation may lead to the improvement of all cardiac changes and the reversal of cirrhotic cardiomyopathy. There are systemic diseases that may affect both the liver and the heart concomitantly including congenital, metabolic and inflammatory diseases as well as alcoholism. This review highlights these hepatocardiac diseases

The role of α7 nicotinic acetylcholine receptor in modulation of heart rate dynamics in endotoxemic rats

Previous reports have indicated that artificial stimulation of the vagus nerve reduces systemic inflammation in experimental models of sepsis. This phenomenon is a part of a broader cholinergic anti-inflammatory pathway which activates the vagus nerve to modulate inflammation through activation of alpha7 nicotinic acetylcholine receptors (α7nACHR). Heart rate variability represents the complex interplay between autonomic nervous system and cardiac pacemaker cells. Reduced heart rate variability and increased cardiac cycle regularity is a hallmark of clinical conditions that are associated with systemic inflammation (e.g. endotoxemia and sepsis). The present study was aimed to assess the role of α7nACHR in modulation of heart rate dynamics during systemic inflammation. Systemic inflammation was induced by injection of endotoxin (lipopolysaccharide) in rats. Electrocardiogram and body temperature were recorded in conscious animals using a telemetric system. Linear and non-linear indices of heart rate variability (e.g. sample entropy and fractal-like temporal structure) were assessed. RT-PCR and immunohistochemistry studies showed that α7nACHR is expressed in rat atrium and is mainly localized at the endothelial layer. Systemic administration of an α7nACHR antagonist (methyllycaconitine) did not show a significant effect on body temperature or heart rate dynamics in naïve rats. However, α7nACHR blockade could further reduce heart rate variability and elicit a febrile response in endotoxemic rats. Pre-treatment of endotoxemic animals with an α7nACHR agonist (PHA-543613) was unable to modulate heart rate dynamics in endotoxemic rats but could prevent the effect of endotoxin on body temperature within 24 h experiment. Neither methyllycaconitine nor PHA-543613 could affect cardiac beating variability of isolated perfused hearts taken from control or endotoxemic rats. Based on our observations we suggest a tonic role for nicotinic acetylcholine receptors in modulation of heart rate dynamics during systemic inflammation.

Intraoperative predictors of short-term mortality in living donor liver transplantation due to acute liver failure

BACKGROUND

Acute liver failure (ALF) is a rare and fatal disease with rapidly deteriorating clinical features. Many predictive models for ALF outcomes have been tested, but none have been adopted as definitive guidelines for prognosis because of inconsistencies in accuracy. Most prognostic models for ALF are based on preoperative patient conditions, thus ignoring various specific intraoperative features relevant to postoperative outcomes. We investigated whether intraoperative factors predicted short-term mortality due to ALF in living donor liver transplantations (LDLT).

METHODS

We retrospectively collected intraoperative data, including surgical time, fluctuations in mean blood pressure (MBP) and heart rate, mean pulmonary arterial pressure (PAP), central venous pressure (CVP), urine output, laboratory data, oxygen indices (PaO(2)/FiO(2)), administered drugs, and transfusion of packed red blood cells (PRBCs) from 101 patients with ALF who underwent LDLT. After simple relationships of individual intraoperative variables with 1-month posttransplant mortality were analyzed, we examined potentially significant intraoperative variables (P < .10) by a multivariate adjustment process with preoperative indicators of ALF prognosis.

RESULTS

Intraoperative MBP fluctuations, first mean PAP and CVP, last oxygen index, administered calcium chloride, and PRBC transfusion showed individual associations with posttransplant mortality of ALF patients (P < .05). After multivariate adjustment, PRBC transfusion of ≥ 10 pints (odds ratio 4.73; 95% confidence interval [CI] 1.06-21.16) and MBP fluctuations (odds ratio 1.26; 95% CI 1.00-1.58) were identified to be independent predictors of 1-month posttransplant mortality, together with preoperative factors, including severe hepatic encephalopathy, and a Model for End-stage Liver Disease score ≥ 30 points (area under the curve 0.82, P < .001).

CONCLUSION

MBP fluctuations and large blood transfusions were intraoperative predictors of short-term mortality after LDLT due to ALF. Increased attention to intraoperative manifestations should provide valuable prognostic information for ALF.

Effect of endotoxin on heart rate dynamics in rats with cirrhosis

Reduced heart rate variability (HRV) is a hallmark of systemic inflammation which carries negative prognostic information in sepsis. Decreased HRV is associated with partial uncoupling of cardiac pacemaker from cholinergic neural control during systemic inflammation. Sepsis is a common complication in liver cirrhosis with high mortality. The present study was aimed to explore the hypothesis that endotoxin uncouples cardiac pacemaker from autonomic neural control and reduces HRV in an experimental model of cirrhosis. Cirrhosis was induced by surgical ligation of the bile duct in rats. Cirrhotic rats were given intraperitoneal injection of either saline or lipopolysaccharide (endotoxin, 1mg/kg). Changes in HRV indices were studied in conscious rats using implanted telemetric probes. The atria were isolated and chronotropic responsiveness to cholinergic stimulation was assessed in vitro. Endotoxin injection induced a significant tachycardia and decreased short-term and long-term HRV indices in control rats. However, endotoxin was unable to increase heart rate in cirrhotic animals. In contrast with control rats, endotoxin induced biphasic changes in short-term HRV in cirrhotic rats. Acute endotoxin challenge reduced long-term HRV with 60-min delay in comparison with control animals. Endotoxin injection was associated with a significant hypo-responsiveness to cholinergic stimulation in control rats in vitro. Endotoxin did not change atrial chronotropic responsiveness to cholinergic stimulation in cirrhotic rats. Our data shows that cirrhosis is associated with development of tolerance to cardiac chronotropic effect of endotoxin in rats.

Physiologic and laboratory correlates of depression, anxiety, and poor sleep in liver cirrhosis

Background

Studies have shown psychological distress in patients with cirrhosis, yet no studies have evaluated the laboratory and physiologic correlates of psychological symptoms in cirrhosis. This study therefore measured both biochemistry data and heart rate variability (HRV) analyses, and aimed to identify the physiologic correlates of depression, anxiety, and poor sleep in cirrhosis.

Methods

A total of 125 patients with cirrhosis and 55 healthy subjects were recruited. Each subject was assessed through routine biochemistry, 5-minutes ECG monitoring, and psychological ratings of depression, anxiety, and sleep. HRV analysis were used to evaluate autonomic functions. The relationship between depression, sleep, and physiologic correlates was assessed using a multiple regression analysis and stepwise method, controlling for age, duration of illness, and severity of cirrhosis.

Results

Reduced vagal-related HRV was found in patients with severe liver cirrhosis. Severity of cirrhosis measured by the Child-Pugh score was not correlated with depression or anxiety, and only had a weak correlation with poor sleep. The psychological distress in cirrhosis such as depression, anxiety, and insomnia were correlated specifically to increased levels of aspartate aminotransferase (AST), increased ratios of low frequency to high frequency power, or reduced nonlinear properties of HRV (α₁ exponent of detrended fluctuation analysis).

Conclusions

Increased serum AST and abnormal autonomic nervous activities by HRV analysis were associated with psychological distress in cirrhosis. Because AST is an important mediator of inflammatory process, further research is needed to delineate the role of inflammation in the cirrhosis comorbid with depression.

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.

Effect of propranolol on the relationship between QT interval and vagal modulation of heart rate variability in cirrhotic patients awaiting liver transplantation

BACKGROUND

Prolonged corrected QT (QT(c)) interval and vagal dysfunction are common occurrences in liver cirrhosis and are determinants of mortality in patients with chronic liver disease. We evaluated whether propranolol can affect the relationship between QT(c) interval and cardiac vagal control of heart rate variability (HRV) in cirrhotic patients awaiting liver transplantation.

METHODS

We compared 50 cirrhotic patients (M/F = 43/7, 52.6 ± 8.4 years, Child-Pugh class A/B/C: 9/24/17) receiving propranolol with a sex-, age-, and liver disease severity-matched control group of 50 patients (M/F = 43/7, 52.0 ± 8.3 year, Child-Pugh class A/B/C: 9/24/17) not receiving propranolol. Among the parameters evaluated were QT(c) interval and cardiac vagal indices of HRV, including the root mean square of successive differences in R-R intervals (RMSSD); spectral power in the high-frequency range (HF); standard deviation (SD)1 in Poincare plot; and sample entropy. Correlations between QT(c) interval and vagal indices of HRV were analyzed.

RESULTS

The mean duration of preoperative propranolol treatment in the propranolol group was 19.4 ± 24.7 months. QT(c) interval was significantly lower, whereas RMSSD, HF, SD1, and sample entropy were significantly higher in the propranolol group than in the control group. Correlation coefficients between QT(c) interval and RMSSD, HF, SD1, and sample entropy were higher in the propranolol group than in the control group.

CONCLUSIONS

The prolonged QT(c) interval observed in cirrhotic patients may be reduced by propranolol administration, an effect attributable to improved vagal cardiac modulation. These findings suggest that propranolol may have a beneficial effect on perioperative mortality in cirrhotic patients awaiting liver transplantation.

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.

Chronic hepatitis C virus infection associated with autonomic dysfunction

BACKGROUND

Impaired autonomic function has been described in patients with chronic liver diseases from different aetiologies, and has proven to be a poor prognostic indicator. To date, it is not known how chronic hepatitis C virus (HCV) infection affects the autonomic nervous system.

AIMS

In the present study, we compared cardiovagal autonomic function in patients with chronic HCV infection and healthy controls and examined the relation between autonomic function and serum levels of aminotransferases, HCV RNA, cryoglobulins, albumin and glucose.

METHODS

Autonomic function was assessed in 45 treatment-naïve patients with chronic HCV infection and in 40 healthy controls by determining spontaneous baroreflex sensitivity (BRS) and heart rate variability (HRV) indices. The R-R interval was determined by electrocardiogram recording; continuous radial artery pressure was monitored simultaneously by applanation tonometry. Laboratory analyses and quantitative polymerase chain reaction for serum HCV RNA level were performed by standard procedures.

RESULTS

BRS and HRV time and frequency domain indices were lower in patients with HCV infection compared with healthy controls [7.1+/-3.4 vs. 11.5+/-6.5 ms/mmHg for BRS, 168.5+/-160.9 vs. 370.7+/-349.4 ms(2) for low-frequency HRV (mean+/-SD); P<0.01]. Multivariate analysis showed that autonomic dysfunction in HCV-infected patients correlated with elevated alanine aminotransferase levels, but was not associated with serum HCV RNA levels and cryoglobulins.

CONCLUSION

Our results suggest that impaired autonomic function is caused by chronic HCV infection. Further studies are needed, however, to identify the underlying 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.

Decreased heart rate variability in patients with cirrhosis relates to the presence and degree of hepatic encephalopathy

Heart rate variability (HRV) is reduced in several clinical settings associated with either systemic inflammation or neuropsychiatric impairment. The possibility that the changes in HRV observed in patients with neuropsychiatric impairment might relate to the overproduction of inflammatory cytokines does not seem to have been considered in the studies undertaken to date. HRV is decreased in patients with liver cirrhosis but its relationship to the impairment of neuropsychiatric performance, commonly observed in these patients, is unknown. The aim of this study was to investigate the relationship between HRV, hepatic encephalopathy, and production of inflammatory cytokines in patients with cirrhosis. Eighty patients with cirrhosis [53 men, 27 women; mean (+/-1SD) age 54 +/- 10 yr], classified as neuropsychiatrically unimpaired or as having minimal or overt hepatic encephalopathy, and 11 healthy subjects were studied. HRV was assessed by applying Poincaré plot analysis to the R-R interval series on a 5-min ECG. Inflammatory cytokines (TNF-alpha, IL-6, IL-10, and IL-12) were measured in a subgroup of patients. Long-term R-R variability was significantly decreased in the patients with cirrhosis, in parallel with the degree of neuropsychiatric impairment (P < 0.01) and independently of the degree of hepatic dysfunction (P = 0.011). The relative risk of death increased by 7.7% for every 1-ms drop in this variable. Plasma levels of IL-6 significantly correlated with indexes of both HRV and neuropsychiatric performance. The changes observed in HRV and in neuropsychiatric status in patients with cirrhosis are significantly correlated, most likely reflecting a common pathogenic mechanism mediated by inflammatory cytokines.