Pathophysiology of thrombosis and embolism + Rheumatic fever/heart disease

Question 1

What term is used to describe normal blood flow?

Answer 1

laminar - smooth

Question 2

what is stasis?

Answer 2

stagnation of blood flow

Question 3

Define turbulence

Answer 3

forceful or unpredictable flow

Question 4

3 parts of virchow’s Triad? what do they mean?

Answer 4

1. Changes in the blood vessel wall
2. Changes in the blood constituents
3. Changes in the pattern of blood flow

they are factors causing thrombosis

Question 5

example of problem that can cause changes to the blood vessel wall?

Answer 5

atheromatous coronary artery

Question 6

Hypercholesterolaemia falls under which of virchow’s triad?

Answer 6

changes in blood constituents

Question 7

examples of problems that cause changes in pattern of blood flow

Answer 7

stasis:-
DVT
post op

turbulent:-
atheromatous plaque
aortic aneurysm

Question 8

define thrombus

Answer 8

a solid mass from the constituents of the blood within the vascular system disrupting the laminar flow of blood. It brings platelets in close contact with the vascular wall. Fibrin meshwork - RBCs become trapped

Question 9

difference between a thrombus and a clot?

Answer 9

thrombus forms inside a healthy vessel - it is an abnormal clot

blood clot is a response to injury of vascular tissue - occurs outwith vessels

Question 10

describe the pathogenesis of thrombosis

Answer 10

endothelial injury, stasis or turbulent blood flow and hypercoagulability of blood

Question 11

what do the consequences of thrombosis depend on?

Answer 11

site, extent and collateral circulation

Question 12

what is collateral circulation?

Answer 12

alternate circulation around a blocked artery or vein via another path such as nearby minor vessels

Question 13

what sort of clinical situations can arise from thrombosis

Answer 13

DVT
Ischaemic limb
Myocardial infarction

Question 14

define thromboembolism

Answer 14

thrombus that has propagated (increased/moved) throughout the body

Question 15

Define emboli

Answer 15

detached intravascular solid, liquid or gaseous mass

Question 16

Types of embolus? (11)

Answer 16

systemic/arterial thromboembolus
venous thromboembolus
fat embolus
Gas embolus
Air embolus
Tumour
septic material 
amniotic fluid
bone marrow
foreign bodies - IV cannulae, sutures
trophoblast - pregnant women

Question 17

Describe systemic/arterial thromboembulus:-

causes, travel, consequences

Answer 17

caused by mural thrombus (mural means they adhere to the wall of a blood vessel - associated with MI or left atrial dilatation + AF). Also by aortic anuerysms, atheromatous plaques, valvular vegetations (lesions)

travels to wide variety of sites - lower limbs most common, brain, other organs

consequences depend on vulnerability of affected tissues to ischaemia, calibre of occluded vessel (diameter) and colateral circulation but usually infarction occurs

Question 18

Describe venous thromboembulus:-

causes, travel, consequences

Answer 18

originate from DV thromboses (lower limbs)
most common form of thromboembolic disease

travel to pulmonary arterial circulation

often have multiple venous thromboses that can become one large one

consequences depend on size of embolus: can be silent, pulmonary haemorrhage/infarction, right heart failure, sudden death.

Question 19

What can having multiple pulmonary embolisms over time lead to?

Answer 19

pulmonary hypertension

and R ventricular failure

Question 20

Risk factors fro DVT and PTE (7)

Answer 20

cardiac failure
severe trauma/burns
post-op/ post-partum (after birth)
nephrotic syndrome (kidney)
oral contraceptives
increasing age 
bed rest/immobilisation

Question 21

define and give examples of air emboli

Answer 21

when air bubble moves into venous system
e.g
head and neck wounds
surgery
Central venous lines

Question 22

give example of situation where gas embolus occurs

Answer 22

decompression syndrome - divers’ disease - N2 forms as bubbles which lodge in capillaries

Question 23

give example of situations where fat emboli can arise

Answer 23

after major fractures or vigorous CPR

lipid molecules leak out of the bone marrow

Question 24

what is rheumatic heart disease

Answer 24

a complication of rheumatic fever in which the heart valves are damaged.
It can sometimes cause - neurological symptoms
- commonly affects children aged 5-15 and boys more so than girls

Question 25

presentation of rheumatic fever

Answer 25

polyarthritis of large joints (wrists, elbows, ankles, knees)
skin rashes
fever

Question 26

what is pancarditis?

Answer 26

inflammation of the entire heart (epicardium, endocardium and myocardium). Heart murmurs are common in the acute phase.

Question 27

how can rheumatic fever cause damage to the heart?

Answer 27

by combination of antibody-mediated and T cell mediated reactions

Question 28

if pancarditis in the acute rheumatic fever phase progresses over time what can a person develop?

Answer 28

chronic rheumatic heart disease, mainly manifesting as valvular abnormalities

Question 29

what is virtually the only cause of mitral stenosis?

Answer 29

rheumatic heart disease

Question 30

what does RHD rarely cause?

Answer 30

aortic stenosis

Question 31

Diagnosis/ investigations of rheumatic heart disease

Answer 31

evidence of strep pyogrenase needed - throat culture, antigen test

ECG - heart block
blood tests - increased inflammatory markers and white cell count

Question 32

management of rheumatic fever

Answer 32

no cure
antibiotics to treat bacterial infection
corticosteroids if evidence of myocarditis
NSAIDs