[Alcohol and arrhythmias]

Extrahepatic Manifestations in Alcoholic Liver Disease

Though liver is the most commonly affected organ in patients with chronic and excessive intake of alcohol, no organ is immune to toxic effects of alcohol and patients with alcohol-related liver disease (ALD) can suffer from a wide list of extrahepatic manifestations involving gastrointestinal tract, central and peripheral nervous systems, cardio vascular system, musculo-skeletal system, disruption of nutritional status, endocrinological abnormalities, hematological abnormalities and immune dysfunction. These extrahepatic organ involvements are usually overlooked by hepatologists and physicians who are mostly focused on managing life threatening complications of ALD. As a result, there is delayed diagnosis, delay in the initiation of appropriate treatment and late referral to other specialists. Some of these manifestations are of utmost clinical importance (e.g. delirium tremans and Wernicke's encephalopathy) because an early diagnosis and treatment can lead to full recovery while delayed or no treatment can result in death. On the other hand, several extrahepatic manifestations are of prognostic significance (such as alcoholic cardiomyopathy and malignancies) in which there is an increased risk of morbidity and mortality. Hence, a clear understanding and awareness of the extrahepatic manifestations of ALD is quintessential for proper management of these patients.

Short-Chained Alcohols Make Membrane Surfaces Conducive for Melittin Action: Implication for the Physiological Role of Alcohols in Cells

Alcohols are a part of cellular metabolism, but their physiological roles are not well understood. We investigated the effects of short-chain alcohols on Daphnia pulex and model membranes mimicking the lipid composition of eukaryotic inner mitochondrial membranes. We also studied the synergistic effects of alcohols with the bee venom membrane-active peptide, melittin, which is structurally similar to endogenous membrane-active peptides. The alcohols, from ethanol to octanol, gradually decreased the heart rate and the mitochondrial ATP synthesis of daphnia; in contrast, in combination with melittin, which exerted no sizeable effect, they gradually increased both the heart rate and the ATP synthesis. Lipid packing and the order parameter of oriented films, monitored by EPR spectroscopy of the spin-labeled probe 5-doxylstrearic acid, revealed gradual alcohol-assisted bilayer to non-bilayer transitions in the presence of melittin; further, while the alcohols decreased, in combination with melittin they increased the order parameter of the film, which is attributed to the alcohol-facilitated association of melittin with the membrane. A ¹H-NMR spectroscopy of the liposomes confirmed the enhanced induction of a non-bilayer lipid phase that formed around the melittin, without the permeabilization of the liposomal membrane. Our data suggest that short-chain alcohols, in combination with endogenous peptides, regulate protein functions via modulating the lipid polymorphism of membranes.

Causes of Death and Survival in Alcoholic Cirrhosis Patients Undergoing Liver Transplantation: Influence of the Patient's Clinical Variables and Transplant Outcome Complications

Background. Clinical and molecular mechanisms involved in the cause and time of death of alcoholic cirrhosis (AC) patients undergoing liver transplantation (LT) are not entirely understood. In sudden death cases, judicial autopsy practice is mandatory for determining the cause and circumstances of death. The medico-legal autopsy data are essential for helping health authorities to guide future public health activities, assess the effectiveness of health systems, and adopt the necessary preventive measures to improve and adapt the treatments in order to increase these patients’ survival. Objective. Our study aimed to determine the different clinical and sociodemographic causes that influence the different causes of death and the short- and long-term survival of AC patients undergoing liver transplantation. Methods. A total of 122 deceased AC patients undergoing LT were analyzed at different times post-transplantation. The main pre- and post-transplant complications were analyzed in relation to the cause of death and the patient’s survival, as well as the causes and time at which the patient’s death occurred. Results. A total of 53.3% of non-sudden death was observed. A large number of the deaths of AC patients undergoing transplantation were due to non-sudden death, sepsis, and graft failure (GF), the main causes of death in the sample being similar in both sexes. In non-sudden deaths, there were no significant differences between the death rates either related or not related to the liver transplant. Sepsis was the main cause, with the highest percentage (21.3%) of mortality, followed by GF (18.9%) and multiorgan failure (15.6%) at ten years. Furthermore, our results showed how pre-transplant clinical complications, such as viral infections and encephalopathy, influence the age at which multiorgan failure occurs in the transplanted patient. Conclusion. Multiorgan failure is the leading cause of sudden death, with higher mortality during the first year after transplantation, followed by sepsis and GF. Our results show the vulnerability of AC patients, both in the hospital period after the transplant and outside.

Plasma Hyperosmolality Prolongs QTc Interval and Increases Risk for Atrial Fibrillation in Traumatic Brain Injury Patients

Introduction: Hyperosmotic therapy with mannitol is frequently used for treatment cerebral edema, and 320 mOsm/kg H₂O has been recommended as a high limit for therapeutic plasma osmolality. However, plasma hyperosmolality may impair cardiac function, increasing the risk of cardiac events. The aim of this study was to analyze the relation between changes in plasma osmolality and electrocardiographic variables and cardiac arrhythmia in patients treated for isolated traumatic brain injury (iTBI). Methods: Adult iTBI patients requiring mannitol infusion following cerebral edema, and with a Glasgow Coma Score below 8, were included. Plasma osmolality was measured with Osmometr 800 CLG. Spatial QRS-T angle (spQRS-T), corrected QT interval (QTc) and STJ segment were calculated from digital resting 12-lead ECGs and analyzed in relation to four levels of plasma osmolality: (A) <280 mOsm/kg H₂O; (B) 280–295 mOsm/kg H₂O; (C) 295–310 mOsm/kg H₂O; and (D) >310 mOsm/kg H₂O. All parameters were measured during five consecutive days of treatment. Results: 94 patients aged 18-64 were studied. Increased plasma osmolality correlated with prolonged QTc (p < 0.001), intensified disorders in STJ and increased the risk for cardiac arrhythmia. Moreover, plasma osmolality >313 mOms/kg H₂O significantly increased the risk of QTc prolongation >500 ms. Conclusion: In patients treated for iTBI, excessively increased plasma osmolality contributes to electrocardiographic disorders including prolonged QTc, while also correlating with increased risk for cardiac arrhythmias.

The Effects of Ethanol on the Heart: Alcoholic Cardiomyopathy

Alcoholic-dilated Cardiomyopathy (ACM) is the most prevalent form of ethanol-induced heart damage. Ethanol induces ACM in a dose-dependent manner, independently of nutrition, vitamin, or electrolyte disturbances. It has synergistic effects with other heart risk factors. ACM produces a progressive reduction in myocardial contractility and heart chamber dilatation, leading to heart failure episodes and arrhythmias. Pathologically, ethanol induces myocytolysis, apoptosis, and necrosis of myocytes, with repair mechanisms causing hypertrophy and interstitial fibrosis. Myocyte ethanol targets include changes in membrane composition, receptors, ion channels, intracellular [Ca²⁺] transients, and structural proteins, and disrupt sarcomere contractility. Cardiac remodeling tries to compensate for this damage, establishing a balance between aggression and defense mechanisms. The final process of ACM is the result of dosage and individual predisposition. The ACM prognosis depends on the degree of persistent ethanol intake. Abstinence is the preferred goal, although controlled drinking may still improve cardiac function. New strategies are addressed to decrease myocyte hypertrophy and interstitial fibrosis and try to improve myocyte regeneration, minimizing ethanol-related cardiac damage. Growth factors and cardiomyokines are relevant molecules that may modify this process. Cardiac transplantation is the final measure in end-stage ACM but is limited to those subjects able to achieve abstinence.

Two case reports of fetal alcohol syndrome: broadening into the spectrum of cardiac disease to personalize and to improve clinical assessment

BACKGROUND

Fetal alcohol spectrum disorder (FASD) refers to a broad spectrum of disabilities, in infants and children, resulting from moderate to excessive prenatal alcohol exposure. Significant associations with alcohol exposure were already reported with congenital structural heart defects: i.e. ventricular septal defects, atrial septal defects, conotruncal defects.

CASES PRESENTATION

We describe two cases of children with FASD, both admitted to the Center for Rare Diseases and Birth Defects of Policlinico Universitario Agostino Gemelli, in whom asymptomatic cardiac rhythm alterations were detected in absence of structural cardiovascular system anomalies or cardiac channelopathies.

CONCLUSIONS

No other reports about cardiac rhythm anomalies in individuals affected by FASD are actually available from the literature. We would like to make an alert for clinician, given the possibility of finding anomalies of heart conduction and rhythm in children affected by FASD even without structural congenital heart disease.

Role of Alcohol Oxidative Metabolism in Its Cardiovascular and Autonomic Effects

Several review articles have been published on the neurobehavioral actions of acetaldehyde and other ethanol metabolites as well as in major alcohol-related disorders such as cancer and liver and lung disease. However, very few reviews dealt with the role of alcohol metabolism in the adverse cardiac and autonomic effects of alcohol and their potential underlying mechanisms, particularly in vulnerable populations. In this chapter, following a brief overview of the dose-related favorable and adverse cardiovascular effects of alcohol, we discuss the role of ethanol metabolism in its adverse effects in the brainstem and heart. Notably, current knowledge dismisses a major role for acetaldehyde in the adverse autonomic and cardiac effects of alcohol because of its low tissue level in vivo. Contrary to these findings in men and male rodents, women and hypertensive individuals are more sensitive to the adverse cardiac effects of similar amounts of alcohol. To understand this discrepancy, we discuss the autonomic and cardiac effects of alcohol and its metabolite acetaldehyde in a model of hypertension, the spontaneously hypertensive rat (SHR) and female rats. We present evidence that enhanced catalase activity, which contributes to cardioprotection in hypertension (compensatory) and in the presence of estrogen (inherent), becomes detrimental due to catalase catalysis of alcohol metabolism to acetaldehyde. Noteworthy, studies in SHRs and in estrogen deprived or replete normotensive rats implicate acetaldehyde in triggering oxidative stress in autonomic nuclei and the heart via (i) the Akt/extracellular signal-regulated kinases (ERK)/nitric oxide synthase (NOS) cascade and (ii) estrogen receptor-alpha (ERα) mediation of the higher catalase activity, which generates higher ethanol-derived acetaldehyde in female heart. The latter is supported by the ability of ERα blockade or catalase inhibition to attenuate alcohol-evoked myocardial oxidative stress and dysfunction. More mechanistic studies are needed to further understand the mechanisms of this public health problem.

Specific Features of Depolarization of the Left and Right Atria in Rats with Alcoholic Cardiomyopathy

Using a translation model of alcoholic cardiomyopathy in rats we showed the presence of an additional abnormal excitation focus in the area of the pulmonary vein lacunae in the left atrium and enhanced heterogeneity of the atrium depolarization pattern. These changes can determine electric instability of the myocardium and induce malignant heart rhythm disturbances including, sudden cardiac death.

Atria Depolarization in Rats with Alcoholic Cardiomyopathy

Chronotopography of atrial subepicardium depolarization has been studied in a rat model of alcoholic cardiomyopathy. Formation of independent sources of initial atrial activity has been detected in the right and left atria. These sources induced the formation of several depolarization fronts that propagated autonomously, and this can be regarded as the cause of atrial arrhythmia.