[New and established aspects of cardiological diagnostics using TEE : Do we need 3D technology in clinical routine?] / Neues und Bewährtes in der kardiologischen Diagnostik mithilfe der TEE : Wird die 3­D-Technik in der klinischen Routine benötigt?

In comparison to transthoracic echocardiography (TTE) transesophageal echocardiography (TEE) enables an acquisition of images with better spatial resolution due to the use of higher ultrasound frequencies. Thus, the morphology and function of cardiac structures can principally be analyzed better and more accurately with TEE than with TTE. In addition, using three-dimensional (3D) TEE data sets standardized sectional planes can be constructed by post-processing, which enables quantitative assessment of the target structures. The size and function of the left ventricle can objectively and reproducibly be measured. End diastolic left ventricular volume and total stroke volume of the left ventricle can be accurately determined in patients with heart valve disease. Furthermore, particular cardiac structures that cannot be totally evaluated by two-dimensional (2D) echocardiography, can be completely analyzed by 3D TEE. In 2D images for example, only analyses of the right coronary cusp of the aortic valve are possible because only the center of the right coronary cusp can be visualized using conventional sectional level presentation. Using 3D TEE the non-coronary cusp and the left coronary cusp can also be visualized in the mid-sectional plane by post-processing of the 3D data set. Additional important structures of 3D TEE analysis are the left atrial auricle, the interatrial septum and the mitral valve. Planimetry of valvular and regurgitation orifices as well as the monitoring of interventions for treatment of structural heart diseases are further fields of application of clinically established 3D TEE diagnostics.

[Alcohol and arrhythmias]. / Alkohol und Rhythmusstörungen.

The effects of alcohol on induction of arrhythmias is dose-dependent, independent of preexisting cardiovascular diseases or heart failure and can affect otherwise healthy subjects. While the probability of atrial fibrillation increases with the alcohol dosage, events of sudden cardiac death are less frequent with low and moderate consumption but occur more often in heavy drinkers with alcoholic cardiomyopathy. Men are first affected at higher dosages of alcohol but women can suffer from arrhythmias at lower dosages. Thromboembolisms and ischemic stroke can occur less often at lower dosages of alcohol; however, hemorrhagic stroke and subarachnoid hemorrhage are increased with higher alcohol dosages. Recognizable protective mechanisms of alcohol with respect to cardiovascular diseases only occur with lower amounts of alcohol of less than 10 g per day. Underlying mechanisms explain these controversial effects. Specific therapeutic options for alcohol-related arrhythmias apart from abstinence from alcohol consumption are not known.

International survey on the management of mechanical ventilation during ECMO in adults with severe respiratory failure.

BACKGROUND: No consensus exists on the optimal settings of mechanical ventilation during veno-venous extracorporeal membrane oxygenation (ECMO). Our aim was to describe how mechanical ventilation and related interventions are managed by adult ECMO centres. METHODS: A cross-sectional, multi-centre, international survey of 173 adult respiratory ECMO centres. The survey was generated through an iterative process and assessed for clarity, content and face validity. RESULTS: One hundred thirty-three centres responded (76.8%). Pressure control was the most commonly used mechanical ventilation mode (64.4%). Although the median PEEP was 10 cmH2O, 22.6% set PEEP <10 cmH2O and 15.5% used 15-20 cmH2O. In 63% of centres PEEP was fixed and not titrated. Recruitment maneuvres, were never used in 34.1% of centres, or used daily in 13.2%. Centres reported using either a "lung rest" (45.7%), or an "open lung" strategy (44.2%). Only 24.8% used chest CT to guide mechanical ventilation. Adjunctive treatments were never or occasionally used. Only 10% of centres extubated patients on ECMO, mainly in more experienced centres. 71.3% of centres performed tracheostomy on ECMO, with large variability in timing (most frequent on days 6-10). Only 27.1% of ECMO centres had a protocol for mechanical ventilation on ECMO. CONCLUSION: We found large variability in ventilatory practices during ECMO. The clinicians' training background and the centres' experience had no influence on the approach to ventilation. This survey shows that well conducted studies are necessary to determine the best practice of mechanical ventilation during ECMO and its impact on patient outcome.

Generation of stationary and moving vortices in active polar fluids in the planar Taylor-Couette geometry.

We study the dynamics of an active polar fluid in the interstitial space between two fixed coaxial cylinders. For sufficiently large expansive or contractive active stresses, the fluid presents roll instabilities of axially symmetric states leading to the spontaneous formation of vortices in the flow field. These vortices are either stationary or travel around the inner cylinder. Increasing the activity further, our numerical solutions indicate the existence of active turbulence that coexists with regular vortex solutions.

Cytosolic calcium, hydrogen peroxide and related gene expression and protein modulation in Arabidopsis thaliana cell cultures respond immediately to altered gravitation: parabolic flight data.

Callus cell cultures of Arabidopsis thaliana (cv. Columbia) were exposed to parabolic flights in order to assess molecular, short-term responses to altered gravity fields. Using transgenic cell lines, hydrogen peroxide (H2 O2 ) and cytosolic Ca(2+) were continuously monitored. In parallel, the metabolism of samples was chemically quenched (RNAlater, Ambion for RNA; acid/base for NADPH, NADP) at typical stages of a parabola [1 g before pull up; end of pull up (1.8 g), end of microgravity (20 s) and end of pull out (1.8 g)]. Cells exhibited an increase in both Ca(2+) and H2 O2 with the onset of microgravity, and a decline thereafter. This behaviour was accompanied by a decrease of the NADPH/NADP redox ratio, indicating Ca(2+) -dependent activation of a NADPH oxidase. Microarray analyses revealed concomitant expression profiles. At the end of the microgravity phase, 396 transcripts were specifically up-, while 485 were down-regulated. Up-regulation was dominated by Ca(2+) - and ROS-related gene products. The same material was also used for analysis of phosphopeptides with 2-D SDS PAGE. Relevant spots were identified by liquid chromatography-MS. With the exception of a chaperone (HSP 70-3), hypergravity (1.8 g) and microgravity modified different sets of proteins. These are partly involved in primary metabolism (glycolysis, gluconeogenesis, citrate cycle) and detoxification of ROS. Taken together, these data show that both gene expression and protein modulation jointly respond within seconds to alterations in the gravity field, with a focus on metabolic adaptation, signalling and control of ROS.

Health impact in children and adolescents.

Obesity in children and adolescents is associated with multiple comorbidities, including metabolic, cardiovascular, gastrointestinal, pulmonary, orthopedic and psychological disorders. In fact, cardiovascular and metabolic impairments in childhood and adolescence constitute major risk factors for developing cardiovascular disease in adulthood. Thus, obesity in childhood and adolescence leads to a higher morbidity and mortality in adulthood. Therefore, strong emphasis must be laid on the prevention and therapy of childhood obesity. Treatment requires a multidisciplinary and multiphase approach including dietary management, physical activity, pharmacotherapy and bariatric surgery. This paper reviews the different comorbidities of childhood obesity supporting the notion of a multidisciplinary therapy concept.

[Does childhood obesity affect sexual development?]. / Beeinflusst die kindliche Adipositas die Pubertätsentwicklung?

The process of pubertal development is only partly understood and is influenced by many different factors. During the twentieth century there was a general trend toward earlier pubertal development. Fat mass is thought to be a major inducer of puberty. Owing to the rising epidemic of childhood obesity, the relationship between body composition in children and the rate and timing of puberty needs to be investigated. Some studies suggest that central obesity is associated with an earlier onset of pubertal development. Rapid weight gain in early life is linked to advanced puberty in both sexes. A clear correlation exists between increasing body mass index (BMI) and earlier pubertal development in girls. In boys the data are controversial: The majority of studies propose that there is an earlier puberty and voice break in obese boys, but some studies show the opposite. There are several factors and mechanisms that seem to link obesity and puberty, for example, leptin, adipocytokines, and gut peptides. Important players include genetic variation and environmental factors (e.g., endocrine-disrupting chemicals). This article presents the latest studies and evidence on this topic, underlining the inconsistencies in the data and, therefore, the need for further research in this area.

[Carbohydrate metabolism disorders among obese children and adolescents. Diabetes mellitus type 2]. / Störungen des Kohlenhydratstoffwechsels bei Kindern und Jugendlichen mit Adipositas. Diabetes mellitus Typ 2.

As obesity has become more prevalent, the incidence of type 2 diabetes mellitus in children and adolescents has also increased. Obesity during adolescence leads to an increased risk for disease and premature death during adulthood, independent of obesity during adulthood. Obesity is the major risk factor impacting insulin sensitivity. Subjects with insulin resistance are at risk for progression to diabetes. Type 2 diabetes mellitus in obese children and adolescents is frequently asymptomatic. It is essential to identify children at high risk who need aggressive lifestyle modification focused on weight reduction and increased physical activity. Early detection and therapy of obese children and adolescents with type 2 diabetes may reduce the risk of cardiometabolic consequences and other long-term complications in adulthood.

The promoter variant -803 G>A in the RBP4 gene is not associated with BMI, metabolic parameters or blood pressure in Caucasian children.

OBJECTIVE: Studies in adults identified the -803 G>A promoter polymorphism (rs3758539) in the RBP4 gene (RBP4) as a functional variant conferring an increased risk for obesity and type 2 diabetes. METHODS: We genotyped this polymorphism in a cohort of 304 lean and 283 obese children to assess a potential association with early onset obesity and blood pressure and evaluated the effect of this SNP on metabolic parameters in a smaller subset. RESULTS: The allele frequency of -803 G>A was similar in obese compared to lean subjects (0.159 vs. 0.191, P=0.318). We did not detect an association of the variant with adiposity parameters nor with parameters of glucose and lipid metabolism or blood pressure in quantitative analyses. CONCLUSION: Our study revealed that the promoter polymorphism -803 G>A in RBP4 is not associated with BMI, metabolic parameters or blood pressure in Caucasian children.

[The platelet and its challenges]. / Der Thrombozyt und seine Tücken.

Thrombocytopenia is frequently observed in intensive care medicine, and it is associated with increased mortality. The causes of thrombocytopenia are manifold and several conditions may occur simultaneously so that an exact correlation with a single etiology may be difficult. The present case report demonstrates the importance of an appropriate pathophysiological and clinical consideration in order to avoid misdiagnoses and inappropriate management.

Leucocytes are a major source of circulating nicotinamide phosphoribosyltransferase (NAMPT)/pre-B cell colony (PBEF)/visfatin linking obesity and inflammation in humans.

AIMS/HYPOTHESIS: Nicotinamide phosphoribosyltransferase (NAMPT) is a multifunctional protein potentially involved in obesity and glucose metabolism. We systematically studied the association between circulating NAMPT, obesity, interventions and glucose metabolism and investigated potential underlying inflammatory mechanisms. METHODS: Fasting morning NAMPT serum levels were measured in cohorts of lean vs obese children, cohorts of intervention by lifestyle, exercise and bariatric surgery, and during an OGTT. In addition, mRNA expression, protein production and enzymatic activity of NAMPT were assessed from isolated leucocytes and subpopulations. RESULTS: Circulating NAMPT was significantly elevated in obese compared with lean children and declined after obesity interventions concomitantly with the decline in BMI, high-sensitivity C-reactive protein (hsCrP) and leucocyte counts. Circulating NAMPT significantly correlated with glucose metabolism and cardiovascular variables in univariate analyses, but only the association with glucose response during an OGTT was independent from BMI. We therefore assessed the NAMPT dynamic following an oral glucose load and found a significant decline of NAMPT levels to 77.0 ± 0.1% as a function of time, and insulin-to-glucose ratio during an OGTT in obese insulin-resistant adolescents. Circulating NAMPT was, however, most strongly associated with leucocyte counts (r = 0.46, p < 0.001). The leucocyte count itself determined significantly and independently from BMI insulin resistance in multiple regression analyses. We systematically evaluated NAMPT expression among several tissues and found that NAMPT was predominantly expressed in leucocytes. In subsequent analyses of leucocyte subpopulations, we identified higher NAMPT protein concentrations in lysates of granulocytes and monocytes compared with lymphocytes, whereas granulocytes secreted highest amounts of NAMPT protein into cell culture supernatant fractions. We confirmed nicotinamide mononucleotide enzymatic activity of NAMPT in all lysates and supernatant fractions. In monocytes, NAMPT release was significantly stimulated by lipopolysaccharide (LPS) exposure. CONCLUSIONS: Leucocytes are a major source of enzymatically active NAMPT, which may serve as a biomarker or even mediator linking obesity, inflammation and insulin resistance.

Vaspin is related to gender, puberty and deteriorating insulin sensitivity in children.

BACKGROUND: Visceral adipose tissue-derived serine protease inhibitor (vaspin) has been suggested as a novel adipocytokine related to obesity and insulin sensitivity in adults. DESIGN: We quantified vaspin serum concentrations in 65 lean and 67 obese children and aimed to evaluate the relationship of vaspin with physical development, obesity, and metabolic and cardiovascular phenotypes in children. We further assessed the acute vaspin response to glucose provocation in 20 obese adolescents and evaluated tissue expression patterns of vaspin in humans. RESULTS: Vaspin levels were significantly higher in girls than in boys. In girls, vaspin increased with age and pubertal stage, whereas there was no change with development in boys. Obese girls had lower vaspin serum levels than those of lean controls, but there was no significant correlation with body mass index (BMI). Independent of sex, age and BMI, lower vaspin was associated with better insulin sensitivity, with higher systolic blood pressure and impaired endothelial function. In response to glucose provocation during an oral glucose tolerance test, vaspin serum levels declined by approximately 25% in adolescents with hyperinsulinemia, whereas there was no significant decline in normoinsulinemic patients. In support of our clinical data, we not only confirmed vaspin mRNA expression in adipose tissue but also found consistent expression of vaspin in the liver and indications for expression in the pancreas and the skin. CONCLUSION: We showed that gender differences in circulating vaspin levels develop during pubertal progression in girls. Although vaspin's association with obesity remains controversial, vaspin was increased with worsening insulin resistance already in children and was acutely down-regulated following glucose provocation in insulin-resistant adolescents independent of obesity. Besides adipose tissue, vaspin expression in the liver and the pancreas may potentially contribute to circulating vaspin levels and their regulation.

Retinol binding protein 4 (RBP4) is primarily associated with adipose tissue mass in children.

OBJECTIVE: Retinol binding protein 4 (RBP4) is a novel adipocytokine that may link obesity and insulin resistance. We aimed to discriminate between primary and secondary associations of RBP4 with obesity and related disease. DESIGN: We applied clinical and experimental approaches to investigate the association of RBP4 levels with normal development, obesity, metabolic and cardiovascular parameters in 68 lean and 61 obese children. RESULTS: RBP4 significantly increased with age and pubertal development in healthy lean children. Obese children had significantly higher RBP4 levels compared with lean controls (30.5±1.4 vs. 26.3±1.1 mg/L, P<0.05) and there was a clear association with BMI independent of age (r=0.33, P<0.0001). RBP4 levels correlated significantly with parameters of lipid and glucose metabolism, as well as cardiovascular parameters in univariate analyses. Multiple regression analyses confirmed the strong association of RBP4 with BMI z-score and age, while the association with most metabolic and cardiovascular parameters was abolished. To assess whether the association of RBP4 with obesity may be attributable to adipogenesis, we evaluated RBP4 expression and secretion during adipocyte differentiation using the human SGBS cell line. In preadipocytes, RBP4 mRNA expression was nearly undetectable but increased during differentiation up to approximately 1600-fold (P<0.05). Likewise, RBP4 secretion was restricted to mature adipocytes, further indicating that RBP4 is strongly related to differentiation of adipocytes. CONCLUSION: RBP4 is a marker of adipose tissue mass and obesity already evident in children. The association of RBP4 with metabolic and cardiovascular sequelae of obesity appears to be secondary to the underlying relationship wtih body fat.

Diversity in sexual health: problems and dilemmas.

The increase in migrant populations in western Europe has led to specific problems and dilemmas in the area of sexual and reproductive health and service provision. In general, these problems and dilemmas can be divided into four categories: (1) epidemiology of diseases and risk factors; (2) psychosocial and cultural aspects; (3) communication; and (4) moral and ethical dilemmas. Regarding epidemiology, there is an increased prevalence in migrant groups of unwanted pregnancy and abortion, HIV/STDs, and sexual violence. Effective contraceptive use is hampered by knowledge deficits, uncertain living conditions, ambivalence regarding the use of contraceptives, and problems accessing (information on) contraception. Psychosocial and cultural aspects relate to the norms and attitudes individuals and groups have regarding the family, social relationships, sexuality, and gender. These norms and attitudes have an impact on the sexual and reproductive choices people make and the possibilities and restrictions they feel in this respect. Problems in communication concern not only language but also communication styles, the way patients present their problems, and the expectations they have from the service provider. Communication problems inevitably lead to a lower quality of care. Moral and ethical dilemmas arise where cultures collide, for example regarding sexuality education and virginity problems. Two examples of practical situations in which migrant patients ask for help with sexual or reproductive health problems will be described.

Acute haemodynamic effects of losartan in anaesthetized cirrhotic rats.

BACKGROUND: Portal hypertension in cirrhosis is the result of increased intrahepatic vascular resistance to portal outflow as well as increased portal tributary blood flow. The angiotensin II type 1 receptor antagonist losartan has been suggested as a portal pressure-lowering drug in patients with cirrhosis. AIM: To investigate the systemic and splanchnic haemodynamic effects of different doses of losartan. METHODS: In 35 anaesthetized rats with secondary biliary cirrhosis, 3, 10 or 30 mg of losartan kg(-1) or solvent were administered intravenously. Ten sham-operated rats served as controls. Mean arterial pressure and portal pressure were measured by catheters in the femoral artery or portal vein. Systemic and splanchnic haemodynamics and mesenterico-systemic shunt rate were determined by the coloured microsphere method. RESULTS: Losartan reduced portal pressure (sham: 9.1 +/- 0.4. cirrhosis: 19.3 +/- 1.1, after 3 mg kg(-1) of losartan 16.4 +/- 0.4, after 10 mg kg(-1) of losartan 15.6 +/- 0.6, after 30 mg kg(-1) of losartan 14.9 +/- 0.6 mmHg) without reducing portal sinusoidal resistance. However, in cirrhotic rats it reduced portal tributary blood flow (sham: 4.3 +/- 0.6. cirrhosis: 8.6 +/- 1.4, after 3 mg kg(-1) of losartan 3.8 +/- 0.7, after 10 mg kg(-1) of losartan 4.7 +/- 0.5, after 30 mg kg(-1) of losartan 5.9 +/- 0.9 mmHg). This was owing either to an increase in splanchnic vascular resistance at the 3 mg kg(-1) dose or to a reduction in the splanchnic perfusion-pressure gradient secondary to a reduction in mean arterial pressure at the 10 and 30 mg kg(-1) doses (mean arterial pressure: sham: 109.7 +/- 4.8. cirrhosis: 109.4 +/- 2.8, after 3 mg kg(-1) of losartan 99.7 +/- 2.9, after 10 mg kg(-1) of losartan 89.9 +/- 3.4, after 30 mg kg(-1) of losartan 81.0 +/- 2.9 mmHg). CONCLUSIONS: Low doses of losartan reduce portal hypertension by an increase in splanchnic vascular resistance without hypotensive side-effects on arterial pressure.

Portal hypertension is associated with increased mRNA levels of vasopressor G-protein-coupled receptors in human hepatic arteries.

BACKGROUND: The contractile response of human splanchnic vessels to different vasoconstrictors is attenuated in cirrhosis. Functional studies indicate a cellular signalling defect upstream of the G-protein level. The aim of the present study was to analyze expression and mRNA levels of the following most relevant vasopressor receptors in the smooth musculature of human hepatic arteries: alpha1 adrenoceptor (AR) subtypes a, b and d, angiotensin II type 1 receptor (AT1), arginine vasopressin receptor type 1a (V1a), endothelin receptor type A (ETA) and B (ETB). MATERIALS AND METHODS: Hepatic arteries were collected from 10 donors (noncirrhotic) and 14 recipients (cirrhotic) at liver transplantations. Real-time-PCR was performed to quantify steady-state levels of receptor mRNAs. RESULTS: alpha 1aAR mRNA levels showed no significant difference between the cirrhotic arteries and the controls while the mRNA levels of the other vasoactive receptors were significantly higher in the cirrhotic hepatic arteries (alpha 1bAR: 4-fold, P = 0.013; AT1: 16-fold, P = 0.024; V1a: 23-fold, P = 0.001; ETA: 4-fold, P = 0.02; ETB: 8-fold, P = 0.008). No mRNA for the alpha 1dAR was detected either in the donor or recipient hepatic arteries. CONCLUSION: We conclude that vascular hyporeactivity to the most relevant endogenous vasoconstrictors of cirrhotic hepatic arteries is not caused by a receptor down-regulation at mRNA levels. In contrast they were up-regulated.

The efficacy of heparinization in prolonging patency of arterial and central venous catheters in children: a randomized double-blind trial.

This study evaluates the efficacy of heparinization in prolonging patency of arterial and central venous catheters in children. A randomized double-blind trial in a tertiary 10-bed pediatric intensive care unit was used to evaluate 300 children (age older than 4 weeks, younger than 18 years). Trial medication consisted of either NaCl 0.9% infusion or NaCl 0.9% infusion to which 1 IU of heparin per milliliter was added. The number of nonpatent arterial and central venous catheters and the duration of stay of patent arterial and central venous catheters were measured. There was a significant risk increase for nonpatency in the nonheparinized arterial catheters (relative risk [RR]: 3.54; 95% confidence interval [CI]: 1.01-12.42). No significant risk increase for nonpatency could be demonstrated for the nonheparinized central venous catheters (RR: 7.63; 95% CI: 0.40-145). The median duration of stay of the patent arterial and central venous catheters was similar for both treatment groups. These results indicate that the use of normal saline in arterial catheters is associated with an increased frequency of catheter nonpatency as compared with heparinized saline.

Contractile hyporesponsiveness of hepatic arteries in humans with cirrhosis: evidence for a receptor-specific mechanism.

Splanchnic vasodilatation and vascular hyporesponsiveness to vasopressors are characteristic features of patients with cirrhosis. Although the vascular response to different vasopressors has been shown to be attenuated in cirrhosis, alterations on the receptor level are discussed controversially. Thus, impaired postreceptor signaling has been postulated. However, so far this has not been studied in human splanchnic vessels. Therefore, we assessed the vascular response of human hepatic arteries after activating the G-protein-dependent signal transduction pathway by stimulation with angiotensin II, the thromboxane A(2) analog U46619, or by G-protein activation with NaF/AlCl(3). After endothelium denudation, cumulative isometric concentration contraction curves were obtained for hepatic arteries from 32 cirrhotic patients undergoing liver transplantation and from 40 organ donors after stimulation with either angiotensin II (10(-11)-10(-5) mol/L), U46619 (10(-10)-10(-6) mol/L) or AlCl(3) (30 micromol/L)/NaF (10(-4)-3 x 10(-2) mol/L). Hepatic arteries from cirrhotic patients were markedly less responsive to angiotensin II (P <.0001) than those from organ donors. Both stimulation of the G-protein phospholipase C pathway via the thromboxane A(2) receptor and receptor-independent G-protein stimulation with AlCl(3)/NaF, induced an intact contractile response. In conclusion, the G-protein-dependent signal transduction system itself is unaltered in cirrhosis. Hence, the cause of the hyporesponsiveness to some vasoconstrictors in cirrhosis appears to be a receptor-specific phenomenon localized upstream from the G-protein level.

Hemodynamic effects of the angiotensin II receptor antagonist irbesartan in patients with cirrhosis and portal hypertension.

BACKGROUND & AIMS: Angiotensin II receptor antagonists have been proposed as new drugs for portal hypertension. This randomized, placebo-controlled, double-blind study aimed to assess the effect of the angiotensin II receptor antagonist irbesartan on portal and systemic hemodynamics and renal function in patients with cirrhosis. METHODS: Thirty-six patients with cirrhosis and portal hypertension received 150 mg/d irbesartan or placebo for 1 week. Systemic hemodynamics, kidney and liver function parameters were recorded regularly; hepatic venous pressure gradient and plasma renin were assessed on days 0 and 7. RESULTS: Irbesartan reduced the hepatic venous pressure gradient by 12.2% +/- 6.6% (P < 0.05) and mean arterial pressure by 5.3% +/- 4.0% in 13 of 18 verum patients. In 4 (22%) verum patients, arterial hypotension, accompanied by significant renal impairment, required withdrawal of irbesartan. In these patients, baseline plasma renin (P < 0.002) and cystatin C (P < 0.001) levels were higher, and creatinine clearance (P < 0.02), serum sodium (P < 0.01), and albumin (P < 0.05) were lower than in patients who tolerated irbesartan. Four of five patients with baseline renin >900 microU/mL developed treatment-limiting hypotension. CONCLUSIONS: The angiotensin II receptor antagonist irbesartan is not advisable in patients with advanced cirrhosis and high plasma renin because it may induce arterial hypotension and only moderately reduces portal pressure.