cardiovascular histology

Question 1

define atherosclerosis?

Answer 1

an arteriosclerosis

atheromatous deposits &
fibrosis

of inner layer of arteries

Question 2

where do atheroma plaques form?

Answer 2

intima then protude into lumen

Question 3

describe the process of atherosclerosis?

Answer 3

smooth endothelium damage

platelets stick to damaged endothelium

endothelium proliferates

fibrous cap fomrs on top of endothelium

choleserol deposits in core of lesion

plaque enlarges, blocking lumen of vessel

Question 4

which study looked at risk factors of atherosclerosis ?

Answer 4

Framingham Heart Study

Question 5

Risk factors have a what type of effect on risk of atherosclerosis?

Answer 5

MULTIPLICATIVE EFFECT

Question 6

list Constitutional Risk Factors (impossible/hard to control) in atheroslcerosis?

Answer 6

age

gender - W: protected premenopause, risk increased post menopause

Genetics - most significant independent risk factor

Question 7

what is the MOA of statins?

Answer 7

inhibit HMG-CoA reductase rate limiting enzyme in liver cholesterol synthesis

Question 8

HTN alone increases risk of IHD by __%

DM increases risk of IHD by __%

Prolonged cigarret smoking increases risk of IHD by __%

Answer 8

60%

double

double

Question 9

ihd is a group of conditions resulting from ….?

Answer 9

from myocardial ischaemia

Question 10

what is the order of extent of injury?

Answer 10

loss of cell function

cell death

microscopic changes

gross changes

Question 11

what are the 4 stages of presentation of ihd?

Answer 11

Angina pectoris
Myocardial infarction
Disease with heart failure
Sudden cardiac death.

Question 12

pathogensis of ihd?

Answer 12

Predominant cause is

insufficient coronary perfusion to suffice myocardial demand

due to chronic progressive atherosclerotic narrowing of epicardial coronary arteries

and variable degrees of superimposed plaque change, thrombosis and vasospasm

Question 13

what are the componesnt of a vulnerable plaque?

Answer 13

Lots foam cells or extracellular lipid
Thin fibrous cap
Few smooth muscle cells
Clusters inflammatory cells

Question 14

why does emotional stress inc risk of sudden death?

Answer 14

Adrenalin increases blood pressure & causes vasoconstriction
Increases physical stress on plaque

Hence emotional stress increases risk of sudden death
Circadian periodicity to sudden death (6am-noon)

Question 15

what level of stenosis is required to see symptoms?

Answer 15

75% stenosis or more generally needed to cause symptoms precipitated by exercise

Vasodilation cannot compensate above this level of stenosis

90% stenosis can lead to pain at rest

Question 16

where do plaques tend to form in the epicardial coronary arteries?

Answer 16

Plaques mainly in first few cm of LAD or LCX

Entire length RCA

Question 17

what are the 3 acute coronary syndromes?

Answer 17

STEMI

NSTEMI

Unstable angina

Question 18

what is the pathophysiology of ACS?

Answer 18

Stable plaque becomes unstable
Due to rupture, erosion, haemorrhage etc

Generally leads to superimposed thrombus which increases occlusion

no plaque disruption in stbale angina though

Question 19

which angina is caused by artery spasm?

Answer 19

prinzmetal

aka variant angina

Question 20

what is a Warning of impending infarction?

Answer 20

unstable angina

Question 21

what is the myocardial response to a sudden disruption to its blood supply?

Answer 21

Myocardial blood supply compromised leading to ischaemia
Loss of contractility within 60 seconds
Therefore heart failure can precede myocyte death
Potentially reversible
Irreversible after 20-30 minutes

Question 22

most common arteries of infarct?

Answer 22

LAD – 50%, ant wall LV, ant septum, apex

RCA - 40%, post wall LV, post septum, post RV

LCx - 20%, lat LV not apex

Question 23

after an mi, which cells are first to repond in order?

Answer 23

neutrophils

macrophages

angioblasts

fibroblasts and collagen

Question 24

how soon after an mi do you see;

Coagulation necrosis, loss nuclei & striations, neutrophils +++

Answer 24

1-3 days

Question 25

how soon after an mi do you see; granulation tissue, macrophages, new blood vessels, myofibroblasts, collagen synthesis

Answer 25

10-14 days

Question 26

how soon after an mi do you see; normal by histology (CK-MB also normal)

Answer 26

under 6 hours

Question 27

what are the worst prognostic factors in MI?

Answer 27

Age, female, DM, previous MI | -> worse prognosis

Question 28

how do you treat a hibernating myocardium?

Answer 28

revascularisation

Question 29

list 3 complications of MI?

Answer 29

Contractile dysfunction – 40% infarct-> cardiogenic shock with 70% mortality rate Arrhythmia Myocardial rupture Pericarditis (Dressler syndrome) 2nd or 3rd day Infarct extension/expansion causing; Mural thrombus and more

Question 30

Most common areas of myocardial rupture?

Answer 30

free wall most common, septum less common, papillary muscle least common

Question 31

mortality in MI?

Answer 31

Total mortality = 30% in one year | 3-4% mortality per year after first

Question 32

describe the heart in chronic IHD vs heaert failure?

Answer 32

``` C IHD: Enlarged heavy heart, hypertrophied, dilated LV Atherosclerosis Maybe mural thrombi Fibrosis (microscopic) ``` Heart failure: Dilated heart, Scarring & thinning of the walls

Question 33

causes of sudden cardiac death?

Answer 33

Marked atherosclerosis (>75% stenosis) in one or more vessels usually >90% 10% non atherosclerotic cause (long QT etc) ½ have plaque rupture

Question 34

what is the presentation of left vs right sided hf?

Answer 34

Left sided (-> SOB, pulmonary oedema) Right sided (-> peripheral oedema, hepatomegaly, raised jvp)

Question 35

aetiology of dilated cardiomyopathy? describe the heart?

Answer 35

Progressive loss of myocytes Dilated heart ``` Causes: Idiopathic Infective – viral myocarditis Toxic: alcohol, chemotherapy (adriamycin, daunorubicin), cobalt, iron thyroid conditions ``` etc

Question 36

aetiology of hypertrophic cardiomyopathy? describe the heart?

Answer 36

Left ventricular hypertrophy Familial in 50% (autosomal dominant, variable penetrance) Beta-myosin heavy chain Thickening of septum narrows left ventricular outflow tract

Question 37

aetiology of restrictive cardiomyopathy? describe the heart?

Answer 37

Impaired ventricular compliance Idiopathic or secondary to myocardial disease eg amyloid, sarcoidosis Normal size heart – big atria

Question 38

list effects of CHRONIC RHEUMATIC VALVULAR DISEASE on heart structures?

Answer 38

thickened valves; Predominantly left-sided valves (almost always mitral) Mitral > Aortic > Tricuspid > Pulmonic Mitral alone 48%, Mitral + aortic 42% Thickening, shortening and fusion of chordae tendineae

Question 39

name the Commonest cause of aortic stenosis? aetiology?

Answer 39

Calcific aortic stenosis ``` 70s or 80s Calcium deposits outflow side cusp Impairs opening Orifice compromised Outflow tract obstruction ```

Question 40

what are the different types of aneurysm?

Answer 40

True - all layers wall False – extravascular haematoma Causes: Weak wall

Question 41

list some causes of aneurysm?

Answer 41

Congenital eg Marfans Atherosclerosis Hypertension

Question 42

atherosclerotic aortic aneurysm typically occur where?

Answer 42

in the abdominal aorta portion (AAA) below the renal arteries

Question 43

list some causes of aortic regard?

Answer 43

Rigidity - rheumatic, degenerative Destruction - microbial endocarditis Disease of aortic valve ring -> dilatation-> valve insufficient to cover increased area: Marfan's Syndrome Dissecting aneurysm Syphilitic aortitis Ankylosing spondylitis