Department of Nursing Sciences,

Faculty of Medicine,

Ahmadu Bello University, Zaria.

Topic;

Disorders of myocardial blood supplyBy;

ABDULLAHI Abbas

(student 400level)

OUTLINE

a) Blood supply to the heart

b) Risk factors of coronary artery diseases

c) Coronary artery diseases(C.A.D)

d) Myocardial infarction

e) Angina pectoris

Blood supply to the heart

Coronary Circulation

Coronary arteries;

Right coronary artery; originates from the right aortic

sinus, descends along the anterior side of the heart towards

the right along the inferior border of the right auricle, then

wraps posteriorly around the heart; gives rise to the

following branches:

SA nodal artery- usually branches from the right coronary

artery; supplies the SA node

Right marginal branch- supplies the right border of the

heart

AV nodal artery- supplies AV node

Posterior interventricular artery- supplies both ventricles

and the interventricular septum from the posterior side of

the heart

Left coronary artery; originates from the left aortic sinus,

descends along the anterior side of the heart towards the

left, courses between the pulmonary trunk and the left

auricle then bifurcates into the following branches:

Anterior interventricular branch (LAD)- descends along the

anterior surface towards the apex supplying the left

ventricle and interventricular septum

Circumflex branch- wraps posteriorly around the heart in

the coronary sulcus, gives rise to the left marginal artery

which supplies the left border of the heart.

Cardiac veins

Coronary sinus; courses along the posterior side of the

heart in the coronary sulcus; drains blood from the following

cardiac veins to the right atrium;

Great cardiac vein (anterior interventricular vein)-

ascends from the apex along the anterior side of the heart

in the anterior interventricular sulcus.

Middle cardiac vein (posterior interventricular vein)-

ascends from the apex along the posterior side of the

heart in the posterior interventricular sulcus.

Small cardiac vein- (right marginal vein)- courses with the

right marginal artery, wraps around the right border of the

heart in the coronary sulcus.

Anterior veins- originate on the anterior surface of the

right ventricle, course over the coronary sulcus to drain

directly into the right atrium.

CORONARY ARTERY DISEASE(C.A.D)

Is an abnormal accumulation of lipid or fatty substances

and fibrous tissues in the lining of the coronary arterial

vessels walls which lead to blockage and narrowing of the

vessels in a way that reduces blood flow to the

myocardium (muscles of the heart).

Risk factors of coronary artery

diseases

Age and gender

Family history and genetic

Diabetes

Hypertension

Tobacco use

Sedentary lifestyle

hyperlipidemia

Obesity

Stress

Poor diet etc.

Clinical manifestation

Asymptomatic.

Chest pain (angina) because of decreased blood flow to

heart muscle and/or increase in myocardial oxygen

demand resulting from stress. Chest pain lasts between 3

to 5 minutes.

Chest pain can occur when the patient is resting.

Pain may radiate to the arms, back, and jaw.

Chest pain occurs after exertion, excitement, or when the

patient is exposed to cold temperatures because there is

an increase in blood flow throughout the body, raising the

rate.

Some times shortness of breath(dyspnea)

Fatigue

Anxiety

restlessness

pathophysiology

Cholesterol, calcium and other elements

Deposited on the coronary artery wall

Narrowing of the artery and reduction of blood flow

Impedes blood supply to the heart muscle

Deposits start as fatty streaks and eventually develop into plaque

Diagnosis

History taking

Chest x-ray

Electrocardiograph

Cardiopulmonary angiography

Blood chemistry

Management

Treatment consists of;

Risk factor modification,

Life style changes,

Medications and,

revascularization.

Weight loss.

Diet change: lower sodium, lower cholesterol and fat,

decreased calorie intake, increased dietary fiber.

Administer low doses of aspirin.

Administer beta-adrenergic blockers to reduce workload

of heart: metroprolol, propranolol, nadolol.

Administer calcium channel blockers to reduce heart rate,

blood pressure,and muscle contractility; helps with

coronary vasodilation; slows AV node conduction.

Administer nitrate if patient has symptomatic chest pains

to reduce discomfort and enhance blood flow to

myocardium.

Platelet inhibitors:dipyridamole clopidogrel and

ticlopidine.

Administer HMG CoA reductase inhibitors (statins)—lowers

cholesterol:

a) lovastatin

b) simvastatin

c) atorvastatin

d) fluvastatin

e) pravastatin

f) rosuvastatin

Fibric acid derivatives reduce synthesis and increase

breakdown of VLDL particles: gemfibrozil.

Nursing diagnosis

Acute pain

Activity intolerance

Impaired gas exchange

Angina Pectoris

A narrowing of blood vessels to the coronary artery,

secondary to arteriosclerosis,

results in inadequate blood flow through blood vessels of

the heart muscle, causing chest pain.

Types of angina

Stable angina pectoris; pain is relieved by rest or nitrates

and symptoms are consistent.

Unstable angina pectoris; pain occurs at rest; is of new

onset; is of increasing intensity, force, or duration; isn't

relieved by rest; and is slow to subside in response to

nitroglycerin.

Prinzmetal angina pectoris; usually occurs at rest or with

minimal formal exercise or exertion; often occurs at

night.

causes

An episode of angina is typically precipitated by physical

activity, excitement, or emotional stress.also due to

diseases such as;

Coronary atherosclerosis

Anaemia

Polycythaemia

Aortic stenosis

Extreme cold

Smoking

pathophysiology

.• Narrowing of coronary artery

.• Inadequate blood flow through the heart

‘

• Reduced myocardial oxygenation that leads to discrepancy btw the oxygen and energy expended

• Causing chest pain, which also radiate to left or both shoulders, arms, neck and jaws

Clinical manifestation

Chest pain lasting 3 to 5 minutes—not all patients get

substernal pain; it may

be described as pressure, heaviness, squeezing, or

tightness. Use the patient’s

words.

Can occur at rest or after exertion, excitement, or

exposure to cold—due to

increased oxygen demands or vasospasm.

Usually relieved by rest—a chance to re-establish oxygen

needs.

Pain may radiate to other parts of the body such as the

jaw, back, or arms—

angina pain is not always felt in the chest. Ask if the

patient has had similar

pain in the past.

Sweating (diaphoresis)—increased work of body to meet

basic physiologic

needs; anxiety.

• Tachycardia—heart pumping faster trying to meet

oxygen needs as anxiety

increases.

• Difficulty breathing, shortness of breath (dyspnea)—

increased heart rate

increases respiratory rate and increases oxygenation.

• Anxiety—not getting enough oxygen to heart muscle, the

patient becomes

nervous.

diagnosis

History taking

Electrocardiography

Echocardiograph

Coronary angiography

Radionuclide imagine

Basic screening;

a) Fasting blood glucose

b) Serum lipids including high

density lipoproteins (HDL)

and triglycerides

c) Full blood count

d) Blood urea and electrolytes

e) Serum urates

management

The goal of treatment is to deliver sufficient oxygen to

the heart muscle to meet its need, 2 to 4 liters of oxygen.

Administer beta-adrenergic blocker e.g. propranolol,

nadolol, atenolol, metoprolol.

Administer nitrates—aids in getting oxygenated blood to

heart muscle.

a) Nitroglycerin—sublingual tablets or spray; timed-release

tablets.

b) Topical nitroglycerin—paste or timed-released patch.

Aspirin for antiplatelet effect.

Analgesic

Nursing diagnoses

Anxiety

Decreased cardiac output

Acute pain

Myocardial Infarction commonly known as heart attack

Is when blood supply to the myocardium is interrupted for a

prolonged time due to the blockage of coronary arteries

resulting in insufficient oxygen reaching cardiac

muscle,causing cardiac muscles to die (necrosis).

causes

Coronary atherosclerosis

Coronary thrombosis

Coronary embolism

Hypovolemic shock

pathophysiology

Blockage of the coronary artery

Resulting to insufficient oxygen supply

Leading to death of the cardiac muscle(necrosis)

Clinical manifestation

Chest pain that is unrelieved by rest or nitroglycerin, unlike

angina

Pain that radiates to arms, jaw, back and/or neck

Shortness of breath, especially in the elderly or women

Nausea or vomiting possible

Maybe asymptomatic, known as a silent MI, which is more

common in diabetic patients

Heart rate >100 (tachycardia) because of sympathetic

stimulation, pain, or low cardiac output

Variable blood pressure

Anxiety

Restlessness

Feeling of impending doom

Pale, cool, clammy skin; sweating (diaphoresis)

Sudden death due to arrhythmia usually occurs within first

hour

diagnosis

History taking

Electrocardiography(ECG)

Erythrocyte sedimentation rate(ESR)

Echocardiography

Radionuclide imaging

Cardiac enzyme analysis; creatinine phosphokinase, lactic

dehydrogenase, and aspartate aminotransferase.

management Treatment is focused on reversing and preventing further

damage to the myocardium.

Early intervention is needed to have the best possible

outcome

Administer oxygen, aspirin.

Administer antiarrhythmics because arrhythmias are

common as are conduction disturbances.

a) Amiodarone.

b) Lidocaine.

c) Procainamide.

Electrical cardioversion for unstable ventricular

tachycardia. An initial shock is administered to the heart

to re-establish sinus rhythm.

Administer antihypertensive to keep blood pressure low

e.g Hydralazine.

Percutaneous revascularization

Administer thrombolytic therapy within 3 to 12 hours of

onset because it can re-establish blood flow in an

occluded artery, reduce mortality, and halt the size of the

infarction.

a) Alteplase.

b) Streptokinase.

c) Anistreplase.

d) Reteplase.

Heparin following thrombolytic therapy.

Administer calcium channel blockers as they appear to

prevent reinfarction and ischemia, only in non–Q-wave

infarctions. e.g. Verapamil, Diltiazem.

Administer beta-adrenergic blockers because they reduce

the duration of ischemic pain and the incidence of

ventricular fibrillation; decreases mortality. Propranolol.

E.g. Nadolol, Metroprolol.

Administer analgesics to relieve pain, reduce pulmonary

congestion, and decrease myocardial oxygen

consumption.e.g. Morphine.

Administer nitrates to reduce ischemic pain by dilation of

blood vessels; helps to lower BP.e.g Nitroglycerin.

Place patient on bed rest in CCU.

No bathroom privileges. Bedside commode only.

Low-fat, low-caloric, low-cholesterol diet.

Nursing diagnoses

Ineffective tissue perfusion

Decreased cardiac output

General complications of myocardial

blood supply disorders

Myocardial ischemia

Pericarditis

Cardiogenic shock

Depression etc.

THANKS FOR READING!

ABDULLAHI Abbas