Cardiovascular Disease Health Article

Cardiovascular Disease

The cardiovascular system comprises the heart, veins, arteries, and capillaries, which carry blood back and forth from the heart to the lungs (pulmonary circulation) and from the heart to the rest of the body (systemic circulation). The heart works on electrical impulses and produces them constantly, unless stress, fear, or danger is involved, in which case the impulses will increase dramatically. The body's largest artery is the aorta and the largest vein is the vena cava. Veins are thinner than arteries, which resemble rubber bands in that they expand more easily (depending on the amount of blood passing through them). Smaller blood vessels, or capillaries, channel oxygen and blood to tissues. The process is a cycle in which the capillaries deliver oxygen-rich blood to the body and pick up oxygen-poor blood, which is then taken into the veins and finally to the heart to be "rejuvenated" or cleansed.

Cardiovascular disease (CVD), and the resulting complications, is the main cause of death for both males and females in the United States and other technologically advanced countries of the world. It usually is in the top five causes of death in lesser-developed countries. Diseases of the cardiovascular system include those that compromise the pumping ability of the heart, cause failure of the valves, or result in narrowing or hardening of the arteries. In addition, toxins and infectious agents may damage the heart and blood vessels. Injury or failure of the cardiovascular system, especially the heart, also will affect the peripheral tissues that depend on the delivery of nutrients and the removal of wastes through the blood vascular system. CVD is a family of diseases that includes hypertension, atherosclerosis, coronary heart disease, and stroke.

Hypertension (High Blood Pressure)

Blood pressure is a measure of the force of blood against the walls of arteries. It is recorded as two numbers: the systolic pressure over the diastolic pressure. Systolic pressure is the pressure as the heart beats, while diastolic pressure measures the pressure when the heart relaxes between beats.

Blood pressure is normally measured at the brachial artery with a sphygmomanometer (pressure cuff) in millimeters of mercury (mm Hg) and given as systolic over diastolic pressure. Normal blood pressure is less than 120 mm Hg systolic and less than 80 mm Hg diastolic—usually expressed as "120 over 80." However, normal for an individual varies with the height, weight, fitness level, age, and health of a person. Blood pressure is normally maintained within narrow limits, but it can drop during sleep or increase during exercise. Hypertension (HTN), or high blood pressure, occurs when the force of blood passing through blood vessels is above normal. The increase in pressure forces the blood to hit the blood vessel walls. HTN is called "the silent killer" because many people do not know they have the condition. Consistently high blood pressure increases the risk for a stroke or a heart attack. It may be caused by poor diet, obesity, smoking, stress , and inactivity. The Dietary Approach to Stop Hypertension (DASH) project recommends a diet that is low in sodium and high in fruits, vegetables, and low-fat dairy products. Other approaches to controlling HTN include weight loss, smoking cessation, increased physical activity, and stress management.

Atherosclerosis

Atherosclerosis, or hardening of the arteries, is the cause of more than half of all mortality in developed countries and the leading cause of death in the United States. When the coronary arteries are involved, it results in coronary artery disease (CAD). The hardening of the arteries is due to the build up of fatty deposits called plaque, and mineral deposits. As a result, the supply of blood to the heart muscle (myocardium) is reduced and can lead to ischema (deficiency of blood) to the heart, causing chest pain or a myocardial infarction (heart attack). The hardening of the arteries causes an increase in resistance to blood flow, and therefore an increase in blood pressure. Any vessel in the body may be affected by atherosclerosis; however, the aorta and the coronary, carotid, and iliac arteries are most frequently affected. The process begins early in life. Therefore, physicians should obtain risk-factor profiles and a family history for children.

Coronary Artery Disease

Coronary artery disease (CAD) refers to any of the conditions that affect the coronary arteries and reduces blood flow and nutrients to the heart. It is the leading cause of death worldwide for both men and women. Atherosclerosis is the primary cause of CAD. Controlled risk factors associated with CAD include hypertension, cigarette smoking, elevated blood lipids (e.g., cholesterol, triglyceride), a high-fat diet (especially saturated fats and trans-fatty acids), physical inactivity, obesity, diabetes, and stress. Lifestyle changes can assist in prevention of CAD. Uncontrolled risk factors include a family history of CAD, gender (higher in males), and increasing age.