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Cardiovascular Overview Cardiovascular disease is the world's leading cause of death. Cardiovascular diseases consist of a broad range of medically important conditions that occur within the cardiovascular system. These include: hypertension, coronary heart disease (CHD) manifested as myocardial infarction (MI) or angina (angina pectoris), congestive heart failure (CHF), stroke (covered in a separate section), rheumatic fever or rheumatic heart disease, and congenital cardiovascular defects. There are additional diseases of the cardiovascular system such as arrhythmias (tachycardia, atrial fibrillation or flutter); diseases of the arteries (atherosclerosis, aortic aneurysm); cardiomyopathy (36% of young athletes who die suddenly are likely to suffer from hypertrophic cardiomyopathy); and peripheral vascular disease (diseases of blood vessels outside the heart and brain, narrowing vessels supplying blood to arm or leg muscles) such as intermittent claudication. Increasing age, gender (men are at higher risk than women), and heredity (racial and genetic) are major risk factors for development of cardiovascular disease. These are largely not controllable. Risk factors amenable to modification or reduction through changes in lifestyle habits include: smoking tobacco products, high cholesterol and/or triglyceride levels, high blood pressure, physical inactivity, overweight or obesity, and diabetes. HMG CoA reductase inhibitors (statins) have been shown to improve endothelium-dependent vasodilation in both coronary and peripheral arteries apart from their cholesterol lowering effect. This improved vasodilation is likely due to the up-regulation of endothelial Nitric Oxide Synthase (eNOS). eNOS is an enzyme having potent anti-atherogenic properties that include a decrease in leukocyte adhesion, platelet aggregation, and vascular smooth muscle cell growth. The mechanism by which HMG-CoA reductase inhibitors increase eNOS expression and activity occurs via stabilization of eNOS mRNA indirectly by regulating the cell cycle of vascular endothelial cells. Increased eNOS amount results in greater vasodilation, improved blood flow, and increased endothelial function, which mitigates some of the risks associated with an ailing cardiovascular system demonstrating decreased blood flow. Additional information about cardiovascular diseases can be obtained from a number of sources. We have identified several excellent sources of information in the Web Links area of this website's Resources section. |
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