Alcohol and cardiac arrhythmias

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.

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 mortality from stroke and coronary heart disease among Japanese men and women: the Japan collaborative cohort study

BACKGROUND AND PURPOSE

Previous studies have demonstrated the association between alcohol consumption and cardiovascular mortality. However, the sex-specific association between alcohol consumption and mortality from stroke and coronary heart disease remains unclear.

METHODS

Between 1988 and 1990, 34,776 men and 48 906 women aged 40 to 79 years completed a self-administered questionnaire including information about alcohol consumption. They were followed-up for a median duration of 14.2 years.

RESULTS

Of the 83,682 respondents, 1628 died from stroke and 736 died from coronary heart disease. For men, heavy drinking (>or=46.0 g ethanol/day) was associated with increased mortality from total, hemorrhagic, and ischemic strokes, whereas light-to-moderate drinking was associated with reduced mortality from total cardiovascular disease, compared with not drinking. The respective multivariable hazard ratios (95% CI) were 1.48 (1.22 to 1.80) for total stoke, 1.67 (1.17 to 2.38) for hemorrhagic stroke, 1.35 (1.04 to 1.75) for ischemic stroke, and 0.88 (0.78 to 1.00) for total cardiovascular disease. Women who were heavy drinkers (>or=46.0 g ethanol/day) showed increased mortality from coronary heart disease, and there was reduced mortality from total cardiovascular disease for drinkers of 0.1 to 22.9 g ethanol per day compared with mortality for nondrinkers. The respective multivariable hazard ratios (95% CI) for the 2 categories of drinkers were 4.10 (1.63 to 10.3) and 0.75 (0.62 to 0.91).

CONCLUSIONS

Heavy alcohol consumption is associated with increased mortality from total stroke, particularly hemorrhagic stroke, and total cardiovascular disease for men, and from coronary heart disease for women, whereas light-to-moderate drinking may be associated with reduced mortality from cardiovascular disease for both sexes.

Autonomic Modulation of Altered Diurnal Hemodynamic Profiles in Ethanol-Fed Hypertensive Rats

BACKGROUND

A recent report from the authors' laboratory showed that circadian hemodynamic rhythms are altered in hypertension due partly to irregularities in cardiovascular autonomic control. This study investigated the long-term effects of chronic ethanol feeding (5% w/v, 12 weeks) on the circadian profiles of blood pressure (BP), heart rate (HR), and their variability in spontaneously hypertensive rats (SHRs) and age-matched Wistar-Kyoto (WKY) rats.

METHODS

Radiotelemetry was used for hemodynamic monitoring. The time-domain measures of the variability of BP (standard deviation of mean arterial pressure [SDMAP]) and HR (standard deviation of R-R intervals [SDRR] and root mean square of successive differences in R-R intervals [rMSSD]) were taken as indices of cardiovascular autonomic activity.

RESULTS

Control WKY rats displayed normal circadian rhythms (i.e., higher dark-time compared with light-time values) of BP, HR, and their variability indices during weeks 6 through 12 of the study. These circadian rhythms were abolished (BP), inverted (HR, SDMAP), or enhanced (SDRR, rMSSD) in SHRs. Ethanol feeding produced sustained hypotension during both light and dark cycles that was 3-fold greater in SHRs than in WKY rats. SDMAP was not affected by ethanol in WKY rats and showed reductions, mostly during light times, in SHRs. Ethanol also caused significant increases in HR in SHRs only during dark periods, probably because of the inhibition of cardiac vagal activity as indicated by temporal reductions in rMSSD.

CONCLUSIONS

These results implicate autonomic factors in the altered diurnal hemodynamic profile by ethanol in SHRs and highlight the possibility of increased risk of cardiac events in hypertensive patients due to alcohol use.

Chronic ethanol–clonidine hemodynamic interaction in telemetered spontaneously hypertensive rats

Our previous studies have established that ethanol, administered acutely or chronically, attenuates the hypotensive action of the centrally acting drug clonidine. In this study, we employed the radiotelemetry technique to evaluate the long-term hemodynamic interaction between the two drugs administered simultaneously to spontaneously hypertensive rats (SHRs). Changes in blood pressure (BP), heart rate (HR), and their variability was determined in pair-fed rats receiving ethanol (5%, w/v), clonidine pellets (10 mg/pellet, s.c.), or their combination for 28 days. Ethanol feeding caused significant decreases and increases in BP and HR, respectively. The time-domain variability indices of BP and HR were also reduced by ethanol. Clonidine produced significant reductions in BP and HR that were evident for only 1-2 days and disappeared thereafter. In rats receiving the combined ethanol and clonidine treatment, hemodynamic changes were identical to those produced by ethanol alone. These findings suggest (i) long-term exposure of SHRs to moderate amounts of ethanol reduces HR variability, possibly due to diminished cardiac vagal modulation, and (ii) the lack of a maintained hypotensive response to clonidine, administered via timed-release pellets, made the evaluation of its chronic interaction with ethanol unfeasible.

Alcohol: matters of life and death

Most of us enjoy alcohol and drink moderately, but some 7 million people in Britain drink more than the old ‘safe’ levels of alcohol — 21 and 14 units a week for men and women respectively. This represents one in eight of the population, or one in six if you exclude children under 15 years of age, difficult to justify these days given the amount of drinking by young children.

Blood alcohol and cardiac arrest

Patients who suffer a cardiac arrest with alcohol present in their blood may, theoretically, differ from patients who arrest in the absence of alcohol. Alcohol may induce certain lethal arrhythmias, deter strenuous resuscitation in the pre-hospital phase and influence the effectiveness of resuscitative manoeuvres. In this study, 150 patients presenting to an Accident and Emergency department with cardiac arrest were tested for the presence of alcohol in their plasma. 49 patients had detectable plasma alcohol and analysis of their pre-hospital resuscitation revealed no significant differences when compared with the 101 patients in whom no alcohol was detected. No particular arrhythmia predominated in the alcohol group, and patients who had alcohol detected in their blood were just as likely to be successfully resuscitated, in terms of both restoration of spontaneous circulation and survival to hospital discharge. The effect of significantly elevated plasma alcohol levels on cardiac arrest outcome remains unclear, however, as only 7/150 patients had plasma alcohol levels above the legal driving limit.