Alcohol and new onset atrial fibrillation: a case-control study of a current series

Alcohol and Atrial Fibrillation: An Update and New Perspectives

In the Western world, sales of alcoholic beverages are skyrocketing1,2. While consumed for its transient euphoric effects, the consumption of alcohol (ethanol) is also a risk factor for the development of heart disease. Here, we review the possible association between alcohol consumption and atrial fibrillation. Using a familiar analogy, we propose that atrial fibrillation is the mere tip of an iceberg (alcohol associated heart disease). Our concern is that the many research studies on the effects of ethanol on the heart have produced inconsistent results. These include studies of individuals drinking only moderate amounts of alcoholic beverages (aka The French Paradox) on the one hand, and paroxysmal atrial fibrillation after binge drinking (the Holiday Heart Syndrome) on the other hand. The evidence available in the literature suggests that hypertension, structured heart disease of any form, neurohumoral stress, and cardiometabolic disorders all favor the development of atrial fibrillation triggered by alcohol. We also suggest that alcohol should be classified as a modifiable risk factor for atrial fibrillation, and also for heart disease in general.

The Impact of Alcohol Intake on Atrial Fibrillation

PURPOSE OF REVIEW

To evaluate (1) the impact of acute and habitual alcohol consumption on atrial fibrillation (AF) and atrial remodeling and (2) the role of alcohol reduction and/or abstinence in the primary and secondary prevention of AF.

RECENT FINDINGS

Acute alcohol consumption appears to be a common AF trigger, with animal and human studies demonstrating changes in electrophysiological parameters, autonomic tone, and cellular properties expected to promote AF. Habitual consumption is associated with adverse atrial remodeling, higher risk of incident AF, and AF recurrence. Randomized data suggest that reduction in excessive alcohol consumption may reduce the risk of recurrent AF episodes and AF burden. Alcohol is an increasingly recognized risk factor for both new onset AF and discrete AF episodes. Excessive consumption should be avoided for primary and secondary prevention of AF.

High Impedance Electrical Accidents: Importance of Source and Subject Impedance

In most cases, the diagnosis of an electrical injury or electrocution is straightforward. However, there is a necessity for much closer analysis in many cases. There exist sophisticated electrical safety standards that predict outcomes for shocks of various currents applied to different parts of the body. Unfortunately, the actual current is almost never known in an accident investigation. A common source of errors is the assumption that the source (including the return) has zero impedance. Another surprisingly common problem is the erroneous assumption that the body current is equal to the source current capability.

METHODS

We used the following methodology for analyzing such cases: (1) Determine body pathway, (2) Estimate body pathway impedance, (3) Determine source voltage, (4) Determine source impedance, (5) Calculate delivered current using total pathway impedance, and (6) Ignore available current as it is largely confounding in most cases.

RESULTS

We analyzed 6 difficult cases using the above methodology. This includes 2 subtle situations involving pairs of matched case-control subjects where a subject was electrocuted while his work partner was not.

CONCLUSIONS

Careful calculations of the amplitude and duration of the shock is required for understanding the limits and potential causation of such electrical injury. This requires the determination of both the source and body pathway impedance. Available current is usually irrelevant and overemphasized.

Alcohol consumption, sinus tachycardia, and cardiac arrhythmias at the Munich Octoberfest: results from the Munich Beer Related Electrocardiogram Workup Study (MunichBREW)

Aims

Alcohol is a risk factor for cardiac arrhythmias. Retrospective analyses suggest supraventricular arrhythmias consecutive to acute alcohol consumption, but prospective data are limited. We intended to prospectively associate acute alcohol consumption with cardiac arrhythmias.

Methods and results

At the 2015 Munich Octoberfest, we enrolled 3028 voluntary participants who received a smartphone-based ECG and breath alcohol concentration (BAC) measurements. ECGs were analysed for cardiac arrhythmias (sinus tachycardia, sinus arrhythmia, premature atrial/ventricular complexes, atrial fibrillation/flutter) and respiratory sinus arrhythmia. By multivariable adjusted logistic regression we associated BACs with cardiac arrhythmias. Similarly, we analysed 4131 participants of the community-based KORA S4 Study (Co-operative Health Research in the Region of Augsburg) and associated cardiac arrhythmias with chronic alcohol consumption. In our acute alcohol cohort (mean age 34.4 ± 13.3 years, 29% women), mean BAC was 0.85 ± 0.54 g/kg. Cardiac arrhythmias occurred in 30.5% (sinus tachycardia 25.9%; other arrhythmia subtypes 5.4%). Breath alcohol concentration was significantly associated with cardiac arrhythmias overall (odds ratio (OR) per 1-unit change 1.75, 95% confidence interval (CI) 1.50-2.05; P < 0.001) and sinus tachycardia in particular (OR 1.96, 95%CI 1.66-2.31; P < 0.001). Respiratory sinus arrhythmia measuring autonomic tone was significantly reduced under the influence of alcohol. In KORA S4, chronic alcohol consumption was associated with sinus tachycardia (OR 1.03, 95%CI 1.01-1.06; P = 0.006).

Conclusions

Acute alcohol consumption is associated with cardiac arrhythmias and sinus tachycardia in particular. This partly reflects autonomic imbalance as assessed by significantly reduced respiratory sinus arrhythmia. Such imbalance might lead to sympathetically triggered atrial fibrillation resembling the holiday heart syndrome.

ClinicalTrials.org accession number

NCT02550340.

Role of Stress Kinase JNK in Binge Alcohol-Evoked Atrial Arrhythmia

BACKGROUND

Excessive binge alcohol drinking has acute cardiac arrhythmogenic effects, including promotion of atrial fibrillation (AF), which underlies "Holiday Heart Syndrome." The mechanism that couples binge alcohol abuse with AF susceptibility remains unclear. We previously reported stress-activated c-Jun N-terminal kinase (JNK) signaling contributes to AF development. This is interesting because JNK is implicated in alcohol-caused organ malfunction beyond the heart.

OBJECTIVES

The purpose of this study was to detail how JNK promotes binge alcohol-evoked susceptibility to AF.

METHODS

The authors found binge alcohol-exposure leads to activated JNK, specifically JNK2. Furthermore, binge alcohol induces AF (24- vs. 1.8-Hz burst pacing-induced episodes per attempt per animal), higher incidence of diastolic intracellular Ca2+ activity (Ca2+ waves, sarcoplasmic reticulum [SR] Ca2+ leakage), and membrane voltage (Vm) and systolic Ca2+ release spatiotemporal heterogeneity (ΔtVm-Ca). These changes were completely eliminated by JNK inhibition both in vivo and in vitro. calmodulin kinase II (CaMKII) is a proarrhythmic molecule known to drive SR Ca2+ mishandling.

RESULTS

The authors report for the first time that binge alcohol activates JNK2, which subsequently phosphorylates the CaMKII protein, enhancing CaMKII-driven SR Ca2+ mishandling. CaMKII inhibition eliminates binge alcohol-evoked arrhythmic activities.

CONCLUSIONS

Our studies demonstrate that binge alcohol exposure activates JNK2 in atria, which then drives CaMKII activation, prompting aberrant Ca2+ waves and, thus, enhanced susceptibility to atrial arrhythmia. Our results reveal a previously unrecognized form of alcohol-driven kinase-on-kinase proarrhythmic crosstalk. Atrial JNK2 function represents a potential novel therapeutic target to treat and/or prevent AF.

Alcohol and Atrial Fibrillation: A Sobering Review

Alcohol is popular in Western culture, supported by a perception that modest intake is cardioprotective. However, excessive drinking has detrimental implications for cardiovascular disease. Atrial fibrillation (AF) following an alcohol binge or the "holiday heart syndrome" is well characterized. However, more modest levels of alcohol intake on a regular basis may also increase the risk of AF. The pathophysiological mechanisms responsible for the relationship between alcohol and AF may include direct toxicity and alcohol's contribution to obesity, sleep-disordered breathing, and hypertension. We aim to provide a comprehensive review of the epidemiology and pathophysiology by which alcohol may be responsible for AF and determine whether alcohol abstinence is required for patients with AF.

Modifying effects of resting heart rate on the association of binge drinking with all-cause and cardiovascular mortality in older Korean men: the Kangwha Cohort Study

BACKGROUND

Although binge drinking and high resting heart rate independently affect cardiovascular and all-cause mortality risk, the combined effect of these two risk factors and their interaction has rarely been studied. This study examined the association between binge drinking and cardiovascular and all-cause mortality and evaluated the potential modifying effect on this association of resting heart rate in Korean men.

METHODS

Men aged 55 years or older in 1985 (n = 2600) were followed for cardiovascular and all-cause mortality for 20.8 years, until 2005. We estimated hazard ratios (HRs) for cardiovascular and all-cause mortality by binge drinking and resting heart rate using the Cox proportional hazard model.

RESULTS

Heavy binge drinkers (≥12 drinks on one occasion) with elevated resting heart rate (≥80 bpm) had a HR of 2.25 (95% confidence interval [CI], 1.47-3.45) for death from cardiovascular disease and 1.37 (95% CI, 0.87-2.14) for all-cause mortality compared to the reference group (non-drinking and resting heart rate 61-79 bpm). The HRs of dying from cardiovascular disease increased linearly from 1.36 to 1.52, 1.71, and 2.25 among individuals with resting heart rate greater than or equal to 80 bpm within the four alcohol consumption categories (non-drinking, non-binge, moderate binge, and heavy binge), respectively.

CONCLUSIONS

Our findings suggest that, among older Korean men, heavy binge drinkers with an elevated resting heart rate are at high risk for cardiovascular and all-cause mortality.

Holiday heart syndrome revisited after 34 years

The cardiovascular effects of alcohol are well known. However, most research has focused on the beneficial effects (the "French paradox") of moderate consumption or the harmful consequences, such as dilated cardiomyopathy, associated with heavy consumption over an extended period. An association between the ingestion of acute alcohol and onset of cardiac arrhythmias was first reported in the early 70's. In 1978, Philip Ettinger described "Holiday heart syndrome" (HHS) for the first time, as the occurrence, in healthy people without heart disease known to cause arrhythmia, of an acute cardiac rhythm disturbance, most frequently atrial fibrillation, after binge drinking. The name is derived from the fact that episodes were initially observed more frequently after weekends or public holidays. Since the original description of HHS, 34 years have passed and new research in this field has increased the volume of knowledge related to this syndrome. Throughout this paper the authors will comprehensively review most of the available data concerning HHS and highlight the questions that remain unresolved.

Risk factors between patients with lone and non-lone atrial fibrillation

Clinical factors such as tall stature, lean body mass, obstructive sleep apnea, alcohol or caffeine, smoking, endurance sports, and genetic factors are proposed as risk factors for lone atrial fibrillation (LAF). The KORAF (KORean Atrial Fibrillation) study is a retrospective multicenter registry that enrolled 3,570 consecutive atrial fibrillation (AF) patients. Data on risk factors were available for 2,133 patients, of whom 398 (18.7%) were identified as having LAF. In univariate analysis, patients with LAF were more likely to be men (82.4% vs 59.8%, P < 0.001) and current smokers (25.9% vs 15.6%, P < 0.01), alcohol drinkers (55.3% vs 31.2%, P < 0.01) and frequent consumers of caffeinated beverages (> 2 cups/day) (31.7% vs 19.3%, P < 0.01), and have a family history of AF (9.0% vs 2.6%, P < 0.001) than the non-LAF patients. Multivariate analysis showed that male gender (OR, 2.30; 95% CI, 1.61-3.27, P < 0.01), family history of AF (OR, 3.12; 95% CI, 1.91-5.12, P < 0.01), current alcohol use (OR, 2.01; 95% CI, 1.46-2.76, P < 0.01), and frequent caffeinated beverage consumption (OR, 1.66; 95% CI, 1.20-2.29, P < 0.01) were independently associated with LAF. In Korean patients, LAF is more closely associated with male gender, family history of AF, current alcohol and frequent caffeinated beverage consumption than non-LAF.

The Estimated Risk of Atrial Fibrillation Related to Alcohol Consumption

The risk of acute heavy alcohol intake on the development of atrial fibrillation (AF), aka ?holiday heart syndrome?, has been well-described. However, whether chronic alcohol intake is also associated with increased risk of AF, or might even be protective as has been observed with other cardiac conditions, is more uncertain. A number of studies, from basic science to large cohort studies have been performed to analyze the association between alcohol and AF. Basic-level studies have found that alcohol causes changes in tissue electrophysiology, ion channels, and circulating hormones, which might promote development and maintenance of AF. Clinical studies have generally shown groups with the highest regular intake of alcohol to be at increased risk, with no association with more moderate use. However, these studies have not always accounted for other AF risk factors, been inconsistent in the assessment and validation of the quantity of alcohol consumed across populations, and been unable to completely separate drinking patterns from overall health of participants. As a result, solid conclusions about a threshold level for ?safe? chronic alcohol intake cannot be made with regard to AF risk, but it appears to be safe within currently recommended limits of 1 drink daily for women and 2 for men. In this review, we discuss these findings, limitations, and conclusions.

Meta-analysis of cohort and case-control studies of type 2 diabetes mellitus and risk of atrial fibrillation

Atrial fibrillation (AF) is 1 of the most clinically diagnosed cardiac disturbances but little is known about its risk factors. Previous epidemiologic studies have reported on the association between diabetes mellitus (DM) and subsequent risk of AF, with inconsistent results. The aim of this study was to conduct a meta-analysis of published studies to reliably determine the direction and magnitude of any association between DM and AF. A systematic review and meta-analysis was conducted. PubMed and EMBASE were searched to identify prospective cohort and case-control studies that had reported on the association between DM and other measurements of glucose homeostasis with incident AF by April 2010. Studies conducted in primarily high-risk populations and participants in randomized controlled trials were excluded. Seven prospective cohort studies and 4 case-control studies with information on 108,703 cases of AF in 1,686,097 subjects contributed to this analysis. The summary estimate indicated that patients with DM had an approximate 40% greater risk of AF compared to unaffected patients (relative risk [RR] 1.39, 95% confidence interval [CI] 1.10 to 1.75, p for heterogeneity <0.001). After correcting for publication bias, the RR was 1.34 (1.07 to 1.68). Studies that had adjusted for multiple risk factors reported a smaller effect estimate compared to age-adjusted studies (RR 1.24, 95% CI 1.06 to 1.44, vs 1.70, 1.29 to 2.22, p for heterogeneity = 0.053). The population-attributable fraction of AF owing to DM was 2.5% (95% CI 0.1 to 3.9). In conclusion, DM is associated with an increased risk of subsequent AF but the mechanisms that may underpin the relation between DM and AF remain speculative.

Lone atrial fibrillation: what is known and what is to come

Atrial fibrillation (AF) is the most prevalent sustained cardiac arrhythmia in adults, affecting >1% of general population. Atrial fibrillation is commonly associated with structural heart disease and is a major cause of significant cardiovascular morbidity and mortality. AF sometimes develops in a subset of young patients (e.g. aged ≤60 years), with no evidence of associated cardiopulmonary or other comorbid disease (including hypertension), and has been referred to as 'lone AF'. The latter generally has a favourable prognosis; the prognostic and therapeutic implications of an accurate identification of patients with truly lone AF (that is, truly at low risk of complications), if any, would be of the utmost importance. The true prevalence of lone AF is unknown, varying between 1.6% and 30%, depending on the particular study population. Nonetheless, novel risk factors for AF, including obesity, metabolic syndrome, sleep apnea, alcohol consumption, endurance sports, anger, hostility, subclinical atherosclerosis and others, have been increasingly recognised. Also, various underlying pathophysiological mechanisms predisposing to AF, including increased atrial stretch, structural and electrophysiological alterations, autonomic imbalance, systemic inflammation, oxidative stress and genetic predisposition, have been proposed. The growing evidence of these diverse (and numerous) pathogenic mechanisms and factors related to AF inevitably raises the question of whether 'lone AF' does exist at all. In this review article, we summarise the current knowledge of the epidemiology, pathophysiology, clinical course and treatment of patients with so-called 'lone AF' and outline emerging insights into its pathogenesis and the potential therapeutic implications of a diagnosis of lone AF.

Alcohol consumption as a risk factor for atrial fibrillation: a systematic review and meta-analysis

BACKGROUND

Alcohol exposure is one of the major risk factors for global burden of disease, but atrial fibrillation (AF) had not yet been included in these estimates. The purpose of this contribution was to examine the dose–response relationship between alcohol consumption and AF and to explore potential causal pathways.

DESIGN AND METHODS

Systematic literature review and meta-analyses.

RESULTS

Overall, a consistent dose–response relationship between the amount of alcohol consumed daily and the probability of the onset of AF was found. Women consuming 24, 60 and 120 g of alcohol daily had relative risks of 1.07 [95%confidence interval (CI): 1.04–1.10], 1.42 (95% CI: 1.23–1.64) and 2.02 (95% CI: 1.60–2.97), respectively, relative to nondrinkers. Among men, the corresponding relative risks were 1.08 (95% CI: 1.04–1.11), 1.44 (95% CI: 1.23–1.69) and 2.09(95% CI: 1.52–2.86). Based on the categorical analyses, we could not exclude the existence of a threshold (three drinks a day for men and two drinks a day for women). Several pathogenic mechanisms for the development of AF in alcohol users were identified.

CONCLUSION

Epidemiological criteria for causality were met to conclude a causal impact of alcohol consumption on the onset of AF with a monotonic dose–response relationship. However, the impact of light drinking is not clear.

Patients presenting with acute toxin ingestion

Organ toxicity caused by poisons or drug therapy is diverse and may not be commonly encountered clinically. In general, commonly encountered conditions caused by drug/toxin pharmacology can be classified into 7 categories by shared mechanisms of organ injury. This review of drug/toxin-induced injury discusses drug or toxin-induced pathology that the clinician may encounter and therapeutic approaches to these syndromes.

Alcohol and arrhythmias: a comprehensive review

The use of alcohol as a social lubricant has been ubiquitous in human societies since ancient times. It has also long been recognized that alcohol produces undesirable cardiovascular effects, especially when imbibed in excess. Numerous investigators have noted a causal relationship between alcohol and arrhythmias, as well as sudden cardiac death. We have undertaken a comprehensive review of the literature on alcohol as a potential trigger for arrhythmias. We have reviewed the major epidemiological studies undertaken on this subject. We have also explored pathophysiological mechanisms that drive the arrythmogenic effects of alcohol. In conclusion, although there is definite proof in the literature to implicate alcohol as a culprit in arrhythmias, the relationship is complex.

Alcohol and illicit drug use as precipitants of atrial fibrillation in young adults: a case series and literature review

BACKGROUND

Atrial fibrillation in young patients (<or=45 years) is uncommon. There is the perception that the precipitant in such cases is alcohol, but we also have noted cases related to illicit drug abuse. There are no clear guidelines on the treatment of atrial fibrillation in patients presenting with "lone atrial fibrillation" precipitated by alcohol or illicit drugs.

METHODS

We retrospectively analyzed young (defined as <or=45 years) patients with "lone" atrial fibrillation who were admitted to the hospital with electrocardiographically confirmed diagnosis of atrial fibrillation or atrial flutter, precipitated by either alcohol or illicit drugs, over a 6-year period.

RESULTS

Eighty-eight patients aged <or=45 years were admitted with atrial fibrillation or atrial flutter. In 22 patients, (mean [SD] age 33.6 [8.4] years; 20 male), alcohol (n = 19) and/or illicit drugs (n = 3) were found to be the precipitant. One patient required electrical cardioversion, with the remaining patients cardioverting back to sinus rhythm either pharmacologically or spontaneously. Twelve (54.5%) were investigated for atrial fibrillation burden by 24-hour Holter monitoring and the majority also underwent a transthoracic echocardiogram (81.8%). At discharge, 14 (63.6%) patients were treated with anti-arrhythmic drugs and 10 received either antiplatelets or anticoagulants. Most (85%) patients were followed-up for at least 12 months, during which time 6 had further paroxysms; all of whom continued to abuse either alcohol or illicit drugs.

CONCLUSIONS

Alcohol and illicit drugs are arrhythmogenic and are associated with atrial fibrillation. Apart from abstinence, the optimal management of such patients and the long-term effects of these substances on the heart and atrial fibrillation recurrences are still unclear.

Alcohol consumption and risk of incident atrial fibrillation in women

CONTEXT

Previous studies suggest that consuming moderate to high amounts of alcohol on a regular basis might increase the risk of developing atrial fibrillation in men but not in women. However, these studies were not powered to investigate the association of alcohol consumption and atrial fibrillation among women.

OBJECTIVE

To prospectively assess the association between regular alcohol consumption and incident atrial fibrillation among women.

DESIGN, SETTING, AND PARTICIPANTS

Participants were 34 715 initially healthy women participating in the Women's Health Study, a completed randomized controlled trial conducted in the United States. Participants were older than 45 years and free of atrial fibrillation at baseline and underwent prospective follow-up from 1993 to October 31, 2006. Alcohol consumption was assessed via questionnaires at baseline and at 48 months of follow-up and was grouped into 4 categories (0, > 0 and < 1, > or = 1 and < 2, and > or = 2 drinks per day). Atrial fibrillation was self-reported on the yearly questionnaires and subsequently confirmed by electrocardiogram and medical record review.

MAIN OUTCOME MEASURE

Time to first episode of atrial fibrillation.

RESULTS

Over a median follow-up of 12.4 years, 653 cases of incident atrial fibrillation were confirmed. Age-adjusted incidences among women consuming 0 (n = 15,370), more than 0 and less than 1 (n = 15,758), 1 or more and less than 2 (n = 2228), and 2 or more (n = 1359) drinks per day were 1.59, 1.55, 1.27, and 2.25 events/1000 person-years of follow-up. Thus, compared with nondrinking women, women consuming 2 or more drinks per day had an absolute risk increase of 0.66 events/1000 person-years. The corresponding multivariate-adjusted hazard ratios (HRs) for incident atrial fibrillation were 1, 1.05 (95% CI, 0.88-1.25), 0.84 (95% CI, 0.58-1.22), and 1.60 (95% CI, 1.13-2.25), respectively. The increased hazard in the small group of women consuming 2 or more drinks per day persisted when alcohol intake was updated at 48 months (HR, 1.49; 95% CI, 1.05-2.11) or when women were censored at their first cardiovascular event (HR, 1.68; 95% CI, 1.18-2.39).

CONCLUSIONS

Among healthy middle-aged women, consumption of up to 2 alcoholic beverages per day was not associated with an increased risk of incident atrial fibrillation. Heavier consumption of 2 or more drinks per day, however, was associated with a small but statistically significant increased risk of atrial fibrillation.

Effects of alcohol on atrial fibrillation: myths and truths

Alcohol is the most consumed drug worldwide. Both acute and chronic alcohol use have been associated with cardiac arrhythmias, in particular atrial fibrillation, or so-called 'holiday heart syndrome'. Epidemiological, clinical and experimental studies have attempted to elucidate the mechanisms involved in this association. However, because most of these studies have shown conflicting results, the connection between ethanol and atrial arrhythmias remains controversial. Historical, epidemiological and pharmacological aspects of alcohol, as well as recent concepts on atrial fibrillation are reviewed. We then examine the literature and provide a critical point of view on the still elusive association between alcohol and atrial fibrillation.

To drink or not to drink? That is the question

Numerous studies have used a J-shaped or U-shaped curve to describe the relationship between alcohol use and total mortality. The nadir of the curves based on recent meta-analysis suggested optimal benefit at approximately half a drink per day. Fewer than 4 drinks per day in men and fewer than 2 per day in women appeared to confer benefit. Reductions in cardiovascular death and nonfatal myocardial infarction were also associated with light to moderate alcohol intake. Although some studies suggested that wine had an advantage over other types of alcoholic beverages, other studies suggested that the type of drink was not important. Heavy drinking was associated with an increase in mortality, hypertension, alcoholic cardiomyopathy, cancer, and cerebrovascular events, including cerebrovascular hemorrhage. Paradoxically, light-to-moderate alcohol use actually reduced the development of heart failure and did not appear to exacerbate it in most patients who had underlying heart failure. Numerous mechanisms have been proposed to explain the benefit that light-to-moderate alcohol intake has on the heart, including an increase of high-density lipoprotein cholesterol, reduction in plasma viscosity and fibrinogen concentration, increase in fibrinolysis, decrease in platelet aggregation, improvement in endothelial function, reduction of inflammation, and promotion of antioxidant effects. Controversy exists on whether alcohol has a direct cardioprotective effect on ischemic myocardium. Studies from our laboratory do not support the concept that alcohol has a direct cardioprotective effect on ischemic/reperfused myocardium. Perhaps the time has come for a prospectively randomized trial to determine whether 1 drink per day (or perhaps 1 drink every other day) reduces mortality and major cardiovascular events.

Alcohol intake and noncoronary cardiovascular diseases

Moderate drinking has complex associations with cardiovascular diseases other than coronary heart disease. Recent cohort studies examining the relationship between alcohol use and ischemic stroke have shown a modest association, with risk ratios approximating 0.8 and the lowest risk among those who drink less than daily. In contrast, alcohol use is generally associated with an approximate dose-dependent risk for hemorrhagic stroke throughout the full range of intake. Several prospective studies of alcohol intake and congestive heart failure have found lower risk with moderate drinking. This risk is also dose dependent through the moderate range, but its underlying mechanism remains uncertain. Accounting for the lower risk of myocardial infarction associated with moderate intake does not eliminate the observed association. Cohort studies have found no association of long-term alcohol intake with risk of atrial fibrillation below levels of at least 3 standard drinks per day. Finally, two prospective studies have found lower risks of claudication or clinically more severe peripheral arterial disease among moderate drinkers, an association also supported by cross-sectional studies of alcohol intake and ankle-brachial index.

Alcohol consumption and risk and prognosis of atrial fibrillation among older adults: the Cardiovascular Health Study

BACKGROUND

The relationship of alcohol consumption with risk of atrial fibrillation (AF) is inconsistent in previous studies, and its relationship with prognosis of AF is undetermined.

METHODS

As part of the Cardiovascular Health Study, a population-based cohort of adults 65 years and older from 4 US communities, 5609 participants reported their use of beer, wine, and spirits yearly. We identified cases of AF with routine study electrocardiograms and validated discharge diagnoses from hospitalizations.

RESULTS

A total of 1232 cases of AF were documented during a mean of 9.1 years of follow-up. Compared with long-term abstainers, the multivariable-adjusted hazard ratios were 1.25 (95% CI, 1.02-1.54) among former drinkers, 1.09 (95% CI, 0.94-1.28) among consumers of less than 1 drink per week, 1.00 (95% CI, 0.84-1.19) among consumers of 1 to 6 drinks per week, 1.06 (95% CI, 0.82-1.37) among consumers of 7 to 13 drinks per week, and 1.09 (95% CI, 0.88-1.37) among consumers of 14 or more drinks per week (P trend = 0.64). In analyses of mortality among participants with AF, the hazard ratios were 1.27 (95% CI, 1.06-1.52) among former drinkers, 0.94 (95% CI, 0.76-1.18) among consumers of less than 1 drink per week, 0.98 (95% CI, 0.78-1.23) among consumers of 1 to 6 drinks per week, 0.73 (95% CI, 0.51-1.03) among consumers of 7 to 13 drinks per week, and 0.81 (95% CI, 0.59-1.11) among consumers of 14 or more drinks per week (P trend = 0.12).

CONCLUSIONS

Current moderate alcohol consumption is not associated with risk of AF or with risk of death after diagnosis of AF, but former drinking identifies individuals at higher risk.

Alcohol abuse in the critically ill patient

Alcohol abuse and dependence disorders are common in the 10% of hospitalised patients who need admission to the intensive care unit (ICU), but these disorders are often undiagnosed. The systemic effects from the excessive use of alcohol increase susceptibility to, or directly cause various important disorders in the critically ill. Early recognition of alcohol abuse and dependence is necessary and should prompt consideration of several alcohol-specific diagnoses that have important prognostic and therapeutic implications for these patients. We discuss the use of screening tests to improve the identification of alcohol abuse and dependence disorders, the epidemiology and pathogenesis of important alcohol-related disorders, differences in the presentation of several common alcohol-related diagnoses in the ICU, and important alcohol-specific therapies.

Cerebrovascular and cardiovascular complications of alcohol and sympathomimetic drug abuse

Alcohol and stimulant abuse represents a major cause of cerebrovascular and cardiovascular disease in young adults. Although mild-to-moderate alcohol consumption has been linked to a decreased risk for stroke and CVD, excessive use is associated with an increased risk for intracranial hemorrhage and cardiomyopathy. Cocaine represents the single largest,cause of medical complications related to illegal drug use. Cocaine has been associated with cerebral infarction, intracranial hemorrhage, myocardial infarction, cardiomyopathy, and cardiac arrhythmias. Abuse of amphetamines is associated with complications similar to those of cocaine. The complications associated with stimulant abuse are thought to be primarily mediated through excess catecholamines, resulting in acute arterial hypertension, vasospasm, thrombosis, and accelerated atherosclerosis. Because many complications of alcohol and stimulant abuse are preventable and reversible, it is important to screen for these in patients with cerebrovascular and cardiovascular disease.

Alcohol consumption and risk of atrial fibrillation in men and women: the Copenhagen City Heart Study

BACKGROUND

The relationship of the full range of alcohol consumption with risk of incident atrial fibrillation has been inconsistent in previous, mainly case-control studies.

METHODS AND RESULTS

In a prospective cohort study, we studied the association between self-reported alcohol use and incident atrial fibrillation among 16,415 women and men enrolled in the Copenhagen City Heart Study. We ascertained use of beer, wine, and spirits individually at up to 3 study visits with a structured questionnaire. We identified cases of atrial fibrillation by routine study ECGs and a validated nationwide registry of all hospitalizations. A total of 1071 cases occurred during follow-up. Among both women and men, alcohol consumption throughout the moderate range was not associated with risk of atrial fibrillation. However, consumption of 35 or more drinks per week among men was associated with a hazard ratio of 1.45 (95% CI 1.02 to 2.04); few women consumed this amount of alcohol. Approximately 5% of cases of atrial fibrillation among men were attributable to heavy alcohol use. Further adjustment for blood pressure and incident coronary heart disease and congestive heart failure did not attenuate the association (hazard ratio 1.63; 95% CI 1.15 to 2.31).

CONCLUSIONS

Heavy alcohol consumption is associated with a higher risk of atrial fibrillation, at least among men. This relationship does not appear to be related to the adverse effects of heavy drinking on coronary heart disease or blood pressure.

Prevalence of and risk factors for atrial fibrillation in Korean adults older than 40 years

Atrial fibrillation (AF) is a common arrhythmia that is a potent independent risk factor for stroke. The incidence of AF increase with age and most affected people have underlying cardiac disease. This study aimed to describe the prevalence of and risk factors for AF in Korean. In this study, 14,540 adults (male 6,573/female 7,967) > or =40 yr old received screening test for general health between April 2000 and December 2000. Participants answered questionnaires and underwent examinations that included blood pressure, electrocardiogram (ECG), total cholesterol, and fasting glucose. Data analysis was done by SPSS 10.0 for Windows. The prevalence of AF was 0.7% in people older than 40 yr and 2.1% in those older than 65 yr. The prevalence in men was 1.2% and women was 0.4% in people older than 40 yr. The prevalence in men was 3.3% and women was 1.1% in people older than 65 yr. Approximately 56.6% of individuals with AF are older than 65 yr. The prevalence of AF was higher at all age group in men than in women. Also, the prevalence of AF was highest in people older than 80 yr. In univariate analysis, male sex, old age (> or =65 yr), hypertension, diabetes mellitus, left ventricular hypertrophy in ECG, stroke, and cardiac disease were associated with an increased risk of AF. In multivariate analysis, however, risk factors of AF were male (odds ratio, OR 4.1; 95% confidence interval [CI] : 2.6 to 6.5; p=0.000), old age (OR 5.3; 95% CI:3.5 to 7.9; p=0.000), and cardiac disease (OR 19.8; 95% CI:12.3 to 31.8; p=0.000). In this study, the most potent risk factors of AF was cardiac disease.

Long-term alcohol consumption and the risk of atrial fibrillation in the Framingham Study

Atrial fibrillation (AF) is a major risk factor for stroke. Although acute alcohol intake has been associated with AF, it is not known whether long-term alcohol consumption in moderation is associated with an increased risk of AF. We used a risk set method to assess the relation of long-term alcohol consumption to the risk of AF among participants in the Framingham Study. For each case, up to 5 controls were selected and matched for age, age at baseline examination, sex, cohort, baseline history of hypertension, congestive heart failure, and myocardial infarction. Within each risk set, alcohol consumption was averaged from baseline until the examination preceding the index case of AF. Of the 1,055 cases of AF occurring during a follow-up of >50 years, 544 were men and 511 were women. In a conditional logistic regression with additional adjustment for systolic blood pressure, age at baseline examination, education, and cumulative history of myocardial infarction, congestive heart failure, diabetes mellitus, left ventricular hypertrophy, and valvular heart disease, the relative risks were 1.0 (reference), 0.97 (95% confidence interval [CI] 0.78 to 1.22), 1.06 (95% CI 0.80 to 1.38), 1.12 (95% CI 0.80 to 1.55), and 1.34 (95% CI 1.01 to 1.78) for alcohol categories of 0, 0.1 to 12, 12.1 to 24, 24.1 to 36, and >36 g/day, respectively. In conclusion, our data indicate little association between long-term moderate alcohol consumption and the risk of AF, but a significantly increased risk of AF among subjects consuming >36 g/day (approximatively >3 drinks/day).

A theoretical model of the role of brain stem nuclei in alcohol-mediated arrhythmogenesis in older adults

Uncertainty about the mechanism of alcohol-mediated arrhythmogenesis and the effect of alcohol use on arrhythmic risk among older adults is an increasing concern in light of population aging and recent reports that moderate alcohol consumption may protect older adults against coronary artery disease. In this review, a theoretical model of the role of brain stem nuclei in alcohol-mediated arrhythmogenesis in older adults is developed. The model is based on the hypothesis that the effects of alcohol on central autonomic pathways of cardiac control may alter the threshold for alcohol-mediated arrhythmogenesis among older adults. Findings from multiple lines of research including cellular, electrophysiological, epidemiological, experimental, and clinical studies in human, animal, and in vitro models were synthesized in developing the model. Suggestions for future research on the topic of alcohol-mediated arrhythmogenesis in older adults are offered.

Benefits and risks of sauna bathing

Although sauna bathing causes various acute, transient cardiovascular and hormonal changes, it is well tolerated by most healthy adults and children. Sauna bathing does not influence fertility and is safe during the uncomplicated pregnancies of healthy women. Some studies have suggested that long-term sauna bathing may help lower blood pressure in patients with hypertension and improve the left ventricular ejection fraction in patients with chronic congestive heart failure, but additional data are needed to confirm these findings. The transient improvements in pulmonary function that occur in the sauna may provide some relief to patients with asthma and chronic bronchitis. Sauna bathing may also alleviate pain and improve joint mobility in patients with rheumatic disease. Although sauna bathing does not cause drying of the skin-and may even benefit patients with psoriasis-sweating may increase itching in patients with atopic dermatitis. Contraindications to sauna bathing include unstable angina pectoris, recent myocardial infarction, and severe aortic stenosis. Sauna bathing is safe, however, for most people with coronary heart disease with stable angina pectoris or old myocardial infarction. Very few acute myocardial infarctions and sudden deaths occur in saunas, but alcohol consumption during sauna bathing increases the risk of hypotension, arrhythmia, and sudden death, and should be avoided.

beta-adrenergic mechanisms in cardiac diseases: a perspective

Several lines of evidence show that neurohumoral systems, especially those involving catecholamines, play a crucial role in cardiac diseases. Changes in the beta-adrenergic receptor (beta-AR) system such as receptor down-regulation, uncoupling from G-proteins, receptor internalization and receptor degradation may account for some of the abnormalities of contractile function in this disease. Increases in the level of inhibitory G-protein subunits also appears to be involved in attenuating the beta-AR signal. Finally beta-AR signalling is strongly regulated by members of the G-protein-coupled receptor kinase family (GRKs), the best known of which is beta-adrenergic receptor kinase 1 (beta-ARK1). beta-ARK1 mRNA, protein level and enzymatic activity is increased in heart disease, further contributing to an attenuation in beta-AR signalling. The combination of these negative alterations are presumably related to the contractile dysfunction seen in human heart disease. The combination of biochemical, physiological and molecular biological studies bearing on the normal function and regulation of these various molecules should provide strategies for elucidating the pharmacological basis of the regulation of myocardial contractility in the normal and failing heart.

[The etiology and associated risk factors in a sample of 300 patients with atrial fibrillation]

PURPOSE

To analyze the etiology and the prevalence of risk factors in patients with atrial fibrillation.

PATIENTS AND METHODS

Applying an unpaired case controlled study, we examined 300 consecutive patients (143 men) with atrial fibrillation and a mean age of 66 +/- 8 years. This group is compared with a control group of 700 patients (mean age 64 +/- 12 years).

RESULTS

In the group with atrial fibrillation the etiology in 32% was arterial hypertension, in 20% coronary heart disease, in 13% valvular heart disease, in 11% heart failure, in 4% hyperthyroidism and in 20% idiopathic. 50% presented hypertension, 29% tobaccoism, 26% left ventricular hypertrophy, 20% consumption of alcohol, 19% hypercholesterolemia and 16% diabetes. Compared with the control group, patients with atrial fibrillation had coronary heart disease (p < 0.05), VHD (p < 0.01), myocardiopathy (p < 0.05), HT (p < 0.001), left ventricular hypertrophy (p < 0.001), diabetes (p < 0.01) and alcohol consumption (p < 0.01) more frequently. In the multivariant analysis heart failure (odds ratio 2.1 [1.2-3.3]), the valvular heart disease (odds ratio 2.2 [1.4-3.5]), the coronary heart disease (odds ratio 1.8 [1.2-2.6]), the arterial hypertension (odds ratio 1.7 [1.2-2.3]), the left ventricular hypertrophy (odds ratio 2.6 [1.7-3.8]), the diabetes (odds ratio 1.9 [1.2-2.9]) and alcoholic habits (odds ratio 2 [1.3-3.9]) were independent risk factors for atrial fibrillation in our population.

CONCLUSIONS

Atrial fibrillation in our study, is more frequent in patients with arterial hypertension, coronary heart disease or valvular heart disease. There are other risk factors such as arterial hypertension, diabetes and consumption of alcohol too, the modification of which could diminish the risk of the appearance of atrial fibrillation.

Alcohol, cardiac arrhythmias and sudden death

Studies in experimental animals have shown varying and apparently opposite effects of alcohol on cardiac rhythm and conduction. Given acutely to non-alcoholic animals, ethanol may even have anti-arrhythmic properties whereas chronic administration clearly increases the animals' susceptibility to cardiac arrhythmias. Chronic heavy alcohol use has been incriminated in the genesis of cardiac arrhythmias in humans. The evidence has come from clinical observations, retrospective case-control studies, controlled studies of consecutive admissions for arrhythmias, and prospective epidemiological investigations. Furthermore, electrophysiological studies have shown that acute alcohol administration facilitates the induction of tachyarrhythmias in selected heavy drinkers. The role of alcohol appears particularly conspicuous in idiopathic atrial fibrillation. Occasionally, ventricular tachyarrhythmias have also been provoked by alcohol intake. Several lines of evidence suggest that heavy drinking increases the risk of sudden cardiac death with fatal arrhythmia as the most likely mechanism. According to epidemiological studies this effect appears most prominent in middle-aged men and is only partly explained by confounding traits such as smoking and social class. The basic arrhythmogenic effects of alcohol are still insufficiently delineated. Subclinical heart muscle injury from chronic heavy use may be instrumental in producing patchy delays in conduction. The hyperadrenergic state of drinking and withdrawal may also contribute, as may electrolyte abnormalities, impaired vagal heart rate control, repolarization abnormalities with prolonged QT intervals and worsening of myocardial ischaemia or sleep apnoea. Most of what we know about alcohol and arrhythmias relates to heavy drinking. The effect of social drinking on clinical arrhythmias in non-alcoholic cardiac patients needs to be addressed further.

Effect of ethanol drinking, hangover, and exercise on adrenergic activity and heart rate variability in patients with a history of alcohol-induced atrial fibrillation

To elucidate the mechanism of alcohol-induced atrial fibrillation (AF) we studied the heart rate variability and parameters of the adrenergic system during alcohol intake, hangover, and exercise in 6 men (mean age 43 years) prone to alcohol-induced AF, together with 6 age-matched controls. The ambulatory (15 hour) electrocardiogram was recorded and blood samples were taken for lymphocytic beta adrenoceptor, plasma catecholamine, and cyclic adenosine monophosphate (cAMP) measurements before and after alcohol intake (blood alcohol 1.5 per thousand), during hangover, and after a standardized bicycle exercise test. The beta-adrenoceptor density in lymphocytes was unchanged in the control group after alcohol intake or during hangover. Each of the AF patients had an increase in beta-adrenoceptor density after ethanol drinking (mean increase 29%, p <0.05). The hangover or exercise beta-receptor values did not differ from those in corresponding controls. Plasma adrenaline concentration tended to decrease and noradrenaline to increase after drinking and during hangover in both groups. Plasma cAMP levels were lower in patients after drinking than in controls (p <0.05). The exercise values of the adrenergic parameters were very similar in AF patients whether or not preceded by alcohol. Analysis of ambulatory electrocardiography showed a very low rate of ectopic beats in both AF patients and controls. Analysis of heart rate variability revealed a tendency toward an increase in sympathetic/parasympathetic component ratio (low-frequency/high-frequency ratio) in AF patients, but not in controls, after ethanol drinking. In conclusion, no signs of arrhythmogenic cardiac disease were detected in patients with AF to explain the tendency toward AF. Increases in beta-adrenoceptor density and low-frequency/high-frequency ratio during ethanol intoxication in patients with AF suggest an exaggerated sympathetic reaction.

Electrophysiologic aspects of human atrial fibrillation

This article reviews the important developments that have led to current understanding of atrial fibrillation, the data that support its mechanistic dependence on various forms of reentrant excitation, and the resultant electrophysiologic and clinical implications of clinicians' evolving understanding.

Alcohol concentration determines the type of atrial arrhythmia induced in a porcine model of acute alcoholic intoxication

Alcohol abuse has long been suspected clinically to cause paroxysmal atrial tachyarrhythmias. However, such a relationship has never been conclusively proven, partly due to the lack of experimental evidence. Although atrial fibrillation (AF) is the most common atrial arrhythmia attributed to acute alcoholic ingestion, atrial flutter has occasionally been noted. We analyzed the possible role of alcohol in initiation and/or maintenance of a variety of atrial tachyarrhythmias in a closed-chest porcine model. Nine pigs underwent nine endocardial right atrial stimulation protocols (RASP) at baseline and 17 RASPs after increasing doses of ethanol (first infusion 1,230 mg/kg, second infusion 870 mg/kg) by means of one multipolar catheter advanced under heavy sedation from the femoral vein. Each RASP included 1, 2, and 3 extrastimuli, and rapid pacing at 5 times diastolic threshold. Venous ethanol concentrations were measured (HPGC method) every 10 minutes and at the time of arrhythmia induction. Atrial tachyarrhythmias were induced in 4 of 9 baseline RASPs, and lasted for a mean of 21 seconds, and in 16 of 17 RASPs after alcohol lasting for a mean of 357 seconds. Only fibrillation was observed at the baseline RASP. The atrial tachyarrhythmias induced after alcohol were AF in 11 RASPs and atrial flutter in 5 RASPs (in 5 animals). The mean venous ethanol concentration at the time of the longest arrhythmia induced for each RASP were 200 +/- 89 mg/dL for RASP inducing fibrillation and 292 +/- 40 mg/dL for RASP inducing flutter (P < 0.05). Flutter tended to be sustained (> 1 minute in duration) more often than fibrillation (4 of 5 flutter vs 2 of 11 fibrillation P < 0.05). In three experiments, atrial flutter persisted for > 10 minutes and was terminated by overdrive atrial pacing. We concluded: (1) in this closed-chest porcine model, an ethanol infusion facilitates a variety of atrial arrhythmias related to the ethanol concentration; (2) flutter tended to be sustained, and its termination by overdrive pacing suggests the possibility of an alcohol induced reentrant mechanism; and (3) the higher concentration required for atrial flutter, exceeding that usually seen in humans, may help to explain the rarity of atrial flutter in clinical alcohol intoxication.

The natural history of atrial fibrillation: incidence, risk factors, and prognosis in the Manitoba Follow-Up Study

PURPOSE

Atrial fibrillation is a common arrhythmia associated with increased cardiovascular morbidity and mortality. This study was undertaken to identify the natural history of this condition, including risk factors for its development, and outcome.

PATIENTS AND METHODS

The incidence of atrial fibrillation among 3,983 male air crew recruits observed continuously for 44 years was calculated based on person-years of observation. Age and 23 variables were examined to identify risk factors for atrial fibrillation. Controlling for age and 9 prognostic variables, the effect of atrial fibrillation on 8 outcomes was examined. Analysis of risk factors for atrial fibrillation and outcome after atrial fibrillation was based on a Cox proportional hazard model using time-dependent covariates.

RESULTS

Of the 3,983 study members, 299 (7.5%) developed atrial fibrillation during 154,131 person-years of observation. The incidence rose with age from less than 0.5 per 1,000 person-years before age 50 to 9.7 per 1,000 person-years after age 70. Risk for atrial fibrillation was increased with myocardial infarction (relative risk [RR] 3.62), angina (RR 2.84), and ST-T wave abnormalities in the absence of ischemic heart disease (RR 2.21). The RR for atrial fibrillation was strongest at the onset of ischemic heart disease and diminished over time. The rate of atrial fibrillation was 1.42 times increased in men with a history of hypertension. Congestive heart failure, valvular heart disease, and cardiomyopathy were important but uncommon risk factors. Atrial fibrillation independently increased the risk for stroke (RR 2.07) and congestive heart failure (RR 2.98). Total mortality rate was increased 1.31 times; cardiovascular mortality including and excluding fatal stroke were also increased (RR 1.41 and 1.37, respectively).

CONCLUSIONS

The incidence of atrial fibrillation in men increases with advancing age. Clinical cardiac abnormalities, particularly recent ischemic heart disease and hypertension, are strongly associated with increased risk for atrial fibrillation. Atrial fibrillation increases morbidity and mortality, but the magnitude of the increase may be less than previously reported.

The risk of alcohol

We have reviewed 156 papers which provided sufficient information to relate individual alcohol consumption to risk for a variety of physical damage. Overall, there was evidence for a dose-response relationship between level of alcohol consumption and risk of harm for liver cirrhosis, cancers of the oropharynx, larynx, oesophagus, rectum (beer only), liver and breast, and blood pressure and stroke. An increased risk of cardiac arrhythmias, cardiomyopathy and sudden coronary death was associated with heavy drinking. There was evidence for a protective effect of alcohol consumption against risk of coronary heart disease, which could be achieved at consumption levels of less than 10 g alcohol a day. The mortality of non-drinkers was higher than that of moderate drinkers in some studies. Level of alcohol consumption and total mortality were dose-related when non-drinkers were excluded. The finding of a dose-relationship between alcohol and harm suggested causality. It was not possible to define individual risk for all harms at a given level of alcohol consumption because of variations in methodology, but some idea of the order of magnitude of the increased risk can be obtained from calculating trends of pooled log-odds ratios. At levels of alcohol consumption of more than 20-30 g a day, all individuals are likely to accumulate risk of harm. Current guidelines on upper limits of lower risk drinking in different countries (168-280 g of alcohol a week for men and 84-140 g a week for women) reflect levels at which the risk of total mortality is not greatly increased above one.