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

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.

Role of Body Mass and Physical Activity in Autonomic Function Modulation on Post-COVID-19 Condition: An Observational Subanalysis of Fit-COVID Study

The harmful effects of coronavirus disease 2019 (COVID-19) can reach the autonomic nervous system (ANS) and endothelial function. Therefore, the detrimental multiorgan effects of COVID-19 could be induced by deregulations in ANS that may persist after the acute SARS-CoV-2 infection. Additionally, investigating the differences in ANS response in overweight/obese, and physically inactive participants who had COVID-19 compared to those who did not have the disease is necessary. The aim of the study was to analyze the autonomic function of young adults after mild-to-moderate infection with SARS-CoV-2 and to assess whether body mass index (BMI) and levels of physical activity modulates autonomic function in participants with and without COVID-19. Patients previously infected with SARS-CoV-2 and healthy controls were recruited for this cross-sectional observational study. A general anamnesis was taken, and BMI and physical activity levels were assessed. The ANS was evaluated through heart rate variability. A total of 57 subjects were evaluated. Sympathetic nervous system activity in the post-COVID-19 group was increased (stress index; p = 0.0273). They also presented lower values of parasympathetic activity (p < 0.05). Overweight/obese subjects in the post-COVID-19 group presented significantly lower parasympathetic activity and reduced global variability compared to non-obese in control group (p < 0.05). Physically inactive subjects in the post-COVID-19 group presented significantly higher sympathetic activity than active subjects in the control group. Parasympathetic activity was significantly increased in physically active subjects in the control group compared to the physically inactive post-COVID-19 group (p < 0.05). COVID-19 promotes changes in the ANS of young adults, and these changes are modulated by overweight/obesity and physical activity levels.

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.

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.

Alcohol-induced autonomic dysfunction: a systematic review

Purpose

Autonomic dysfunction is a known consequence of chronic and excessive alcohol consumption. The aim of this systematic review was to characterise this phenomenon, describe the frequency at which it occurs and to explore the best management strategies.

Methods

A systematic, computer-based search was conducted using the PubMed database. All studies identified by the search were evaluated independently by at least three authors. For inclusion, studies had to report human subjects consuming ethanol in excess. Case reports and non-original studies were excluded from this review.

Results

A total of 55 studies were included in this review. According to cardiovascular reflex tests, 16–73% of chronic alcohol abusers suffer from autonomic dysfunction. The most commonly occurring symptom is erectile dysfunction, whilst other features such as postural dizziness are rare. The most important risk factor for this condition is total lifetime dose of ethanol, although there is mixed evidence supporting the role of other risk factors. The only management strategy currently explored in the literature is abstinence, which appears to lead to significant improvement in autonomic investigations.

Conclusion

Current literature includes studies of highly heterogeneous populations, consuming differing volumes of alcohol over variable periods of time and utilising a number of different autonomic test batteries and criteria to diagnose autonomic dysfunction. Therefore, further research using homogeneous methods for measuring autonomic dysfunction in the field is needed. Despite this limitation, our review demonstrated that autonomic dysfunction is very common among alcohol abusers.

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.

Peculiar characteristics of portal-hepatic hemodynamics of alcoholic cirrhosis

Alcohol-related cirrhosis is a consequence of heavy and prolonged drinking. Similarly to patients with cirrhosis of other etiologies, patients with alcoholic cirrhosis develop portal hypertension and the hepatic, splanchnic and systemic hemodynamic alterations that follow. However, in alcoholic cirrhosis, some specific features can be observed. Compared to viral cirrhosis, in alcohol-related cirrhosis sinusoidal pressure is generally higher, hepatic venous pressure gradient reflects portal pressure better, the portal flow perfusing the liver is reduced despite an increase in liver weight, the prevalence of reversal portal blood flow is higher, a patent paraumbilical vein is a more common finding and signs of hyperdynamic circulations, such as an increased cardiac output and decreased systemic vascular resistance, are more pronounced. Moreover, alcohol consumption can acutely increase portal pressure and portal-collateral blood flow. Alcoholic cardiomyopathy, another pathological consequence of prolonged alcohol misuse, may contribute to the hemodynamic changes occurring in alcohol-related cirrhosis. The aim of this review was to assess the portal-hepatic changes that occur in alcohol-related cirrhosis, focusing on the differences observed in comparison with patients with viral cirrhosis. The knowledge of the specific characteristics of this pathological condition can be helpful in the management of portal hypertension and its complications in patients with alcohol-related 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.

Noninvasive assessment of portal hypertension in patients with cirrhosis

Severe portal hypertension is responsible for complications and death. Although measurement of the hepatic venous pressure gradient is the most accurate method for evaluating the presence and severity of portal hypertension, this technique is considered invasive and is not routinely performed in all centers. Several noninvasive techniques have been proposed to measure portal hypertension. Certain methods evaluate elements related to the pathogenesis of portal hypertension through the measurement of hyperkinetic syndrome, for example, or they investigate the development of hepatic fibrosis through the measurement of increased intrahepatic vascular resistance. Other methods evaluate the clinical consequences of portal hypertension, such as the presence of esophageal varices or the development of portosystemic shunts. Methods evaluating increased hepatic vascular resistance are fairly accurate and mainly involve the detection of hepatic fibrosis by serum markers and transient elastography. The radiological assessment of hyperkinetic syndrome probably has value but is still under investigation. The assessment of severe portal hypertension by the presence of varices may be performed with simple tools such as biological assays, computed tomography, and esophageal capsules. More sophisticated procedures seem promising but are still under development. Screening tools for large populations must be simple, whereas more complicated procedures could help in the follow-up of already diagnosed patients. Although most of these noninvasive methods effectively identify severe portal hypertension, methods for diagnosing moderate portal hypertension need to be developed; this shows that further investigation is needed in this field.

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.