Topic 4 - Cardiovascular Diseases

Question 1

Define ischemia

Answer 1

A deficiency in blood supply to (part of) an organ, depriving the affected tissues of oxygen supply

Question 2

Ischemia is usually cased by…

Answer 2

Problems with blood vessels which may cause damage to or dysfunction of the tissue

Question 3

Define infarction

Answer 3

Defined as the death of affected tissue due to ischemia

Question 4

What is thrombosis?

Answer 4

It is the formation of a thrombus within vascular system during life

Question 5

What is a thrombus?

Answer 5

A solid mass of blood constituents attached to the endothelium of the blood vessel

Question 6

What is the vichow’s triad?

Answer 6

consists of endothelial injury, altered blood flow and hypercoaguability

Question 7

What is endothelial injury, what does it lead to? What does it initiate?

Answer 7

Endothelial injury leads to exposure of sub

Question 8

What conditions can cause endothelial injury?

Answer 8

Myocardial infarction, valvulitis, ulcerated plaques in atherosclerotic arteries and traumatic/inflammatory vascular injury

Question 9

How can you describe normal blood flow?

Answer 9

Laminar flow, where platelets flow centrally, separated from the endothelium by a clear plasma zone. The flow of fresh blood dilutes the clotting factors,platelets and thrombin and this preventing thrombus formation.

Question 10

What is stasis?

Answer 10

where normal laminar flow of blood is lost. WBC and platelets fall out of the mainstream and accumulate in the peripheral plasma zone.

Question 11

What are the four things that will happen with stasis?

Answer 11

• Disrupt laminar flow and bring platelets into contact with the endothelium.
• Promotes endothelial cell activation this predisposing to local thrombosis.
• Prevents deletion of activated clotting factors by fresh flowing blood.
• Slows down the inflow of clotting factor inhibitors and permits the build-up of thrombus

Question 12

Examples of conditions where stasis can happen are..?

Answer 12

Myocardial infarction, prolonged bed rest and mitral stenosis

Question 13

What is turbulence?

Answer 13

Local increase in lumen and WBC and platelets fall out of the mainstream and accumulate in the peripheral plasma zone.

Question 14

Two things that will happen when there is turbulence?

Answer 14

• disruption of laminar flow of blood
• bringing platelets into contact with the endothelium
• promotion of endothelial cell activation predisposing to local thrombus

Question 15

Conditions where turbulence can occur are…

Answer 15

Varicose veins, aneurysm and ulcerated atherosclerotic plaques

Question 16

What are the two types of hyper-coagulability?

Answer 16

Primary hyper-coagulability which is due to genetic cause and secondary hyper-coagulability which is acquired after birth due to incident or health condition

Question 17

Examples of primary hyper-coagulability?

Answer 17

Anti-thrombin III , protein c or s deficiency and fibrinolysis defects

Question 18

Examples of secondary hyper-coagulability ?

Answer 18

Prolonged bed rest and immobilisation, myocardial infarction, cardiomyopathy and intake of certain drugs such as oral contraceptives

Question 19

State the four fates of thrombosis.

Answer 19

Propagation, embolism, dissolution and organisation/ recanalization

Question 20

What is propagation?

Answer 20

Stage at which thrombus accumulates more fibrin and platelets, causing it to increase in size and cause further obstruction of blood vessel

Question 21

What is embolism?

Answer 21

Happens when a thrombus gets dislodged from the site of origin and travels with the blood stream, subsequently getting lodged in a distant site along the vascular tree where the lumen narrows

Question 22

What is dissolution?

Answer 22

Where the thrombus is removed by fibrinolytic activity

Question 23

What is organisation or recanalization?

Answer 23

Where the thrombus induces inflammation and fibrosis and may become recanalised with blood channels through the thrombus

Question 24

What is a pulmonary embolism? (Where it originates, what kind of thrombosis and where it lodges)

Answer 24

Emboli originates from systemic veins, is due to venous thrombosis and lodges in the pulmonary arterial system.

Emboli follows the venous return to the right heart and onward to pulmonary circulation. It is the most common preventable cause of death in hospitalised patients.

Question 25

What is a systemic embolism?

Answer 25

Emboli originates in the left side of the heat and systemic arteries due to cardiac or arterial thrombosis and will be lodged in the distal systemic arteries

Emboli will follow the systemic arterial circulation

Question 26

What is normal, borderline and high blood pressure?

Answer 26

Normal - less than 130/80
Borderline - 130-139/80-89
High - >140/>90

Question 27

What are the two etiological classifications of hypertension? Elaborate. (What is it and what causes it, when does it occur)

Answer 27

Primary hypertension has no evident cause and usually occurs after 40 years of age, with familial tendencies. It is usually associated with high dietary intake of sodium in genetically predisposed individuals.
Secondary hypertension is ostentation that results from other disease that cause sodium and or water retention or an increase in peripheral resistance.

Question 28

What are the two pathological classification of hypertension? Elaborate.

Answer 28

Benign hypertension is symptomatic and is usually found during a medical examination.
Malignant hypertension is severe hypertension (BP>200/140) and is a serious condition that requires prompt treatment.

Question 29

What are the clinical features of hypertension?

Answer 29

Usually asymptomatic but may present with headache, visual disturbances, heart disease, renal disease and cerebral disease.

Question 30

What are the consequences of hypertension?

Answer 30

Consequences include stroke, blindness, heartattack, heart failure, kidney failure, and/or arteriosclerosis.

Question 31

Define shock

Answer 31

A cardiovascular collapse characterised by low blood pressure (>90 systolic), mean bp decrease by 30 mmhg

A decreased blood volume/cardiac output results in widespread hypoperfusion of tissues or redistribution of blood leading to inadequate effective circulating volume

It progressively leads to death.

Question 32

State the three stages of shock.

Answer 32

Stage of compensation, stage of impaired tissue perfusion and stage of de,compensation

Question 33

What happens during stage of compensation?

Answer 33

Decreased cardiac output stimulates the sympathetic reflex. Heart rate and peripheral vasoconstriction increases to maintain blood pressure to the heart and brain.
Due to peripheral vasoconstriction, there will be cold and clammy skin. Vasoconstriction in renal arterioles result in decreased renal blood flow and GFR , therefore resulting in decreased urine output.

Question 34

What happens during stage 2 of shook?

Answer 34

Prolonged excessive vasoconstriction in impairs tissue perfusion and results in (1) impaired tissue fluid exchange and oxygenation therefore causing (2) anaerobic glycolysis leading to lactic acidosis and (3) resulting in cell necrosis.

Question 35

What happens during stage 3?

Answer 35

It occurs when reflex peripheral vasoconstriction fails. It results in widespread vasodilation and stasis and leading to a progressive drop in blood pressure.
It can lead to cerebral hypoxia leading to acute brain dysfunction or myocardial hypoxia leading to worsening of cardiac output and death.

Question 36

What are the five types of shock ?

Answer 36

Cardiogenic, hypovolemic/hemorrhagic, septic, neurogenic and anaphylactic

Question 37

What is cardiogenic shock ?

Answer 37

It is the failure of the myocardial pump due to intrinsic myocardial damage. It is due to myocardial infarction and arrhythmias

Question 38

What of hypovolemic/hemorrhagic shock?

Answer 38

Inadequate blood or plasma volume due to fluid loss. Can be due to severe Burns or trauma.

Question 39

What is septic shock?

Answer 39

vasodilation and peripheral pooling of blood due to systemic immune reaction to the infection. Due to bacteremia

Question 40

What is Neurogenic shock?

Answer 40

Vasodilation & peripheral pooling of blood due to anesthetic accidents or spinal cord injury

Question 41

What is anaphylactic shock?

Answer 41

Systemic vasodilation & increased vascular
permeability due to Type I hypersensitivity
reaction