CVS S10 - Ischaemic Heart Disease

Question 0

Give examples of conditions originating in the lungs and pleura which can cause chest pain

Answer 0

Pneumonia
Pneumothorax
Pulmonary embolism

Question 1

What are the general common sources of chest pain?

Answer 1

Lungs & Pleura
GI system
Chest wall
CVS - heart & great vessels

Question 2

Give examples of conditions originating in the GI system which can cause chest pain

Answer 2

Oesophagus (reflux)
Peptic ulcer disease
Gall bladder (cholecystitis, biliary colic)

Question 3

Give examples of conditions originating in the chest wall which can cause chest pain

Answer 3

Fractured ribs
Muscles
Skin

Question 4

Give examples of conditions originating in the CVS which can cause chest pain

Answer 4

Myocardium - angina, MI
Pericardium - pericarditis
Aorta - aortic dissection

Question 5

Give some non-modifiable risks for coronary atheroma (and by extension, IHD)

Answer 5

Increasing age
Gender
Genetics (family history)

Question 6

Give some modifiable risks for coronary atheroma (and by extension, IHD)

Answer 6

Hyperlipidaemia
Smoking
Hypertension
Diabetes mellitus
Exercise
Obesity
Stress

Question 7

Describe ischaemic chest pain

Answer 7

Central, retrosternal or left-sided
Described as crushing, tightening, heavy, constricting
Can radiate along jaw, arm, neck and back (particularly left side of all)

Question 8

Is IHD-caused chest pain always the same?

Answer 8

Can be different in different people
Can have radiation or not, can be only referred pain, can vary in intensity, duration, precipitating and relieving factors

Question 9

Describe stable angina

Answer 9

Mild to moderate IHD chest pain brought on by exertion or emotion, particularly after meals or in cold weather
Relieved by rest
Occurs when >70% of the lumen of a coronary artery is occluded by an atheromatous plaque

Question 10

How is angina treated?

Answer 10

Acutely: sub-lingual GTN spray
Preventatively: beta blockers, Ca channel blockers, oral nitrates
Preventing cardiac events: aspirin, statins, ace inhibitors
Long term: consider revascularisation

Question 11

Describe unstable angina

Answer 11

Ischaemic chest pain which occurs at rest or with minimal exertion. Described as severe and as having a crescendo pattern (becoming distinctly more severe, prolonged or frequent than before)
Caused by worsened stable angina as plaques grow and more coronary lumen is occluded

Question 12

How would a patient with an MI present?

Answer 12

With very serious ischaemic chest pain at rest
Not alleviated by rest or GTN spray
May have no precipitant
Autonomic features eg sweating pallor nausea vomiting
Breathlessness and fainting due to LV dysfunction

Question 13

How does a myocardial infarction occur?

Answer 13

Complete occlusion of a coronary artery leads to ischaemia and infarction of the myocardium it supplies
The fibrous cap of an atheromatous plaque can erode or fissure, allowing blood to the necrotic core & causing thrombus formation which can completely occlude a coronary artery

Question 14

What are the two general categories of myocardial infarction?

Answer 14

STEMI

NSTEMI

Question 15

Describe a STEMI

Answer 15

A myocardial infarction where the ST wave on an ECG is elevated, leading to the abbreviation (ST Elevated Myocardial Infarction)
Occurs when the infarct is the full thickness of the myocardium

Question 16

Describe a NSTEMI

Answer 16

An MI where the ST wave of an ECG is not elevated

Occurs when the infarct is not the full thickness of the myocardium

Question 17

Discuss the diagnosis of angina

Answer 17

ECG is usually normal so an exercise stress test is used
Diagnosis is based on history so these may contribute to diagnosis:
High BP
Corneal arcus
Evidence of atheroma elsewhere eg peripheral vascular disease
LV dysfunction

Question 18

Describe an exercise stress test

Answer 18

Graded exercise whilst connected to an ECG until:

• Target heart rate reached
• Chest pain
• ECG changes
• Other problems (arrhythmia, low bp, ect)

Question 19

What constitutes a positive exercise stress test result for diagnosis of angina?

Answer 19

ST depressions of >1mm

Question 20

What is acute coronary syndrome?

Answer 20

A group of symptoms attributed to the obstruction of coronary arteries as a result of NSTEMI, STEMI or unstable angina

Question 21

How can an unstable arrhythmia be differentiated from an NSTEMI?

Answer 21

UA has no myocardial necrosis whereas NSTEMI has some
So UA would have no bio markers like troponin in the blood but an NSTEMI would have a small amount
In an ECG, there may or may not be a difference

Question 22

How can a STEMI be differentiated from an NSTEMI?

Answer 22

An NSTEMI has partially occluded coronary arteries whereas a STEMI would have complete occlusion
A STEMI would also have significantly more necrosis than an NSTEMI so significantly more troponin and CK bio marker release
On an ECG, a STEMI would show ST elevation but NSTEMI wouldn’t

Question 23

What does a deep or pathological q wave indicate?

Answer 23

A previous myocardial infarction which has since healed

Question 24

What troponin isotopes are looked for in suspected MI? Discuss timescales of appearance

Answer 24

Cardiac troponin I (cTnI) and T (cTnT) Rise 3-4h after onset of ischaemic chest pain Peak 18-36h after Slowly decline over the next 10-14 days

Question 25

What creatine kinase isotopes are looked for in suspected MI? Discuss timescales of appearance

Answer 25

CK-MB is the cardiac iso-enzyme Rises 3-8h after onset of ischaemic chest pain Peaks after 24h Returns to normal in 48-72h

Question 26

Give examples of bio markers seen in the blood after an MI

Answer 26

``` Troponin (types I and T) Creatine kinase (the MB isoenzyme) ```

Question 27

What does presence of CK-MB, cTnI or cTnT in the blood indicate?

Answer 27

There has been death of myocardium

Question 28

How may progression of thrombosis be achieved?

Answer 28

Anti platelet agents eg aspirin | Anticoagulants eg heparin

Question 29

How may perfusion be restored to partially occluded vessels?

Answer 29

Early percutaneous coronary intervention (PCI) aka angioplasty Coronary artery bypass graft (CABG)

Question 30

What medications are used in ischaemic heart disease?

Answer 30

``` ACE-inhibitors Beta-blockers Statins Organic nitrates Pain control Oxygen ```

Question 31

Describe an angiography

Answer 31

Can be used to view any vessel occlusions | The findings of this procedure may be used to make choices about revascularisation surgeries

Question 32

Describe percutaneous coronary intervention (PCI)

Answer 32

Angioplasty and stenting A balloon is inflated in the occluded vessel to increase lumen diameter A mesh stent is expanded simultaneously, which holds the vessel open

Question 33

Describe coronary bypass grafting

Answer 33

Involves taking a blood vessel from elsewhere in the body eg internal mammary artery, radial artery, reversed saphenous vein This vessel is then grafted onto the heart to provide blood flow around an occlusion

Question 34

Give the typical presentation of acute pericarditis

Answer 34

Central or left-sided chest pain Sharp pain which is worse on inhalation Pain is relieved by leaning forward

Question 35

What can cause acute pericarditis?

Answer 35

``` Infection (viral, TB) Post MI or cardiac surgery Autoimmune Uraemia (kidney failure) Malignant deposits ```