© 2012 mcgraw-hill companies. all rights reserved. chapter 15

© 2012 McGraw-Hill Companies. All Rights Reserved.

Cardiovascular Health

Chapter 15


Cardiovascular disease (CVD)› Leading cause of death in the U.S.› Affects nearly 81 million Americans› Claims one life every 38 seconds› About 2,300 Americans die every day› CVD is largely due to our way of life

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Consists of the heart and blood vessels With lungs, known as the cardiorespiratory system

The Heart Four-chambered, fist-sized muscle located just beneath the sternum Blood travels through two separate circulatory systems: Pulmonary circulation

› Right side of heart pumps blood to lungs. Systemic circulation

› Left side of heart pumps blood through the rest of the body

Path of blood flow:1. Through venae cavae into atrium (right upper chamber)2. From atrium to ventricle (right lower chamber)3. Pulmonary artery to the lungs4. In lungs, picks up oxygen and discards carbon dioxide5. Through pulmonary veins into heart’s left atrium6. Left atrium fills, pumps blood into left ventricle7. When left ventricle full, pumps blood through aorta for

distribution to the rest of the body’s blood vessels

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Systole › The heart’s contraction

Diastole› The period of relaxation

Blood pressure › Force exerted by blood on the walls of the

blood vessels, created by pumping action of the heart

Heartbeat› Controlled by nerve impulses

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Blood Vessels (classified by size and function)› Veins

Carry blood to the heart Thin walls

› Arteries Carry blood away from the heart Thick elastic walls expand and relax with the volume of blood Coronary arteries

Two large vessels that supply blood to the heart

› Capillaries Smallest arteries, only one cell thick

› Venules Blood empties from capillaries into venules that connect to veins

that return the blood back to the heart

› 150-pound person has about 5 quarts of blood that circulates about once each minute

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Two categories of increased risk for CVD1. Major risk factors2. Contributing risk factors

Controllable aspects of lifestyle that can be changed Major risk factors that can be changed

› American Heart Association identified six major risk factors.

1. Tobacco use2. High blood pressure3. High cholesterol4. Physical inactivity5. Obesity6. Diabetes

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1 in 5 deaths from CVD is a smoker Smokers have 2 to 3 times higher risk of death from

a heart attack than do nonsmokers Smoking doubles risk of stroke Damages the lining of arteries Reduces HDL (“good” cholesterol) Raises triglycerides and LDL Nicotine increases blood pressure and heart rate CO displaces O2 Causes platelets to become sticky and increases

blood thickness Speeds the development of fatty deposits in the

arteries

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Hypertension› Too much pressure against blood vessel walls

Short periods of high blood pressure are normal, but chronic high blood pressure is a health risk

Atherosclerosis› Heart has to work harder, weakens, enlarges, arteries

narrow, scar, and harden

About 33% (73 million) of adults have hypertension 37% of adults have prehypertension Test your blood pressure at least once every two

years

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Fatty, waxlike substance that circulates through the bloodstream› Important component of:

Cell membranes Sex hormones Vitamin D Fluid that coats the lungs Protective sheaths around nerves

Excessive cholesterol clogs the arteries› Increased risk of CVD

Good versus bad cholesterol› Low –density lipoproteins (LDL) (“bad” cholesterol)

Shuttle cholesterol from the liver to organs and tissues› High-density lipoproteins (HDL) (“good” cholesterol)

Shuttle unused cholesterol back to the liver for recycling By removing cholesterol from blood vessels, HDL helps

protect against atherosclerosis Recommended blood cholesterol levels Benefits of controlling cholesterol

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40-60 million Americans are so sedentary that they are at high risk for developing CVD

Exercise reduces risk› Closest thing we have to a magic bullet against heart

disease› Controls blood pressure and resting heart rate› Lowers LDL› Increases HDL› Maintains weight› Improves the condition of blood vessels› Helps prevent or controls diabetes

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Risk of death from CVD is two to three times more likely in obese people (BMI ≥ 30)

Increased strain on the heart Strongly associated with:

› Hypertension› High cholesterol› Insulin resistance› Diabetes› Physical inactivity› Increasing age› Endothelial cell dysfunction

Coronary arteries constrict instead of dilate› Hypertrophy (ventricular enlargement)

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Doubles the risk of CVD for men Triples the risk of CVD for women Loss of 5-10 years off your life Higher risk

› Hypertension› Obesity› Unhealthy blood lipid levels› Elevated blood glucose and insulin can

damage the endothelial cells lining the arteries

› More vulnerable to atherosclerosis

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High triglyceride levels› Blood fats that are a reliable predictor of heart disease

Psychological and social factors› Stress› Chronic hostility and anger› Suppressing psychological distress› Depression › Anxiety› Social isolation› Low socioeconomic status

Alcohol and drugs

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Heredity › CVD has genetic component; high cholesterol levels,

hypertension, diabetes, and obesity Aging

› Over the age of 65 Being male

› Men have higher risk earlier in life Ethnicity

› African Americans higher risk of hypertension; Hispanics greater risk of HBP and angina; Asians lower rates of CVD

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Insulin resistance and metabolic syndrome Homocysteine

› Amino acid circulating in the blood Infectious agents

› Chlamydia pneumoniae – flulike respiratory infections Lipoprotein(a) – Lp(a)

› Strong genetic component LDL particle size

› Particles differ in shape and size Blood viscosity (thickness) and iron Uric acid Time of day and time of year

› More heart attacks and sudden death occur between 6:00AM and noon

› 50% more occur in winter months than in summer months

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Atherosclerosis - narrowed by fatty deposits› Plaques accumulate in artery walls› Coronary heart disease (CHD)› Coronary artery disease (CAD)› Peripheral arterial disease (PAD)

Heart attack – heart tissue is damaged and part of it may die from lack of blood› Myocardial infarction (MI)› American Heart Association

785,000 people have a first heart attack each year 470,000 people have recurrent attack 195,000 people suffer a symptomless or “silent” heart attack

each year

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Chest pain or pressure Arm, neck, or jaw pain Difficulty breathing Excessive sweating Nausea and vomiting Loss of consciousness

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Angina – arteries narrowed by disease, but under stress heart cannot receive enough oxygen› Angina pectoris› Usually felt as an extreme tightness in the chest and

heavy pressure behind the breastbone or in the shoulder, neck, arm, hand, or back

Arrhythmias and sudden cardiac death – electrical conduction system is disrupted› Sudden cardiac death (cardiac arrest) often caused by

an arrhythmia called ventricular fibrillation

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Most victims die within 2 hours from initial symptoms

Give one adult aspirin tablet (325 mg) Cardiopulmonary resuscitation (CPR) Refer to Take Charge box “What to Do

in Case of a Heart Attack, Cardiac Arrest, or Stroke”

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Electrocardiogram (ECG or EKG) Electron-beam computed tomography (EBCT) Echocardiography – sound waves Multi-slice computed tomography (MSCT) Magnetic resonance imaging (MRI) Nuclear myocardial perfusion imaging Positron Emission Tomography (PET) Angiogram Balloon angioplasty Coronary bypass surgery

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2 million brain cells die per minute during a stroke

Ischemic stroke – blockage in a blood vessel

› Thrombotic stroke - clot forms in a cerebral artery› Embolic stroke - wandering blood clot

Hemorrhagic stroke - blood vessel ruptures in the brain› Intracerebral hemorrhage› Subarachnoid hemorrhage› Aneurysm

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Interruption of the blood supply to any area of the brain prevents the nerve cells from functioning, in some cases causing death

Usually suffer some lasting disability› Paralysis› Walking disability› Speech impairment› Memory loss› Changes in behavior

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Prompt recognition of symptoms:› Sudden numbness or weakness of face, arm, leg, or one

side of the body› Loss of speech or difficulty speaking› “Three Simple Ways to Recognize a Stroke”

1. Ask the person to smile. If her smile droops on one side, or if she is unable to move or open one side of her mouth, she may be having a stroke.

2. Ask the person to hold his arms out. If the person cannot move one arm or hold one arm still, it may be a sign of a stroke.

3. Ask the person to repeat a simple sentence, such as “Take me out to the ball game.” If she has trouble speaking or cannot speak, a stroke is possible.

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Transient ischemic attack (TIA)› Temporary stroke-like symptoms (ministroke)

Computed tomography (CT) MRI Ultrasound Drugs Carotid endarterectomy surgery – plaque is

removed from the artery Rehabilitation

› Physical therapy› Speech and language therapy› Occupational therapy

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PAD – atherosclerosis in the leg (or arm) arteries, which can limit or block the blood flow

Patients typically also have coronary artery disease About 8 million people in the U.S. have PAD Risk factors:

› Smoking› Diabetes› Hypertension› High cholesterol

Symptoms› Claudication (aching or fatigue in the affected leg)› Rest pain (limb artery cannot supply enough blood at rest)

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Number of conditions› High blood pressure› Heart attack› Atherosclerosis› Alcoholism› Viral infections› Rheumatic fever› Birth defects

Pulmonary edema - fluid accumulates in the lungs› Heart can not maintain regular pumping rate; fluid backs up

Controlled by: › Reducing cardiac load› Eliminating excess fluid› Restriction of salt › Drug therapy

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Congenital heart defects› Malformation of the heart or major blood vessel

Hypertrophic cardiomyopathy (HCM)› Occurs in 1 out of 500 people › Most common cause of sudden death in athletes younger

than 35› May be identified by a murmur

Rheumatic heart disease › Streptococcal infections cause damage to the heart muscle

and valves› Strep throat needs to be treated

Heart valve disorders› Congenital heart defects and certain types of infections› Mitral valve prolapse

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Eat heart-healthy Decrease fat and cholesterol

› Total fats less than 30% of total calories› Low saturated fats

Increase fiber intake Decrease sodium intake and increase

potassium intake Moderation of alcohol

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Omega-3 fatty acids Plant stanols and sterols Folic acid Vitamins B-6 and B-12 Calcium Soy protein Healthy carbohydrates Total calories DASH

› Dietary Approaches to Stop Hypertension

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Moderate physical activity Avoid tobacco Know and manage your blood pressure

(monitor once every two years) Know and manage your cholesterol

levels Develop effective ways to handle

stress and anger

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© 2012 mcgraw-hill companies. all rights reserved. chapter 15

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heart pumps blood

quarts of blood

bodys blood vessels

chronic high blood pressure

blood thickness speeds

sternum blood travels

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body path of blood flow