Stable Angina: Investigation, Diagnosis and Management Flashcards
1
Q
What is angina?
A
A discomfort in the chest and/or adjacent areas associated with myocardial ischaemia but without myocardial necrosis
2
Q
What is angina pectoris?
A
Cardiac chest pain
3
Q
Why does myocardial ischaemia occur?
A
Mismatch between supply of O2 and metabolites to myocardium and the myocardial demand for them
4
Q
What is the main cause of myocardial ischaemia?
A
Reduction in coronary blood flow to the myocardium
5
Q
What can cause a reduction in coronary blood flow to the myocardium?
A
- Obstructive coronary atheroma (very common)
- Coronary artery spasm (uncommon)
- Coronary inflammation/arteritis (very rare)
6
Q
What uncommon causes of myocardial ischaemia are there?
A
- Due to reduced O2 transport
- Due to pathologically increased myocardial O2 demand
7
Q
What condition can cause reduced O2 transport?
A
Anaemia of any cause
8
Q
What conditions can cause an increase in myocardial O2 demand?
A
- Left ventricular hypertrophy
- Thyrotoxicosis
9
Q
What can cause left ventricular hypertrophy?
A
-Significant persistent hypertension -Significant aortic stenosis -Hypertrophic cardiomyopathy -
10
Q
What is the most common cause of angina?
A
Coronary atheroma
11
Q
How do the symptoms of angina occur?
A
On activity with the increased myocardial oxygen demand obstructed coronary blood flow leads to myocardial ischaemia and then the symptoms of angina
12
Q
Give examples of situations in which myocardial oxygen demand increases.
A
When HR and BP rise:
- Exercise
- Anxiety/emotional stress
- After a large meal
- Cold weather
13
Q
What is the typical distribution of pain and discomfort in angina?
A
Across left chest and down medial side of left arm
14
Q
What must happen to coronary arteries before symptoms of angina are experienced?
A
Obstructive plaque that covers >70%
15
Q
What will spontaneous plaque rupture and local thrombosis with degrees of occlusion result in?
A
Acute coronary syndromes
16
Q
What symptoms will there be will a fatty streak in coronary arteries?
A
No symptoms
17
Q
What symptoms will there be with a non-obstructive plaque in the coronary arteries?
A
No symptoms
18
Q
Why is history essential to making a diagnosis of angina?
A
Essential to establish the characteristics of patients pain to differentiate from other causes of chest pain
19
Q
How is angina pain described?
- Site
- Character
- Radiation
- Aggravating and relieving factors
A
- Site: retrosternal (watch for patients gestures)
- Character: often tight band/pressure/heaviness
- Radiation: neck and/or into jaw, down arms
- Aggravating factors: exertion and emotional stress
- Relieving factors: physical rest, rapid improvement with GTN
20
Q
What features make it unlikely to be angina?
A
- Sharp/stabbing pain, pleuritic or pericardial
- Associated with body movements or respiration
- Very localised; pinpoint site
- Superficial with/or without tenderness
- No pattern to pain, particularly if often occurring at rest
- Begins some time after exercise
- Lasting for hours
21
Q
In the differential diagnosis, what are CV causes?
A
- Aortic dissection
- Pericarditis
22
Q
In the differential diagnosis, what are the respiratory causes?
A
- Pneumonia
- Pleurisy
- Peripheral pulmonary emboli
23
Q
In the differential diagnosis what are the musculoskeletal causes?
A
- Cervical disease
- Costochondritis
- Muscle spasm or strain
24
Q
In the differential diagnosis, what are the GI causes?
A
- Gastro-oesophageal reflux
- Oesophageal spasm
- Peptic ulceration
- Biliary colic
- Cholecystitis
- Pancreatitis
25
In the very rare occasion that myocardial ischaemia occurs with no chest pain, what other symptom may it present with on exertion?
- Breathlessness on exertion
- Excessive fatigue on exertion for activity undertaken
- Near syncope on exertion
26
Who is more likely to have symptoms other than chest pain n myocardial ischaemia?
-Elderly
-Those with diabetes mellitus
Probably dues to reduced pain sensation
27
What are the degrees of severity according to the Canadian classification of angina severity CCS?
I Ordinary physical activity does not cause angina, symptoms only on significant exertion
II Slight limitation of ordinary activity, symptoms on walking 2 blocks or >1 flight of stairs
III Marked limitation, symptoms o walking 1-2 blocks or 1 flight of stairs
IV Symptoms on any activity, getting washes/dressed causes symptoms
28
What non-modifiable risk factors are there?
- Age
- Gender
- Creed
- Family history
- Genetic factors
29
What modifiable risk factors are there?
- Smoking
- Lifestyle
- Diabetes mellitus
- Hypertension
- Hyperlipidaemia
30
What signs might be found on examination?
- Tar stains on fingers
- Obesity
- Xanthalasma and corneal arcus
- Hypertension
- Abdominal aortic aneurysm arterial brutis, absent or reduced peripheral pulses
- Diabetic retinopathy, hypersensitive retinopathy on fundoscopy
31
What are signs of exacerbating or associated conditions?
- Pallor of anaemia
- Tachycardia, tremor, hyper-flexia of hyperthyroidism
- Ejection systolic murmur, plateau pulse of aortic stenosis
- Pansystolic murmur of mitral regurgitation
- Signs of heart failure such as basal crackles, elevated JVP, peripheral oedema
32
What investigations should be carried out?
- Bloods
- CXR
- ECG
- Exercise tolerance test
- Myocardial perfusion imaging
- CT coronary angiography
- Invasive angiography
- Cardiac catheterisation/ coronary angiography
33
What bloods should be done?
- FBC
- Lipid profile
- Fasting glucose
- Electrolytes
- Liver and thyroid tests
34
Why is a CXR carried out?
Often helps show other causes of chest pain and can help show pulmonary oedema
35
What is the result of most ECGs in the investigation of angina?
Normal in >50% of cases
36
What may be seen on an ECG in the investigation of angina?
- Prior myocardial infarction (pathological Q-waves)
| - Left ventricular hypertrophy (high voltages, lateral ST-segment depression or strain pattern)
37
Which investigation can often confirm the diagnosis of angina?
ETT
38
What does the ETT rely on?
Ability to walk for long enough to produce sufficient CV stress
39
What indicates a positive ETT result?
Typical symptoms and ST segment depression
40
What does a negative ETT result mean?
- Doesn't exclude significant coronary atheroma
| - If negative at high workload, overall prognosis is good
41
In what ways s myocardial perfusion imaging superior to ETT?
- Detection of CAD
- Localisation of ischaemia
- Assessing size of area affected
42
What are disadvantages of myocardial perfusion imaging?
- Expensive
- Involves radiotherapy
- Depends on availability
43
What type of stress is used in myocardial perfusion imaging?
- Exercise
| - Pharmacological stress
44
Give examples of pharmacological stress used in myocardial perfusion imaging? (3)
- Adenosine
- Dipyridamole
- Dobutamine
45
How is myocardial perfusion imaging carried out?
- Radionuclide tracer is injected at peak stress on one occasion, images obtained and at rest on another
- Comparison between stress and rest images
- Normal myocardium takes up tracer
46
How is ischaemia indicated in myocardial perfusion imaging?
Tracer seen at rest but not after stress
47
How is infarction indicated in myocardial perfusion imaging?
Tracer seen neither at rest or after stress
48
When is invasive angiography indicated?
- Early or strongly positive ETT
- Angina refractory to medical therapy
- Diagnosis not clear after non-invasive tests
- Young cardiac patients due to work/life effects
- Occupation or lifestyle with risk
49
What aids in the decision over which treatment options are possible?
Definition of coronary anatomy with sites, distribution and nature of atheromatus disease by cardiac catheterisation/ coronary angiography
50
What are the treatment options available?
- Medication
| - Percutaneous coronary interventions (angioplasty and stenting or CABG surgery)
51
How is cardiac catheterisation/coronary angiography carried out?
- Almost always done under local anaesthetic
- Arterial cannula inserted into femoral or radial artery
- Coronary catheters passed to aortic root and introduced into the ostium of coronary arteries
- Radio-opaque contrast injected down coronary arteries and visualised on X-ray
52
Why are vies of the coronary arteries take in different planes?
Atheroma often eccentric in nature
53
Why is invasive coronary angiography a 2-D lumenogram?
Iodinated contrast or dye is passed through the arteries
54
What general measures are considered in treatment strategies?
Address risk factors
- BP
- DM
- Cholesterol
- Lifestyle
55
What medical treatment is considered in treatment strategies?
-Drugs to reduce disease progression and symptoms
56
When would revascularisation be considered as a treatment option?
If symptoms are not controlled
57
What revascularisation options are there?
- Percutaneous coronary intervention
| - Coronary artery bypass grafting
58
What drugs are available to influence disease progression?
- Statins
- ACE inhibitors
- Aspirin
59
When should statins be considered?
If total cholesterol >3.5mmol/L
60
What do statins do?
Reduce LDL cholesterol deposition in atheroma and also stabilise atheroma reducing plaque rupture and ACS
61
When should ACE inhibitors be considered?
If increased CV risk and atheroma
62
What do ACE inhibitors do?
Stabilise endothelium and also reduce plaque rupture
63
What dosage of aspirin should be given?
75mg
64
What is the substitute for aspirin if someone is intolerant?
Clopidogrel
65
What does aspirin do?
May not directly affect plaque but does protect endothelium and reduces platelet activation/aggregation
66
What drugs can be used for the relief of symptoms?
- B-blockers
- Ca channel blockers
- Ik channel blockers
- Nitrates
- K channel blockers
67
What is the aim of drugs used for the relief of symptoms?
Achieve resting heart rate <60bpm
68
What do B-blockers for?
Reduces myocardial work and have anti-arrhythmic effects
69
Give examples of central acting Ca channel blockers. (2)
- Diltiazem
| - Verapamil
70
What is Ivabridine (Ik channel blocker)?
A new medication which reduces sinus node rate
71
Give examples of peripheral acting Ca channel blockers.
- Amlodipine
| - Felodipine
72
What do Ca channel blockers do?
Produce vasodilatation
73
What do nitrates do?
Produce vasodilation
74
How are nitrates used?
Used as short or prolonged acting tablets, patches or as rapidly acting sublingual GTN spray for immediate use
75
What is an example of a K channel blocker?
Nicorandil
76
What are helpful in pre-conditioning
Nitrate molecule and K channel
77
What procedures are classed as percutaneous coronary intervention?
- Percutaneous transluminal coronary angioplasty
| - Stenting
78
How is PCI carried out?
-Similar beginnings to coronary angiography but cross stenotic lesion with guide wire and squash atheromatous plaque into walls with balloon and stent.
79
Why are aspirin and clopidogrel used together after somone has had a stent fitted
Taken whilst endothelium covers the stent struts and it is no longer seen as a foreign body with associated risk of thrombosis
80
PCI is effective at managing symptoms but what are the disadvantages?
- No evidence it improves prognosis in stable disease
- Small risk of procedural complications
- Risk of restenosis
- Still need to continue disease modifying medication
81
What is the best form of CABG for stable angina?
Multi-vessel CABG
82
In what subgroups might CABG confer prognostic benefit?
- Those with >70% stenosis of left main stem artery
- Significant proximal 3 vessel coronary artery disease
- 2 vessel coronary artery disease that includes significant stenosis of proximal left anterior descending coronary artery and who have an ejection fraction <50%
83
How do the up front risk of CABG compare to PCI?
Significantly increased
84
What are the lasting benefits of CABG?
80% symptom free 5 years later
85
What is the predictable deterioration in vein grafts?
10 years
