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Flashcards in Stable Angina Deck (36)
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1
Q

How is angina pectoris caused?

A

Caused by reduced blood flow to the heart causing Ischaemia

2
Q

What is the most common cause (type) of angina?

A

Coronary atheroma

  • On activity with the increased myocardial oxygen demand obstructed coronary blood flow leads to myocardial ischaemia and then the symptoms of angina.
3
Q

In what situations does myorcardial oxygen demand increase?

A

It increases in situations where HR and BP rise for example: exercise, anxiety/emotional stress and after a large meal.

4
Q

At what stenosis does angina occur?

A

Occurs when >70% stenosis (>70% of the the artery is blocked by plaque build)

  • This stenosis occurs the heart to work a lot harder.
5
Q

How can the heart muscle wall affect angina?

A

If the heart muscle wall thickens, it can cause angina.
This is caused by:
- Hypertrophic cardiomyopathy (genetic)
- Pumping against high pressures e.g. Aortic stenosis, hypertension.

6
Q

What are features of angina pectoris?

A

1, Constricting/ heavy discomfort to the chest, jaw, neck, shoulders or arms.

  1. Symptoms brought on by exertion!
  2. Symptoms relieved within 5 min by rest or GTN.
7
Q

Symptoms of angina pectoris

A
  • Pressure or squeezing in left arm, chest, shoulders, back.
  • Shortness of breath
  • Diaphoresis (sweating)
  • Symptoms relieved after stress.
8
Q

What are features making angina less likely?

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
9
Q

What are other symptoms on exertion for stable angina?

A
  • Breathlessness on exertion
  • Excessive fatigue on exertion for activity undertaken
  • Near syncope on exertion
10
Q

Features of the Canadian classification of angina severity (CCS)

A
  1. Ordinary physical activity does not cause angina, symptoms only on significant exertion.
  2. Slight limitation of ordinary activity, symptoms on walking 2 blocks or >1 flight of stairs.
  3. Marked limitation, symptoms on walking only 1-2 blocks or 1 flight of stairs.
  4. Symptoms on any activity, getting washed/dressed causes symptoms.
11
Q

What are modifiable risk factors coronary artery disease/angina?

know this!

A
  • Smoking
  • Lifestyle: exercise and diet
  • Diabetes mellitus (glycaemic control reduced CV risk)
  • Hypertension (BP control reduced CV risk)
  • Hyperlipidaemia (lowering reduces CV risk)
12
Q

What are non-modifiable risk factors coronary artery disease/angina?

know this!

A
  • Age
  • Gender
  • Creed
  • Family history
  • Genetic factors
13
Q

Examination features for stable angina?

A
  • Tar stains on fingers
  • Obesity (centripedal)
  • Xanthalasma and corneal arcus (hypercholesterolaemia)
  • Hypertension
  • Abdominal aortic aneurysm arterial bruits, absent or reduced peripheral pulses.
  • Diabetic retinopathy, hypertensive retinopathy on fundoscopy.
14
Q

Signs of exacerbating or associated conditions for stable angina

A
  • Pallor of anaemia
  • Tachycardia, tremor, hyper-reflexia of hyperthyroidism
  • Ejection systolic murmur, plateau pulse of aortic stenosis.
  • Pansystolic murmur of mitral regurgitation, and
  • Signs of heart failure such as basal crackles, elevated JVP, peripheral oedema.
15
Q

What methods would you use to investigate stable angina?

A
  • Bloods
  • Chest X-ray
  • Electrocardiogram
  • Exercise tolerance test/ETT
  • Myocardial perfusion imaging
  • Computed tomography (CT) coronary angiography
  • Invasive angiography
  • Cardiac catherisation/coronary angiography
16
Q

What would an X-ray be useful to show?

A

Often helps show other causes of chest pain and can help show pulmonary oedema

17
Q

Features of electrocardiogram in stable angina?

A
  • Normal in over 50% of cases
  • May be evidence of prior myocardial infarction i.e. pathological Q-waves
  • May be evidence of left ventricular hypertrophy i.e. high voltages, lateral ST-segment depression or “strain pattern”.
18
Q

Features of exercise tolerance test/ETT

A
  • Often can confirm diagnosis of angina.
  • Relies on ability to walk for long enough to produce sufficient CV stress.
  • Typical symptoms and ST-segment depression for positive test.
  • -ve ETT doesn’t exclude significant coronary atheroma but if negative at high workload overall prognosis is good.
19
Q

Features of myocardial perfusion imaging in stable angina

A
  • Superior to ETT in detection of CAD, localisation of ischaemia and assessing size of area affected.
  • Expensive, involves radioactivity; depending on availability used where ETT not possible/equivocal.
  • Either exercise or pharmacological stress: adenosine, dipyridamole or dobutamine.
20
Q

When would invasive angiography be used?

A

If:

  • Early or strongly positive ETT (suggests multi-vessel ds)
  • 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 e.g. drivers etc.
21
Q

Features of cardiac catherisation/ coronary angiography

A
  • 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.
22
Q

What are the different treatment strategies for stable angina?

A
  • General measures: adress risk factors.
  • Medical treatment
  • Revascularisation (if treatment not controlled)
23
Q

Medical treatments for influencing disease progression of stable angina

A
  • Statins: consider if total cholesterol >3.5mmol
  • ACE inhibitors: if increased Cv risk and atheroma
  • Aspirin, 75mg or clopidogrel if intolerant of aspirin
24
Q

What do statins do?

A

They reduce LDL-cholsterol deposition in atheroma and also stabilise atheroma reducing plaque rupture and ACS.

25
Q

What do ACE inhibitors do?

A

Stabilise endothelium and also reduce plaque rupture

26
Q

What does aspirin do in stable angina?

A

May or may not affect plaque but does protect endothelium and reduces platelet activation/aggregation.

27
Q

Medical treatments for relief of symptoms

A
  • Beta blockers : achieve resting hr <60bpm.
  • Ca2+ channel blockers: achieve resting hr< 60 bpm
  • Ik channel blockers: achieve resting hr <60bpm
  • Nitrates: produce vasidilation
  • K+ channel blockers:: nicorandil
28
Q

What do beta blockers do?

A

Reduced myocardial work and have anti-arrythmic effects

29
Q

What do Ca2+ channel blockers do?

A

Central acting e.g. diltiazem/verapamil if B-blockers C-I

30
Q

What do Ik channel blockers do?

A

Ivabridine is a new medication which reduces sinus node rate

31
Q

What do nitrates do?

A

Used as short or prolonged acting tablets, patches or as rapidly acting sublingual GTN spray for immediate use.
- Produce vasodilation

32
Q

What do K+ channel blockers do?

A

Nitrate molecule and K+ channel helpful in ‘pre-conditioning’

33
Q

Examples of percutaneous coronary intervention (PCI)

A

Percutaneous transluminal coronary angioplasty (PTCA) and stenting!!

  • Similar beginnings to coronary angiography but cross stenotic lesion with guidewire and squash atheromatous plaque into walls with balloon and stent.
34
Q

What are risks with percutaneous coronary intervention?

A

PCI is effective for symptoms, but

  • No evidence it improves prognosis in stable disease.
  • Small risk of procedural complication: death = 0.1%, MI = 0.2%, emergency CABG = 0.05%
  • Risk of restenosis
35
Q

Features of coronary artery bypass surgery (CABG)

A
  • In diffuse multi-vessel CABG often best option for stable angina
  • ‘Up front’ risks are much greater than PCI, death 1.3%, Q-wave MI = 3.9% - these increase in presence of co-morbidity.
  • But good lasting benefit, 80% symptom free 5 years later.
36
Q

Which patients derive prognostic benefit from CABG (coronary artery bypass surgery)?

A
  • With >70% stenosis of left main stem artery.
  • Significant proximal three-vessel coronary artery disease.
  • Two vessel coronary artery disease that includes significant stenosis of proximal left anterior descending coronary artery and who have ejection fraction <50%.