Prevalence of three cardinal risk factors in a random sample of men and in patients with ischaemic heart disease

Interaction of chronic cigarette and ethanol use on myocardium

Chronic cigarette use is common in persons who habitually use other cardioactive agents that have been causally associated with heart disease. This study was undertaken to determine if cigarette use intensifies the abnormalities of myocardial function and composition observed in experimental alcoholism over an 18-month period. Young adult male beagles with tracheostomy were divided into four groups. There were 10 controls (group 1); 9 smoked seven cigarettes per day (group 2); 7 were fed ethanol as 20% of calories (group 3), and 6 received both ethanol and cigarettes (group 4). After a period of 18 months, left ventricular function was assessed under anesthesia. Heart rate, left ventricular end-diastolic pressures, and volumes (indicator dilution) did not differ in the four groups. An index of contractility derived by normalizing peak dP/dt for pre- and afterload was reduced significantly below the level of 2.41 +/- 0.7 cm/s in controls to 1.41 +/- 0.35 in group 2, 1.19 +/- 0.38 in group 3, and 1.28 +/- 0.17 in the ethanol cigarette group (each p less than 0.002). Arterial pressures were moderately elevated above group 1 in all three experimental groups without evidence of left ventricular hypertrophy. In contrast to smoking, which elicited no abnormalities of myocardial cation composition, ethanol reduced myocardial potassium and sodium in group 3 without a gain of water content. In group 4, no further decline of tissue cations was observed. Thus, cigarette use when combined with ethanol over a relatively long period produced no greater myocardial abnormalities than ethanol alone and may not be essential to the genesis of cardiomyopathy in alcoholics.

Risk factors and coronary heart disease--facts or fancy?

The importance of the many well-published epidemiologic studies for the philosophy of prevention of ischemic heart disease has led to this analysis of the background design and early results of three such studies, i.e., the Framingham study, the National Pooling Project, and the Stockholm Prospective Study. Besides indicating certain flaws in the early design, it is demonstrated that the authors usually press their factual data to conclusions that are not only really valid, with some exceptions. This analysis leads to the conclusion that high blood pressure and cigarette smoking seem to be much more important for the development of ischemic heart disease than high serum lipids in the populations studied. They are, furthermore, selected in such a way that the results cannot have any bearing on the general population and, in particular, on its lower and higher social strata.

Cardiovascular effects of long-term cigarette smoking and nicotine administration

The nature of the cardiovascular risk in cigarette smokers has not been characterized. To compare the relative effects of long-term smoking and nicotine administration on the cardiovascular system, 18 month old beagle littermates were prepared with a permanent tracheostomy. They were classified into three groups: I, seven control dogs; II, nine dogs that smoked seven cigarettes/day; and III, eight dogs that received an equivalent amount of nicotine. After a period of up to 22 months, the animals were catheterized under anesthesia for assessment of left ventricular function and volumes by indicator-dilution technique. Heart rate, stroke volume, left ventricular end-diastolic pressure and volume and intraventricular conduction times did not differ significantly in the three groups. Left ventricular ejection fraction was 44 +/- 3 percent (mean +/- standard error of the mean) in the control group, 35 +/- 3 percent in the dogs that smoked cigarettes (P less than 0.05) and 27 +/- 3 percent in those given nicotine (P less than 0.01) despite similar values for end-diastolic variables in the three groups. The first derivative of left ventricular pressure (dP/dt) normalized for pre- and afterload was 2.4 +/- 0.2 cm/sec -1 in the control group, 1.41 +/- 0.12 in the cigarette-smoking group (P less than 0.005) and 1.34 +/-0.08 in the nicotine group (P less than 0.01). Although mean aortic pressure was significantly elevated in both the smoking (127 +/- mm Hg) and nicotine (127 +/- 10 mm Hg) groups, there was no significant correlation with the contractility indexes. Reduction of afterload to normal levels did not affect the abnormal ventricular performance. Hypertrophy, inflammation and abnormalities of cell ultrastructures were not present, and myocardial lipid and cation composition were normal. Since interstitial fibrosis was evident in both experimental groups, an alteration of elastic elements may be operative. These cardiovascular abnormalities appear to be predominantly dependent on the nicotine of cigarettes.