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Chapter 14 Cardiovascular Diseases: Understanding Risks and Measures of Prevention

Chapter 14 Cardiovascular Diseases: Understanding Risks and Measures of Prevention. Understanding Cardiovascular Diseases. More than 70 million Americans have some form. Fifty percent of all deaths in the United States each year result from cardiovascular disease.

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Chapter 14 Cardiovascular Diseases: Understanding Risks and Measures of Prevention

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  1. Chapter 14Cardiovascular Diseases:Understanding Risks and Measures of Prevention

  2. Understanding Cardiovascular Diseases • More than 70 million Americans have some form. • Fifty percent of all deaths in the United States each year result from cardiovascular disease. • The term refers to a number of conditions that damage the heart or arteries. • If the coronary arteries (large blood vessels that carry blood to and from the heart) become diseased or blocked, a heart attack may result.

  3. Understanding Cardiovascular Diseases • If the heart does not receive a continual supply of blood and oxygen, the heart cells die and an infarction occurs. • If the blood supply to the heart is only partially blocked, the condition is called ischemia. • A stroke occurs when there is damage to the brain from an insufficient supply of blood to the brain cells. • Cardiovascular diseases are preventable and primarily are lifestyle diseases.

  4. The Heart and Blood Vessels • Arteries—Carry oxygenated blood from the heart to all organs and tissues in the body • Veins—Return blood to the heart after oxygen and nutrients have been exchanged for carbon dioxide and waste products • Capillaries—Tiny blood vessels that branch out from arteries and veins and circulate blood to all the cells in the body • Myocardium—Muscular wall of the heart • Heart—About the size of a fist

  5. Heart and Major Arteries

  6. The Heart • Has four chambers: • Upper two chambers are called the left atrium and right atrium. • Lower two chambers are called the left ventricle and right ventricle.

  7. Flow of Blood Through the Heart • Blood that is depleted of oxygen returns to the heart via the right atrium. • It flows to the right ventricle and is pumped to the lungs, where it is reoxygenated and returned to the left atrium via the pulmonary vein. • This fresh blood is pumped throughout the body’s tissues from the left ventricle through the large artery called the aorta.

  8. Regulating Blood Flow • The cardiovascular system is equipped with one-way valves in the chambers of the heart and blood vessels. • With every heartbeat, the valves open and close to allow blood to flow in one direction. • If the veins in the legs are weakened, blood tends to accumulate in the legs, producing varicose veins. • Varicose veins are a common, but less serious, form of valve damage.

  9. Heart Valves

  10. Atherosclerosis • Hardening of the arteries • One form is the formation of plaque. • If coronary arteries become partially blocked and the heart does not receive enough oxygen, chest pain, called angina pectoris, occurs. • If the coronary artery is blocked completely, a heart attack occurs.

  11. Atherosclerosis

  12. Diagnosis of a Heart Attack • More than a million people are admitted to hospitals annually with possible heart attacks. • Diagnosing a heart attack is time-consuming and costly. • Blood levels of the following proteins change during a heart attack: • Creatine kinase • Troponin • Myoglobin • Myosin

  13. Repairing Blocked Arteries • Angiocardiography—Procedure that visualizes the flow of blood through the arteries and chambers of the heart to confirm a blocked artery or restricted blood flow. • Arteriography—Invasive procedure that gives a precise image of the flow of blood through the coronary arteries that supply blood to the heart.

  14. Repairing Blocked Arteries • Coronary bypass surgery—The diseased segment of the artery is cut out and replaced with a grafted piece of good artery to restore normal flow of blood to the heart. • Open-heart surgery—Heart is exposed while being repaired and blood is diverted through a heart–lung machine.

  15. Repairing Blocked Arteries • An alternative surgical procedure is percutaneous transluminal coronary angioplasty, in which a balloon is inserted into the artery and inflated so it pushes the plaque against the wall of the artery, opening the artery. • Costs less than bypass surgery, but the blockage recurs many times.

  16. Repairing Blocked Arteries • Alternative to bypass surgery is “stenting,” which involves inserting a catheter into an artery in the arm or leg, threading it to the blockage point, and inserting props or “stents” to open the artery.

  17. Repairing Blocked Arteries • Carotid endarterectomy is used to clear plaque. • A stent is inserted into the carotid artery during the procedure to keep blood from flowing to the brain.

  18. Stroke • Third leading cause of death in the United States after coronary heart disease and cancer. • High blood pressure is related to at least 70% of all strokes. • It is a form of cardiovascular disease that affects arteries supplying blood to the brain. • Brain cells die within minutes without oxygen. • A person who has had a stroke can lose the ability to speak, have one arm or leg become paralyzed, become paralyzed on one side of the body, or die.

  19. Stroke • Can occur from injuries to the head or from weak spots in the arteries, called aneurysms, that balloon and rupture. • Can occur when a weak heart cannot pump enough blood to the brain. • Four kinds of strokes are defined medically.

  20. Stroke • Two kinds of stroke are caused by clots that block blood flow to the brain. • Cerebral thrombosis and cerebral embolism are the most common types of stroke; both are caused by clots. • Two are caused by the rupture and hemorrhage of an artery supplying blood to the brain. • Cerebral and subarachnoid hemorrhages are caused by ruptured blood vessels. These occur less frequently, but have a high fatality rate.

  21. Warning Signs of a Stroke • Signs of a stroke include: • Sudden weakness or numbness of the face, arm, or leg on one side of the body • Sudden dimness or loss of vision, especially in one eye • Loss of speech, difficulty understanding speech, or trouble talking • Sudden, severe headaches with no known cause • Unexplained unsteadiness, dizziness, or fall

  22. Preventing a Stroke • Reduce the risk factors that are controllable largely by changes in lifestyle: • High blood pressure • Heart disease • Cigarette smoking • Transient ischemic attacks • High red blood cell count

  23. Risk Factors for Cardiovascular Disease • Research seems to indicate that plaque begins to build up in the arteries at an early age; this is why positive lifestyle behaviors are important at all ages. • Cholesterol—There are two major kinds of cholesterol: HDL (“good” cholesterol) and LDL (“bad” cholesterol). • Familial hyperlipidemia—A rare inherited disease that results in high levels of cholesterol in the blood.

  24. Measuring Cholesterol Levels • Total cholesterol levels are measured in milligrams per deciliter (mg/dl) of blood. • Cholesterol level below 200 mg/dl indicates a relatively low risk of coronary heart disease. • A level of 240 mg/dl or higher doubles the risk of coronary heart disease (CHD). • Total cholesterol may not be a reliable indicator because high levels of HDL may counteract the bad effects of a high LDL count.

  25. Cholesterol, Statins, and Inflammation • Statins are a class of drugs that reduce the level of blood cholesterol. • Statins also reduce the level of reactive protein in the blood.

  26. High Blood Pressure • If the cause of high blood pressure (HBP) is unknown, it is referred to as essential hypertension. • This includes 90% to 95% of cases of HBP. • The remaining HBP cases are symptoms of recognizable diseases, such as kidney abnormality, congenital defect of the aorta, or adrenal gland tumor. • These types of hypertension are referred to as secondary hypertension.

  27. Measuring Blood Pressure • The systolic pressure is the maximum pressure in the arteries that occurs when the heart contracts. • The diastolic pressure is the pressure between contractions, when the pressure falls as blood flows from one chamber to another. • Normal blood pressure is defined as less than 140/90 (systolic/diastolic).

  28. Lowering Blood Pressure • Can be lowered by making the following lifestyle changes: • Lowering excessive caloric intake • Increasing physical activity • Decreasing salt and alcohol consumption • Consuming adequate amounts of potassium

  29. Stages of High Blood Pressure

  30. Cigarettes and CVD • Cigarette smoking is a major risk factor contributing to the development of heart disease, heart attacks, and strokes. • Smokers have a two to four times greater risk of dying from a heart attack than nonsmokers. • Risk of heart disease from secondhand smoke is also significant. • Smoking damages blood vessels carrying blood to the arms and legs, which could lead to gangrene.

  31. The Metabolic Syndrome • Factors that are shared by people at risk for diabetes, CVD, and heart attack: • Waist circumference larger than 40 inches in men and 35 inches in women • Serum triglyceride level of 150 mg/dl or greater • Blood pressure 135/85 or higher

  32. Stress • Main risk factor for heart disease is stress. • Type A behavior includes: • Irritation and impatience while waiting in lines. • Constantly feeling pressured. • Not letting other people finish what they are saying. • Always trying to show others how to do things correctly. • Playing games to win every time. • Not allowing time for relaxation.

  33. Diet and CVD • A deficiency of only one nutrient can impair the body’s ability to use all others, even if the others are present in sufficient amounts. • Vitamin E: Antioxidant that removes lingering oxygen atoms that can damage body tissues. • B vitamins: Lower the levels of homocysteine in the blood. • Calcium: Deficiency is a risk factor for hypertension in persons of all ages.

  34. Diet and CVD • Soy products: Help remove cholesterol from the blood and block oxidation of LDL, which prevents it from sticking to the walls of arteries. • Fish oils: Populations that consume large amounts of fish show lower rates of CHD than populations that do not. • Tea: Green and black tea contain antioxidant chemicals that help block oxidation of LDL in the blood.

  35. Diet and CVD • Aspirin: Significantly reduces the risk of CHD and heart attacks. Helps “thin” blood and combats inflammation. If you feel you might be having a heart attack, call 911, and then take a couple of aspirin to help prevent clotting. • Alcohol: In one study, men who had one or two drinks a day over 12 years reduced their risk of dying from a heart attack by about 20% compared with men who did not drink alcohol.

  36. Preventing Cardiovascular Disease • Now that you are armed with knowledge about reducing the chances of heart attacks and stroke, what needs to be done? • Reduce weight • Reduce consumption of foods with saturated fats • Eat a lot of fruits and vegetables • Take supplements • Don’t smoke • Be active

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