Ethyl alcohol and myocardial metabolism

Alcohol intake is associated with altered pulmonary function

Little is known about the effect of moderate alcohol intake on lung function in the general population. Because moderate alcohol intake appears to reduce cardiovascular disease risk, we hypothesized that moderate alcohol intake is associated with better pulmonary function. To test this hypothesis, we examined the association between alcohol intake and pulmonary function, measured by spirometry, in a representative sample of U.S. adults who participated in the Third National Health and Nutrition Examination Survey. A stratified multistage clustered probability design was used to select a population-based sample. Data analyzed included alcohol intake, smoking status, education, body mass, sex, age, race, diabetes status, and CHF status. The Third National Health and Nutrition Examination Survey was conducted from 1988 to 1994 by the National Center for Health Statistics of the Centers for Disease Control and Prevention, Atlanta, GA. We analyzed data from 15,294 study participants who completed extensive questionnaires in the household and a comprehensive physical examination, including pulmonary function testing, either in the household or at a specially equipped mobile examination center. Low-to-moderate alcohol intake was not associated with reduced odds of obstructive lung function. In fact, increased odds for obstructive lung pattern were observed only in former heavy drinkers. In contrast, low-to-moderate alcohol intake was associated with better forced vital capacity and forced exhaled volume in 1s in the absence of obstruction, consistent with reduced odds for lung restriction. Using a logistic regression model, we found that individuals reporting alcohol consumption had a lower risk of lung restriction both before and after adjusting for confounding factors including smoking (P< or =.001). Alcohol intake-related reduced risk for restriction was associated with lower risk of CHF, diabetes, obesity, and lower markers of inflammation (white blood cell, fibrinogen, and C-reactive protein) consistent with less lung congestion, external restriction, and/or lung inflammation. Our analyses indicate that alcohol consumption, even at very modest intake levels, is associated with less lung restriction.

Ultrastructural and histochemical observations in human and experimental alcoholic cardiomyopathy

The morphologic features of alcoholic cardiomyopathy in human sudden death compared with those of experimental alcoholic cardiomyopathy (6 weeks of alcohol administration and simultaneous inhibition of catalase activity) proved to be nearly identical. Regular and similar alterations in alcoholic cardiomyopathy in both human victims of sudden death and experimental rats are described as a complex of alterations characteristic of alcoholic cardiomyopathy. This complex of changes was used as the basis for morphologic diagnosis of endomyocardial biopsy in two groups of patients: I) chronic alcoholics (second to third stages), and II) patients with clinically diagnosed congestive cardiomyopathy. Typical signs of alcoholic cardiomyopathy were found in 9 of the 11 patients in the first group and in 6 of 18 in the second group. The fact that the features of alcoholic cardiomyopathy were not found in all cases of chronic alcoholism supports the hypothesis that the administration of alcohol itself is not sufficient for the development of this disease. The level of enzyme activity in the metabolism of alcohol appears to be of great importance. This hypothesis is confirmed by experiments with rats in which this disease developed only when there was simultaneous alcohol administration and inhibition of catalase activity. Histochemical study showed that the alterations of enzyme (both energetic and alcohol metabolism) in rats were similar to those found in the biopsy specimens from patients with alcoholic cardiomyopathy. Certain questions regarding the pathogenesis of alcoholic cardiomyopathy are discussed.

The relative resistance of normal young women to ethanol-induced myocardial depression

In contrast to previous reports from our own laboratory utilizing systolic time intervals (STI) and by others using ultrasound, no evidence of acute myocardial depression was observed in response to an ethanol (ETOH) dose of 1.25 ml/lb consumed over a period of 60 minutes by 6 young women (22.7 ± 7 years; 133 ± 6 lbs) who were monitored for 3 hours thereafter. Specifically, there was no significant change in fractional shortening (%ΔD), ejection frac tion, or mean circumferential fiber shortening velocity. Cardiac index and stroke index also remained stable, although heart rate increased ( P < 0.005) and systolic and diastolic blood pressure fell ( P < 0.01 and 0.25 respectively).

To examine further this unanticipated cardiac resistance to ETOH, we re- examined the sex-specific difference of STI response to acute ETOH exposure in a previously reported group of 32 normal subjects (20 men and 12 women). Significant increases in PEP, PEPI, ICT, and PEP/LVET ( P < 0.005, 0.005, 0.005, and 0.001 respectively) were observed in men only. Because we have previously observed that chronic ETOH consumption blunts acute myocardial depression, and because only 1 of 7 STI subjects historically consuming the least ETOH (< 1 oz/day) was a woman, STIs, were reassessed only in those subjects with a chronic consumption of 1 or more oz/day (14 men and 11 women). Myocardial depression as estimated by an increased ICT ( P < 0.05) and PEP/ LVET (P < 0.02) was again observed in men only.

We concluded that women are less susceptible than men to acute ETOH induced myocardial depression, as has recently been suggested for chronic ETOH consumption as well.

Magnesium deficiency and cardiac disorders

Magnesium deficiency can occur in congestive heart failure, after diuresis with furoxemide, ethacrynic acid and mercurials, and with digitalis intoxication, diabetic acidosis, acute and chronic alcoholism, delerium tremens, cirrhosis, malabsorption syndromes, protracted postoperative cases, open heart surgery, the diuretic phase of acute tubular necrosis, and with hypoparathyroidism, primary aldosteronism, juxta-glomerular hyperplasia and pancreatitis. Two cases of serious ventricular arrhythmias associated with magnesium depletion are described. Clinical manifestations are vague but center around neurologic symptoms such as weakness, tremors, stupor, coma, nausea, vomiting and anorexia. Serious cardiac arrhythmias also occur with magnesium depletion. Magnesium appears to be very useful in hypomagnesemic or digitalis-toxic tachyarrhythmias. Magnesium may also be valuable in normomagnesemic tachyarrhythmias. Ten to fifteen milliliters of a 20 percent magnesium sulfate solution, given intravenously over 1 minute, followed by a slow 4 to 6 hour infusion of 500 ml of 2 per cent magnesium sulfate in 5 per cent dextrose in water is recommended. Recurrence of arrhythmias is common and a second infusion of magnesium sulfate may be necessary. Hypermagnesemia occurs frequently in renal insufficiency, and magnesium therapy may then be contraindicated. Serum levels above 5.5 meq/liter should be avoided. Loss of deep tendon reflexes and a decrease in respiratory rate can be used as guides to magnesium therapy. A plea is made for frequent analysis of serum magnesium so that more knowledge can be gained regarding this important biologic element in cardiovascular disorders.