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YourHealthTodayChapter14.pptx

14: Cardiovascular Disease, Diabetes, and Chronic Lung Diseases

Your Health Today, 6th edition

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Cardiovascular Disease

Cardiovascular disease (CVD): any disease involving the heart and/or blood vessels

Currently the leading cause of death in the United States, accounting for one in three deaths

CVD is a general term for diseases that include heart attack, stroke, peripheral artery disease, congestive failure, and others

Disease process underlying many forms of CVD is atherosclerosis, or hardening of the arteries

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Figure 14.1 Cardiovascular disease mortality trends for males and females, United States, 1979–2009.

Sources: Centers for Disease Control and Prevention/National Center for Health Statistics, www.cdc.gov/nchs; “Heart Disease and Stroke Statistics—2015 Update,” Chart 13-17, American Heart Association, 2015, Dallas: AHA.

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Figure 14.2 Percentage of deaths from types of CVD, United States, 2013.

Nearly half the deaths from CVD (47.7%) are caused by coronary heart disease.

Source: “Heart Disease and Stroke Statistics—2015 Update,” Chart 13-5, American Heart Association, 2015, Dallas: AHA.

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The Cardiovascular System

Cardiovascular system: the heart and blood vessels that circulate blood throughout the body

Pulmonary (lung) circulation: the pumping of oxygen-poor blood to the lungs and oxygen-rich blood back to the heart by the right side of the heart

Systemic (body) circulation: the pumping of oxygen-rich blood to the body and oxygen-poor blood back to the heart by the left side of the heart

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The Cardiovascular System (2)

Aorta: largest artery in the body

Leaves the heart and branches into smaller arteries, arterioles, and capillaries carrying oxygen-rich blood to body tissues

Inferior and superior vena cava: largest veins

Carry oxygen-poor blood from the body back to the heart

Coronary arteries: medium-sized arteries that supply oxygen- and nutrient-rich blood to the heart muscle

Sinus node or sinoatrial (SA) node: group of cells in the right atrium where the electrical signal is generated that establishes the heartbeat

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Figure 4.3 The heart, showing interior changes, valves, and major arteries and veins.

Jump to long image description

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Atherosclerosis

Atherosclerosis is a common form of arteriosclerosis that involves a thickening or hardening of the arteries due to buildup of fats and other substances

Damage to the inner lining leads to formation of a fatty streak—an accumulation of lipoproteins: a combination of proteins, phospholipids, and cholesterol

Together with white blood cells, collagen and other proteins form a plaque (accumulation of debris)

Reduces the amount of blood that can reach the tissue

Plaque can break off and completely block artery

Stretching of the weakened artery wall can also cause an aneurysm that can tear or rupture, causing sudden death

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Figure 14.4 The process of atherosclerosis.

The process begins with damage to the lining of an artery and progresses to narrowing or blockage of the artery by fatty deposits and plaques.

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Coronary Heart Disease and Heart Attack

Coronary heart disease (CHD): atherosclerosis of the coronary arteries, which can result in a heart attack

CHD is the leading form of all cardiovascular diseases

An estimated 15.5 million Americans are living with CHD

Those who survive a heart attack are often left with damaged hearts and significantly altered lives

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Coronary Heart Disease and Heart Attack (2)

Ischemia: insufficient supply of oxygen and nutrients to tissue, caused by narrowed or blocked arteries

Myocardial infarction: lack of blood flow to the heart muscle with resulting death of heart tissue, often called a heart attack

Coronary thrombosis: blockage of a coronary artery by a blood clot that may cause sudden death

Angina: pain, pressure, heaviness, or tightness in the center of the chest caused by a narrowed coronary artery

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Arrhythmias and Sudden Cardiac Death

Arrhythmia: irregular or disorganized heartbeat

Normal adult heart rate is 60–100 beats per minute

Sudden cardiac death: abrupt loss of heart function caused by an irregular or ineffective heartbeat

Ventricular fibrillation: type of arrhythmia in which the ventricles contract rapidly and erratically, causing the heart to quiver or “tremor” rather than beat

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Stroke

Stroke or cerebrovascular accident (CVA): when blood flow to the brain or part of the brain is blocked

Fourth leading cause of death in the United States and a leading cause of severe, long-term disability

Ischemic stroke: caused by blockage in a blood vessel in the brain; accounts for 87% of all strokes

Thrombus: blood clot in a narrowed artery

Embolism: blood clot elsewhere that travels to the brain

Hemorrhagic stroke: caused by rupture of a blood vessel in the brain, with bleeding into brain tissue

Transient ischemic attacks (TIAs), or “ministrokes”: periods of restricted blood supply that produce stroke symptoms

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Figure 14.5 Types of stroke.

Hemorrhagic stroke: caused by ruptured blood vessels followed by blood leaking into tissue

Ischemic stroke: caused by blockage in brain blood vessels; potentially treatable with clot-busting drugs; less serious than hemorrhagic stroke

Subarachnoid hemorrhage: a bleed into the space between the brain and the skull

Intracerebral hemorrhage: a bleed from a blood vessel into the brain

Embolic stroke: caused by emboli, blood clots that travel from elsewhere in the body to the brain blood vessels

Thrombotic stroke: caused by thrombi, blood clots that form where an artery has been narrowed by atherosclerosis

Source: Harvard Health Letter, April 2000.

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Congestive Heart Failure

Congestive heart failure: heart is not pumping the blood as well as it should, allowing blood and fluids to back up in the lungs

Can develop after a heart attack or as a result of hypertension, heart valve abnormality, or disease of the heart muscle

Person with this condition experiences difficulty breathing, shortness of breath, coughing, fatigue, and confusion

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Other Cardiovascular Diseases

Heart valve disorders: one of the four heart valves does not open well or does not close tightly

Congenital heart disease: structural defect at birth

Peripheral vascular disease (PVD): result of atherosclerosis in the arms and legs

Cardiomyopathy: disease of the heart muscle

Dilated cardiomyopathy: enlargement of the heart in response to weakening of the muscle

Hypertrophic cardiomyopathy: abnormal thickening of one part of the heart, frequently the left ventricle

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Major Factors Contributing to Cardiovascular Health

Four health behaviors contribute to ideal cardiovascular health:

Avoid tobacco

Eat a healthy diet

Be physically active

Maintain a healthy BMI

Three measurable health factors also contribute:

Blood pressure levels

Blood glucose levels

Cholesterol levels

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Maintain Healthy Blood Pressure Levels

Blood pressure: exerted by blood against artery walls

Systolic pressure: produced by the heart contracting and pushing blood out into the arteries; the top number

Diastolic pressure: in the arteries when the heart muscle is relaxed and the ventricles are filling

Hypertension: high blood pressure, forceful enough to damage artery walls

Untreated hypertension can weaken and scar the arteries and make the heart work harder; and increases risk for heart attack, stroke, congestive heart failure, and kidney disease

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Maintain Healthy Blood Glucose Levels

Elevated levels of glucose in the body cause damage to artery walls, changes in some blood components, and damage to peripheral nerves and organs

People with diabetes are 2–4 times more likely to develop cardiovascular disease

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Table 14.1 Blood Pressure Guidelines

Normal: systolic pressure of less than 120 mmHg and diastolic pressure of less than 80 mmHg

Prehypertension: systolic pressure of 120–139 mmHg, or diastolic pressure of 80–89 mmHg

Hypertension stage 1: systolic pressure of 140–159 mmHg, or diastolic pressure of 90–99 mmHg

Hypertension stage 2: systolic pressure of 160 mmHg and above, or diastolic pressure of 100 mmHg and above

Source: “The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure” (NIH Publication No. 03-5233), 2003, Bethesda, MD: National Heart, Lung, and Blood Institute, National Institutes of Health.

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Maintain Healthy Cholesterol Levels

Low-density lipoproteins (LDLs): “bad cholesterol” associated with atherosclerosis

The higher the LDL level, the higher the risk

Cholesterol-lowering statin therapy can reduce risk

For those with a history of cardiovascular disease

For those with LDL cholesterol over 190 mg/dl

For those over 40 with diabetes and LDL cholesterol over 70 mg/dl

For those with a 10-year risk of heart attack greater than 7.5%

High-density lipoproteins (HDLs): “good” cholesterol

Help clear cholesterol from cells and atherosclerotic deposits

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Contributing Factors in Cardiovascular Health

Triglyceride levels

Triglycerides: blood fats similar to cholesterol

High levels are a risk factor for CVD

Alcohol intake

Heavy drinking can damage the heart

Light drinking can increase HDL levels, and therefore may help protect against heart disease and stroke risk

Mental wellbeing

Sleep

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Contributing Factors in Cardiovascular Health (2)

Age

Probably the most important noncontrollable risk factor

Deaths due to heart disease and stroke rise significantly after age 65, due to the accumulation of risk factors

Gender and postmenopausal status

Death rates for CVD are higher in women

Genetics and family history

Socioeconomic status; and ethnicity and race

Minorities and low-income populations carry a disproportionate burden of CVD

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Areas of Interest for Future CVD Research

Researchers are looking at how the following are associated with CVD:

Low levels of vitamin D

High blood levels of homocysteine, an amino acid

Metabolic syndrome

Inflammation and high levels of C-reactive protein

Lower birth weight

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Testing and Treatment

Diagnostic testing for heart disease:

Electrocardiogram (ECG or EKG) to detect abnormal rhythms, inadequate blood flow, and heart enlargement

Echocardiogram (like an ultrasound) to visualize the heart structure and motion

Exercise stress test to evaluate heart functioning

Diagnostic testing for stroke:

CT scan or MRI to detect stroke and help determine cause

Further testing to find the source of any blockage

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Testing and Treatment (2)

Management of heart disease:

Medications, especially anti-arrhythmics, anti-anginals, and anti-coagulants

Surgeries, such as angioplasty (balloon catheter), a coronary stent, or coronary artery bypass grafting

Management of stroke:

If thrombotic, thrombolytic medications

If hemorrhagic, depends on the underlying cause of the bleed; sometimes surgery is necessary

Rehabilitation, usually including physical therapy, is an important component

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Diabetes

Diabetes: metabolic disorder in which production or use of insulin is disrupted

Most common disorder of the endocrine or metabolic system and the seventh leading cause of death in the U.S.

Rates of diabetes doubled every 15 years between 1950 and 2008 but now appear to have leveled off

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Figure 14.7 Normal insulin and glucose uptake, and with Type-1 and Type-2 diabetes.

Normal

A healthy person’s body releases a normal amount of insulin from the pancreas after meals. Insulin binds to receptors on the surface of a cell and signals special transporters in the cell to transport glucose inside.

Type-1 diabetes

The pancreas produces little or no insulin. Thus, no signal is sent instructing the cell to transport glucose, and glucose builds up in the bloodstream.

Type-2 diabetes

The pancreas produces too little insulin and/or the body’s cells are resistant to it. Some insulin binds to receptors on the cell’s surface, but the signal to transport glucose is blocked. Glucose builds up in the bloodstream.

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Type-1 Diabetes

Caused by the destruction of insulin-producing cells in the pancreas by the immune system

Insulin must be provided from an external source to keep blood glucose levels under control

Onset usually occurs before age 20

Probably a result of a combination of genetic, autoimmune, and environmental factors

Physical activity is an important component of control and reduction in long-term complications

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Type-2 Diabetes

Caused by insulin resistance in insulin receptors

Pancreas responds by increasing production of insulin, but eventually cannot keep up

Accounts for 90–95% of all diabetes cases

Incidence rising in parallel with obesity levels

Visceral fat and lack of physical activity are strong indicators of risk

Prediabetes: fasting blood glucose levels between 100 and 126 mg/dl

Dietary changes, exercise, and weight loss can prevent or delay onset

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Risk Factors

Type-2 diabetes is a multifactorial disease with an increased risk if there is a family history of diabetes and other risk factors

Higher abdominal fat

Lack of physical activity

Being over 40 years of age

Racial and ethnic minorities and people with low socioeconomic status are disproportionately affected

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Risk Factors (2)

Metabolic syndrome is a set of conditions that significantly increases the risk for developing diabetes and other health complications

Fasting glucose level at or above 100

HDL cholesterol under 40 in men, or under 50 in women

Triglycerides at or above 150

Waist circumference at or above 40″ for men; or at or above 35″ for women

Systolic blood pressure at or above 130 and diastolic blood pressure at or above 85

Prevention and Treatment

Screening involves tests for blood glucose levels

Dietary changes, exercise, and weight loss can prevent diabetes, delay its onset, and treat it

Treatment includes lifestyle modification, oral medications, and eventually insulin replacement

Exercise is especially important

Long-term control is monitored by a blood test called the hemoglobin A1c test

Closer blood glucose is to the normal range, the lower the risk of complications

Gestational Diabetes

Develops in 2–10% of pregnancies

Hormonal changes affect the body’s response to insulin

Higher risk for pregnancies after age 35

In 5–10% of cases, diabetes becomes an ongoing condition

Women with a history of gestational diabetes are at a higher risk of developing diabetes in the next 10–20 years

Chronic Lung Diseases

Also known as chronic lower respiratory diseases, chronic lung diseases are the third leading cause of death in the U.S.

Two most common forms:

Asthma

Larger genetic component

Chronic obstructive pulmonary disease (COPD)

More typical in older adults

Both are triggered by smoking, infection, and pollution

Figure 14.8 The respiratory system.

Air, breathed in, travels down the trachea and enters the lungs through the bronchi (bronchial tubes)

Bronchi carry air through bronchioles (a series of branching airways) into alveoli (tiny air sacs), which are surrounded by capillaries (tiny blood vessels) where gas exchange takes place

Oxygen is passed from the alveoli into the blood in capillaries, and carbon dioxide moves from the capillaries into the alveoli

Carbon dioxide is then pushed back through the bronchioles and exhaled, while oxygen travels through the bloodstream to body cells

Asthma

Chronic inflammation, obstruction, and constriction of the airways, causing wheezing, coughing, chest tightness, and shortness of breath

Attack occurs in response to a trigger: an allergen or an irritant in the air

Diagnostic categories:

Intermittent: no symptoms between episodes

Mild persistent: symptoms a few times a week

Moderate: daily symptoms limit some normal activity

Severe: daily symptoms place extreme limits on normal activity

Asthma (2)

Bronchodilators: quick-relief medications used during an attack to reduce symptoms

Delivered through an inhaler

For long-term control:

Inhaled steroid that works within the bronchioles to reduce inflammation

Avoidance of common triggers such as tobacco smoke, allergens, and air pollution

Flu shots are recommended if viruses and infections are triggers

Chronic Obstructive Pulmonary Disease

COPD tends to develop from cumulative damage to airways and alveoli; the primary cause is smoking

Chronic bronchitis: persistent inflammation of the bronchioles; excess mucus

Bronchial congestion and a chronic cough

Emphysema: alveoli become less elastic, and walls between alveoli are damaged or destroyed

Person is breathless and gasps for air

Strains the heart

Cannot be reversed; supplemental oxygen may be necessary at later stages

Preventing Chronic Diseases

Eat a heart-healthy diet

Maintain a healthy weight

Don’t smoke, and avoid secondhand smoke

Be physically active

Limit alcohol consumption

Maintain healthy blood pressure levels

Maintain healthy lipid levels

Maintain healthy blood glucose levels

Manage stress, and take care of your mental, emotional, and social health

In Review

What is cardiovascular disease?

What is diabetes?

What is asthma?

What is chronic obstructive pulmonary disease?

What are the best ways to protect against the diseases discussed in this chapter?

Appendix A

Long image descriptions

Figure 14.3 The Heart Appendix

Significant features of the heart:

Interior and superior vena cava, by which blood returns from the body

Right and left pulmonary veins, by which blood returns from the lungs

Pulmonary trunk

Right atrium and left atrium

Tricuspid valve on the right; and mitral valve on the left

Right ventricle and left ventricle

Interventricular septum

Myocardium (muscular tissue of the heart)

Aorta, by which blood is supplied to the body (systemic circulation)

Aortic valve

Right and left pulmonary arteries, by which blood is supplied to the lungs (pulmonary circulation)

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