infarction and embolism

Question 1

distinguish thrombosis from embolism

Answer 1

thrombosis is from a ruptured atherosclerosis which has clotting factors triggered causing an occlusion. Embolism is any abnormal body in the circulations, can be air, a clot and it travels and lodges in artery

Question 2

state some locations where you can have an embolism

Answer 2

spleen, lung, kidney, heart anywhere with a blood supply theoretically

Question 3

define infarct

Answer 3

An infarct is an area of ischaemic necrosis within
a tissue or organ, produced by occlusion of either its arterial
supply or its venous drainage.

Question 4

aside from embolism and thrombosis what else can cause infarcts

Answer 4

hypo tension, not enough perfusion but this is more rare

Question 5

what are people post surgery or reduced mobility at great risk of

Answer 5

dvt in calf muscle causing pulmonary embolism. due to blood clot travelling from leg to lung via circulation

Question 6

why is venous infarction less common

Answer 6

VENOUS INFARCTION is less common because arrest of blood
flow due to venous obstruction is unusual (most tissues have
numerous venous anastomoses).

Question 7

name veins where anastomoses is weak and their is a slight risk of infarction

Answer 7

Thrombosis of the mesenteric veins -> intestinal infarction

Question 8

when do white infarcts occur

Answer 8

With arterial occlusion and

2. In solid tissues e.g. heart, spleen, kidneys

Question 9

why is STEMI considered to be a worse infarction than NSTEMI

Answer 9

TRANSMURAL INFARCT – the ischaemic necrosis involves
the full or nearly full thickness of the ventricular wall in the
distribution of a single coronary artery. Usually associated
with coronary atherosclerosis, plaque rupture and superimposed
thrombosis.

Question 10

what is a subendocardial infarct

Answer 10

UBENDOCARDIAL INFARCT – this constitutes an area of
ischaemic necrosis limited to the inner one-third, or at most
one-half, of the ventricular wall. There is diffuse stenosing
coronary atherosclerosis and global reduction of coronary
flow (e.g. due to shock) but no plaque rupture and no
thrombosis.

Question 11

name for 4 morphological (shape of the heart sdue to dead tissue) complications following a heart attack

Answer 11

pericarditis, cardiac rupture, mural thrombosis, ventricular aneurysm,

Question 12

what is cardiac rupture

Answer 12

mechanicial weakening of the heart wall can cause rupture depdning on location effects can differ, septum left right shunt, ventricular wall lead to tamponade

Question 13

what is ventricular aneurysm

Answer 13

VENTRICULAR ANEURYSM. A late complication that most
commonly results from a large anteroseptal, transmural infarct
that heals into a large area of thin scar tissue that paradoxically
bulges during systole.

Question 14

what is mural thrombosis

Answer 14

MURAL THROMBOSIS (15-40 % of cases). The combination of a
local myocardial abnormality in contractility (causing stasis) and
endocardial damage (causing a thrombogenic surface) leads to
mural thrombosis and thromboembolism.

Question 15

define embolism

Answer 15

DEFINITION. Embolism is the transfer of abnormal material
by the bloodstream and its impaction in a vessel.
The impacted material = the embolus.

Question 16

name types of emboli (7)

Answer 16

• Fragments of thrombus (commonest type)
• Material from ulcerating atheromatous plaques (common
in distal leg arteries)
• Septic emboli
• Fragment of tumour growing into a vein
• Fat globules
• Air emboli
• Parenchymal cells

Question 17

why is infarction never co extensive with area of distribution

Answer 17

nfarction is never co-extensive with the area of distribution
(because of collateral vessels and the bronchial
circulation).