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A 53-year-old man presents with recurrent chest

pain that has gotten progressively worse over thelast several weeks. He says that approximately a

year ago the pain would occasionally occur when

he was mowing his yard but now the painsometimes occurs while he is sitting in a chair at

night reading a book. The pain which is localized

over the sternum, lasts much longer now than it

did a few months ago.

What type of disease does this individual have at

present ?

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I. Ischemic heart disease

Coronary heart disease orCoronary artery disease.

Definition:

A group of closely related disorders

caused by myocardial ischemia due to an

imbalance between oxygen demand and

supply by the blood.

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Etiology of IHD

1. Reduced coronary blood flow (90% 0f cases)a- Disease of the coronary:

mostlydue to atherosclerosis associated with

thrombosis or vasospasm.Other uncommon causes include emboli from IE,

vasculitis, vasospasm, coronary ostialnarrowing as in syphilis.

b- severe tachycardia (shortening of diastole)

C- Aortic valve disease as stenosis or regurge

D- severe hypotension as in shock.

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Etiology of IHD

2. Increased myocardial demand.eg

tachycardia, myocardial hypertrophy.

3.Hypoxia due to diminished oxygentransport eg severe anemia, advanced

lung disease, and cyanotic congenital

heart disease.

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Pathogenesis of ischemic injury:-

Hypoxia: is the most important factor leading to ATP

depletion, increase cytosolic calcium and shift to anaerobic

respiration resulting into either reversible cell injury (cloudy

swelling and fatty change) or irreversible cell injury(necrosis)

Failure to remove waste products (metabolites) e.g.,

accumulation of metabolites may explain the pain of muscleischemia.

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Classification of

ischemic heart disease

1.Angina pectoris.

2. Myocardial infarction.

3. Chronic ischemic heart disease

with congestive heart failure.

4. Sudden cardiac death.

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I. ANGINA PECTORIS

A clinical syndromecharacterized by

intermittent or episodic

chest pain or discomfortcaused by:

transient and reversible

myocardial ischemia

which is not severe enough to

cause death of myocardial

muscles.

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crushing , squeezing,constricting or knife like.

It may radiate to the

back , neck or left arm.

PAIN

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Types of Angina pectoris

1- Stable (typical) angina.

2-Variant (Prinzmetal) angina.

3-Unstable angina.

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Angina pectoris

Stable AnginaIt is associated

with chronic fixed

atheroscleroticnarrowing of the

coronaries.Variant AnginaIt is associated with

coronary artery

spasm near an

advancedatherosclerotic

plaque .

Unstable AnginaIt is precipitated by

fissuring or disruption of

the fixed atherosclerotic

plaque with superadded

thrombosis or

vasospasm but thelumen is still opened.

No Myocardial

Necrosis

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II. MYOCARDIAL INFARCTION

Definition: Development of an area of

coagulative necrosis of the cardiac muscle

due to sudden complete occlusion ofarterial supply with deficient collateral

circulation.

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MI - Types

Transmural

Full thickness

Superimposed thrombus in

atherosclerosis

Focal damage

Sub-endocardial

Inner 1/3 to half of

ventricular wall Decreased circulating blood

volume( shock,

Hypotension, Lysed

thrombus)

Circumferential

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Transmural infarct Subendocardial infarct

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MI- Microscopic featuresOne-day-oldinfarct

coagulative necrosis

wavy fibers

Up to 3 days duration

Neutrophilic infiltrate

1 -2 weeks

Granulation tissue

Scar

>3 weeks

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III. CHRONIC ISCHEMIC HEART

DISEASE

Definition:Development of progressive

congestive heart failure in elderly patients

with multivessel coronary atheroscleroticnarrowing.

Mechanism: It occurs due to post infarction

cardiac decompensation that followsexhaustion of the hypertrophied viable

myocardium.

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Morphology:

*Enlarged heart due to hypertrophy and

dilatation of all chambers.

*Atherosclerotic coronary narrowing.

*Multiple areas of fibrous scar due to

healed myocardial infarction.

*Thickened endocardium covered by

thrombi

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Clinical picture:

1. Progressive congestive heart failurein patients with previous attacks ofangina &/ or MI.

2. Arrythmias are common.3. Death caused by

- Arrythmias

- CHF.

- Acute myocardial infarction

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IV. SUDDEN CARDIAC DEATH

Definition: unexpected cardiac death within

one hour of symptom onset.

Due to Fatal

arrythmias

especilallyventricular

fibrillation

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Mechanism: Lethal cardiac arrythmias

especially ventricular fibrillation.

Morphology:

Complicated coronary atherosclerotic

plaque

recent or old MI or scarring.