Primary alcoholic heart disease

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.

Intravenous saline has no effect on blood ethanol clearance

For patients presenting to emergency departments with ethanol intoxication, intravenous (i.v.) fluids are initiated for varied reasons. This investigation determined the effect of i.v. fluid therapy on the rate of blood ethanol clearance in such patients. Volunteers received a predetermined dose of ethanol on two separate occasions. On the second occasion, volunteers rapidly received a liter of i.v. saline directly following ethanol ingestion. At intervals on both occasions, blood ethanol levels were estimated using a breath analyzer. Using linear regression analysis, no difference was found in rates of alcohol clearance with or without i.v. fluid intervention. The common rate of clearance between both groups was 15 mg/dL/h (95% CI 12 to 18). We conclude that i.v. fluid therapy does not accelerate ethanol clearance in intoxicated patients. While such therapy may be justified for other reasons, practitioners are cautioned against initiating fluids in such patients solely to expedite ethanol elimination.

Decrease of epinephrine-induced arrhythmia threshold in ethanol exposed rats

An association between cardiac arrhythmias and ethanol use has been observed for some time. The sympathetic nervous system presumably plays an important role in the manifestation of cardiovascular ethanol responses. Therefore, we investigated the effects of ethanol treatment on epinephrine-induced arrhythmias. Female Wistar rats received 10 vol% ethanol or 2.5% glucose (control group) in their drinking water for 45 days. In ether anesthetized animals of both groups epinephrine (10 micrograms/kg.min) was infused via a lateral tail vein. The threshold dose for arrhythmias after epinephrine infusion (mainly 2nd and 3rd degree AV-blocks) was reduced beginning 2 days after the start of the ethanol treatment and the incidence of AV-blocks during epinephrine infusion was increased. During the ethanol treatment the prohypertensive epinephrine effect was slightly increased. The reflex bradycardia was not changed after repeated epinephrine infusion by ethanol treatment, whereas it was nearly abolished in the control group. No blood ethanol could be detected during the time of epinephrine infusion (9-12 a.m.), but determinations at 11 p.m. yielded a concentration of 0.13 +/- 0.02 mg/g. The results show that the epinephrine-induced bradyarrhythmia threshold is reduced and the frequency of arrhythmic events is augmented in rats exposed to ethanol in the drinking fluid.

Ethanol-induced changes in cardiac lipid metabolism

The influence of ethanol on cardiac lipid metabolism has been investigated in the rat. Acute in vitro ethanol significantly stimulated the incorporation of 14C-1-acetate but not 14C-U-glucose into cardiac lipid in rats fed a diet free of ethanol for 3 weeks. Stimulation of incorporation was not uniform but was confined to the diglyceride and triglyceride fractions. This response of cardiac tissue lipid metabolism to acute ethanol was not observed in rats pair fed an isocaloric diet containing 36% of calories as ethanol. Chronic ethanol feeding significantly increased cardiac triglyceride content when compared with pair-fed controls. It also stimulated oxidation of labeled palmitate, but did not affect in vitro lipogenesis.

Effect of alcohol on the atrial fibrillation threshold in dogs

The atrial fibrillation threshold was measured in 10 anesthetized dogs by delivering a series of impulses directly to the right atrium after infusion of 4.5 ml of 5% glucose per kilogram of body weight, and after 1.5 ml of absolute alcohol per kilogram in 3 ml/kg of 5% glucose. There were no changes in the atrial fibrillation threshold after glucose. The mean AFT before alcohol was 6.8 volts. Immediately after alcohol infusion, the arterial blood alcohol concentration (BAC) was 300.7 mg/100 ml, and the AFT increased to 9.75 volts (P less than 0.01); 20 minutes later the BAC was 181.2 mg/100 and the AFT 8.5 (P less than 0.02). There was no rebound decrease in AFT up to 65 minutes. The findings suggest that in anesthetized normal dogs, alcohol may have a direct mild antiarrhythmic effect on the atria. Atrial fibrillation in alcoholics may be due to alcohol indirectly through electrolyte, autonomic, or histologic changes.

Inhibition of epinephrine-induced myocardial necrosis in rats by administration of single doses of ethanol

The oral administration of single doses (0.5-6.0 g/kg) of ethanol to rats, shortly before injecting them with a large dose (3.0 mg base/kg) of epinephrine subcutaneously, significantly reduced the severity of the myocardial damage produced by the epinephrine. The larger the dose of ethanol, the greater was the protective effect. The results were the same, regardless of the method used to determine the degree of cardiac injury. Experiments employing various agents to determine the mechanisms of ethanol action have tentatively suggested that a platelet de-aggregating or an osmotic effect of alcohol may be involved.