iBSc: Question 1

By Alan McLeod

Getting the best marks

Read the whole question – a latter section may give you a

clue about an earlier one.

To see how many points you need look at the marks

allocated – for example a 3 point question is generally looking for 3 salient points

If giving a list answer put the best answers first – examiners will not usually mark answers too

far down a list

Always write something – it may get you part of a mark and is anonymised so

no one will think you are stupid!

If you genuinely have no clue then re-write the question to see if this sparks

some ideas.

If not then move on and come back at the end. And remember – always

write something.

Good luck!

Question 1

Mr Smith, a 68 year old smoker,

presents to A+E with a 2 hour

history of severe crushing chest

pain.

• Q1.1• List 5 differentials for

chest pain (5)

Question 1

Your SHO asks you to do an ECG and

cardiac specific bloods

Q1.2• What ECG changes might

you expect if the cause is STEMI or NSTEMI? (3)

Q1.3• What cardiac specific

blood tests would you request? (2)

Question 1

After ECG and blood tests, Mr Smith is diagnosed with

STEMI caused by occlusion of one of

his coronary vessels

Q1.4

Label these vessels (4)

Question 1

The loss of blood supply can

damage cardiac muscle

Q1.5• List differences

between cardiac and skeletal muscle (3)

Question 1

In this case, atherosclerotic disease is to

blame.

Q1.5• Describe a model for the formation

of atherosclerotic plaques (5)

Q1.6• List 2 modifiable and 2 non-

modifiable risk factors for atherosclerotic disease (2+2 = 4 pts)

AA

DD

BB

CC

EndocardiumEndocardium

FoldFold

EE

Question 1.7Lable these layers of cardiac muscle and other tissues

Question 1

In this patient’s notes is a letter from his GP stating that Mr

Smith is ‘non-compliant with

smoking cessation measures’.

Q1.8

• Describe compliance and concordance (2)

• 33 marks total for question 1

The Answers

View these on ‘note view’ rather than on full screen – additional

notes are provided for some slides

Generating Differentials:I’D GET VINO…

I Infectious / inflammatory

D Degenerative

G Genetic / Idiopathic

E Endocrine

T Trauma

V Vascular

I Iatrogenic / ingested

N Neoplastic

O Organs

Causes of Chest Pain I Infectious / inflammatory Pneumonia, pleurisy, Costochondritis

D Degenerative

G Genetic / ideopathic

E Endocrine

T Trauma Fractured rib, pulled muscle, pneumothorax

V VascularMyocardial infarction, angina, aortic dissection, PE

I Iatrogenic / ingested Surgical scar

N Neoplastic Bony mets

O Organs / other

Oesophagus (spasm, reflux), heart (pericarditis)Lung, Aorta, bones, muscle, cartilage, anxiety

STEMI and NSTEMIA: Normal ECG

B: ST Elevation

C: ST Depression

ST elevation in response to Isoelectric line (I)

I

B

C

A

P TQRS

ST Segment

Evolution of ECG Changes in STEMI

• Minutes to hours– Peaked T waves

• Hours– ST elevation

• Hours to days– T wave inversion– Loss of R wave

• Days– Pathological Q wave

Cardiac Enzymes

Right: Right Ventricle, most of Right Atrium, Part of Left Atrium

Left: Left Ventricle, part of Right atrium, most of Left atrium

Left circumflex: Left margin of heart and its entire posterior wall, Left atrium, posterior IV septum

LAD: Anterior 2/3 of IV septum, anterior portion of LV, whole apex

SA Node: Right 51-65%, Left 35-45%, Bilateral <10%

AV Node: Right 80-90%, Left 10-20%

ALL HIGHLY VARIABLE!!!

Plaque Formation

Plaque Formation

Plaque Formation

Plaque Formation

Plaque Anatomy

Plaque Anatomy (early)• Free Lipid• Foam cells• Increased myointimal

cells• Collagen• Disruption of internal

elastic lamina

Plaque Anatomy (later)• Collagen cap• Extracellular lipid mass• Foam cells• Myointimal cells• Disrupted internal elastic

lamina• Pressure atrophy of

muscle collagenous replacement

Atheroma – Risk factors

Non-preventable• Increasing age• Male sex• Family history

Preventable• Hyperlipidaemia

– LDL and Cholesterol

• Hypertension– Diastolic most

important

• Diabetes• Smoking

Muscle Comparison

Skeletal Cardiac Smooth

Voluntary Involuntary Involuntary

Striated Striated Non-striated

Multinucleated Mononucleated Mononucleated

Unbranched Branched Unbranched

No gap junctions Gap junctions No gap junctions

Fibrous Pericardium

Fibrous Pericardium

Parietal Layer of Serous PericardiumParietal Layer of

Serous Pericardium

MyocardiumMyocardium

Pericardial Space

Pericardial Space

EndocardiumEndocardium

FoldFold

Visceral Layer of Serous PericardiumVisceral Layer of

Serous Pericardium

Layers of the Heart

Health Behaviour

• Compliance– Extent to which

patient’s behaviour matches recommendations from the prescriber

• Adherence– Extent to which the

patient’s behaviour matches agreed recommendations from the prescriber.

• Concordance– Extent to which the

patient’s behaviour matches agreed recommendations from the prescriber after exploring and discussing the patients beliefs, views and opinions.

The End

The slides here should allow you to mark your own work – remember 1 mark per

answer up to the maximum for the question. Multiply by 3 to get percentage points. I assume a 60% pass mark. Sorry but I am unable to give further advice on

answers due to time constraints.