21. Stable Angina: diagnosis, investigation and management (stable ischaemic heart disease) Flashcards
1
Q
Define angina.
A
- Simply means pain, but has been adopted to mean cardiac chest pain (angina pectoris).
- a discomfort in chest and/or adjacent areas associated with myocardial ischaemia but without myocardial necrosis
2
Q
Define ischaemia.
A
inadequate blood supply to an organ or tissue, especially the heart muscle
3
Q
What is the main cause of a stable angina?
A
- Pathophysiolgoy of myocardial ischaemia and resultant anginal symptoms
- Mismatch between supply of O2 and metabolites to myocardium and the myocardial demand for them
4
Q
What is the number 1 cause for stable angina?
A
due to reduction in coronary blood flow to the myocardium
5
Q
What are 3 causes of reduction in coronary blood flow to myocardium?
A
- obstructive coronary atheroma (very common)
- coronary artery spasm (uncommon)
- coronary inflammation/ arteritis (very rare)
6
Q
What are uncommon causes for stable angina? (2)
A
- due to reduced O2 transport in anaemia of any cause
- due to pathologically increased myocardial O2 demand and increased metabolic rate e.g. left ventricular hypertrophy or thyrotoxicosis
7
Q
What is thyrotoxicosis?
A
- main cause is hyperthyroidism
- overactivity of the thyroid gland producing excess levels of thyroid hormones
8
Q
In which conditions is left ventricular hypertrophy (LVH) seen which causes ischaemia? (3)
A
- persistent hypertension
- significant aortic stenosis
- hypertrophic cardiomyopathy
9
Q
What is the most common cause of angina?
A
coronary atheroma
10
Q
How does increased myocardial oxygen demand lead to symptoms of angina?
A
On activity, increased O2 demand is needed due to obstructed coronary flow which leads to myocardial ischaemia and therefore symptoms of angina.
11
Q
In what situations does myocardial oxygen demand increase? (5)
A
Where heart rate and BP rise. eg. :
- exercise
- anxiety/emotional stress
- after a large meal
- cold weather
- on exertion
12
Q
What is meant by STABLE angina?
A
Chest pain which occurs on activity or emotional stress(due to poor blood flow in coronary vessels when there is precipitated excess myocardial oxygen demand)
13
Q
What is a common description of angina by patients? (3)
A
- heaviness
- squeezing sensation (tightness)
- hand over central chest sometimes pain going over left arm
14
Q
To which locations can angina pain spread to? (5)
A
- back
- jaw
- arm (most often left)
- neck
- shoulder
15
Q
When is plaque considered “obstructive”?
A
when plaque takes up >70% of lumen
16
Q
At what stage of plaque formation can symptoms usually begin to appear?
A
begin to appear when lumen narrowing is >70% obstructed
17
Q
Describe stages of plaque formation.
A
1, normal
- fatty streak
- non-obstructive plaque
- obstructive plaque (>70% of lumen)
- spontaneous plaque rupture
18
Q
When does acute coronary syndrome become apparent? (what are features of the plaque)
A
spontaneous plaque rupture and local thrombosis with degrees of occlusion
19
Q
During which breathing stage do atherosclerosis symptoms become apparent?
A
on exertion
20
Q
During which breathing stage does acute coronary syndrome become apparent?
A
symptoms not exclusive to exertion only but also at rest (symptoms can be noticed at any stage of breathing)
21
Q
What is the main component of history taking that will help distinguish angina from other differential diagnosis options?
A
essential to establish the characteristics of patient’s PAIN
22
Q
What features of pain should be found out in patient’s history who presents with angina-like symptoms? (4)
A
- SITE of pain; watch for patient’s gestures, retrosternal (behind sternum)
- CHARACTER of pain; often tight band, pressure, heaviness
- RADIATION sites; neck and/or into jaw, down arms
- AGGRAVATING; with exertion, emotional stress and relieving factors (e.g. rapid improvement with GTN or physical rest)
23
Q
What is myocardial ischaemia almost always characterised as?
A
characterised as being relieved with GTN within 2 or 3 minutes
24
Q
What features of pain make angina not likely? (7)
A
- sharp/stabbing/ sudden pain; pleuritic or pericardial
- associated with body movements or respiration
- very localised, pinpoint site
- superficial with/or without tenderness
- no pattern of pain, particularly if often occuring at rest
- begins some time AFTER exercise
- lasting for hours
25
What 4 body systems are differential diagnoses for chest pain? (with characteristics different to angina)
1. cardiovascular causes
2. respiratory causes
3. musculoskeletal causes
4. GI causes
26
What are the other cardiovascular causes for chest pain which are part of the differential diagnosis but have different characteristics to angina?(2)
1. aortic dissection; tear in part of aorta (intra-scapular tearing)
2. pericarditis
27
What are the other respiratory causes for chest pain which are part of the differential diagnosis but have different characteristics to angina? (3)
1. pneumonia
2. pleurisy
3. peripheral pulmonary emboli (pleuritic)
28
What are the other musculoskeletal causes for chest pain which are part of the differential diagnosis but have different characteristics to angina? (3)
1. cervical disease
2. costochondritis
3. muscle spasm or strain
29
What are the other GI causes for chest pain which are part of the differential diagnosis but have different characteristics to angina? (6)
1. gastro-oesophageal reflux
2. oesophageal spasm
3. peptic ulceration
4. biliary colic (gallstone blocking bile duct)
5. cholecystitis (inflammation of gallbladder)
6. pancreatitis
30
What treatment is given to confirm angina?
relieved symptoms with GTN or rest
31
What other symptoms on exertion may indicate angina (myocardial ischaemia) that are NOT chest pain?(3)
1. breathlessness on exertion
2. excessive fatigue on exertion for activity undertaken
3. near syncope on exertion (fainting)
32
What is another name for angina?
myocardial ischaemia
33
What group of patients present with angina symptoms on EXERTION that are not chest pain? Why?
- elderly
- patients with diabetes mellitus
(probably due to reduced pain sensation)
34
What system is used to distinguish severity of angina?
Canadian classification of angina severity (CCS)
35
What is stage 1 of CCS of angina classification?
Ordinary physical activity does not cause angina, symptoms only on significant exertion (least severe)
36
What is stage 2 of CCS of angina classification?
Slight limitation of ordinary activity, symptoms on walking 2 blocks or>1 flight of stairs
37
What is stage 3 of CCS angina classification?
marked limitation, symptoms on walking only 1-2 blocks or 1 flight of stairs
38
What is stage 4 of CCS angina classification?
Symptoms on any activity, getting washed/ dressed causes symptoms (most severe)
39
What are non-modifiable risk factors for coronary heart disease? (6)
1. age
2. gender
3. creed (religion)
4. ethnicity
5. family history
6. genetic factors
40
What are modifiable risk factors for coronary heart disease? (6)
1. smoking
2. lifestyle exercise and diet
3. diabetes mellitus (glycaemic control reduces CV risk)
4. hypertension ( BP control reduces CV risk)
5. hyperlipidaemia (lowering reduces CV risk)
6. people living at higher latitudes
41
What are clinical signs seen on examination in patients with stable angina? (6)
1. tar stains on fingers
2. obesity (centripedal)
3. xanthalasma and corneal arcus (hypercholesterolaemia)
4. hypertension
5. abdominal aortic aneurysm arterial bruits, absent or reduced peripheral pulses
6. diabetic retinopathy, hypertensive retinopathy on fundoscopy
42
What is a bruit?
- Turbulent sound of blood flow
- Usually caused by a narrowing of an artery
- sound usually heard over artery or vascular channel
43
What is xanthalasma?
yellowish deposit of fat underneath the skin
44
What is a corneal arcus?
white/blue or grey opaque ring in the corneal margin or white ring in front of the periphery of the iris
45
What are signs on examination that show signs of exacerbating or associated conditions? (5)
1. pallor of anaemia (pale skin)
2. tachycardia, tremor, hyper-reflexia of hyperthyroidism
3. ejection systolic murmur; plateau pulse of aortic stenosis
4. pansystolic murmur of mitral regurgitation
5. signs of heart failure
46
What are main signs of heart failure? (3)
1. basal crackles
2. elevated JVP
3. peripheral oedema
47
What investigations are needed for stable angina diagnosis? (8)
1. bloods
2. chest x ray
3. electrocardiogram (ECG)
4. exercise tolerance test (ETT)
5. myocardial perfusion imaging
6. CT coronary angiography
7. invasive angiography
8. cardiac catherisation/ coronary angiography
48
What needs to be found specifically in the full blood count for diagnosing stable angina?(4)
1. lipid profile
2. fasting glucose
3. electrolytes
4. liver and thyroid tests
49
What does chest x ray usually indicate in stable angina patients additionally to the diagnosis? (2)
- may show other causes of chest pain
| - can help show pulmonary oedema
50
What may ECG indicate in stable angina patients? (3)
- may show prior myocardial infarction evidence e.g. pathological Q-waves
- may show evidence of left ventricular hypertrophy (e.g. high voltages, lateral ST segment depression or strain pattern)
- it' normal in over 50% of patients so doesn't necessarily rule out stable angina
51
How does exercise tolerance test work? (EET)
(can confirm angina)
- relies on ability to walk for long enough to produce sufficient CV stress
- it reproduces people exerting themselves
52
What confirms a positive exercise tolerance test? (confirms stable angina) (2)
1. typical symptoms
| 2. ST segment depression for positive test
53
What does a negative exercise tolerance test reveal?
- doesn't exclude significant coronary atheroma
| - if negative at high workload then overall prognosis is good
54
What are cons to exercise tolerance test? (ETT) (3)
- limited to people who can't exercise since it can't be used effectively
- poor sensitivity and specificity; is single vessel disease it will not be picked up unless multiple vessel disease
- less sensitive in women, middle aged and hypotensive
55
Which part of the ECG is changed in stable angina patients?
ST segment depression
56
Why is myocardial perfusion imaging better for detecting coronary artery disease (e.g. myoacardial ischaemia) than exercise tolerance test? (2)
1. better localisation of ischaemia
| 2. better at assessing size of area affected
57
What are cons for myocardial perfusion imaging? (2)
- expensive
- involves lots of radioactivity depending on availability used where ET; exercise tolerance test not possible/ equivocal
58
What types of "stresses" are needed for myocardial perfusion imaging? Give examples of specific names
1. exercise
2. pharmacological
(e. g. adenosine, dipyridamole or dobutamine)
59
When is radionuclide tracer injected through iv?
at peak stress on one occasion then images obtained and then at rest on another (comparison between stress and rest images made)
60
What happens to the tracer injected in myocardial perfusion imaging?
normal myocardium takes up the tracer
61
What does it mean when tracer is seen at rest but not after stress?
ischaemia (reduced/ restricted blood supply); some blood still getting through
62
What does it mean when tracer is seen neither at rest or after stress?
infarction (obstruction of the blood supply to an organ or region of tissue, typically by a thrombus or embolus, causing local death of the tissue); no blood getting through and tracer not taken up
63
What colour are the areas on myocardial perfusion images where tracer has been taken up?
yellow/red zone
64
What does CT coronary angiography tell us in relation to angina?
if angina related to coronary heart disease (good for patients with low cardiac disease risk)
65
When to do invasive angiography on a patient as a form of investigation?
1. early or strong positive ETT (suggests multi-vessel disease)
2. angina refractory to medical therapy
3. diagnosis not clear after non-invasive tests
4. young cardiac patients due to work/life effects
5. occupation or lifestyle with risk e.g. drivers
66
What investigation is needed for CHRONIC stable angina?
1. cardiac catherisation (tube;catheter is inserted in an artery or vein in your groin, neck or arm and threaded through your blood vessels to your heart.)/ with coronary angiography (taking x rays of heart's coronary arteries by inserting a dye through catherter)
67
What does cardiac catherisation and coronary angiography enable?
- what treatment options are available
| - shows coronary anatomy with sites, distribution and nature of atheromatous disease
68
What are possible general treatment option for chronic stable angina? (3)
- medication alone
OR
- percutaneous coronary intervention (PCI) most often angioplasty and stenting
- coronary artery bypass graft (CABG) surgery
69
Describe the process of cardiac catherisation/ coronary angiography in steps.
1. almost always local anaesthetic given
2. arterial canula inserted into femoral or radial artery
3. coronary catheters passed through groin, neck or arm to aortic root and introduced into ostium of coronary arteries
4. radio-opaque contrast medium injected down coronary arteries and visualised on x ray
70
What dye is used for invasive coronary angiography?
iodinated contrast/ dye passed through the arteires (iodine absorbs x rays which show vessels)
71
What is specifically shown in invasive coronary angiography once images come up?
lumen of coronary arteries and not vessel walls (looks eccentric; not central)
72
What are 3 types of treatment measures which can be considered for stable angina?
1. general measures (modifiable)
2. medical treatment (drugs reduce disease progression and symptoms)
3. revascularisation (if symptoms not controlled)
73
What are general (treatment) measures for stable angina? (4)
Address risk factors:
1. BP
2. diabetes mellitus
3. cholesterol
4. lifestyle
74
What are 2 revascularisation strategies for stable angina?
1. percutaneous coronary intervention (PCI)
| 2. coronary artery bypass graft (CABG)
75
What are medical treatment options for stable angina which influence disease PROGRESSION. (3)
1. statins
2. ACE inhibitors (ACEI)
3. aspirin; 75mg or clopidogrel if intolerant to aspirin
76
What effect do statins have in reducing progression of stable angina? (2)
- reduce LDL-cholesterol deposition in atheroma
| - stabilise atheroma reducing plaque rupture and ACS (acute coronary syndrome)
77
When are statins considered for treatment for stable angina? (what must cholesterol level be?)
total cholesterol >3.5 mmol/L
78
When are ACE inhibitors considered for treatment of stable angina?
if increased CV risk and atheroma risk
79
What effect do ACE inhibitors have in reducing progression of stable angina? (2)
- stabilise endothelium
| - reduce plaque rupture
80
What is used instead if patient intolerant to Aspirin?
Clopidogrel
81
What effect does Aspirin (or Clopidogrel) have in reducing progression of stable angina? (2)
may not directly affect plaque but
- does protect endothelium
- reduces of platelet activation/aggregation
82
What are medical treatment options for stable angina for the RELIEF of symptoms? (3)
1. Beta blockers
2. Ca channel blockers
3. K channel blockers
4. Nitrates (produce vasodilation)
83
What effect do Beta blockers have for relief of stable angina symptoms? (3)
- reduced myocardial work
- have anti-arrythmic effects
- achieve resting hr, 60bpm
84
What effect do Ca channel blockers have for relief of stable angina symptoms? (2)
- central acting r.g. diltiazem/ verapamil if Beta blockers used
- achieve resting hr<60bpm
- produce vasodilation
85
What effect do K channel blockers have for relief of stable angina symptoms? (2)
- Ivabridine is a new medication which reduces sinus node rate
- achieves resting hr<60bpm
86
What are common Ca channel blockers used for relief of stable angina symptoms? (3)
1. diltiazem/verapamil
peripherally acting dihydropyridines;
2. amlodipine
3. felodipine
87
What effect do nitrates have for relief of stable angina symptoms and how are they administered?
- vasodilation
| - used as short or prolonged acting tablets, patches or as rapidly acting sublingual GTN spray for immediate use
88
What is the name of a K channel blocker for treatment of stable angina?
Nicorandil (nitrate molecule and K channel helpful in pre-conditioning
89
What are different types of treatment for stable angina generally? (4)
1. general measures (e.g. lifestyle)
2. medical treatment
3. percutaneous coronary intervention (PCI) + angiography
4. CABG (coronary artery bypass graft)
90
Usually, how many anti-anginals will be administered to patients?
usually 2 anti-anginals
91
What is the most common type of percutaneous coronary intervention (PCI)?
percutaneous transluminal coronary angioplasty (PTCA) and stenting; now used in ~95% procedures
92
Describe difference between;
- coronary angiography
- coronary angioplasty
1. coronary angiography is a procedure that uses contrast dye, usually iodine, and x ray pictures to detect blockages in the coronary arteries that are caused by plaque buildup.
2. coronary angioplasty has similar beginnings to coronary angiography as dye inserted but cross stenotic lesion is widened with a guidewire and squashes atheromatous plaque into walls with balloon and stent ; ballon is later removed and stent remains to keep arteries open
93
What 2 medications are taken when stent is placed into arteries whilst endothelium covers stent and is no longer seen as a foreign body with associated risks of thrombosis.
1. aspirin
| 2. clopidogrel
94
Percutaneous coronary intervention (PCI) is effective for symptoms, but what are its limitations? (3)
1. no evidence it improves prognosis in stable disease
2. small risk of procedural complication (death; 0.1%, MI; 0.2%, emergency CABG: 0.05%)
3. risk of restenosis; varying from 10-15% with bare metal stents and <10% with drug eluting stents (that remove drugs) - they can cause narrowing despite stent being there
95
What must patients who underwent percutaneous coronary intervention (PCI) continue with?
they must continue with disease modifying medication
96
What is the main disadvantage of CABG compared to PCI (percutaneous coronary intervention)?
- Up-front risks are much higher for CABG than PCI
| - death= 1.3% and Q wave MI=3.9% which increase in presence of co-morbidities
97
What is the main advantage of doing CABG surgery rather than PCI?
Has very good lasting benefits; 80% patients are symptom free 5 years later
98
When is CABG surgery used in patients?
- usually one of the last treatment options since serious surgery
- used for patients with worse type of coronary heart disease
- usually patients have diffused coronary disease over all 3 coronary arteries
99
What patients derive prognostic benefit from CABG surgeries? (3)
patients with:
1. >70% stenosis of left main stem artery
2. significant proximal three-vessel coronary artery disease
3. two vessel coronary artery disease that includes significant stenosis of proximal left anterior descending coronary artery AND who have ejection fraction <50%
100
What must patients continue with after their CABG surgeries? (2)
- must continue with disease modifying medication
| - must have predictable deterioration in vein grafts after 10 years
101
What does CABG surgery involve?
- Involves taking a blood vessel from another part of the body – usually the chest, leg or arm – and attaching it to the coronary artery above and below the narrowed area or blockage. The blood then bypasses the blockage. This new blood vessel is known as a graft.
102
What will the number of grafts needed in CABG surgeries depend on?
The number of grafts needed will depend on how severe your coronary heart disease is and how many of the coronary blood vessels are narrowed.
103
What vessels are commonly used in coronary bypass grafting? (CABG) (3)
1. pieces of a vein from your leg (e.g. saphenous vein)
2. artery in your chest.
3. artery from your wrist
104
What aids the correct diagnosis of angina? (3)
1. clinical history
2. identification of risk factors for coronary atheroma
3. evidence of myocardial ischaemia diagnostic
(cardiovascular profile high + exertion problems= most likely angina)
105
What should higher-risk patients with stable angina be offered?
should have coronary angiography and CABG (revascularisation indicated mainly for symptoms)
106
When must symptoms for stable angina occur?
on exertion (if not then it's not stable angina)
