Bile acids induce arrhythmias: old metabolite, new tricks

Coronary Microvascular Dysfunction in Acute Cholestasis-Induced Liver Injury

BACKGROUND

Previous studies have shown cardiac abnormalities in acute liver injury, suggesting a potential role in the associated high mortality.

METHODS

We designed an experimental study exploring the short-term effects of acute cholestasis-induced liver injury on cardiac function and structure in a rodent bile duct ligation (BDL) model to elucidate the potential interplay. Thirty-seven male Sprague-Dawley rats were subjected to BDL surgery (n = 28) or served as sham-operated (n = 9) controls. Transthoracic echocardiography, Doppler evaluation of the left anterior descending coronary artery, and myocardial contrast echocardiography were performed at rest and during adenosine and dobutamine stress 5 days after BDL. Immunohistochemical staining of myocardial tissue samples for hypoxia and inflammation as well as serum analysis were performed.

RESULTS

BDL animals exhibited acute liver injury with elevated transaminases, bilirubin, and total circulating bile acids (TBA) 5 days after BDL (TBA control: 0.81 ± 2.54 µmol/L vs. BDL: 127.52 ± 57.03 µmol/L; p < 0.001). Concurrently, cardiac function was significantly impaired, characterized by reduced cardiac output (CO) and global longitudinal strain (GLS) in the echocardiography at rest and under pharmacological stress (CO rest control: 120.6 ± 24.3 mL/min vs. BDL 102.5 ± 16.6 mL/min, p = 0.041; GLS rest control: -24.05 ± 3.8% vs. BDL: -18.5 ± 5.1%, p = 0.01). Myocardial perfusion analysis revealed a reduced myocardial blood flow at rest and a decreased coronary flow velocity reserve (CFVR) under dobutamine stress in the BDL animals (CFVR control: 2.1 ± 0.6 vs. BDL: 1.7 ± 0.5 p = 0.047). Immunofluorescence staining indicated myocardial hypoxia and increased neutrophil infiltration.

CONCLUSIONS

In summary, acute cholestasis-induced liver injury can lead to impaired cardiac function mediated by coronary microvascular dysfunction, suggesting that major adverse cardiac events may contribute to the mortality of acute liver failure. This may be due to endothelial dysfunction and direct bile acid signaling.

Effect of Bile on Hemodynamics and Blood Micro-Rheological Parameters in Experimental Models of Bilhemia

As a rare complication of liver injury and certain interventions, bile can enter the bloodstream depending on the pressure gradient, resulting in bilhemia. Its micro-rheological and hemodynamic effects are still unclear. We aimed to study these parameters in experimental bilhemia models. Under general anesthesia, via laparotomy, bile was obtained by gallbladder puncture from pigs and by choledochal duct cannulation from rats. In vitro, 1 µL and 5 µL of bile were mixed with 500 µL of anticoagulated autologous blood. The systemic effect was also assessed (i.v. bile, 200 µL/bwkg). Hemodynamic and hematological parameters were monitored, and red blood cell (RBC) deformability and aggregation were determined. RBC deformability significantly decreased with the increasing bile concentration in vitro (1 µL: p = 0.033; 5 µL: p < 0.001) in both species. The RBC aggregation index values were concomitantly worsened (1 µL: p < 0.001; 5 µL: p < 0.001). The mean arterial pressure and heart rate decreased by 15.2 ± 6.9% and 4.6 ± 2.1% in rats (in 10.6 ± 2.6 s) and by 32.1 ± 14% and 25.2 ± 11.63% in pigs (in 48.3 ± 18.9 s). Restoration of the values was observed in 45 ± 9.5 s (rats) and 130 ± 20 s (pigs). Bilhemia directly affected the hemodynamic parameters and caused micro-rheological deterioration. The magnitude and dynamics of the changes were different for the two species.

Cirrhotic Cardiomyopathy Following Bile Duct Ligation in Rats-A Matter of Time?

Cirrhotic patients often suffer from cirrhotic cardiomyopathy (CCM). Previous animal models of CCM were inconsistent concerning the time and mechanism of injury; thus, the temporal dynamics and cardiac vulnerability were studied in more detail. Rats underwent bile duct ligation (BDL) and a second surgery 28 days later. Cardiac function was assessed by conductance catheter and echocardiography. Histology, gene expression, and serum parameters were analyzed. A chronotropic incompetence (P_d31 < 0.001) and impaired contractility at rest and a reduced contractile reserve (P_d31 = 0.03, P_dob-d31 < 0.001) were seen 31 days after BDL with increased creatine (P_d35, P_d42, and P_d56 < 0.05) and transaminases (P_d31 < 0.001). A total of 56 days after BDL, myocardial fibrosis was seen (P_d56 < 0.001) accompanied by macrophage infiltration (CD68: P_group < 0.001) and systemic inflammation (TNFα: P_group < 0.001, white blood cell count: P_group < 0.001). Myocardial expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) was increased after 31 (P_d31 < 0.001) and decreased after 42 (P_d42 < 0.001) and 56 days (P_d56 < 0.001). Caspase-3 expression was increased 31 and 56 days after BDL (P_d31 = 0.005; P_d56 = 0.005). Structural changes in the myocardium were seen after 8 weeks. After the second surgery (second hit), transient myocardial insufficiency with secondary organ dysfunction was seen, characterized by reduced contractility and contractile reserve.

Gut Microbiota and Atrial Fibrillation: Pathogenesis, Mechanisms and Therapies

Over the past decade there has been an interest in understanding the role of gut microbiota in the pathogenesis of AF. A number of studies have linked the gut microbiota to the occurrence of traditional AF risk factors such as hypertension and obesity. However, it remains unclear whether gut dysbiosis has a direct effect on arrhythmogenesis in AF. This article describes the current understanding of the effect of gut dysbiosis and associated metabolites on AF. In addition, current therapeutic strategies and future directions are discussed.

Acute myocardial injury secondary to severe acute liver failure: A retrospective analysis supported by animal data

To investigate whether acute liver failure (ALF) leads to secondary acute myocardial injury, 100 ALF patients that were retrospectively identified in a single center based on ICD 10 codes and 8 rats from an experimental study that died early after bile duct ligation (BDL) were examined. Creatine kinase (CK), creatine kinase-MB isoenzyme (CKMB) and cardiac troponin-I (cTnI) were analyzed as markers of myocardial injury. For histological analysis, hematoxylin-eosin (HE), elastic Van Gieson (EVG), CD41 and myeloperoxidase were used to stain rat hearts. Major adverse cardiac events (MACEs) were a critical factor for mortality (p = 0.037) in human ALF. Deceased patients exhibited higher levels of CKMB than survivors (p = 0.023). CKMB was a predictor of mortality in ALF (p = 0.013). Animals that died early after BDL exhibited increased cTnI, CKMB, tumor necrosis factor α (TNFα) and interleukin-6 (IL-6) levels compared to controls (cTnI: p = 0.011, CKMB: p = 0.008, TNFα: p = 0.003, IL-6: p = 0.006). These animals showed perivascular lesions and wavy fibers, microthrombi and neutrophilic infiltration in the heart. MACEs are decisive for mortality in human ALF, and elevated CKMB values indicate that this might be due to structural myocardial damage. Accordingly, CKMB was found to have predictive value for mortality in ALF. The results are substantiated by data from a rat BDL model demonstrating diffuse myocardial injury.

Management of Intrahepatic Cholestasis of Pregnancy: Recommendations of the Working Group on Obstetrics and Prenatal Medicine - Section on Maternal Disorders

Intrahepatic cholestasis of pregnancy (ICP) is the most common liver disease specific to pregnancy. The cardinal symptom of pruritus and a concomitant elevated level of bile acids in the serum and/or alanine aminotransferase (ALT) are suggestive for the diagnosis. Overall, the maternal prognosis is good. The fetal outcome depends on the bile acid level. ICP is associated with increased risks for adverse perinatal outcomes, including preterm delivery, meconium-stained amniotic fluid, and stillbirth. Acute fetal asphyxia and not chronic uteroplacental dysfunction leads to stillbirth. Therefore, predictive fetal monitoring is not possible. While medication with ursodeoxycholic acid (UDCA) improves pruritus, it has not been shown to affect fetal outcome. The indication for induction of labour depends on bile acid levels and gestational age. There is a high risk of recurrence in subsequent pregnancies.

TGR5 Expression Is Associated with Changes in the Heart and Urinary Bladder of Rats with Metabolic Syndrome

Adipose-derived cytokines may contribute to the inflammation that occurs in metabolic syndrome (MetS). The Takeda G protein-coupled receptor (TGR5) regulates energy expenditure and affects the production of pro-inflammatory biomarkers in metabolic diseases. Etanercept, which acts as a tumor necrosis factor (TNF)-α antagonist, can also block the inflammatory response. Therefore, the interaction between TNF-α and TGR5 expression was investigated in rats with high-fat diet (HFD)-induced obesity. Heart tissues isolated from the HFD-induced MetS rats were analyzed. Changes in TGR5 expression were investigated with lithocholic acid (LCA) as the agonist. Betulinic acid (BA) was used to activate TGR5 in urinary bladders. LCA was more effective in the heart tissues of HFD-fed rats, although etanercept alleviated the function of LCA. STAT3 activation and higher TGR5 expression were observed in the heart tissues collected from HFD-fed rats. Thus, cardiac TGR5 expression is promoted by HFD through STAT3 activation in rats. Moreover, the urinary bladders of female rats fed a HFD showed a low response, which was reversed by etanercept. Relaxation by BA in the bladders was more marked in HFD-fed rats. The high TGR5 expression in HFD-fed rats was characterized using a mRNA assay, and the increased cAMP levels were found to be stimulated by BA in the isolated bladders. Therefore, TGR5 expression increases with a HFD in both the hearts and urinary bladders. Collectively, cytokine-medicated TGR5 activation was observed in the hearts and urinary bladders of rats.

[Intrahepatic cholestasis of pregnancy]

Die Schwangerschaftscholestase („intrahepatic cholestasis of pregnancy“, ICP) ist die häufigste schwangerschaftsspezifische Lebererkrankung. Das Leitsymptom Juckreiz sowie eine begleitende Serumkonzentrationserhöhung von Gallensäuren und/oder der Alaninaminotransferase (ALT) sind wegweisend in der Diagnosestellung. Die mütterliche Prognose ist gut. Das fetale Outcome ist abhängig von der Gallensäurenkonzentration. Die ICP ist dabei sowohl mit Frühgeburt als auch mit intrauterinem Fruchttod (IUFT) assoziiert. Dieser ist Folge einer akuten fetalen Asphyxie, nicht einer chronischen uteroplazentaren Dysfunktion. Ein prädiktives Monitoring, z. B. durch Kardiotokographie (CTG) oder Ultraschall gibt es nicht. Eine medikamentöse Therapie mit Ursodeoxycholsäure (UDCA) bessert den Juckreiz, aber beeinflusst das fetale Outcome nicht nachweislich. Eine Entbindungsindikation ist in Abhängigkeit von Gallensäurenkonzentration und Gestationsalter gegeben. In Folgeschwangerschaften besteht ein hohes Wiederholungsrisiko.

Cirrhotic Cardiomyopathy

Cirrhotic cardiomyopathy (CCM), cardiac dysfunction in end-stage liver disease in the absence of prior heart disease, is an important clinical entity that contributes significantly to morbidity and mortality. The original definition for CCM, established in 2005 at the World Congress of Gastroenterology (WCG), was based upon known echocardiographic parameters to identify subclinical cardiac dysfunction in the absence of overt structural abnormalities. Subsequent advances in cardiovascular imaging and in particular myocardial deformation imaging have rendered the WCG criteria outdated. A number of investigations have explored other factors relevant to CCM, including serum markers, electrocardiography, and magnetic resonance imaging. CCM characteristics include a hyperdynamic circulatory state, impaired contractility, altered diastolic relaxation, and electrophysiological abnormalities, particularly QT interval prolongation. It is now known that cardiac dysfunction worsens with the progression of cirrhosis. Treatment for CCM has traditionally been limited to supportive efforts, but new pharmacological studies appear promising. Left ventricular diastolic dysfunction in CCM can be improved by targeted heart rate reduction. Ivabradine combined with carvedilol improves left ventricular diastolic dysfunction through targeted heart rate reduction, and this regimen can improve survival in patients with cirrhosis. Orthotopic liver transplantation also appears to improve CCM. Here, we canvass diagnostic challenges associated with CCM, introduce cardiac physiology principles and the application of echocardiographic techniques, and discuss the evidence behind therapeutic interventions in CCM.

A Bitter Taste in Your Heart

The human genome contains ∼29 bitter taste receptors (T2Rs), which are responsible for detecting thousands of bitter ligands, including toxic and aversive compounds. This sentinel function varies between individuals and is underpinned by naturally occurring T2R polymorphisms, which have also been associated with disease. Recent studies have reported the expression of T2Rs and their downstream signaling components within non-gustatory tissues, including the heart. Though the precise role of T2Rs in the heart remains unclear, evidence points toward a role in cardiac contractility and overall vascular tone. In this review, we summarize the extra-oral expression of T2Rs, focusing on evidence for expression in heart; we speculate on the range of potential ligands that may activate them; we define the possible signaling pathways they activate; and we argue that their discovery in heart predicts an, as yet, unappreciated cardiac physiology.

Educational Case: Intrauterine Fetal Demise and Intestinal Atresia: An Autopsy Investigation

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, seehttp://journals.sagepub.com/doi/10.1177/2374289517715040.¹

Role of bile acids in the diagnosis and progression of liver cirrhosis: A prospective observational study

The accumulation of toxic bile acids (BAs) is closely related to liver injury, inflammation and tumorigenesis. The aim of the present study was to determine the role of the serum BA spectrum in the diagnosis and progression of liver cirrhosis. This was a prospective observational study involving patients with chronic hepatitis (n=23), liver cirrhosis (n=101), and cirrhosis complicated with hepatocellular carcinoma (CC-HCC; n=56). The 6-month survival of cirrhotic patients was recorded after blood collection. Comparisons of serum total BAs and individual BAs between different groups were performed using the Mann-Whitney U or Kruskal-Wallis tests. Correlation analysis was conducted by Spearman's correlation. Diagnosis and prediction analyses were performed using receiver operating characteristic curves. Survival was analyzed using the Kaplan-Meier method and multivariable Cox regression analysis. The concentrations of total BAs, glycocholic acid (GCA), glycochenodeoxycholic acid (GCDCA), taurocholic acid (TCA), taurochenoxycholic acid and tauroursodeoxycholic acid (TUDCA) were increased significantly in patients with early cirrhosis compared to patients with chronic hepatitis (P<0.05) and were associated with the diagnosis of cirrhosis (P=0.049, 0.004, 0.002, 0.003, 0.010 and 0.009, respectively). The levels of total BAs, primary conjugated BAs, and TUDCA increased as liver cirrhosis progressed (P<0.05). Serum total BAs, GCA, GCDCA, and TCA predicted the 6-month survival of patients with liver cirrhosis (P=0.0003, 0.005, 0.002, and 0.010 respectively). Based on multivariate Cox regression analysis, the level of total BAs was an independent predictor of mortality in cirrhotic patients (hazard ratios, 4.046; 95% CI, 1.620-10.108; P=0.003). In the early-stage cirrhosis group, the concentrations of total BAs and primary conjugated BAs were significantly elevated in patients with CC-HCC compared with patients with cirrhosis alone. In conclusion, total and individual BAs, especially primary conjugated BAs, are effective non-invasive markers in the diagnosis and prognosis of liver cirrhosis, and may be potential indicators in the occurrence of hepatocellular carcinoma in patients with early cirrhosis.

Ursodeoxycholic acid inhibits uptake and vasoconstrictor effects of taurocholate in human placenta

Intrahepatic cholestasis of pregnancy (ICP) causes increased transfer of maternal bile acids to the fetus and an increased incidence of sudden fetal death. Treatment includes ursodeoxycholic acid (UDCA), but it is not clear if UDCA protects the fetus. This study explores the placental transport of the bile acid taurocholate (TC) by the organic anion-transporting polypeptide, (OATP)4A1, its effects on the placental proteome and vascular function, and how these are modified by UDCA. Various methodological approaches including placental villous fragments and Xenopus laevis oocytes were used to investigate UDCA transport. Placental perfusions and myography investigated the effect of TC on vasculature. The effects of acute TC exposure on placental tissue were investigated using quantitative proteomics. UDCA inhibited OATP4A1 activity in placental villous fragments and oocytes. TC induced vasoconstriction in placental and rat vasculature, which was attenuated by UDCA. Quantitative proteomic analysis of villous fragments showed direct effects of TC on multiple placental pathways, including oxidative stress and autophagy. The effects of TC on the placental proteome and vasculature demonstrate how bile acids may cause fetal distress in ICP. UDCA inhibition of OATP4A1 suggests it will protect the mother and fetus against the vascular effects of TC by inhibiting its cellular uptake. UDCA may protect the fetus in ICP by inhibiting OATP4A1-mediated bile acid transfer and TC-induced placental vasoconstriction. Understanding the physiologic mechanisms of UDCA may allow better therapeutic interventions to be designed specifically for the fetus in the future.-Lofthouse, E. M., Torrens, C., Manousopoulou, A., Nahar, M., Cleal, J. K., O'Kelly, I. M., Sengers, B. G., Garbis, S. D., Lewis, R. M. Ursodeoxycholic acid inhibits uptake and vasoconstrictor effects of taurocholate in human placenta.

TGR5 activation induces cytoprotective changes in the heart and improves myocardial adaptability to physiologic, inotropic, and pressure-induced stress in mice

INTRODUCTION

Administration of cholic acid, or its synthetic derivative, 6-alpha-ethyl-23(S)-methylcholic acid (INT-777), activates the membrane GPCR, TGR5, influences whole body metabolism, reduces atherosclerosis, and benefits the cardiovascular physiology in mice. Direct effects of TGR5 agonists, and the role for TGR5, on myocardial cell biology and stress response are unknown.

METHODS

Mice were fed chow supplemented with 0.5% cholic acid (CA) or 0.025% INT-777, a specific TGR5 agonist, or regular chow for 3 weeks. Anthropometric, biochemical, physiologic (electrocardiography and echocardiography), and molecular analysis was performed at baseline. CA and INT-777 fed mice were challenged with acute exercise-induced stress, acute catecholamine-induced stress, and hemodynamic stress induced by transverse aortic constriction (TAC) for a period of 8 weeks. In separate experiments, mice born with constitutive deletion of TGR5 in cardiomyocytes (CM-TGR5^del ) were exposed to exercise, inotropic, and TAC-induced stress.

RESULTS

Administration of CA and INT-777 supplemented diets upregulated TGR5 expression and activated Akt, PKA, and ERK1/2 in the heart. CA and INT-777 fed mice showed improved exercise tolerance, improved sensitivity to catecholamine and attenuation in pathologic remodeling of the heart under hemodynamic stress. In contrast, CM-TGR5^del showed poor response to exercise and catecholamine challenge as well as higher mortality and signs of accelerated cardiomyopathy under hemodynamic stress.

CONCLUSIONS

Bile acids, specifically TGR5 agonists, induce cytoprotective changes in the heart and improve myocardial response to physiologic, inotropic, and hemodynamic stress in mice. TGR5 plays a critical role in myocardial adaptability, and TGR5 activation may represent a potentially attractive treatment option in heart failure.

Total bile acid levels are associated with left atrial volume and cardiac output in patients with cirrhosis

BACKGROUND AND AIMS

Bile acids (BAs) are potent signaling molecules involved in the regulation of several metabolic and functional aspects of cardiovascular homeostasis. BA pool alteration in cirrhosis may contribute toward the development of hemodynamic and cardiac disturbances. We aimed to investigate the association between total BA levels and echocardiographic and biochemical markers of cardiac dysfunction in cirrhotic patients.

METHODS

Cirrhotic patients were enrolled prospectively in this hypothesis-generating study and evaluated for cardiac and hemodynamic dysfunction through clinical, echocardiographic, and biochemical means. Associations between total serum BA concentrations and markers of systolic or diastolic dysfunction and the presence of cirrhotic cardiomyopathy were tested through univariate and multivariate analyses.

RESULTS

Fifty-eight patients with cirrhosis were assessed in this monocentric study. 49 (85%) patients had decompensated cirrhosis according to the Child class. The median total BA level was 45 µmol/l. There was no correlation between BA levels and the etiology of cirrhosis (P=0.2), current alcohol use (P=0.8), sex (P=0.1), smoking status (P=0.2), age, or BMI. Systolic and diastolic dysfunction were rare in the cohort. Total BA levels associated with several echocardiographic parameters of the hyperdynamic syndrome in univariate analysis but only with left atrial volume in multivariate analysis (P=0.007). BA concentrations did not differ according to the presence of echocardiographically diagnosed cirrhotic cardiomyopathy in the two models tested.

CONCLUSION

Total serum BA levels are associated with enlarged left atrial volume and markers of the hyperdynamic circulation in patients with cirrhosis irrespective of the etiology or the severity of liver disease.

Heart and bile acids - Clinical consequences of altered bile acid metabolism

Cardiac dysfunction has an increased prevalence in diseases complicated by liver cirrhosis such as primary biliary cholangitis and primary sclerosing cholangitis. This observation has led to research into the association between abnormalities in bile acid metabolism and cardiac pathology. Approximately 50% of liver cirrhosis cases develop cirrhotic cardiomyopathy. Bile acids are directly implicated in this, causing QT interval prolongation, cardiac hypertrophy, cardiomyocyte apoptosis and abnormal haemodynamics of the heart. Elevated maternal serum bile acids in intrahepatic cholestasis of pregnancy, a disorder which causes an impaired feto-maternal bile acid gradient, have been associated with fatal fetal arrhythmias. The hydrophobicity of individual bile acids in the serum bile acid pool is of relevance, with relatively lipophilic bile acids having a more harmful effect on the heart. Ursodeoxycholic acid can reverse or protect against these detrimental cardiac effects of elevated bile acids.

Bile acids and cardiovascular function in cirrhosis

Cirrhotic cardiomyopathy and the hyperdynamic syndrome are clinically important complications of cirrhosis, but their exact pathogenesis is still partly unknown. Experimental models have proven the cardiotoxic effects of bile acids and recent studies of their varied receptor-mediated functions offer new insight into their involvement in cardiovascular dysfunction in cirrhosis. Bile acid receptors such as farnesoid X-activated receptor and TGR5 are currently under investigation as potential therapeutic targets in a variety of pathological conditions. These receptors have also recently been identified in cardiomyocytes, vascular endothelial cells and smooth muscle cells where they seem to play an important role in cellular metabolism. Chronic cholestasis leading to abnormal levels of circulating bile acids alters the normal signalling pathways and contributes to the development of profound cardiovascular disturbances. This review summarizes the evidence regarding the role of bile acids and their receptors in the generation of cardiovascular dysfunction in cirrhosis.

Arrhythmia risk in liver cirrhosis

Interactions between the functioning of the heart and the liver have been described, with heart diseases affecting the liver, liver diseases affecting the heart, and conditions that simultaneously affect both. The heart is one of the most adversely affected organs in patients with liver cirrhosis. For example, arrhythmias and electrocardiographic changes are observed in patients with liver cirrhosis. The risk for arrhythmia is influenced by factors such as cirrhotic cardiomyopathy, cardiac ion channel remodeling, electrolyte imbalances, impaired autonomic function, hepatorenal syndrome, metabolic abnormalities, advanced age, inflammatory syndrome, stressful events, impaired drug metabolism and comorbidities. Close monitoring of cirrhotic patients is needed for arrhythmias, particularly when QT interval-prolonging drugs are given, or if electrolyte imbalances or hepatorenal syndrome appear. Arrhythmia risk may persist after liver transplantation due to possible QT interval prolongation, persistence of the parasympathetic impairment, post-transplant reperfusion and chronic immunosuppression, as well as consideration of the fact that the transplant itself is a stressful event for the cardiovascular system. The aims of the present article were to provide a review of the most important data regarding the epidemiology, pathophysiology, and biomarkers of arrhythmia risk in patients with liver cirrhosis, to elucidate the association with long-term outcome, and to propose future research directions.

Evaluation of ventricular repolarization in pregnant women with intrahepatic cholestasis

BACKGROUND

Bile acids can induce arrhythmia by altering cardiomyocyte contractility or electrical conduction. The aim of this study was to investigate, by means of QT dispersion parameter detected by simple standard electrocardiogram (ECG), ventricular repolarization changes in pregnant women with and without intrahepatic cholestasis of pregnancy (ICP).

METHODS

In this case-control study including 75 pregnant women with cholestasis and 35 healthy, uncomplicated pregnancy cases, electrocardiographic QT interval durations and QT dispersion (QT-disp) parameters, corrected for the patients' heart rate using the Hodges formula, were investigated.

RESULTS

Maximum corrected QT interval values were significantly higher in the severe ICP group than in the control group (p < 0.001) and significantly higher in the severe ICP group than in the mild ICP group (p = 0.01). The values of the mild ICP and control groups were similar. Corrected QT-disp values were also significantly higher in both ICP groups than in the control group and significantly higher in the severe ICP group than in the mild ICP group.

CONCLUSION

Cholestatic diseases predispose patients to cardiovascular complications. Our data clearly demonstrated that QT-disp values were significantly altered in pregnant women with cholestasis when compared to the normal ones. This simple ECG parameter can be used to screen high-risk women, in order to better target counseling regarding lifestyle modifications and to conduct closer follow up and management of women with a history of ICP.

Prediction of cardiovascular risk by electrocardiographic changes in women with intrahepatic cholestasis of pregnancy

OBJECTIVE

We aimed to investigate P wave characteristics in pregnant women with and without intrahepatic cholestasis of pregnancy (ICP).

METHODS

In this case-control study, including 59 pregnant women with intrahepatic cholestasis and 28 with healthy uncomplicated pregnancies, electrocardiographic maximum (Pmax) and minimum (Pmin) P-wave durations and P-wave dispersion (Pd) parameters were investigated.

RESULTS

While Pmin and Pd values were significantly lower in women both with mild and severe ICP when compared to healthy pregnant women (p < 0.001), there was no significant difference between mild and severe disease groups.

CONCLUSION

Intrahepatic cholestasis predisposes to cardiovascular complications. P-wave durations and Pd constitute a recent contribution to the field of noninvasive electrocardiology. Our data clearly demonstrated that these parameters were significantly altered in pregnant women with ICP when compared to the normal ones. This important association can be used to screen for women with an increased risk to better target counseling on lifestyle modifications and to closer follow-up and management of women with a history of ICP.

Effect of cholic acid on fetal cardiac myocytes in intrahepatic choliestasis of pregnancy

This study examined the effect of cholic acid (CA) on cultured cardiac myocytes (CMs) from neonatal rats with an attempt to explore the possible mechanism of sudden fetal death in intrahepatic cholestasis of pregnancy (ICP). Inverted microscopy was performed to detect the impact of CA on the beating rates of rat CMs. MTT method was used to study the effect of CA on the viability of CMs. CMs cultured in vitro were incubated with 10 μmol/L Ca(2+)-sensitive fluorescence indicator fluo-3/AM. The fluorescence signals of free calcium induced by CA were measured under a laser scanning confocal microscope. The results showed that CA decreased the beating rates of the CMs in a dose-dependent manner. CA could suppress the activities of CMs in a time- and dose-dependent manner. CA increased the concentration of intracellular free calcium in a dose-dependent manner. Our study suggested that CA could inhibit the activity of CMs by causing calcium overload, thereby leading to the sudden fetal death in ICP.