disorders of myocardial blood supply

1. Department of Nursing Sciences,
Faculty of Medicine,
Ahmadu Bello University, Zaria.
Topic;
Disorders of myocardial blood supply
By;
ABDULLAHI Abbas
(student 400level)

2. 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

3. Blood supply to the heart

5. 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

6.  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

7. 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.

8. 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.

9.  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.

10. 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).

11. 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.

12. 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.

13.  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

14. 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

15. Diagnosis
 History taking
 Chest x-ray
 Electrocardiograph
 Cardiopulmonary angiography
 Blood chemistry

16. Management
 Treatment consists of;
 Risk factor modification,
 Life style changes,
 Medications and,
 revascularization.

17.  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.

18.  Administer nitrate if patient has symptomatic chest pains
to reduce discomfort and enhance blood flow to
myocardium.
 Platelet inhibitors:dipyridamole clopidogrel and
ticlopidine.

19.  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.

20. Nursing diagnosis
 Acute pain
 Activity intolerance
 Impaired gas exchange

21. 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.

22. 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.

23. 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

24. 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

25. 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.

26.  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.

27.  • 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.

28. 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

29. 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

30. Nursing diagnoses
 Anxiety
 Decreased cardiac output
 Acute pain

31. 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).

32. causes
 Coronary atherosclerosis
 Coronary thrombosis
 Coronary embolism
 Hypovolemic shock

33. pathophysiology
Blockage of the coronary artery
Resulting to insufficient oxygen
supply
Leading to death of the cardiac
muscle(necrosis)

34. 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

35.  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

36. diagnosis
 History taking
 Electrocardiography(ECG)
 Erythrocyte sedimentation rate(ESR)
 Echocardiography
 Radionuclide imaging
 Cardiac enzyme analysis; creatinine phosphokinase, lactic
dehydrogenase, and aspartate aminotransferase.

37. 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.

38.  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

39.  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.

40.  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.

41. Nursing diagnoses
 Ineffective tissue perfusion
 Decreased cardiac output

42. General complications of myocardial
blood supply disorders
 Myocardial ischemia
 Pericarditis
 Cardiogenic shock
 Depression etc.

44. THANKS FOR READING!
ABDULLAHI Abbas