CVS S10 - Chest pain and IHD

Question 1

List the 4 general types of chest pain

Answer 1

Cardiovascular, Respiratory, GI, Musculoskeletal

Question 2

List the different causes of cardiovascular chest pain and how the pain would feel

Answer 2

MI - Tightening

Pericarditis - Sharp

Aortic dissection - Tearing

Question 3

Give an example for each of the other types of pain (GI/ Musculoskeletal/ Respiratory)

Answer 3

Respiratory - Infection, pneumothorax

GI - reflux oesophagitis, pancreatic disease

MSK - trauma, bone metastases, muscle pain

Question 4

List the modifiable and non-modifiable risk factors for CAD

Answer 4

M- hyperlipidaemia, diabetes, smoking, hypertension

NM- increasing age, male gender, family history

Question 5

What is the cause of stable angina?

Answer 5

Stable plaque- small necrotic core, thick fibrous cap, cap less likely to fissure

Moderate reduction in blood flow results in transient ischaemic attacks during periods of high oxygen demand

Question 6

How would the chest pain present in a patient with stable angina?

Answer 6

• Central tightening pain
• Brief episodes with radiation to left/right/both arms or shoulders and neck, jaw or back
• Brought on by exertion and relieved by rest or nitrates

Question 7

How would a diagnosis of stable angina be made?

Answer 7

• Based on history
• No specific signs on examination but may have signs related to risk factors e.g. increased BP, corneal arcus, signs of atheroma elsewhere due to absent pulses
• Resting ECG usually normal

Question 8

What can be done if the diagnoses of stable angina is uncertain?

Answer 8

• Exercise stress ECG Test
• Patient connected to ECG and undertakes graded exercise on a treadmill until target heart rate reached or chest pain occurs/
• ECG changes/ other problems such as fall in BP

Question 9

What would be the results of an exercise stress test in a patient with stable angina?

Answer 9

• Transient sub-endocardial ischaemia with exercise- ST depression of more than 1mm
• With rest ST segment goes back to baseline

Question 10

What does a strongly positive exercise test indicate?

Answer 10

Critical stenosis

Question 11

What are the aims of treatment for stable angina?

Answer 11

• Reduce myocardial oxygen demand
• Increase blood flow by revascularisation
• Prevent progression of atheroma, stabilise plaque, prevent thrombosis

Question 12

What factors does myocardial oxygen supply depend on?

Answer 12

O2 carrying capacity of blood and coronary blood flow (depends on perfusion pressure (DBP) and coronary artery resistance)

Question 13

What factors must be altered to reduce myocardial oxygen demand?

Answer 13

Wall tension, heart rate, contractility

Question 14

What drugs can be given to reduce myocardial oxygen demand?

Answer 14

Nitrates, calcium channel blockers, beta blockers

Question 15

What are the two potential methods of revascularisation?

Answer 15

Percutaneous Coronary Intervention and stenting (PCI)

Coronary Artery Bypass Grafting (CABG)

Question 16

What are the two different types of Acute Coronary syndrome?

Answer 16

STEMI- occlusion complete, persistent, no collaterals, severe ischaemia and necrosis

NSTEMI/Unstable Angina- non occlusive thrombus, brief, collaterals present, less severe ischaemia

Question 17

How does unstable angina differ from NSTEMI?

Answer 17

NSTEMI is a non ST segment elevation MI with necrosis and biomarkers present

Unstable angina is ischaemia but no infarction so no necrosis and no biomarkers present

Question 18

How would a patient with unstable angina present?

Answer 18

• Acute worsening of stable angina- more frequent, more severe and longer duration
• Angina at rest
• Recent onset of new, effort limiting angina
• Presence of risk factors

Question 19

How would patient with MI present?

Answer 19

• Severe central crushing chest pain with typical radiation
• Persistent and continues at rest
• Not relieved by rest/ nitrate spray
• Autonomic features present e.g. sweating/pallor
• Nausea/ vomiting/ breathlessness/ faint

Question 20

What would you find on examination of a patient with an MI?

Answer 20

• Sweating, pallor
• Cold, clammy skin
• Tachycardia/ Arrythmias
• Low BP
• Signs of heart failure- S3/S4, crackles in lung bases

Question 21

What are the main biochemical markers of myocyte damage?

Answer 21

Cardiac Troponin I and Cardiac Troponin T

Rise 4 hours after onset of pain, peak 18-36 hours, decline slowly up to 10-14 days

Question 22

What other biochemical marker can be used to detect myocyte damage?

Answer 22

Creatine Kinase (CK-MB)

Rise 3-8 hours after onset, peak at 24 hours, back to normal 48-72 hours

Question 23

How would a STEMI be treated?

Answer 23

Emergency Percutaneous coronary intervention (PCI) within 90-120 minutes

If not available then fibrinolytic therapy

Question 24

How would an NSTEMI be treated?

Answer 24

Prevent extension of thrombus with anti-thrombotic therapy

Possible PCI/CABG but not emergency

Question 25

What are the long term treatments given after an MI and why?

Answer 25

Aspirin- decrease mortality and re infarction

Beta Blocker- decrease mortality and re infarction

ACE Inhibitors- improved survival

Statins- decrease mortality and re infarction

Manage risk factors via lifestyle modifications

Question 26

List some potential complications of MI

Answer 26

• Sudden cardiac death
• Arrhythmias- tachycardia/ bradycardia
• Heart block- primary/ secondary/ tertiary
• Ventricular tachycardia/ fibrillation
• Atrial fibrillation
• Heart failure
• Cardiogenic shock

Question 27

How can MI lead to bradycardia?

Answer 27

SA node ischemia

Question 28

How can MI lead to ventricular tachycardia?

Answer 28

Ventricular ishaemia causes re-entry circuits or increased automatic firing

Question 29

How can MI lead to heart failure?

Answer 29

Loss of myocardium causes decreased myocardial contractility

Question 30

How can MI lead to cardiogenic shock?

Answer 30

• > 40% myocardium infarcted
• Severely decreased CO
• Systolic BP