© McGraw-Hill Companies. All rights reserved. Preventing Cardiovascular Disease Chapter 2

© McGraw-Hill Companies. All rights reserved. Cardiovascular Disease the leading cause of death in the U.S.— 37.3% of all deaths the leading cause of death in the U.S.— 37.3% of all deaths Approximately 25% of Americans have one or more forms of heart or blood vessel disease. Approximately 25% of Americans have one or more forms of heart or blood vessel disease. Approximately 330,000 Approximately 330,000 people die annually of people die annually of coronary heart disease coronary heart disease (CHD). (CHD).

© McGraw-Hill Companies. All rights reserved. The Heart Consists of cardiac muscle Consists of cardiac muscle Weighs 8 to 10 ounces Weighs 8 to 10 ounces Has two halves (pumps) Has two halves (pumps) divided by the septum Halves are divided into upper chambers (atria) and lower chambers (ventricles) Halves are divided into upper chambers (atria) and lower chambers (ventricles)

© McGraw-Hill Companies. All rights reserved. Circulation The primary function of circulation is to provide a constant supply of blood and nutrients to cells while removing their waste products The left side of the heart (systemic pump) receives the oxygenated blood from the lungs and pumps it to all the tissues in the body The left side of the heart (systemic pump) receives the oxygenated blood from the lungs and pumps it to all the tissues in the body The right side of the heart (pulmonary pump) receives deoxygenated blood from the body and pumps it to the lungs The right side of the heart (pulmonary pump) receives deoxygenated blood from the body and pumps it to the lungs

© McGraw-Hill Companies. All rights reserved. Circulation The heart has its own conduction system The heart has its own conduction system The beating rate and rhythm are established by the sinoatrial (SA) node (pacemaker) The beating rate and rhythm are established by the sinoatrial (SA) node (pacemaker) The electrical contraction pauses at the atrioventricular (AV) node, allowing the ventricles to fill with blood The electrical contraction pauses at the atrioventricular (AV) node, allowing the ventricles to fill with blood

© McGraw-Hill Companies. All rights reserved. Circulation The heart is supplied with blood from coronary circulation after it has been ejected from the heart The heart is supplied with blood from coronary circulation after it has been ejected from the heart Blood is so important to the heart that every muscle fiber is supplied by at least one capillary Blood is so important to the heart that every muscle fiber is supplied by at least one capillary

© McGraw-Hill Companies. All rights reserved. Cardiovascular Disease Coronary heart disease (coronary artery disease; CAD) is diagnosed when any artery is narrowed by 60% or more Coronary heart disease (coronary artery disease; CAD) is diagnosed when any artery is narrowed by 60% or more A myocardial infarction (heart attack; death of the heart muscle) occurs when blood flow to the heart muscle is disrupted A myocardial infarction (heart attack; death of the heart muscle) occurs when blood flow to the heart muscle is disrupted Most heart attacks occur after age 65, but the problems leading up to them begin as early as adolescence Most heart attacks occur after age 65, but the problems leading up to them begin as early as adolescence

© McGraw-Hill Companies. All rights reserved. Myocardial Infarction The medical term for heart attack is myocardial infarction (MI) Up to one third of all heart attacks are silent—without obvious signs or symptoms Up to one third of all heart attacks are silent—without obvious signs or symptoms –Silent ischemia, reduced blood flow, can initiate heart attacks without warning

© McGraw-Hill Companies. All rights reserved. Cardiovascular Disease (2) Americans as young as 8 have obstructions in their coronary arteries caused by atherosclerosis Americans as young as 8 have obstructions in their coronary arteries caused by atherosclerosis

© McGraw-Hill Companies. All rights reserved. Stroke (Brain Attack) Strokes are caused by a thrombus or an embolus (70% to 80%) or a cerebral hemorrhage Strokes are caused by a thrombus or an embolus (70% to 80%) or a cerebral hemorrhage Brain cells die, causing loss of function of some parts of the body Brain cells die, causing loss of function of some parts of the body Strokes have similar risk and prevention factors as heart disease Strokes have similar risk and prevention factors as heart disease

© McGraw-Hill Companies. All rights reserved. Unchangeable Risk Factors for Heart Disease Age Age –55% of heart attacks occur after age 65 Male gender Male gender –Heart disease is the leading cause of death for both males and females –Females have a lower rate than males –Rate is increasing among females, particularly those who smoke and use oral contraceptives Heredity & Race Heredity & Race

© McGraw-Hill Companies. All rights reserved. Major Risk Factors That Can Be Changed Cholesterol is a steroid that does not dissolve in blood, so it is transported to cells by protein packages Cholesterol is a steroid that does not dissolve in blood, so it is transported to cells by protein packages A certain amount of cholesterol is necessary for good health A certain amount of cholesterol is necessary for good health –The best way to lower serum (blood) cholesterol is to reduce intake of saturated fat –Saturated fat increases the liver’s production of cholesterol

© McGraw-Hill Companies. All rights reserved. Major Risk Factors That Can Be Changed Low-density lipoproteins (LDL), the primary transporters of cholesterol, are the most capable of producing atherosclerosis Low-density lipoproteins (LDL), the primary transporters of cholesterol, are the most capable of producing atherosclerosis People with low blood levels of LDL (less than 100 mg/dl) rarely have heart attacks People with low blood levels of LDL (less than 100 mg/dl) rarely have heart attacks

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More Risk Factors That Can Be Changed:

© McGraw-Hill Companies. All rights reserved. Blood Pressure (1) Blood pressure is the force exerted against artery walls as blood travels through the circulatory system Blood pressure is the force exerted against artery walls as blood travels through the circulatory system –High blood pressure (hypertension) has no signs or symptoms –An estimated 90% to 95% of hypertension is essential (of unknown origin) –Prehypertension includes blood pressures ranging from 120/80 to 139/89 –Hypertension= 140/90 mmHg

© McGraw-Hill Companies. All rights reserved. Blood Pressure (2) Long-term uncontrolled hypertension increases the work of the heart, causes it to hypertrophy, and leads to congestive heart failure Long-term uncontrolled hypertension increases the work of the heart, causes it to hypertrophy, and leads to congestive heart failure Hypertension is the most important risk factor for strokes Hypertension is the most important risk factor for strokes

© McGraw-Hill Companies. All rights reserved. Cigarette Smoking/Tobacco Use Cigarette smoking is considered to be the most harmful of the preventable risk factors for chronic illness and premature death Cigarette smoking is considered to be the most harmful of the preventable risk factors for chronic illness and premature death –These illnesses include chronic bronchitis, emphysema, strokes, and 87% of all lung cancers –Loss of life from smoking represents a life expectancy drop of ~18% Passive smoking, inhaling the smoke of others, causes the deaths of 38,000 to 43,000 nonsmokers annually Passive smoking, inhaling the smoke of others, causes the deaths of 38,000 to 43,000 nonsmokers annually

© McGraw-Hill Companies. All rights reserved. Physical Inactivity Physical inactivity increases the risk of coronary heart disease by 1.5 to 2.4 times Physical inactivity increases the risk of coronary heart disease by 1.5 to 2.4 times The greatest health benefits are gained when people expend 1500 to 2000 calories (walk 15 to 20 miles) per week The greatest health benefits are gained when people expend 1500 to 2000 calories (walk 15 to 20 miles) per week Exercise for health does not have to be as strenuous as exercise for physical fitness Exercise for health does not have to be as strenuous as exercise for physical fitness –But physical fitness is an important factor in cardiovascular health

© McGraw-Hill Companies. All rights reserved. Physical Inactivity Physical activity is any physical movement that results in energy expenditure—walking, mowing the lawn, vacuuming Physical activity is any physical movement that results in energy expenditure—walking, mowing the lawn, vacuuming “Every U.S. adult should accumulate 30 minutes or more of moderate intensity physical activity on most, preferably all, days of the week.” (ACSM/CDC statement) “Every U.S. adult should accumulate 30 minutes or more of moderate intensity physical activity on most, preferably all, days of the week.” (ACSM/CDC statement)

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Obesity Obese people who have no other risk factors are still more likely to develop heart disease or stroke. Obese people who have no other risk factors are still more likely to develop heart disease or stroke. Fat that accumulates in the upper half of the body (central abdominal obesity) is significantly more likely to contribute to heart disease Fat that accumulates in the upper half of the body (central abdominal obesity) is significantly more likely to contribute to heart disease A 5% to 10% weight loss that is maintained can significantly reduce the risk of heart disease A 5% to 10% weight loss that is maintained can significantly reduce the risk of heart disease

© McGraw-Hill Companies. All rights reserved. Diabetes Mellitus Diabetes is a metabolic disorder in which the body cannot properly use sugar (glucose) as fuel Diabetes is a metabolic disorder in which the body cannot properly use sugar (glucose) as fuel Type II (90% of all diabetes) typically occurs in older, overweight, sedentary adults Type II (90% of all diabetes) typically occurs in older, overweight, sedentary adults –It is being seen more and more in children, adolescents, and young adults Diabetes increases the risk of coronary artery disease 2 to 4 times that of non-diabetics Diabetes increases the risk of coronary artery disease 2 to 4 times that of non-diabetics

© McGraw-Hill Companies. All rights reserved. Changeable Risk Factors Stress Stress elevates heart rate, blood pressure, breathing rate, and blood sugar levels, activates the immune response, and causes other physiological changes Stress elevates heart rate, blood pressure, breathing rate, and blood sugar levels, activates the immune response, and causes other physiological changes Chronic (long-term) distress significantly strains the body Chronic (long-term) distress significantly strains the body

© McGraw-Hill Companies. All rights reserved. Preventable / Changeable Risk Factors: Cholesterol Cholesterol Blood Pressure Blood Pressure Cigarette Smoking/Tobacco Use Cigarette Smoking/Tobacco Use Physical Inactivity Physical Inactivity Obesity Obesity Diabetes Mellitus Diabetes Mellitus Stress Stress

© McGraw-Hill Companies. All rights reserved. Preventing and Reversing Heart Disease Preventing includes: Exercising regularly Exercising regularly Maintaining an optimal Maintaining an optimal body weight Practicing sound nutrition Practicing sound nutrition Nonuse of tobacco and other drugs Nonuse of tobacco and other drugs Nonuse or moderate use of alcohol Nonuse or moderate use of alcohol Dealing constructively with stress Dealing constructively with stress Periodic medical examinations Periodic medical examinations

© McGraw-Hill Companies. All rights reserved. Preventing and Reversing Heart Disease Reversing includes: Following a low-fat diet Following a low-fat diet Stopping tobacco use Stopping tobacco use Managing stress Managing stress Attending support group Attending support group meetings regularly Exercising consistently at a Exercising consistently at a moderately intense level moderately intense level

© McGraw-Hill Companies. All rights reserved. Other Risk Factors Other factors include: Iron-enriched blood Iron-enriched blood Homocysteine Homocysteine Lipoprotein Lipoprotein High Sensitivity C-Reactive High Sensitivity C-ReactiveProtein Fibrinogin Fibrinogin

© McGraw-Hill Companies. All rights reserved. Diagnostic Techniques Medical examination and patient history Medical examination and patient history Exercise stress tests Exercise stress tests Thallium treadmill test Thallium treadmill test Echocardiography Echocardiography Cardiac catheterization Cardiac catheterization

© McGraw-Hill Companies. All rights reserved. Medical Treatment Low-dose aspirin therapy Low-dose aspirin therapy Coronary artery bypass surgery Coronary artery bypass surgery Balloon angioplasty Balloon angioplasty Coronary stent Coronary stent Artificial valves Artificial valves Left ventricular assist devices Left ventricular assist devices Heart transplants Heart transplants

© McGraw-Hill Companies. All rights reserved. Preventing Cardiovascular Disease Chapter 2