Coronary Heart DiseaseCoronary Heart Disease(CHD)(CHD)

Grade 8, Semester 1Year 2011-2012

Blood Supply to the HeartBlood Supply to the Heart

Coronary arteries: blood vessels that supply blood and oxygen to the heart muscle.

Coronary arteries branch from the main aorta

Blood PressureBlood Pressure

Measuring blood pressure can reveal cardiovascular problems

Typical blood pressure for a healthy young adult is about 120/70 mmHg (systolic/diastolic).

Hypertension (above 140/90 mm Hg) can cause CHD.

Artery

Rubber cuffinflatedwith air

Arteryclosed

120 120

Pressurein cuff above 120

Pressurein cuff below 120

Pressurein cuff below 70

Sounds audible instethoscope

Sounds stop

Blood pressurereading: 120/70

70

What is CHD?What is CHD?

Coronary heart disease (CHD) is a narrowing of the small blood vessels that supply blood and oxygen to the heart.

What can cause CHD?What can cause CHD?

Coronary heart disease is usually caused by a condition called atherosclerosis.

Occurs when fatty material and a substance called plaque build up on the walls of arteries causing them to get narrow.

As the coronary arteries narrow, blood flow to the heart can slow down or stop. This can cause chest pain (angina), shortness of breath, heart attack, and other symptoms.

One type of cardiovascular disease, atherosclerosis◦Is caused by the buildup of cholesterol within

arteries

Figure 42.18a, b

(a) Normal artery (b) Partly clogged artery50 µm 250 µm

Smooth muscleConnective tissue Endothelium Plaque

Understanding CHDUnderstanding CHD

CausesCauses

Bad genes (heredity) can increase your risk. You are more likely to develop the condition if someone in your family has had a history of heart disease

Poor lifestyle: Smoking, lack of exercise, stress

DiabetesHigh blood cholesterol

Hypertension, or high blood pressure◦Promotes atherosclerosis and increases the risk of

heart attack and strokeA heart attack

◦Is the death of cardiac muscle tissue resulting from blockage of one or more coronary arteries

A stroke◦Is the death of nervous tissue in the brain, usually

resulting from rupture or blockage of arteries in the head

SymptomsSymptoms

Signs & Symptoms

ChestPain

ShortnessOf Breath

HeartAttack

None

PreventionPrevention

Avoid or reduce stress.

Don't smoke.

Eat well-balanced meals that are low in fat and cholesterol

and include several daily servings of fruits and vegetables.

Get regular exercise.

Keep your blood pressure below 130/80 mmHg if you have

diabetes or chronic kidney disease, and below 140/90

otherwise

Keep your cholesterol and blood sugar under control.

Treatment (Bypass surgery)Treatment (Bypass surgery)

• Healthy blood vessel is removed from leg, arm or chest.

• Blood vessel is used to create new blood flow path in your heart.

• The “bypass graft” enables blood to reach your heart by flowing around the blocked portion of the diseased artery.