CARDIOVASCULAR DISEASE AND PHYSICAL ACTIVITY

CARDIOVASCULAR DISEASE AND PHYSICAL ACTIVITY

CHAPTER 20CHAPTER 20

Learning Objectives

Find out the major causes of chronic diseases in the United States and how a lack of physical activity contributes to these conditions.

Learn how atherosclerosis, hypertension, and coronary artery disease (CAD) develop and at what age they begin.

Discover what specific physiological alterations that result from exercise training reduce the risk of death from CAD, hypertension, and heart disease.

(continued)

Learning Objectives

Learn what blood pressure changes result from endurance exercise training in moderately hypertensive individuals.

Review the value of cardiac rehabilitation in treating a person who has suffered a heart attack.

Find out if there is any risk of death with endurance exercise training.

1995 CAUSES OF DEATH IN THE U.S.

DECLINE IN DEATHS

Factors Contributing to Decline in Deaths

Better and earlier diagnosis

Better emergency and medical care

Improved drugs for specific treatment

Improved public awareness

Increased use of preventive measures, including lifestyle changes

Cardiovascular Diseases

Coronary artery disease (CAD)

Hypertension and stroke

Congestive heart failure

Peripheral vascular disease

Valvular, rheumatic, and congenital heart disease

Coronary Artery Disease

Atherosclerosis—progressive narrowing of arteries due to build up of plaque

Coronary artery disease (CAD)—atherosclerosis in the coronary arteries

Ischemia—deficiency in blood to heart caused by CAD

Myocardial infarction—heart attack due to ischemia

Did You Know…?

Atherosclerosis begins in infancy and progresses at different rates, depending primarily on heredity and lifestyle choices such as smoking history, diet practices, physical activity, and stress.

Classification of Blood Pressure for Adults, Age 18 Years and Older

Normal < 130 < 85

High normal 130-139 85-89

Hypertension 140 90

Stage 1 (mild) 140-159 90-99

Stage 2 (moderate) 160-179 100-109

Stage 3 (severe) 180-209 110-119

Stage 4 (very severe) 210 120

Systolic DiastolicCategory (mmHg) (mmHg)

Hypertension

Is chronically elevated blood pressure

Causes the heart to work harder

Is uncommon in childhood but can appear during midadolescence

Places strain on arteries causing them to become less elastic over time

Affects about one in every four adult Americans

Stroke

Also called a cerebral vascular accident (CVA).

Cerebral infarction refers to when blood flow is blocked to one part of the brain due to a blood clot or atherosclerosis.

Cerebral hemorrhage refers to a rupture of a blood vessel that diminishes blood flow beyond the rupture.

CEREBRAL INFARCTION AND HEMORRHAGE

Congestive Heart Failure

Heart muscle becomes too weak to meets oxygen demands of the body

Can result from damage to heart, hypertension, atherosclerosis, and heart attack

Blood backs up in veins causing edema

Can progress to irreversible damage, thus requiring a heart transplant

AN ARTERY WALL

DEVELOPMENT OF ATHEROSCLEROSIS

Primary Risk Factors of CAD

Cigarette smoking

Hypertension

Elevated blood lipids (cholesterol and triglycerides)

Physical inactivity

Secondary Risk Factors of CAD

Obesity

Diabetes and high blood levels of insulin

Family history of CAD

Male gender

Advanced age

Did You Know…?

The ratio of total cholesterol (Total-C) to high-density-lipoprotein cholesterol (HDL-C) may be the most accurate lipid index of risk for CAD. Values of 5.0 and greater indicate increased risk while values of 3.0 and lower represent low risk.

Controllable Risk Factors for Hypertension

Insulin resistance

Obesity

Diet

Use of oral contraceptives

Physical inactivity

Uncontrollable Risk Factors for Hypertension

Family history of hypertension

Advanced age

Race

Did You Know…?

It appears that hypertension, coronary artery disease, obesity, and diabetes are linked through the common pathway of insulin resistance. Metabolic syndrome, syndrome x, and civilization syndrome are terms used to describe this interrelationship.

AMERICANS AT INCREASED CAD RISK

Did You Know…?

Epidemiological evidence shows that physical inactivity doubles the risk of CAD. Low-intensity activity is sufficient to reduce the risk of this disease.

Aerobic Training Adaptations

Produces larger coronary arteries

Increases heart size

Increases heart pumping capacity

Improves circulation of blood to vessels surrounding heart

Reduces blood pressure in individuals with moderate hypertension

How Exercise Reduces Risk of Disease

Improves the heart’s contractility, work capacity, and circulation

Improves ratio of blood lipids

Controls and prevents moderate hypertension

Controls weight, reduces body fat, and increases muscle mass

Reduces insulin resistance

Alleviates stress and decreases cigarette smoking

ARTERY COMPARISONS

Key Points

There is an increased risk of heart attack during actual exercise; however, over a 24-hour period, those who exercise regularly have a reduced risk of heart attack.

Deaths during exercise are rare.

Risk of Death During Exercise

In people over 35 most deaths during exercise are caused by a cardiac arrhythmia due to atherosclerosis.

Deaths during exercise in people under age 35 are usually caused by hypertrophic cardiomyopathy, congenital conditions, aortic aneurysm, or myocarditis.

HEART ATTACK RISK AND EXERCISE