Alcohol and the heart

Toxic Mechanisms of the Heart: A Review*

Toxic injury is one of the many ways by which the functional integrity of the heart may become compromised. Any of the subcellular elements may be the target of toxic injury, including all of the various membranes and organelles. Understanding the mechanisms underlying cardiotoxicity may lead to treatment of the toxicity or to its prevention. Doxorubicin and its analogs are very important cancer chemotherapeutic agents that can cause cardiotoxicity. Other agents which are cardiotoxic and which have profound public health implications include the alkaloid emetine in ipecac syrup, cocaine, and ethyl alcohol. The most important cardiotoxic mechanisms proposed for doxorubicin include oxidative stress with its resultant damage to myocardial elements, changes in calcium homeostasis, decreased ability to produce ATP, and systemic release of cardiotoxic humoral mediators from tissue mast cells. Each of the first 3 mechanisms can lead to each of the other 2, and the causal relationships between all of these mechanisms are not clear. New evidence suggests that doxorubicinol, one of the metabolites of doxorubicin may be the moiety responsible for cardiotoxicity. Several other potential mechanisms also have been proposed for doxorubicin. Emetine in ipecac syrup is the first aid treatment of choice for many acute toxic oral ingestions and the alkaloid, itself, is used to treat amebiasis. Cardiotoxicity occurs following chronic exposure, such as occurs therapeutically in amebiasis and with ipecac abuse by bulemics. A number of mechanisms are proposed for emetine cardiotoxicity, but the current mechanistic literature is quite scarce. Cocaine abuse recently has caught the public interest, in particular because of the drug-related sudden deaths of certain athletes. Cocaine can cause hypertension, arrhythmias, and reduced coronary blood flow, each of which can contribute to its lethality. However, it may be possible that cocaine sudden death episodes are more related to hyperthermia and convulsive seizures, rather than to cardiovascular toxicity. Chronic alcohol use leads to dilated cardiomyopathy and failure as part of the general physical degeneration that occurs with alcoholism. Several mechanisms are proposed for the cardiomyopathy, but only 2 things seem clear. The cardiotoxicity is due to an intrinsic effect of alcohol, rather than to malnutrition or co-toxicity, and abstinence is the only effective treatment for the cardiomyopathy. Recent articles indicate that very moderate use of alcohol may be beneficial and protect against cardiovascular-related morbidity. One explanation for these findings seems to be that the non-drinking groups, against whom the moderate drinking comparisons were made, were enriched in former drinkers with significant alcohol-related cardiovascular pathology.

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.

Identification of strategies to prevent death after pesticide self-poisoning using a Haddon matrix

Despite pesticide self-poisoning causing around 300 000 deaths each year in the rural Asia Pacific region, no comprehensive public health response has yet been formulated. The authors have developed a Haddon matrix to identify factors that increase the risk of fatal rather than non-fatal pesticide self-poisoning in Sri Lanka. Many important host factors such as age, gender, and genetics are not alterable; factors that could be changed-alcohol use and mental health-have previously proved difficult to change. Interventions affecting agent or environmental factors may be easier to implement and more effective, in particular those limiting the human toxicity and accessibility of the pesticides, and the quality, affordability, and accessibility of health care in the community. Controlled studies are required to identify effective strategies for prevention and harm minimization and to garner political support for making the changes necessary to reduce this waste of life. Lessons learnt from Sri Lanka are likely to be highly relevant for much of rural Asia.

Effects of alcohol on skeletal and cardiac muscle

The acute and chronic toxic effects of alcohol on skeletal and cardiac muscle are clinically important. Muscle weakness and atrophy are the main manifestations of skeletal myopathy, and arrhythmias and progressive left-ventricular dysfunction are those of cardiomyopathy. Most patients remain asymptomatic from these effects for a long time. Myocyte atrophy and death are the main pathological findings. A clear dose-related effect has been established with ethanol consumption, with gender and some specific gene polymorphisms being factors of increased susceptibility to alcohol-induced muscle damage. Pathogenic mechanisms are pleiotropic, the most relevant being disturbances in carbohydrate, protein, and energy cell turnover, signal transduction, and induction of apoptosis and gene dysregulation. Ethanol abstinence is the only effective treatment, although controlled drinking is useful in patients who do not achieve abstinence. Persistent high-dose consumption results in deterioration of muscle and heart function, with a high mortality due to arrhythmias and progression of heart failure.

Sex differences in L-type calcium current after chronic ethanol consumption in rats

Chronic ethanol consumption elicits a progressive cardiac contractile dysfunction, and studies in rats suggest that this alcoholic heart muscle disease is more pronounced in males than females. Cellular changes associated with the ethanol-induced cardiotoxicity remain largely undefined; however, it is possible that L-type Ca(2+) channel current (I(Ca,L)) is affected. Using whole-cell patch-clamp techniques, this study examined I(Ca,L) in adult ventricular myocytes isolated from male and female P-rats that had consumed drinking water (controls) or a 25% ethanol/water mixture for 14 months. The peak amplitude and maximum conductance of I(Ca,L) were 32 and 26% greater, respectively, in cardiomyocytes isolated from ethanol-consuming compared to control male rats. In contrast, no differences in the amplitude or conductance of I(Ca,L) were observed when comparing myocytes isolated from control and ethanol-consuming females. Ethanol treatment had no significant effects on the kinetics I(Ca,L) inactivation or on steady-state activation and inactivation in either gender. In conclusion, male but not female cardiomyocytes respond to chronic ethanol consumption with an increased I(Ca,L) that may represent a compensatory response to the depressed contractility.

Effects of gender on the cardiac toxicity elicited by chronic ethanol intake in rats

Experiments were designed to determine if gender influences the cardiac toxicity elicited by chronic high-level ethanol intake. Male and female ethanol-preferring P-rats were allowed free access to drinking water or water containing 25% ethanol for 6 months. Left atrial preparations were then isolated, bathed in Krebs-Henseleit solution (37 degrees C), and used to examine basal contractility at 3.0 Hz stimulation, the force-frequency relationship, and the positive inotropic response to the beta-adrenoceptor agonist isoproterenol. Basal contractile function was not affected significantly by ethanol in either gender; however, atria from ethanol-treated male rats displayed diminished contractility compared to control males when measured at slow stimulation frequencies (0.1 and 0.2 Hz), during post rest potentiation (at rest intervals of 20-60 s), and in response to higher concentrations of isoproterenol (> or =3 x 10(-7) M; EC50 values were not affected). In contrast, female atria showed no effect of chronic ethanol consumption. These data suggest that ethanol consumption diminishes the cardiac reserve in male, but not female rats.

Cardiomyopathy in AIDS: a pathophysiological perspective

This report addresses issues of pathogenesis, pathophysiology, and epidemiology of an increasingly prevalent cardiomyopathy in acquired immunodeficiency syndrome (AIDS). As patient survival increases with more effective antiretroviral therapy, cardiomyopathy in AIDS will become more apparent. The interactions of cellular and organism factors in AIDS and their relationships to the development of cardiomyopathy are reviewed herein. Amongst the factors addressed in this review are: (1) comorbid conditions found with AIDS, (2) the role of inflammatory heart disease and cytokines in the development of AIDS cardiomyopathy, (3) the pathogenetic role of vascular cells and myocardial cells in the development of cardiomyopathy, (4) the role of myocardial retroviral infection in AIDS, and (5) the impact of toxicity from antiretroviral therapy on the development of cardiomyopathy. Because it is possible that more than 1 of these factors is present in a given patient inflicted with AIDS, a multifactorial pathogenesis in AIDS cardiomyopathy must be considered.

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.

Comparison of alcoholic cardiomyopathy in women versus men

To compare the prevalence and cardiac status of male and female alcoholics with alcoholic cardiomyopathy during a 5-year period, all chronic alcoholics with dilated cardiomyopathy who had clinical symptoms of heart failure were included. Alcoholic cardiomyopathy was diagnosed in 10 chronic alcoholic women and in 26 men; the prevalence of alcoholic cardiomyopathy was similar in both sexes. No significant differences were observed in age, nutritional parameters, and clinical and radiologic data of heart failure between the 2 groups. Alcoholic women reported a significantly lower daily dose of ethanol (p = 0.002), a shorter duration of alcoholism (p = 0.017), and a lower total lifetime dose of ethanol consumption (p = 0.001), and had a lower New York Heart Association functional class than men. Women also had lesser ventricular dysfunction than men. In a multivariate analysis, left ventricular systolic dysfunction was related to the total lifetime dose of ethanol consumption (p <0.04), but not to gender. Finally, when patients were matched for left ventricular ejection fraction, women had consumed a lower total lifetime dose of ethanol than men (p <0.001). The prevalence of alcoholic women with dilated cardiomyopathy was found to be similar to that of alcoholic men, although women required a lower total lifetime dose of ethanol to develop the disease.

Alcohol and heart muscle disease

Ethanol consumption may induce acute and chronic effects on the myocardium. High-dose acute ethanol intake may induce a decrease in myocardial contraction and produce a variety of rhythm disturbances. These effects are more relevant in patients with underlying cardiomyopathy. Chronic ethanol intake may induce the development of a dilated cardiomyopathy, which is clinically and functionally similar to idiopathic dilated cardiomyopathy. Alcoholic cardiomyopathy is potentially reversible with abstinence. The prognosis depends on the persistence or abstinence of ethanol intake. There is a positive correlation between alcoholic cardiomyopathy and the presence of other ethanol-related diseases, such as skeletal myopathy and cirrhosis. In patients with a specific ethanol-related disease, the possible presence of other complications of alcoholism should be ruled out. Although there are several factors potentially implicated in the pathogenesis of alcohol-related myocardial damage, ethanol itself may induce direct myocardial lesions, which are dose-related and independent of nutrition, protein or ionic deficiencies. The most relevant pathogenic studies on alcoholic cardiomyopathy are based on the disruption of membrane permeability and ionic fluxes mediated by ethanol, inducing a decrease in the calcium transients through the sarcolemma and interfering with the excitation-contraction coupling of myocytes. Cell energy depletion or protein-turnover disruption may contribute to the deleterious effect of ethanol on the myocardium.

Effect of ethanol on function of the rat heart and skeletal muscles

The present study was undertaken to evaluate the acute effects of ethanol on responses of the rat heart and skeletal muscles both in vivo and in vitro. In the anesthetized rat, intravenous infusion of ethanol at 0.1-0.5 g/kg body weight (33-167 mM) decreased the breathing rate by 8-83%, heart rate by 4-52%, and QRS amplitude by 5-27%, and increased the P-R interval by 1-49%. In the anterior tibialis muscle subjected to repetitive nerve stimulation at 100 Hz for 0.5 sec, ethanol at 0.1 g/kg increased the amplitude of the muscle action potential (AP) by 7%, whereas at 0.5 g/kg it decreased the muscle AP by 32%. The nerve-evoked tetanic tension was reduced by 7-34% at 0.1-0.5 g/kg ethanol. In the isolated rat heart, perfusion of ethanol at 0.1-3.0% (22-651 mM) decreased the heart rate by 8-48% and QRS amplitude by 10-39%, and increased the P-R interval by 5-61%. Left ventricular pressure was increased by 10% at 0.1% ethanol, and decreased by 80% at 3.0% ethanol. In the isolated rat phrenic nerve-diaphragm muscle preparation subjected to repetitive nerve stimulation at 100 Hz for 0.5 sec, 0.1-3.0% ethanol decreased the amplitude of the nerve AP by 5-89%, nerve-evoked muscle AP by 2-96%, and peak tetanic tension by 1-87%. On repetitive direct muscle stimulation at 100 Hz for 0.5 sec, 0.1-3.0% ethanol decreased the amplitude of the muscle-evoked muscle AP by 8-65%, and muscle-evoked tetanic tension by 2-65%. These studies indicate that ethanol causes smaller reduction in responses of the heart and skeletal muscles at clinical concentrations, but marked reduction in these responses at higher concentrations due to direct action on excitability of these tissues. At higher concentrations, ethanol causes greater reduction in excitability of the skeletal muscle than of the heart.

Unrecognized left ventricular dysfunction in an apparently healthy alcohol abuse population

To examine effects of chronic alcohol abuse on left ventricular function, 162 otherwise relatively healthy alcohol abusers, having been admitted to a rehabilitation program, underwent cardiac evaluation including chest X-ray, electrocardiogram, and radionuclide angiography after 2 weeks abstinence. Twenty-nine of the 162 alcoholic subjects (18%) with left ventricular dysfunction were identified. Twenty-two had regional wall motion abnormalities, suggesting a localized process, of whom 12 also had depressed ejection fractions. Seven others had a depressed ejection fraction alone with a more global myopathic process. Only 4 of these 29 patients had any history suggesting prior heart disease. Two of the 29 had Q-waves greater than or equal to 0.4 s and 8 had an abnormal cardiothoracic ratio on chest X-ray. Chronic alcohol abusers appear to be at relatively high risk for left ventricular dysfunction; most of which is unrecognized. Routine screening methods failed to identify 85% of our subjects who later were recognized by radionuclide angiography. Since historical and electrocardiographic abnormalities are often absent in this population, detection of left ventricular dysfunction by other methods such as radionuclide angiography must be used.

Acute effects of alcohol and food intake on cardiac performance

Alcohol and food intake induce changes in LV performance which can be evaluated by radionuclide cardiographic methods. Alcohol probably exerts its effects by a direct action of ethanol in the blood on the myocardium, while the postprandial hemodynamic changes are related to the effects of food in the intestine. Alcohol intoxication causes a dose-dependent impairment of LV emptying at rest, whereas compensatory mechanisms other than an increased sympathetic nervous activity counterbalance this effect during exercise. In patients with coronary artery disease, alcohol induces only small changes in LV volumes at rest, possibly because of a concomitant vasodilation. Food intake seems to have a considerable influence on central hemodynamics leading to an increase in cardiac output both in healthy subjects and in patients with coronary artery disease. In healthy subjects an increase is recorded in the LVEDV and LVESV after a meal. The autonomic nervous system is probably responsible for most of the hemodynamic changes.

Efeitos da intoxicação crônica com o etanol na evolução da Tripanosomíase cruzi experimental no camundongo

Dois experimentos foram realizados para estudar o efeito da intoxicação crônica com o etanol (solução a 7% como única fonte de líquido) sobre a evolução da infecção pelo T. cruzi em camundongos: (1) animais após 60 dias de infecção com cepa miotrópica do T. cruzi foram submetidos à intoxicação crônica com o etanol durante 6 meses; (2) animais cronicamente intoxicados com etanol durante 5 meses foram infectados com a mesma cepa do T. cruzi e, continuando a ingestão do etanol, foram acompanhados até 45 dias após a infecção. Os animais infectados e tratados com etanol apresentaram, em relação aos que não ingeriram álcool etílico: (a) mortalidade semelhante nos dois experimentos; (b) parasitemia mais alta na fase aguda e parasitemia patente mais freqüente na fase crônica; (b) miocardite com exsudato inflamatório menos intenso e fibrose miocárdica mais extensa na fase crônica; (c) no músculo esquelético, miosite menos intensa e arterite com trombose hialina menos freqüente.

Epidemiology of idiopathic dilated and hypertrophic cardiomyopathy. A population-based study in Olmsted County, Minnesota, 1975-1984

Using the records linkage system of the Mayo Clinic and of the Rochester Epidemiology Project, which accesses diagnostic data on the entire population of Olmsted County, Minnesota, we identified 45 new cases of idiopathic dilated cardiomyopathy (DCM) and 19 new cases of hypertrophic cardiomyopathy (HCM) among county residents for the years 1975-1984. Overall age- and sex-adjusted incidence rates were 6.0/100,000 and 2.5/100,000 person-years, respectively. The incidence of DCM doubled from 3.9/100,000 in the first 5 years to 7.9/100,000 person-years in the last 5 years of study. The corresponding change for HCM was from 1.4 to 3.6/100,000 person-years. Age- and sex-adjusted prevalence rates as of January 1, 1985, for DCM and HCM were 36.5/100,000 and 19.7/100,000 population, respectively. The prevalence of DCM in persons less than 55 years old was 17.9/100,000, over a third of whom were New York Heart Association functional Class III or IV at diagnosis. These estimates may be of value in determining the potential use of health care resources, particularly cardiac transplantation.

Psychophysiological effects of oral ethanol in alcoholics and social drinkers

The acute and extended effects of ethanol ingestion were examined in five alcoholic subjects, and five "social" drinkers. Six physiological and four subjective report measures were taken before, during and up to 90 min after the ingestion of ethanol in three doses and placebo. Findings showed that alcohol exerted significant dose-related physiological effects in the initial minutes of ingestion, and in extended analyses of physiological and subjective measures in both groups of drinkers. Alcoholics and social drinkers generally did not differ in their physiological responses to alcohol doses and placebo, while some evidence for tolerance to reported euphoric effects of alcohol in the alcoholic subjects was found. The possibility is raised that early physiological responses observed during ethanol ingestion may arise not only from pharmacological effects of the drink, but may also be evidence for conditional predrink responses.

Calcium transport properties of cardiac sarcoplasmic reticulum from cardiomyopathic Syrian hamsters (BIO 53.58 and 14.6): evidence for a quantitative defect in dilated myopathic hearts not evident in hypertrophic hearts

Calcium uptake was measured in homogenates and microsomal preparations enriched in sarcoplasmic reticulum vesicles isolated from hearts of hypertrophic (BIO 14.6) and dilated (BIO 53.58) cardiomyopathic as well as control (F1B) Syrian hamsters at 3, 7, 9, and 11 months of age. Calcium uptake studies were done using the Millipore filtration technique under conditions known to restrict transport to the sarcoplasmic reticulum. Steady-state calcium uptake capacity was used as a measure of the relative amounts of sarcoplasmic reticulum in homogenates prepared from individual hearts. At 3 months of age, there were no differences in calcium uptake in homogenates from control or myopathic hearts. However, by 9 months, although calcium uptake of homogenates from control and hypertrophic hearts was the same, calcium uptake by homogenates from dilated hearts was significantly depressed both in initial rate and capacity. Similar trends were seen in the microsomal vesicle preparations, but the decrease in calcium uptake in the dilated hearts was significantly lower by 3 months of age. The catalytic activity of the sarcoplasmic reticulum transport enzyme was estimated from the ratio of velocity to capacity, which provides a measure of the fractional rate of filling of the sarcoplasmic reticulum with calcium. The velocity-to-capacity ratios were not different at any of the ages in both the homogenate and microsomal preparations. The results of this study demonstrate that a major defect in the dilated cardiomyopathy may be due to a decrease in the volume or number of sarcoplasmic reticulum calcium transport sites rather than a decrease in specific activity of the transport enzyme.

L-carnitine treatment improves cardiac performance and restores high-energy phosphate pools in cardiomyopathic Syrian hamster

Hamsters with either the dilated (BIO 53.58) or hypertrophic (BIO 14.6) form of cardiomyopathy and an inbred control strain of hamster (F1B) were treated for 6 months with high-dose L-carnitine (1 g/kg/day i.p.). After treatment, the animals were killed and their hearts perfused by the isolated working technique. Mechanical performance (as indicated by the double product of heart rate and left ventricular [LV] peak systolic pressure) of both carnitine-treated cardiomyopathic groups was increased significantly above their respective sham-treated groups. Associated with these increases in mechanical performance were significant increases in both peak-positive LV dP/dt (index of contractility) and peak negative dP/dt (index of relaxation) in both carnitine-treated myopathic groups. Serum carnitine levels were increased 10-15 times within 2 hours after injection of L-carnitine in all 3 groups. Myocardial free-carnitine levels were increased twofold in both control and dilated myopathic hearts above their respective sham-treated groups, restoring the level in the dilated hearts comparable to those of controls. Myocardial carnitine levels in the hypertrophic group were not significantly affected by treatment. Total high-energy phosphate stores, i.e., ATP plus creatine phosphate, were restored to control levels by L-carnitine treatment in both cardiomyopathic groups. Levels of the breakdown products of ATP were maintained primarily in the more readily convertible adenosine diphosphate and adenosine monophosphate forms in all three treated groups. These changes resulted in significantly higher ratios of (ATP)/(ADP + AMP + adenosine) and (creatine phosphate)/(creatine) in the treated hearts. This is the first study demonstrating that high-dose L-carnitine treatment results in improved cardiac performance and increased myocardial total high-energy phosphate stores in the Syrian hamster model with one of two distinct forms of cardiomyopathy, i.e., dilated or hypertrophic. The mechanisms for these effects of exogenous L-carnitine treatment cannot be totally explained by changes in oxidative energy metabolism.

Effect of ethanol on regional myocardial blood flow and hemodynamics, before and after coronary artery ligation in dogs

The effects on regional myocardial blood flows (RMBF) and hemodynamics due to ethanol administered before and after acute coronary artery ligation (CAL) in 18 anesthetized dogs were studied. Ethanol was administered to seven dogs (group I) prior to CAL and to six dogs (group II) after CAL; five dogs (group III, control) received only saline before and after CAL. Uniform blood ethanol levels (180 +/- 30 mg/dl) were maintained in groups I and II after initial ethanol administration. In these groups the heart rate and rate-pressure product (which reflects myocardial oxygen consumption) remained stable, but pulmonary arterial pressures were elevated. Other hemodynamic parameters remained stable in all groups. Ethanol caused a significant transmural increase of RMBF (p less than 0.001) in both groups I and II. In group II the increase was significant in both nonischemic and ischemic tissues, with no apparent redistribution of flow among the myocardial layers. The percentage increase of RMBF due to ethanol was highest in group II nonischemic tissue (95-107%) compared to the corresponding ischemic tissue (57-60%) and the group I myocardial tissue (36-47%) prior to CAL (p less than 0.001). The observed differences between ethanol pre- and posttreatments suggest different interactions between ethanol and catecholamines. The results also confirm that vasodilatory reserve is present in the acutely ischemic myocardium and that the local availability of ethanol is important for coronary vasodilatation.

Animal models of chronic alcohol ingestion: the liquid diet

A suitable animal model that mimics the effects of chronic alcohol intake in man has long been sought. The ethanol-containing liquid diet, although often finding favour in a variety of experimental studies, has recently been criticised for being nutritionally inadequate. Results of this study indicate liquid diets are capable of maintaining the growth of female, but not male, rats at rates comparable to those of similar animals fed on commercially available rodent pellets or on laboratory-prepared pelleted diets. In addition preliminary data are reported indicating the suitability of this model for inducing tolerance to alcohol.

Failure of a branched chain amino acid-enriched diet to reverse ethanol inhibition of cardiac protein synthesis in the rat

The fractional rate of protein synthesis was determined in the hearts of rats in vivo fed on diets containing 27% of energy as ethanol or on this diet supplemented with 5% of equimolar amounts of branched chain amino acids (BCAA). Administration of ethanol significantly decreased the fractional synthetic rate of mixed cardiac proteins and this depression was not ameliorated by concomitant feeding of BCAA. These data are discussed in relation to the stimulation of cardiac protein synthesis by BCAA observed in vitro.

Changes in lipid composition of rat heart mitochondria after chronic ethanol administration

Triacylglycerols and phospholipids of mitochondria from heart ventricular muscle were analyzed following chronic ethanol administration (2 and 10 g/kg of body weight/day) to adult rats for 21 days via intragastric intubation. Triacylglycerols were elevated 57% in the high ethanol group as compared to controls, but cholesterol level was not altered. Most of the phospholipids, including lysophospholipids, showed a small increase in level after ethanol administration. However the greatest increase (50%) occurred in ethanolamine plasmalogens. Although small changes in the acyl group composition of phosphatidylethanolamines and phosphatidylcholines were observed, the acyl group profile of cardiolipin remained unaltered. It is concluded that myocardial membranes respond to the disordering effects of ethanol by altering the synthesis of selected lipids more than through altering the phospholipid acyl group composition. Some of these changes may be responsible for altered mitochondrial functions in the myocardium.

Acute alcohol ingestion reduces heart rate variability

Blood pressure, heart rate and heart rate variability (HRV) prior and during acute ethanol intoxication (0.7 g/kg) were studied in 8 healthy volunteers. Blood pressure and heart rate remained unaltered during intoxication. While HRV was significantly reduced immediately after ingestion (2P = 0.01). It is speculated that the reduction of HRV after heavy ethanol consumption contributes to the genesis of cardiac arrhythmias in chronic alcoholics with or without clinical evidence of heart disease.

Ethanol and heart disease. An underestimated contributing factor

With the number of chronic heavy users of ethanol in the United States estimated to be 15 to 20 million and the evidence increasing that ethanol causes serious cardiac metabolic disturbances, ethanol abuse is obviously a serious problem and most likely is an important contributing factor to cardiac morbidity and mortality. However, a direct cause-and-effect relationship between the biochemical dysfunctions produced by ethanol and the clinical entity of alcoholic cardiomyopathy has not been clearly established. What is lacking is a method to differentiate the damage secondary to ethanol abuse from that secondary to other causes. Sorely needed is a biochemical or anatomic marker (perhaps evaluated by serial myocardial biopsy) for alcoholic cardiomyopathy and a study to detect which cases of dilated cardiomyopathy indeed are due to ethanol-induced damage. Further longterm studies are also needed to demonstrate the benefits of abstinence upon large groups of patients, the effects of abstinence upon sudden death, and the effects of discontinuance of ethanol use for patients in the early stages of alcoholic cardiomyopathy. Ethanol is probably an underestimated contributing factor to cardiac disease. The importance of determining ethanol's impact on cardiovascular morbidity and mortality is underscored by the facts that alcoholic heart disease is completely avoidable and is largely reversible by abstinence.

Effects of maternal alcohol intoxication on fetal circulation and myocardial function: an experimental study in the ovine fetus

To determine whether acute alcohol ingestion during pregnancy could affect fetal myocardial function, studies were carried in six chronically catheterized fetal sheep during maternal alcohol infusion. Absolute ethyl alcohol (0.8 ml/kg) was administered to the mother over 10 minutes via the jugular vein. These infusions were repeated every 30 minutes during 3 hours, and peak maternal and fetal blood concentrations close to 200 mg/dl alcohol were reached. Fetal PCO2 decreased from a baseline of 43.15 +/- 3.75 to 36.13 +/- 2.6 torr 1 hour after the start of alcohol infusion (P less than 0.05). Similarly, pH rose from 7.37 +/- 0.027 to 7.44 +/- 0.015 (P less than 0.05). Both values returned to baseline level at the end of alcohol infusion. PO2 remained within physiologic limits. The systolic time intervals of the fetal heart showed a rapid and prolonged modification. The pre-ejection period from 58 +/- 8 to 66 +/- 4 msec (P less than 0.05) during the infusion; this change was related to an increase in the isometric contraction period. The ratio of the pre-ejection period over the ejection time was also significantly increased (P less than 0.01), and remained elevated until the end of the experiment (12 hours). A rise in fetal systolic and diastolic pressures was observed at about 2 hours after the start of the alcohol infusion, and lasted 4 hours. This study suggests that an episode of maternal alcohol intoxication causes rapid depression of fetal myocardial contractility that is maintained several hours after cessation of alcohol ingestion.

Ethanol toxicity in primary cultures of rat myocardial cells

The potential cardiotoxicity of ethanol (EtOH) was evaluated in primary cultures of rat myocardial cells. EtOH cardiotoxicity was assessed in the cells on the basis of cell morphology, lactate dehydrogenase (LDH) leakage, succinate dehydrogenase (SDH) activity, and beating rates. Cells were treated with EtOH at concentrations of 600, 800, and 1000 mg% for duration of 1, 4, and 24 h and then evaluated for cardiotoxicity. Vacuole formation occurred 1 h after exposure to EtOH at 800 and 1000 mg%; by 4 h, cytosolic granular material appeared in these cells. Exposure for 24 h to all concentrations of EtOH resulted in vacuole, granule, and pseudopod formation and loss of cross-striations. Significant LDH leakage occurred at 1 h and 4 h with 800 and 1000 mg% EtOH. LDH release was significantly increased after 24 h with all concentrations. SDH activity was significantly depressed after 24 h with all concentrations of EtOH. Beating rates were altered as early as 1 h after exposure to 800 and 1000 mg% EtOH. After 24 h, those cells exposed to the highest concentrations of EtOH were not beating at all. These data suggest that primary myocardial cell cultures may be used to assess the in vitro cardiotoxicity of EtOH to the myocardial cell.

Ultrastructural features of ethanol-induced cardiomyopathy in turkey poults

Alcoholic cardiomyopathy, characterized by cardiac hypertrophy, was induced in young turkey poults with 5% ethanol. Ultrastructural features included accumulation of glycogen, swollen mitochondria, myofibrillar lysis, increased number of lysosomes, dilated sarcoplasmic reticulum and dense myofibers. Similarity of these alterations to those described in human alcoholic cardiomyopathy confirms the usefulness of the turkey poult as an animal model for this disease syndrome.

Inhibition by ethanol of cardiac protein synthesis in the rat

Protein synthesis and degradation were measured in the hearts of rats fed on diets containing 27% of calories as ethanol. Feeding of ethanol decreased the rate of synthesis of mixed cardiac proteins but was without effect on the rate of breakdown of myofibrillar and sarcoplasmic proteins. Concentrations of RNA in the hearts were not altered by ethanol feeding, indicating a decrease in RNA activity for protein synthesis.