Chest pain and acute coronary syndrome

Question 1

Systematic approach to chest pain causes

Answer 1

Skin - shingles
MSK - bone/muscle/cartilage
Trachea
Lungs
Heart
GI
Blood vessels - aorta

Question 2

Cardiac vs resp causes of chest pain

Answer 2

Cardiac - acute coronary syndromes, stable angina, pericarditis

Resp - pneumonia

MSK - Costochondritis, rib fracture

Question 3

Two types of chest pain

Answer 3

Cardiac ischaemic

Pleuritic

Question 4

Different nerve innervations for different pain types

Answer 4

Heart muscle - Visceral pain (visceral afferent fibres)

Lung pleura/pericardial sac/MSK - Somatic pain (somatic afferent vessels)

Question 5

Cardiac ischaemic chest pain described

Answer 5

Visceral (afferent nerves in sympathetic fibres)
Dull, central chest pain
Poorly localised
Referred pain (shoulder/jaw)

Question 6

Why does cardiac pain radiate to arm?

Answer 6

Visceral afferent send signals towards T1-T4/T5

Sensory/somatic afferents from T1-T4/5 dermatomes enter at same level

Brain interprets signals as arising from skin - pain felt in T1-T4/5 dermatomes

Question 7

Pleuritic chest pain described

Answer 7

Somatic afferent nerves
Brain perceives somatic pain
SHARP WELL LOCALISED - made worse with inspiration/coughing

Question 8

Cardiac causes chest pain

Answer 8

Pericardium (somatic afferents) - pericarditis

Cardiac muscle (visceral afferents) - stable angina, acute coronary syndromes

Question 9

Pericarditis presentation history

Answer 9

Males > females risk

Infection - typically viral

Question 10

Pericarditis pain presentation

Answer 10

Sharp
Front of chest
Leaning forward relieves pain, lying down makes it worse

Question 11

Pericarditis clinical examination results

Answer 11

Pericardial rub on auscultation (scratchy noise)

ECG - widespread ST elevation (if STEMI only in certain leads)

FBC - CRP raised?

Question 12

Acute coronary syndrome cases

Answer 12

Unstable angina

NSTEMI
STEMI
(myocardial infarction)

NOT STABLE ANGINA

Question 13

What is ischaemic heart disease?

Answer 13

Insufficient blood supply to heart muscle due to atherosclerotic disease of coronary arteries

eg stable/unstable angina, NSTEMI, STEMI

Question 14

Stable angina pathophysiology

Answer 14

Atherosclerosis

Stable, fixed atherosclerotic plaque narrowing coronary artery

Question 15

Acute coronary syndrome risk factors

Answer 15

same as atherosclerosis:
Age
Male
Family history 
Ethnicity 

Smoking 
Diabetes
Hypertension
Hyperlipidaemia 
Obesity

Question 16

Pathophysiology of acute coronary syndrome

Answer 16

Stable (chronic) occlusion (atherosclerotic plaque)
Plaque ruptures (acute)
Thrombus formation
Sudden increased occlusion
Severity of occlusion determines UA, NSTEMI STEMI

= ischaemia and INFARCTION

Question 17

Unstable angina

Answer 17

Plaque disruption and platelet aggregation

Question 18

NSTEMI

Answer 18

Thrombus formed on plaque - not fully occluding

Question 19

STEMI

Answer 19

Thrombus fully occluding vessel

Question 20

What will all ACS present with?

Answer 20

Cardiac ischaemic sounding chest pain

Question 21

How do we differentiate between SA and UA?

Answer 21

Chest pain goes away with rest in SA

Ischaemia will only show when exercising

Question 22

How do we differentiate between UA and NSTEMI?

Answer 22

Both could have ST depression

BUT NSTEMI will have raised troponins

Question 23

Which chest pain = raise in troponins?

Answer 23

INFARCTION so NSTEMI or STEMI

Question 24

Evolution waves in STEMI

Answer 24

Hyperacute T waves + ST elevation (acute)
Q wave begins + ST elevation (hours)
T wave inversion + deeper Q wave (day 1-2)
ST normalise + inverted T waves (days)
ST and T normal, Q wave persists (pathological Q waves, weeks)