Alcohol and arrhythmias: a comprehensive review

Alcoholic cardiomyopathy: an update

Alcohol-induced cardiomyopathy (AC) is an acquired form of dilated cardiomyopathy (DCM) caused by prolonged and heavy alcohol intake in the absence of other causes. The amount of alcohol required to produce AC is generally considered as >80 g/day over 5 years, but there is still some controversy regarding this definition. This review on AC focuses on pathogenesis, which involves different mechanisms. Firstly, the direct toxic effect of ethanol promotes oxidative stress in the myocardium and activation of the renin-angiotensin system. Moreover, acetaldehyde, the best-studied metabolite of alcohol, can contribute to myocardial damage impairing actin-myosin interaction and producing mitochondrial dysfunction. Genetic factors are also involved in the pathogenesis of AC, with DCM-causing genetic variants in patients with AC, especially titin-truncating variants. These findings support a double-hit hypothesis in AC, combining genetics and environmental factors. The synergistic effect of alcohol with concomitant conditions such as hypertension or liver cirrhosis can be another contributing factor leading to AC. There are no specific cardiac signs and symptoms in AC as compared with other forms of DCM. However, natural history of AC differs from DCM and relies directly on alcohol withdrawal, as left ventricular ejection fraction recovery in abstainers is associated with an excellent prognosis. Thus, abstinence from alcohol is the most crucial step in treating AC, and specific therapies are available for this purpose. Otherwise, AC should be treated according to current guidelines of heart failure with reduced ejection fraction. Targeted therapies based on AC pathogenesis are currently being developed and could potentially improve AC treatment in the future.

Alcohol and the risk of all-cause death, atrial fibrillation, ventricular arrhythmia, and sudden cardiac arrest

The risk of having atrial fibrillation (AF) is associated with alcohol intake. However, it is not clear whether sudden cardiac arrest (SCA) and ventricular arrhythmia (VA) including ventricular tachycardia, flutter, or fibrillation have similar associations with alcohol. We aimed to evaluate the association of alcohol intake with all-cause death, new-onset AF, VA, and SCA using single cohort with a sufficient sample size. A total of 3,990,373 people without a prior history of AF, VAs, or SCA was enrolled in this study based on nationwide health check-up in 2009. We classified the participants into four groups according to weekly alcohol consumption, and evaluated the association of alcohol consumption with each outcome. We observed a significant association between mild (hazard ratio [HR] = 0.826; 95% confidence interval [CI] = 0.815-0.838) to moderate (HR = 0.930; 95% CI = 0.912-0.947) drinking with decreased risk of all-cause mortality. However heavy drinking (HR = 1.108; 95% CI = 1.087-1.129) was associated with increased all-cause death. The risk of new-onset AF was significantly associated with moderate (HR = 1.129; 95% CI = 1.097-1.161) and heavy (HR = 1.298; 95% CI = 1.261-1.337) drinking. However, the risk of SCA showed negative association with all degrees of alcohol intake: 20% (HR = 0.803; 95% CI = 0.769-0.839), 15% (HR = 0.853; 95% CI = 0.806-0.902), and 8% (HR = 0.918; 95% CI = 0.866-0.974) lower risk for mild, moderate, and heavy drinkers, respectively. Mild drinking was associated with reduced risk of VA with moderate and heavy drinking having no associations. In conclusion, the association between alcohol and various outcomes in this study were heterogeneous. Alcohol might have different influences on various cardiac disorders.

A Common East Asian aldehyde dehydrogenase 2*2 variant promotes ventricular arrhythmia with chronic light-to-moderate alcohol use in mice

Chronic heavy alcohol use is associated with lethal arrhythmias. Whether common East Asian-specific aldehyde dehydrogenase deficiency (ALDH2*2) contributes to arrhythmogenesis caused by low level alcohol use remains unclear. Here we show 59 habitual alcohol users carrying ALDH2 rs671 have longer QT interval (corrected) and higher ventricular tachyarrhythmia events compared with 137 ALDH2 wild-type (Wt) habitual alcohol users and 57 alcohol non-users. Notably, we observe QT prolongation and a higher risk of premature ventricular contractions among human ALDH2 variants showing habitual light-to-moderate alcohol consumption. We recapitulate a human electrophysiological QT prolongation phenotype using a mouse ALDH2*2 knock-in (KI) model treated with 4% ethanol, which shows markedly reduced total amount of connexin43 albeit increased lateralization accompanied by markedly downregulated sarcolemmal Nav1.5, Kv1.4 and Kv4.2 expressions compared to EtOH-treated Wt mice. Whole-cell patch-clamps reveal a more pronounced action potential prolongation in EtOH-treated ALDH2*2 KI mice. By programmed electrical stimulation, rotors are only provokable in EtOH-treated ALDH2*2 KI mice along with higher number and duration of ventricular arrhythmia episodes. The present research helps formulate safe alcohol drinking guideline for ALDH2 deficient population and develop novel protective agents for these subjects.

The potential role of yeasts in the mitigation of health issues related to beer consumption

Food consumption of healthier products has become an essential trend in the food sector. This is also the case in beer, a biochemical process of transformation performed by yeast cells. More and more studies proclaim the need to reduce ethanol content in alcoholic drinks, certainly the most important health issue of beer consumption. In this review we gather key health issues related to beer consumption and the last advances regarding the use of yeast to attenuate those health problems. Furthermore, we have included the latest findings about the general positive impact of yeast in health as a consequence of its ability to biotransform polyphenolic compounds present in the wort, producing healthy compounds as hydroxytyrosol or melatonin, and its ability to perform as a probiotic driver. Besides, a group of population with chronic diseases as diabetes or celiac disease could take advantage of low carbohydrate or gluten-free beers, respectively. The role of yeast in beer production has been traditionally associated to its fermentative power. But here we have found a change in this dogma in the last years toward yeasts being a main driver to enhance healthy aspects of beer. The key findings are discussed and possible future directions are proposed.

Association between Alcohol Intake and Arterial Stiffness in Healthy Adults: A Systematic Review

Background: Arterial stiffness as assessed by Pulse Wave Velocity (PWV) represents an independent predictor of cardiovascular disease. Several dietary compounds and lifestyle factors could influence arterial stiffness. The debate on the significance of the correlation between alcohol consumption and arterial stiffness is still open, given that the relationship is complex and potentially affected by several factors such as alcohol type, consumption levels, gender and age differences. Objective: This systematic literature review aims to examine the evidence supporting an association between alcohol use and PWV, in electronic databases including PubMed/MEDLINE and the Cochrane Library, from January 2010 to November 2020. Screening and full-text reviews were performed by three investigators and data extraction by two. Considering the significant heterogeneity of data only a qualitative analysis (systematic review) was performed. Results: A total of 13 studies met the inclusion criteria. Alcohol consumption was independently associated with arterial stiffness in a J-shaped way in most of the studies included. A benefit of alcohol consumption on arterial stiffness was found in four experimental studies, whilst an unfavorable increasing linear association was found in four others. Associations were confirmed with both oscillometric and tonometric PWV assessment methods. In some studies, a gender and age correlation was found with a more pronounced association in older males. In all studies elevated levels of alcohol consumption were associated with a worsening of arterial stiffness. Conclusions: Despite the variable findings across studies, the current review provides preliminary evidence that light-to-moderate alcohol consumption is associated with arterial stiffness values lower than expected, and evidence that high doses accelerate arterial ageing. These findings could be useful for clinicians who provide recommendations for patients at cardiovascular (CV) risk. Nevertheless, given the heterogeneity of study designs, interventions, measurement methods and statistical evaluations, the protective role of moderate alcohol consumption on arterial stiffness is likely but not certain, warranting additional trials and evidence.

Arrhythmias in patients with in-hospital alcohol withdrawal are associated with increased mortality: Insights from 1.5 million hospitalizations for alcohol withdrawal syndrome

Background

Atrial arrhythmias are commonly noted in patients with alcohol withdrawal syndrome (AWS), requiring inpatient admission.

Objective

The burden of arrhythmias and the association with in-hospital outcomes are incompletely defined in patients hospitalized with AWS.

Methods

The nationwide inpatient sample database was accessed from September 2015 to December 2018 to identify hospitalizations for AWS. We studied a cohort of patients with arrhythmias noted during hospitalization using the appropriate International Classification of Diseases, Tenth Revision billing codes. We compared patient characteristics, outcomes, and hospitalization costs between alcohol withdrawal hospitalizations with and without documented arrhythmias. Propensity score matching (PSM) and multivariate regression were performed to control confounders and develop odds ratios (OR), respectively.

Results

Among 1,511,155 hospitalization with AWS, 146,825 (9.72%) had concurrent arrhythmias. After PSM, we identified 135,540 cases in each group. Hospitalizations with AWS and concurrent arrhythmias had higher in-hospital mortality (4.19% vs 1.95%, OR 1.76, confidence interval [CI] 1.67–1.85, P < .0001). The most common arrhythmia was atrial fibrillation (66.7%). Arrhythmias in AWS were also associated with poorer in-hospital outcomes, including a higher risk of acute heart failure (8.40% vs 4.58%, OR 1.97, CI 1.90–2.05, P < .0001), acute kidney injury (21.32% vs 15.27%, OR 1.39, CI 1.36–1.43, P < .0001), and acute respiratory failure (9.19% vs 5.49%, OR 1.70, CI 1.64–1.76, P < .0001) requiring intubation. The length of hospital stay (6 days vs 4 days P < .0001) and cost of hospital care ($12,615 [$6683–$27,330] vs $7860 [$4482–$15,868], P < .0001) were higher in AWS with arrhythmias.

Conclusion

Arrhythmia in AWS is associated with higher in-hospital mortality and poorer in-hospital outcomes.

QTc prolongation in adolescents with acute alcohol intoxication

In adults, alcohol intoxication is associated with prolongation of the QT interval corrected for heart rate (QTc). The QTc is influenced by age and sex. Although alcohol intoxication is increasingly common in adolescents, there are no data on the prevalence of QTc prolongation in adolescents with alcohol intoxication. This study aimed to determine the prevalence of QTc prolongation in adolescents with alcohol intoxication and identify at-risk adolescents. In this observational study including adolescents aged 10-18 years, heart rate and QT interval were automatically assessed from an electrocardiogram (ECG) at alcohol intoxication using a validated algorithm. The QTc was calculated using both the Bazett formula (QTc_B) and Fridericia formula (QTc_F). If present, an ECG recorded within 1 year of the date of admission to the emergency department was obtained as a reference ECG. A total of 317 adolescents were included; 13.3% had a QTc_B and 7.9% a QTc_F longer than the sex- and age-specific 95th-percentile. None of the adolescents had a QTc_B or QTc_F > 500 ms, but 11.8% of the adolescents with a reference ECG had a QTc_B prolongation of > 60 ms, while no adolescents had a QTc_F prolongation of > 60 ms. QTc prolongation was mainly attributable to an increase in heart rate rather than QT prolongation, which underlies the differences between QTc_B and QTc_F. Male sex and hypokalaemia increased the likelihood of QTc prolongation.Conclusion: QTc prolongation was seen in approximately 10% of the adolescents presenting with alcohol intoxication, and although no ventricular arrhythmias were observed in this cohort, QTc prolongation increases the potential for malignant QT-related arrhythmias. Clinicians must be aware of the possibility of QTc prolongation during alcohol intoxication and make an effort to obtain an ECG at presentation, measure the QT interval, and give an adequate assessment of the findings. We advocate admitting adolescents with alcohol intoxication and QTc prolongation. During hospital admission, we recommend limiting exposure to QTc-prolonging medication, increasing potassium levels to a high-normal range (4.5-5.0 mmol/L) and obtaining a reference ECG at discharge.

Sudden Unexpected Death after a mild trauma: The complex forensic interpretation of cardiac and genetic findings

A 55-year-old man affected by a psychotic disorder suddenly died during a quarrel with his father. The autopsy excluded traumatic causes of death, and the cardiac examination identified a severe cardiomegaly with biventricular dilatation of very likely multifactorial origin. Toxicological and pharmacogenetic analyses excluded a fatal intoxication and identified the presence of the antipsychotic drug fluphenazine in the therapeutic range in a normal metabolizer. The screening for genetic variations highlighted a novel heterozygous single-nucleotide variant in the exon 36: c 0.4750C>A (p.Pro1584Thr) of the Ryanodine Receptor Type 2 (RYR2) gene. The mutation detected can be classified as Likely Pathogenic according to the American College of Medical Genetics and Genomics (ACMG) criteria. RYR2 variation has been associated to catecholaminergic polymorphic ventricular tachycardia (CPVT), a disease currently recognized as one of the most malignant cardiac channelopathies, expressed mostly in young patients, normally in the absence of structural heart disease. The victim late middle age, compared to juvenile onset of CPVT reported in literature, his clinical history, his structurally altered heart, circumstances at death and the absence of phenotype-related variations of dilated cardiomyopathy genes, suggested that the fatal arrhythmia could have been caused by an acquired form of dilated cardiopathy/cardiomyopathy. However, the contribution of the genetic variant to death cannot be completely ruled out, since the significance of a VUS or of a novel variant depends on the data available at the time of investigation, and should be periodically evaluated. We discuss the contribution of the structural alteration and of the variant detected, as well as the role of the molecular autopsy in forensic examination, which can make a significant contribution for inferring both cause and manner of death.

Characteristics of post-mortem beta-hydroxybutyrate-positivet cases - A retrospective study on age, sex and BMI in 1407 forensic autopsies

BACKGROUND

Post-mortem biochemistry, including the analysis of beta-hydroxybutyrate (BHB), is increasingly employed in forensic medicine, especially in conditions such as diabetes and chronic alcoholism. However, not much is known about the associations between age, body mass index (BMI), and sex and BHB concentrations in ketoacidotic conditions.

AIM

To retrospectively study the association between age, BMI and sex in several conditions, such as diabetic ketoacidosis (DKA), alcoholic ketoacidosis (AKA), and elevated post-mortem BHB concentrations.

METHODS

1407 forensic autopsy cases analysed for BHB were grouped by diagnosis: DKA, AKA, HHS [hyperosmolar hyperglycaemic state], acidosis NOS [not otherwise specified], or hypothermia. Age, sex, BMI and the concentrations of blood alcohol, vitreous glucose and blood BHB were recorded.

RESULTS

Cases of AKA and DKA were most numerous (184 and 156, respectively). In DKA and in its male subgroup, cases with severe ketosis (BHB>1000 µg/g) were younger and had a lower BMI than those with moderate ketosis (BHB 250-1000 µg/g) and controls (P<0.001). In DKA and in its female subgroup, cases with moderate ketosis cases were older (P = 0.0218 and P = 0.0083) than controls. In AKA and in its male subgroup, cases with severe ketosis had a lower BMI than those with moderate ketosis (P = 0.0391 and P = 0.0469) and controls (P<0.001). Cases with moderate ketosis had a lower BMI than controls (P<0.001).

CONCLUSIONS

BHB concentration is associated with BMI in DKA and AKA, and with both BMI and age in DKA. Constitutional factors should, therefore, be considered in potential AKA and DKA cases.

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.

Frequent Alcohol Intoxication and High Alcohol Tolerance During Adolescence as Predictors of Mortality: A Birth Cohort Study

PURPOSE

Long-term prospective studies evaluating the health burden that is consequent to adolescent drinking are needed. The aim of this study was to examine the predictive associations between self-reported alcohol tolerance and frequent intoxication at age 15-16 years and the risk of death by age 33 years.

METHODS

A sample (n = 6,615; 49.3% males) of the Northern Finland Birth Cohort Study 1986 was studied. Self-reported alcohol tolerance (drinks needed to feel intoxicated) and frequency of alcohol intoxication at age 15-16 years were analyzed along with background variables and data regarding subsequent psychiatric diagnoses. Categories were formed for both predictive variables from self-reported tolerance and frequency of intoxication in mid-adolescence. Cox regression was used to calculate hazard ratios (HRs) with 95% confidence interval (95% CI) for death by age 30 years.

RESULTS

By the age of 33 years, of all 6,615 participants, 53 (.8%) were deceased. The HR for death by age 33 years was 3.08 (95% CI 1.17-8.07) among adolescents with high alcohol tolerance compared with adolescents without alcohol use or intoxication. The frequency of alcohol intoxication was also associated with mortality; HR 2.05 (95% CI 1.01-4.16) for those who had been intoxicated one to two times and HR 3.02 (95% CI 1.21-7.54) for those who had been intoxicated three or more times in the past 30 days compared with adolescents without intoxication.

CONCLUSIONS

High self-reported alcohol tolerance and frequent alcohol intoxication during mid-adolescence significantly predicted death by age 33 years. These behaviors carry long-term repercussions with respect to premature loss of life. Substantial efforts should be made to diminish this mortality risk.

Acute heart failure after liver transplantation: A narrative review

Acute heart failure (AHF) is an under recognized yet potentially lethal complication after liver transplantation (LT) surgery. The increase in incidence of liver transplantation amongst high-risk patients and the leniency in the criteria for transplantation, predisposes these patients to postoperative AHF and the antecedent morbidity and mortality. The inability of conventional preoperative cardiovascular testing to accurately identify patients at risk for post-LT AHF poses a considerable challenge to clinicians caring for these patients. Even if high-risk patients are identified, there is considerable ambiguity in the candidacy for transplantation as well as optimization strategies that could potentially prevent the development of AHF in the postoperative period. The intraoperative and postoperative management of patients who develop AHF is also challenging and requires a well-coordinated multidisciplinary approach. The use of mechanical circulatory support in patients with refractory heart failure has the potential to improve outcomes but its use in this complex patient population can be associated with significant complications and requires a stringent risk-benefit analysis on a case-by-case basis.

Aldehyde Dehydrogenase 2 Ameliorates Chronic Alcohol Consumption-Induced Atrial Fibrillation through Detoxification of 4-HNE

Aldehyde dehydrogenase 2 (ALDH2) is an enzyme that detoxifies reactive oxygen species (ROS)-generated aldehyde adducts such as 4-hydroxy-trans-2-nonenal (4-HNE). Previous meta-analyses have shown an increase in the risk of atrial fibrillation (AF) in patients with chronic alcohol consumption. ALDH2*2, a common dysfunctional polymorphism in the ALDH2 gene, has been linked to an increased risk of cancer and heart disease. We tested the effect of ALDH2 deficiency on alcohol-induced AF in a murine model of chronic-binge ethanol feeding, with ALDH2*2 knock-in (KI) mice generated by a CRISPR/CAS9 system. In addition, right atrial appendages were obtained from eight patients with AF undergoing open heart surgery. The results showed that burst atrial pacing induced a greater susceptibility to AF in ALDH2*2 KI mice exposed to chronic ethanol intoxication than in wild-type mice, resulting from a higher degree of 4-HNE accumulation and collagen deposition in their atria. Alda-1 attenuated transforming growth factor beta 1 (TGF-β1) expression and collagen deposition in the atria and reduced AF inducibility. Patients with AF and the ALDH2*2 allele exhibited greater oxidative stress and substrate remodeling in their atria than non-carriers. In conclusion, ALDH2 deficiency may increase the risk of chronic alcohol and tachypacing-induced AF through the accumulation of 4-HNE and increased ROS production.

Heavy Drinking Habits Are Associated with Worse In-Hospital Outcomes in Patients with Acute Coronary Syndrome: An Insight from the AMIS Plus Registry

BACKGROUND

The association between alcohol consumption and the occurrence of coronary heart disease is well described in the literature, while data regarding the impact of regular alcohol consumption on in-hospital outcomes in the setting of acute coronary syndrome (ACS) are lacking. We aimed to evaluate the impact of self-reported alcohol consumption on in-hospital outcomes in patients with ACS.

METHODS

Data derived from patients enrolled between 2007 and 2019 in the Acute Myocardial Infarction in Switzerland (AMIS) Plus registry were retrospectively analyzed. Patients were stratified based on alcohol drinking pattern. Primary outcome was all-cause in-hospital mortality, while secondary outcomes were set as incidence of major adverse cardiac and cerebrovascular events (MACCEs). Outcome comparisons according to quantity of daily alcohol intake were also performed.

RESULTS

Records concerning alcohol consumption were available in 25,707 patients; 5,298 of them (21%) fulfilled the criteria of regular alcohol consumption. Regular drinkers were predominantly male, younger, smokers, more comorbid and with a worse clinical presentation as compared with abstainers/occasional drinkers. Daily alcohol intake was reported in 4,059 (77%) of these patients (regular drinkers). Among them, 2,640 were light drinkers (≤2 drinks/day) and 1,419 heavy drinkers (>2 drinks/day). In-hospital mortality and MACCEs of heavy drinkers were significantly higher compared with those of light drinkers (5.4 vs. 3.3% and 7.0 vs. 4.4%, both p = 0.001). When tested together with Global Registry of Acute Coronary Events risk score parameters, heavy alcohol consumption was independently associated with in-hospital mortality (p = 0.004).

CONCLUSIONS

Our results support that heavy alcohol consumption is an independent predictor of in-hospital mortality in patients presenting with ACS.

Impaired Glycolysis Promotes AlcoholExposure-Induced Apoptosis in HEI-OC1 Cells via Inhibition of EGFR Signaling

Glucose metabolism is an important metabolic pathway in the auditory system. Chronic alcohol exposure can cause metabolic dysfunction in auditory cells during hearing loss. While alcohol exposure has been linked to hearing loss, the mechanism by which impaired glycolysis promotes cytotoxicity and cell death in auditory cells remains unclear. Here, we show that the inhibition of epidermal growth factor receptor (EGFR)-induced glycolysis is a critical mechanism for alcohol exposure-induced apoptosis in HEI-OC1 cells. The cytotoxicity via apoptosis was significantly increased by alcohol exposure in HEI-OC1 cells. The glycolytic activity and the levels of hexokinase 1 (HK1) were significantly suppressed by alcohol exposure in HEI-OC1 cells. Mechanistic studies showed that the levels of EGFR and AKT phosphorylation were reduced by alcohol exposure in HEI-OC1 cells. Notably, HK1 expression and glycolytic activity was suppressed by EGFR inhibition in HEI-OC1 cells. These results suggest that impaired glycolysis promotes alcohol exposure-induced apoptosis in HEI-OC1 cells via the inhibition of EGFR signaling.

Alcohol use disorders and the heart

Alcohol use is an important preventable and modifiable cause of non-communicable disease, and has complex effects on the cardiovascular system that vary with dose. Observational and prospective studies have consistently shown a lower risk of cardiovascular and all-cause mortality in people with low levels of alcohol consumption when compared to abstainers (the 'J'-shaped curve). Maximum potential benefit occurs at 0.5 to one standard drinks (7-14 g pure ethanol) per day for women (18% lower all-cause mortality, 95% confidence interval (CI) = 13-22%) and one to two standard drinks (14-28 g ethanol) per day for men (17% lower all-cause mortality, 95% CI = 15-19%). However, this evidence is contested, and overall the detrimental effects of alcohol far outweigh the beneficial effects, with the risk of premature mortality increasing steadily after an average consumption of 10 g ethanol/day. Blood pressure (BP) is increased by regular alcohol consumption in a dose-dependent manner, with a relative risk for hypertension (systolic BP > 140 mm Hg or diastolic > 90 mm Hg) of 1.7 for 50 g ethanol/day and 2.5 at 100 g/day. Important reductions in BP readings can be expected after as little as 1 month of abstinence from alcohol. Heavy alcohol consumption in a binge pattern is associated with the development of acute cardiac arrhythmia, even in people with normal heart function. Atrial fibrillation is the most common arrhythmia associated with chronic high-volume alcohol intake, and above 14 g alcohol/day the relative risk increases 10% for every extra standard drink (14 g ethanol). Ethanol and its metabolites have toxic effects on cardiac myocytes, and alcoholic cardiomyopathy (ACM) accounts for a third of all cases of non-ischaemic dilated cardiomyopathy. Screening people drinking alcohol above low-volume levels and delivering a brief intervention may prevent the development of cardiovascular complications. Although people with established cardiovascular disease show improved outcomes with a reduction to low-volume alcohol consumption, there is no safe amount of alcohol to drink and patients with ACM should aim for abstinence in order to optimize medical treatment.

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.

Mechanisms of cardiac ethanol toxicity and novel treatment options

Ethanol can acutely and chronically alter cardiomyocyte and whole-organ function in the heart. Importantly, ethanol acutely and chronically predisposes to arrhythmias, while chronic abuse can induce heart failure. However, the molecular mechanisms of ethanol toxicity in the heart are incompletely understood. In this review, we summarize the current mechanistic knowledge on cardiac ethanol toxicity, with a focus on druggable pathways. Ethanol effects on excitation-contraction coupling, oxidative stress, apoptosis, and cardiac metabolism, as well as effects of ethanol metabolites will be discussed. Important recent findings have been gained by investigation of acute ethanol effects. These include a renewed focus on reactive oxygen species (ROS) and induction of SR Ca²⁺ leak by CaMKII-mediated pathways downstream of ROS. Furthermore, a clinical outlook into potential novel treatment options is provided.

Effect of heptanol and ethanol on excitation wave propagation in a neonatal rat ventricular myocyte monolayer

In this work, the action of heptanol and ethanol was investigated in a two-dimensional (2D) model of cardiac tissue: the neonatal rat ventricular myocyte monolayer. Heptanol is known in electrophysiology as a gap junction uncoupler but may also inhibit voltage-gated ionic channels. Ethanol is often associated with the occurrence of arrhythmias. These substances influence sodium, calcium, and potassium channels, but the complete mechanism of action of heptanol and ethanol remains unknown. The optical mapping method was used to measure conduction velocities (CVs) in concentrations of 0.05-1.8 mM heptanol and 17-1342 mM ethanol. Heptanol was shown to slow the excitation wave significantly, and a mechanism that involves a simultaneous action on cell coupling and activation threshold was suggested. Whole-cell patch-clamp experiments showed inhibition of sodium and calcium currents at a concentration of 0.5 mM heptanol. Computer modeling was used to estimate the relative contribution of the cell uncoupling and activation threshold increase caused by heptanol. Unlike heptanol, ethanol slightly influenced the CV at clinically relevant concentrations. Additionally, the critical concentrations for re-entry formation in ethanol were determined.

Extracorporeal membrane oxygenation for cardiogenic shock due to alcoholic cardiomyopathy: a long-term follow-up of 4 cases

Even though alcoholism is a major health concern, alcoholic cardiomyopathy is a little-known pathology. The exact prevalence remains elusive (20-40% of dilated cardiomyopathy). However, it can lead to dilated cardiomyopathy, heart failure and refractory cardiogenic shock. The literature on cardiogenic shock in alcoholic cardiomyopathy is limited. We report 4 cases of patients with refractory cardiogenic shock due to heavy alcohol consumption, who were treated with venoarterial extracorporeal membrane oxygenation. The evolution was favourable with recovery in 3 patients and the need for heart transplantation in 1 patient. After 3-5 years, all patients are alive, 2 of 4 are sober, all of them are on cardiac follow-up and none of them have presented with a cardiac relapse.

Electrocardiogram Changes with Acute Alcohol Intoxication: A Systematic Review

Background:

Acute alcohol intoxication has been associated with cardiac arrhythmias but the electrocardiogram (ECG) changes associated with acute alcohol intoxication are not well defined in the literature.

Objective:

Highlight the best evidence regarding the ECG changes associated with acute alcohol intoxication in otherwise healthy patients and the pathophysiology of the changes.

Methods:

A literature search was carried out; 4 studies relating to ECG changes with acute alcohol intoxication were included in this review.

Results:

Of the total 141 patients included in the review, 90 (63.8%) patients had P-wave prolongation, 80 (56%) patients had QTc prolongation, 19 (13.5%) patients developed T-wave abnormalities, 10 (7%) patients had QRS complex prolongation, 3 (2.12%) patients developed ST-segment depressions.

Conclusion:

The most common ECG changes associated with acute alcohol intoxication are (in decreasing order of frequency) P-wave and QTc prolongation, followed by T-wave abnormalities and QRS complex prolongation. Mostly, these changes are completely reversible.

Diagnostic and therapeutic challenge of heart failure after liver transplant: Case series

Heart failure (HF) following liver transplant (LT) surgery is a distinct clinical entity with high mortality. It is known to occur in absence of obvious risk factors. No preoperative workup including electrocardiogram, echocardiography at rest and on stress, reasonably prognosticates the risk. In patients of chronic liver disease, cirrhotic cardiomyopathy, alcoholic cardiomyopathy, and stress induced cardiomyopathy have each been implicated as a cause for HF after LT. However distinguishing one etiology from another not only is difficult, several etiologies may possibly coexist in a given patient. Diagnostic dilemma is further compounded by the fact that presentation and management of HF irrespective of the possible underlying cause, remains the same. In this case series, 6 cases are presented and in the light of existing literature modification in the preoperative workup are suggested.

Dose-related ethanol intake, Cx43 and Nav1.5 remodeling: Exploring insights of altered ventricular conduction and QRS fragmentation in excessive alcohol users

BACKGROUND

Chronic, excessive ethanol intake has been linked with various electrical instabilities, conduction disturbances, and even sudden cardiac death, but the underlying cause for the latter is insufficiently delineated.

METHODS

We studied surface electrocardiography (ECG) in a community-dwelling cohort with moderate-to-heavy daily alcohol intake (grouped as >90g/day, ≤90g/day, and nonintake).

RESULTS

Compared with nonintake, heavier alcohol users showed markedly widened QRS duration and higher prevalence of QRS fragmentation (64.3%, 50.9%, and 33.7%, respectively, χ² 12.0, both p<0.05) on surface ECG across the 3 groups. These findings were successfully recapitulated in 14-week-old C57BL/6 mice that were chronically given a 4% or 6% alcohol diet and showed dose-related slower action potential upstroke, reduced resting membrane potential, and disorganized or decreased intraventricular conduction (all p<0.05). Immunodetection further revealed increased ventricular collagen I depots with Cx43 downregulation and remodeling, together with clustered and diminished membrane Nav1.5 distribution. Administration of Cx43 blocker (heptanol) and Nav1.5 inhibitor (tetrodotoxin) in the mice each attenuated the suppression ventricular conduction compared with nonintake mice (p<0.05).

CONCLUSIONS

Chronic excessive alcohol ingestion is associated with dose-related phenotypic intraventricular conduction disturbances and QRS fragmentation that can be recapitulated in mice. The mechanisms may involve suppressed gap junction and sodium channel functions, together with enhanced cardiac fibrosis that may contribute to arrhythmogenesis.

Sudden cardiac death with stress and restraint: The association with sudden adult death syndrome, cardiomyopathy and coronary artery disease

OBJECTIVE

The aim of this study was to report on sudden cardiac death (SCD) during or immediately after a stressful event in a predominately young cohort.

METHODS

This study used retrospective non-case-controlled analysis. A total of 110 cases of SCD in relation to a stressful event such as altercation (45%), physical restraint (31%) in police custody (10%), exams/school/job stress (7.27%), receiving bad news (4%), or a car accident without injuries (2.73%) were retrospectively investigated. The majority of the subjects experiencing SCD were male (80.91%). The mean age was 36 ± 16 years (range 5-82 years). Twenty-three cases (20.91%) were psychiatric patients on antipsychotic medication.

RESULTS

Fifty-three per cent of cases died with a negative autopsy and a morphologically normal heart, indicating sudden adult death which is linked to cardiac channelopathies predisposing to stress-induced SCD. Cardiomyopathy was found in 16 (14.5%) patients and coronary artery pathology in 19 (17%) patients, with atherosclerosis predominating in older patients.

CONCLUSIONS

This study highlights SCD during psychological stress, mostly in young males where the sudden death occurred in the absence of structural heart disease. This may reflect the proarrhythmic potential of high catecholamines on the structurally normal heart in those genetically predisposed because of cardiac channelopathy. Structural cardiomyopathies and coronary artery disease also feature prominently. Cases of SCD associated with altercation and restraint receive mass media attention especially when police/other governmental bodies are involved. This study highlights the rare but important risk of SCD associated with psychological stress and restraint in morphologically normal hearts and the importance of an expert cardiac opinion where prolonged criminal investigations and medico-legal issues often ensue.

The Wearable Cardioverter Defibrillator in Nonischemic Cardiomyopathy: A US National Database Analysis

BACKGROUND

The wearable cardioverter defibrillator (WCD) is often used in patients at risk of sudden cardiac death (SCD) who are not yet candidates for an implantable cardioverter defibrillator (ICD). Newly diagnosed cardiomyopathy may be reversible, and a WCD may protect patients during the initial period of risk. We evaluate the benefit and compliance of the WCD in patients with nonischemic cardiomyopathy (NICM).

METHODS

We reviewed a national database of patients with NICM who used WCDs and who self-reported a history of excess alcohol use, although other causes of cardiomyopathy could not be excluded. The database contained demographic data, initial ejection fraction (EF), reason for WCD prescription, compliance and use data, any detected arrhythmias, therapies, and reason for discontinuing WCD. Statistical analyses were performed using SAS, version 9.3 (SAS Institute, Cary, NC).

RESULTS

Of the 127 patients, 88% were men with a mean age of 52.6 ± 11.0 years. The mean initial EF was 19.9% ± 7.4%. Patients wore the WCD for a median of 51 days and a median daily use of 18.0 hours per day. The most common reasons for discontinuing the WCD were improvement in EF (33%) or ICD implantation (23.6%). Seven patients (5.5%) had 9 sustained ventricular arrhythmia events, which were successfully treated with 100% conversion. There were 11 deaths (8.6%) during 100 days of follow-up. No deaths resulted from WCD shock failure or undersensing.

CONCLUSIONS

NICM may have a significant risk of ventricular arrhythmias and death in the first few months. The WCD delivered appropriate therapy in 5.5% of patients. This study suggests that a WCD may be effective temporary prophylaxis for prevention of SCD in patients with newly diagnosed NICM.

Cardiovascular risks and benefits of moderate and heavy alcohol consumption

The heart and vascular system are susceptible to the harmful effects of alcohol. Alcohol is an active toxin that undergoes widespread diffusion throughout the body, causing multiple synchronous and synergistic effects. Alcohol consumption decreases myocardial contractility and induces arrhythmias and dilated cardiomyopathy, resulting in progressive cardiovascular dysfunction and structural damage. Alcohol, whether at binge doses or a high cumulative lifetime consumption-both of which should be discouraged-is clearly deleterious for the cardiovascular system, increasing the incidence of total and cardiovascular mortality, coronary and peripheral artery disease, heart failure, stroke, hypertension, dyslipidaemia, and diabetes mellitus. However, epidemiological, case-control studies and meta-analyses have shown a U-type bimodal relationship so that low-to-moderate alcohol consumption (particularly of wine or beer) is associated with a decrease in cardiovascular events and mortality, compared with abstention. Potential confounding influences-alcohol-dose quantification, tobacco use, diet, exercise, lifestyle, cancer risk, accidents, and dependence-can affect the results of studies of both low-dose and high-dose alcohol consumption. Mendelian methodological approaches have led to doubts regarding the beneficial cardiovascular effects of alcohol, and the overall balance of beneficial and detrimental effects should be considered when making individual and population-wide recommendations, as reductions in alcohol consumption should provide overall health benefits.

Alcohol consumption and risk of atrial fibrillation: a prospective study and dose-response meta-analysis

BACKGROUND

Although high alcohol consumption has been associated with increased risk of atrial fibrillation (AF), the role of light to moderate drinking remains unclear.

OBJECTIVES

The study sought to investigate the association between alcohol consumption and AF risk in a prospective study of Swedish men and women and to conduct a meta-analysis of prospective studies to summarize available evidence.

METHODS

We followed 79,019 men and women who, at baseline, were free from AF and had completed a questionnaire about alcohol consumption and other risk factors for chronic diseases. Incident AF cases were ascertained by linkage to the Swedish Inpatient Register. For the meta-analysis, studies were identified by searching PubMed through January 10, 2014, and by reviewing references of pertinent publications. Study-specific relative risks (RRs) were combined using a random effects model.

RESULTS

Over 859,420 person-years of follow-up (1998 to 2009), 7,245 incident AF cases were identified in our own cohort study. The association between alcohol consumption and AF did not differ by sex (p for interaction = 0.74). Compared with current drinkers of <1 drink/week (12 g alcohol/drink), the multivariable RRs of AF were 1.01 (95% confidence interval [CI]: 0.94 to 1.09) for 1 to 6 drinks/week, 1.07 (95% CI: 0.98 to 1.17) for 7 to 14 drinks/week, 1.14 (95% CI: 1.01 to 1.28) for 15 to 21 drinks/week, and 1.39 (95% CI: 1.22 to 1.58) for >21 drinks/week. Results were similar after excluding binge drinkers. In a meta-analysis of 7 prospective studies, including 12,554 AF cases, the RRs were 1.08 (95% CI: 1.06 to 1.10) for 1 drink/day, 1.17 (95% CI: 1.13 to 1.21) for 2 drinks/day, 1.26 (95% CI: 1.19 to 1.33) for 3 drinks/day, 1.36 (95% CI: 1.27 to 1.46) for 4 drinks/day, and 1.47 (95% CI: 1.34 to 1.61) for 5 drinks/day, compared with nondrinkers.

CONCLUSIONS

These findings indicate that alcohol consumption, even at moderate intakes, is a risk factor for atrial fibrillation.

Alcoholic cardiomyopathy

Alcohol is the most frequently consumed toxic substance in the world. Low to moderate daily intake of alcohol has been shown to have beneficial effects on the cardiovascular system. In contrast, exposure to high levels of alcohol for a long period could lead to progressive cardiac dysfunction and heart failure. Cardiac dysfunction associated with chronic and excessive alcohol intake is a specific cardiac disease known as alcoholic cardiomyopathy (ACM). In spite of its clinical importance, data on ACM and how alcohol damages the heart are limited. In this review, we evaluate available evidence linking excessive alcohol consumption with heart failure and dilated cardiomyopathy. Additionally, we discuss the clinical presentation, prognosis and treatment of ACM.

Chronic heavy drinking and ischaemic heart disease: a systematic review and meta-analysis

Previous meta-analyses have reported either a protective, neutral or detrimental association from chronic heavy drinking in relation to ischaemic heart disease (IHD). We investigated the potential for systematic error because of study design. Using MOOSE guidelines, studies were identified through MEDLINE, EMBASE and Web of Science up to end of March, 2014. Epidemiological studies reporting on chronic heavy drinking and IHD risk in population studies and samples of people with alcohol use disorder (AUD) were included. Random-effects meta-analysis was used to pool eligible studies. The I² statistic was used to assess heterogeneity across studies. In total, 34 observational studies with 110 570 chronic heavy drinkers and 3086 IHD events were identified. In population studies among men, the pooled risk for IHD incidence (fatal+non-fatal events) among chronic heavy drinkers (on average ≥60 g pure alcohol/day) in comparison to lifetime abstainers (n=11 studies) was relative risk (RR)=1.04 (95% CI 0.83 to 1.31, I²=54%). Few studies were available for women. In patients with AUD, the risk of IHD mortality in comparison to the general population was elevated with a RR=1.62 (95% CI 1.34 to 1.95, I²=81%) in men and RR=2.09 (95% CI 1.28 to 3.41, I²=67%) in women. There was a general lack of adjustment other than sex and age in studies among patients with AUD. There is no systematic evidence for a protective association from any type of chronic heavy drinking on IHD risk. Patients with AUD were at higher risk for IHD mortality, but better quality evidence is needed with regard to potential confounding.

Ethanol, Trauma, and the Brain

Alcohol intoxication plays a significant and causal role in various fatal injuries. In comparison to sober individuals, intoxicated people have a greater generic risk for being involved in hazardous activities that may result in fatal injuries. However, it is not clear whether the biological effects of acute alcohol intoxication result in worse injuries than those sustained by sober individuals who are injured by identical mechanisms. Alcohol intoxication has a neuroprotective effect in experimental animal models of traumatic brain injury (TBI) but the evidence for a similar effect in humans is controversial. Earlier studies found such a protective effect, but more recent large epidemiological studies have not confirmed this finding; some studies also suggest a dose-related protective or exacerbating effect of alcohol intoxication on TBI. There are two apparent alcohol-associated syndromes in which an otherwise survivable blunt force impact to the head of an intoxicated individual is fatal at the scene. The first is a fatal cardiorespiratory arrest (the so-called alcohol concussion syndrome or “commotio medullaris”); the second is “traumatic basilar subarachnoid hemorrhage” (secondary to tears in the cerebral arteries, particularly the intracranial and extracranial vertebral arteries).

Alcohol and cardiovascular health: the dose makes the poison…or the remedy

Habitual light to moderate alcohol intake (up to 1 drink per day for women and 1 or 2 drinks per day for men) is associated with decreased risks for total mortality, coronary artery disease, diabetes mellitus, congestive heart failure, and stroke. However, higher levels of alcohol consumption are associated with increased cardiovascular risk. Indeed, behind only smoking and obesity, excessive alcohol consumption is the third leading cause of premature death in the United States. Heavy alcohol use (1) is one of the most common causes of reversible hypertension, (2) accounts for about one-third of all cases of nonischemic dilated cardiomyopathy, (3) is a frequent cause of atrial fibrillation, and (4) markedly increases risks of stroke-both ischemic and hemorrhagic. The risk-to-benefit ratio of drinking appears higher in younger individuals, who also have higher rates of excessive or binge drinking and more frequently have adverse consequences of acute intoxication (for example, accidents, violence, and social strife). In fact, among males aged 15 to 59 years, alcohol abuse is the leading risk factor for premature death. Of the various drinking patterns, daily low- to moderate-dose alcohol intake, ideally red wine before or during the evening meal, is associated with the strongest reduction in adverse cardiovascular outcomes. Health care professionals should not recommend alcohol to nondrinkers because of the paucity of randomized outcome data and the potential for problem drinking even among individuals at apparently low risk. The findings in this review were based on a literature search of PubMed for the 15-year period 1997 through 2012 using the search terms alcohol, ethanol, cardiovascular disease, coronary artery disease, heart failure, hypertension, stroke, and mortality. Studies were considered if they were deemed to be of high quality, objective, and methodologically sound.

Diosmin protects against ethanol-induced hepatic injury via alleviation of inflammation and regulation of TNF-α and NF-κB activation

The present investigation was designed to evaluate the efficacy of diosmin against ethanol-induced hepatotoxicity in rats by modulating various mechanisms including ethanol metabolizing enzymes, generation of free radicals, imbalance in oxidant-antioxidant status, oxidative damage to membrane lipids, activation of transcription factors and elevation in inflammatory markers involved in ethanol-induced hepatic damage. Diosmin is a flavone glycoside, having anti-inflammatory and anti-cancer properties. Thirty female Wistar rats segregated in five groups, each with six animals. Group I as control followed by Group II, III and IV were treated with ethanol for 28 days. While groups III and IV were administered with diosmin at 10 mg/kg b wt (D1) and 20 mg/kg b wt (D2) respectively prior to ethanol administration. Group V was given only higher dose of diosmin. In ethanol-treated group, ethanol metabolizing enzymes viz., CYP 450 2E1 and alcohol dehydrogenase (ADH) significantly increased by 77.82% and 32.32% in liver tissues respectively as compared with control group and this enhancement is significantly normalized with diosmin administration. Diosmin administration (D1 & D2) significantly (p < 0.001) attenuates oxidative stress markers i.e., LPO, GSH, GPx, GR and XO by 90.77 & 137.55%, 17.18 & 25%, 37.3 & 49.86%, 21.63 & 44.9% and 56.14 &77.19% respectively. Serum ALT, AST and LDH significantly increased by 102.03, 116.91 and 45.20% in ethanol-treated group as compared with control group. Group III and IV animals showed significant reduction in the serum toxicity markers. Diosmin further alleviated ethanol-induced NF-κB activation, enhanced expression of TNF-α, COX-2 and iNOS. Findings from the present study permit us to conclude that diosmin alleviates alcoholic liver injury via modulating ethanol metabolizing pathway, inhibition of oxidative stress markers and suppression of inflammatory markers. This may represent a novel protective strategy against ethanol-induced liver diseases.

DNA damage and neurotoxicity of chronic alcohol abuse

Chronic alcohol abuse results in a variety of pathological effects including damage to the brain. The causes of alcohol-induced brain pathology are presently unclear. Several mechanisms of pathogenicity of chronic alcoholism have been proposed, including accumulation of DNA damage in the absence of repair, resulting in genomic instability and death of neurons. Genomic instability is a unified genetic mechanism leading to a variety of neurodegenerative disorders. Ethanol also likely interacts with various metabolic pathways, including one-carbon metabolism (OCM). OCM is critical for the synthesis of DNA precursors, essential for DNA repair, and as a methyl donor for various methylation events, including DNA methylation. Both DNA repair and DNA methylation are critical for maintaining genomic stability. In this review, we outline the role of DNA damage and DNA repair dysfunction in chronic alcohol-induced neurodegeneration.

Mechanisms of alcohol-induced endoplasmic reticulum stress and organ injuries

Alcohol is readily distributed throughout the body in the blood stream and crosses biological membranes, which affect virtually all biological processes inside the cell. Excessive alcohol consumption induces numerous pathological stress responses, part of which is endoplasmic reticulum (ER) stress response. ER stress, a condition under which unfolded/misfolded protein accumulates in the ER, contributes to alcoholic disorders of major organs such as liver, pancreas, heart, and brain. Potential mechanisms that trigger the alcoholic ER stress response are directly or indirectly related to alcohol metabolism, which includes toxic acetaldehyde and homocysteine, oxidative stress, perturbations of calcium or iron homeostasis, alterations of S-adenosylmethionine to S-adenosylhomocysteine ratio, and abnormal epigenetic modifications. Interruption of the ER stress triggers is anticipated to have therapeutic benefits for alcoholic disorders.

Alcoholic cardiomyopathy: a review

Alcohol abuse can cause cardiomyopathy indistinguishable from other types of dilated nonischemic cardiomyopathy. Most heavy drinkers remain asymptomatic in the earlier stages of disease progression, and many never develop the familiar clinical manifestations that typify heart failure. We review the current thinking on the pathophysiology, clinical characteristics, and treatments available for alcoholic cardiomyopathy. The relationship of alcohol to heart disease is complicated by the fact that in moderation, alcohol has been shown to afford a certain degree of protection against cardiovascular disease.

ALDH2 in alcoholic heart diseases: molecular mechanism and clinical implications

Alcoholic cardiomyopathy is manifested as cardiac hypertrophy, disrupted contractile function and myofibrillary architecture. An ample amount of clinical and experimental evidence has depicted a pivotal role for alcohol metabolism especially the main alcohol metabolic product acetaldehyde, in the pathogenesis of this myopathic state. Findings from our group and others have revealed that the mitochondrial isoform of aldehyde dehydrogenase (ALDH2), which metabolizes acetaldehyde, governs the detoxification of acetaldehyde formed following alcohol consumption and the ultimate elimination of alcohol from the body. The ALDH2 enzymatic cascade may evolve as a unique detoxification mechanism for environmental alcohols and aldehydes to alleviate the undesired cardiac anomalies in ischemia-reperfusion and alcoholism. Polymorphic variants of the ALDH2 gene encode enzymes with altered pharmacokinetic properties and a significantly higher prevalence of cardiovascular diseases associated with alcoholism. The pathophysiological effects of ALDH2 polymorphism may be mediated by accumulation of acetaldehyde and other reactive aldehydes. Inheritance of the inactive ALDH2*2 gene product is associated with a decreased risk of alcoholism but an increased risk of alcoholic complications. This association is influenced by gene-environment interactions such as those associated with religion and national origin. The purpose of this review is to recapitulate the pathogenesis of alcoholic cardiomyopathy with a special focus on ALDH2 enzymatic metabolism. It will be important to dissect the links between ALDH2 polymorphism and prevalence of alcoholic cardiomyopathy, in order to determine the mechanisms underlying such associations. The therapeutic value of ALDH2 as both target and tool in the management of alcoholic tissue damage will be discussed.

Chemical cardiomyopathies: the negative effects of medications and nonprescribed drugs on the heart

The heart is a target of injury for many chemical compounds, both medically prescribed and not medically prescribed. Pathophysiologic mechanisms underlying the development of chemical-induced cardiomyopathies vary depending on the inciting agent, including direct toxic effects, neurohormonal activation, altered calcium homeostasis, and oxidative stress. Numerous chemicals and drugs are implicated in cardiomyopathy. This article discusses examples of medication and nonprescribed drug-induced cardiomyopathies and reviews their pathophysiologic mechanisms.

Cellular and mitochondrial effects of alcohol consumption

Alcohol dependence is correlated with a wide spectrum of medical, psychological, behavioral, and social problems. Acute alcohol abuse causes damage to and functional impairment of several organs affecting protein, carbohydrate, and fat metabolism. Mitochondria participate with the conversion of acetaldehyde into acetate and the generation of increased amounts of NADH. Prenatal exposure to ethanol during fetal development induces a wide spectrum of adverse effects in offspring, such as neurologic abnormalities and pre- and post-natal growth retardation. Antioxidant effects have been described due to that alcoholic beverages contain different compounds, such as polyphenols as well as resveratrol. This review analyzes diverse topics on the alcohol consumption effects in several human organs and demonstrates the direct participation of mitochondria as potential target of compounds that can be used to prevent therapies for alcohol abusers.

Alcohol and acetaldehyde in public health: from marvel to menace

Alcohol abuse is a serious medical and social problem. Although light to moderate alcohol consumption is beneficial to cardiovascular health, heavy drinking often results in organ damage and social problems. In addition, genetic susceptibility to the effect of alcohol on cancer and coronary heart disease differs across the population. A number of mechanisms including direct the toxicity of ethanol, its metabolites [e.g., acetaldehyde and fatty acid ethyl esters (FAEEs)] and oxidative stress may mediate alcoholic complications. Acetaldehyde, the primary metabolic product of ethanol, is an important candidate toxin in developing alcoholic diseases. Meanwhile, free radicals produced during ethanol metabolism and FAEEs are also important triggers for alcoholic damages.