Acute Coronary Syndrome Flashcards
(95 cards)
1
Q
Acute coronary syndrome (ACS) is an umbrella term for which three conditions?
A
- Unstable angina (UA)
- Non-ST elevation myocardial infarction (NSTEMI)
- ST elevation myocardial infarction (STEMI)
2
Q
What does angina refer to?
A
Chest pain
3
Q
What is the difference between stable and unstable angina
A
Stable angina - is chest pain on exertion as the demands of oxygen by the heart increases. Pain goes away at rest.
Unstable angina - is chest pain even at rest.
4
Q
What is the key characteristic of acute coronary syndrome?
A
ACS is characteristed by the occlusion or reduction in blood supply through a coronary artery to myocardial tissue
5
Q
How occluded are the coronary arteries for ST elevation myocardial infaraction (STEMI) to occur?
A
Total occlusion of a coronary artery
6
Q
What occludes the coronary arteries in ST elevation myocardial infaraction (STEMI)?
A
A thrombus
7
Q
What has to happen for a thrombus to form?
A
Thrombus is formed when an atherosclerotic plaque rupture
8
Q
What is the difference between Ischaemia and Infarction?
A
Ischaemia: refers to the reduction/lack of blood flow to the tissue, which can cause angina type symptoms
Infarction: refers to the cellular changes that can occur as a result of reduced/no perfusion to the tissue.
9
Q
Define Bundle branch block
A
Bundle branch block is when electrical impulses travel through the ventricles is slower than is normal because of a block in the coronary arteries.
This causes slower depolarisation of the ventricles.
10
Q
When a thrombus totally occludes the coronary artery which is the features that may be evident on an ECG?
A
ST elevation
OR
New left bundle branch block (LBBB)
11
Q
What are the two key features that are indicative of ST elevation myocardial infarction (STEMI)?
A
ST elevation on ECG or new LBBB
AND
Rise in troponin levels
12
Q
When does troponin rise?
A
Troponin is an indicator of cardiac tissue damage.
Rises when there is ischaemic present
13
Q
When a thrombus forms in a fast flowing artery it is made up mostly of what?
A
Platelets.
Hence anti-platelet medications such as aspirin, clopidogrel and ticagrelor are the mainstay of treatment.
14
Q
How occluded are the coronary arteries for non ST elevation myocardial infaraction (NSTEMI) to occur?
A
Occurs when there is partial occlusion of a coronary artery causing ischaemia and infarction
15
Q
What are the ECG changes associated with heart tissue ischaemia?
A
T waves and/or ST changes
16
Q
What are the modifiable risk factors associated with the developing of atherosclerosis?
A
- High cholesterol
- Hypertension
- Smoking
- Diabetes
- Obesity
17
Q
What are the non-modifiable risk factors associated with the developing of atherosclerosis?
A
- Age
- Family history
- Male sex
- Premature menopause
18
Q
Fill in the blanks
A
19
Q
What are the clinical features of acute coronary syndrome
A
Symptoms
- Chest pain > 15 minutes: central crushing or pressing pain +/- radiation to neck and/or left arm
- Shortness of breath
- Sweating
- Nausea and vomiting
- Palpitations
Signs
- Pale
- Clammy
- Tachycardia
- Cardiac failure (e.g. pulmonary oedema, hypotension)
20
Q
Define a silent MI?
A
This is the presence of an MI without any signs or symptoms
This typically occurs in elderly patients or those with significant co-morbidities e.g. diabetes mellitus
21
Q
What are the ECG changes associated with ST elevation myocardial infarction (STEMI)?
A
ST segment elevation in leads consistent with an area of ischaemia
ANR / OR
New Left Bundle Branch Block
22
Q
What are the ECG changes associated with non-ST elevation myocardial infarction (NSTEMI)?
A
ST segment depression in a region
Deep T Wave inversion
Pathological Q Waves
23
Q
Name the inferior leads of an ECG?
A
Leads II, III and aVF
24
Q
What leads are associated with the Anterolateral area of the heart?
A
Leads:
I
aVL
V3-6
25
What leads are associated with the anterior aspect of the heart?
Leads V1-4
26
What leads are associated with the lateral aspect of the heart?
Leads I, aVL, V5-6
27
What leads are associated with the inferior aspect of the heart?
II, III, aVF
28
Leads II, III and avF is associated with which kind of MI?
Inferior MI
29
Leads V1-4 is associated with which kind of MI?
Anteroseptal MI
30
Leads I, avL and V5-6 are assoicated with which kind of MI?
Lateral MI
31
Which **artery** is usually affected in an **inferior MI**
Typically the right coronary artery that is affected.
32
Which leads are associated with a Posterior MI
No ST elevation on routine ECG
However may be seen as ST depression
33
Which **artery** is usually affected in an **Anteroseptal** **MI**
Left anterior descending artery
34
Which **artery** is usually affected in an **Lateral MI**
The left circumflex artery
35
_For Inferior MI which:_
a) Artery is affected?
b) Which leads will have the ECG changes present?
a) Right coronary artery
b) Leads II, III and avF
36
_For Anteroseptal MI which:_
a) Artery is affected?
b) Which leads will have the ECG changes present?
a) Left anterior descending artery (LAD)
b) V1- V4
37
_For Lateral MI which:_
a) Artery is affected?
b) Which leads will have the ECG changes present?
a) Left circumflex artery
b) Leads I, avL, V5 and V6)
38
Which artery supplies the inferior wall of the heart?
Right coronary artery
39
Which artery supplies the anterior wall and septum?
Left anterior descending artery
40
Which artery supplies the lateral wall of the left ventricle, posterior surface and sometimes the inferior wall?
Left circumflex artery
41
Which ECG change is a sign of previous myocardial infarction?
Pathologic Q waves
42
Define reciprocal changes on an ECG?
Reciprocal changes refers to ST depression in the leads opposite those with ST elevation
43
What is the name given to this kind of change seen on an ECG?
ST elevation
44
What is the name given to this kind of change seen on an ECG?
ST depression
45
What is the name given to this kind of change seen on an ECG?
T wave inversion
46
Complete heart block i.e. 3rd degree heart block, may occur as a complication following an acute myocardial infarction
Which MI are the most at risk of causing complete heart block?
Inferior MI
47
Why is the inferior MI the most likely to cause a complete heart block
This is because the right coronary artery, the artery causing inferior MI, supplies the tissue that surrounds the AV node system.
The infarction of the tissue surrounding the AV node causes the AV node to no longer works
The result is firing lower down in the conduction system, which is independent from SA node i.e. complete disassociation between the P waves (atria depolarisation) and QRS complex (ventricular depolarisation)
48
What are the ECG features of a complete heart block
No observable relationship between P waves and QRS complexe
P waves are normal because the atria are conducting normally
QRS rate is slow
49
Name the three mainstay investigations for ACS
Clinical features
ECG
Serum troponin
50
What are Troponins
They are proteins found in cardiac muscle.
51
Why is a rise in troponin is consistent with myocardial ischaemia
A rise in troponin is consistent with myocardial ischaemia as the proteins are released from the ischaemic muscle.
52
Troponins are non-specific. What does this mean?
It means that although a raised troponin is suggestive for ACS it is not specific for it and is raised for other reasons too e.g. stress
53
In unstable angina, there is no detectable rise in troponi. How is the diagnosis made?
The diagnosis is made on the basis of the clinical history and ECG changes.
54
Name other conditions in which troponin is raised (other than MI)?
Congestive heart failure
Pulmonary embolism
Sepsis
55
Describe how coronary angiogram works?
X-ray image using contrast dye. A catheter is inserted into the aorta via the femoral artery. The contrast dye is injected into the coronary arteries and x-ray-based imaging is then used to visualise the coronary arteries showing any blockage that may be present.
56
What is the immediate management of suspected ACS
Mnemonic MONA
## Footnote
**M:** Morphine - administeredwith an anti-emetic to relieve chest pain
**O**: Oxygen - should be reserved if saturations \<94% or if \<88% in patients at risk of hypercapnic respiratory failure (target in these patients is 88-92%). Limited benefit in patients with preserved oxygen saturations (94% or greater), and may indeed be harmful
**N**: Nitrates - Sublingual GTN
**A**: Aspirin - loading dose i.e. 300mg
57
Patients diagnosed with STEMI should be referred for emergency coronary angiography +/- primary percutaneous coronary intervention (PCI) if they present with how many hours from:
a) onset of chest pain?
b) diagnosis of STEMI?
a) Within 12 hours of onset of chest pain
b) Within 2 hours of diagnosis of STEMI
58
What is involved in coronary angiography?
Coronary angiography involves insertion of a catheter via the femoral artery or radial artery.
From here, the catheter can be passed to the coronary artery vessels with x-rays for guidance and contrast injected.
The injection of contrast allows visualisation of the coronary anatomy.
During the procedure a balloon catheter can be inserted to open up a blockage.
A stent can be then be inserted into the blocked artery.
59
If PCI is unable to be performed what should be considered instead?
Fibrinolysis with fibrinolytic agents e.g. alteplase while arranging transfer to a PCI centre.
Coronary angiography +/- PCI should be performed in the following 2-24 hours after fibrinolysis
60
Describe the Dual anti-platelet therapy (DAPT) in the management of STEMI?
Combination of aspirin and a second anti-platelet agent
Should be initiated prior to PCI
Usually ticagrelor however clopidogrel could be used particularly if there is a high bleeding risk
61
How long should dual anti-platelet therapy continue after coronary angiogram +/- PCI?
Minimum 12 months after
62
Whe nis antithrombotic agents usually given in the management of STEMI?
Usually given at the time of PCI.
63
When would Glycoprotein IIb/IIIa inhibitors be useful in the mangement of STEMI?
Can be given at the time of PCI if there is high thrombus burden
64
Give an example of a Glycoprotein IIb/IIIa inhibitors
Tirofibanmay
65
Give an example of a Antithrombotic agents
Unfractionated heparin
Low molecular weight heparin (LWMH)
66
Fill in the blanks of the initial management of acute coronary syndrome
67
Fill in the blanks of the definitive management of STEMI
68
Which scoring system is used to estimate the six-month mortality risk in patients with NSTEMI / UA
GRACE Score
69
GRACE Score categories patients in various groups. Name these groups and what is the management of each?
**Low risk**: discharge on medical treatment
**Intermediate risk**: PCI within 96 hours
**High risk**: PCI within 2 hours
70
What are the two principle pharmacological agents to treat NSTEMI / unstable angina?
Additional antiplatelet agent e.g. clopidogrel, ticargrelor
Antithrombotic agent e.g. fondaparinux, unfractionated heparin
71
Following an MI, several medications should be initiated to help in the secondary prevention of major cardiovascular events.
Name these agents?
**_The 6As:_**
## Footnote
**1) Aspirin** 75mg once daily
**2) Another** **antiplatelet**: e.g. clopidogrel or ticagrelor for up to 12 months
**3) Atorvastatin** or another high dose statin
**4) ACE** **inhibitors** or Angiotensin receptor blocker can be an alternative if side-effects or intolerant to ACE inhibitor
**5) Atenolol** or other beta blocker
**6) Aldosterone** **antagonist** i.e. mineralocorticoid antagonist, for those with clinical heart failure (i.e. eplerenone titrated to 50mg once daily)
72
Following an MI, mineralocorticoid antagonist could be considered for which kind of patients?
Patients with LV dysfunction i.e. heart failure
73
Atorvastatin is an example of which kind of drug class?
Statin
74
Why is it important to continue dual anti-platelet therapy for 12 months folloiwng a coronary stent at PCI?
Prevents stent thrombosis
75
What is the acute NSTEMI management?
Mnemonic **BATMAN**:
## Footnote
**B** – Beta-blockers unless contraindicated
**A** – Aspirin 300mg stat dose
**T** – Ticagrelor 180mg stat dose (clopidogrel 300mg is an alternative if higher bleeding risk)
**M** – Morphine titrated to control pain
**A** – Anticoagulant: Fondaparinux (unless high bleeding risk)
**N** – Nitrates (e.g. GTN) to relieve coronary artery spasm
*Give oxygen only if their oxygen saturations are dropping (i.e. \<95%).*
76
Name the complications of MI?
Mnemonic **DREAD:**
## Footnote
**D** – Death
**R** – Rupture of the heart septum or papillary muscles
**E** – “oEdema” (Heart Failure)
**A** – Arrhythmia and Aneurysm
**D** – Dressler’s Syndrome
77
Describe Dressler’s Syndrome
Also known as post-myocardial infarction syndrome
Usually occurs around 2-3 weeks after an MI
Caused by a localised immune response and causes pericarditis (inflammation of the pericardium around the heart)
78
What are the clinical features of Dressler's Syndrome
Presents with:
* Pleuritic chest pain
* Low grade fever
* Pericardial rub on auscultation.
It can cause a pericardial effusion and rarely a pericardial tamponade
79
How is Dressler's Syndrome diagnosed?
A diagnosis can be made with an:
1. ECG (global ST elevation and T wave inversion)
2. Echocardiogram (pericardial effusion)
3. Raised inflammatory markers (CRP and ESR)
80
What is the management of Dressler's Syndrome?
NSAIDs (aspirin / ibuprofen)
In more severe cases steroids e.g. prednisolone
They may need pericardiocentesis to remove fluid from around the heart.
81
Name some of the secondary prevention lifestyle modifications a patient can make following acute coronary syndrome?
Stop smoking
Reduce alcohol consumption
Mediterranean diet
Cardiac rehabilitation (a specific exercise regime for patients post MI)
Optimise treatment of other medical conditions (e.g. diabetes and hypertension)
82
Right Coronary Artery (RCA) supplies which parts of the heart?
Right atrium
Right ventricle
Inferior aspect of left ventricle
Posterior septal area
83
Circumflex Artery supplies which parts of the heart?
Left atrium
Posterior aspect of left ventricle
84
Left Anterior Descending (LAD) supplies which part of the heart
Anterior aspect of left ventricle
Anterior aspect of septum
85
What is the Acute NSTEMI treatment
BATMAN
## Footnote
B – Beta blockers unless contraindicated
A – Aspirin 300mg stat dose
T – Ticagrelor 180mg stat dose
M – Morphine titrated to control pain
A – Anticoagulant: Low Molecular Weight Heparin (LMWH) at treatment dose (e.g. enoxaparin 1mg/kg twice daily for 2-8 days)
N – Nitrates (e.g. GTN) to relieve coronary artery spasm
86
When does troponin start to rise in ACS (STEMI and NSTEMI)
Levels start to elevate within 2-3 hours after the onset of chest pain
87
Which type of STEMI is associated with ECG changes in V1-V4
Anteroseptal MI
88
Which type of STEMI is associated with ECG changes in II, III, aVF
Inferior MI
89
Which type of STEMI is associated with ECG changes in V4-6, I, aVL
Anterolateral MI
90
Which type of STEMI is associated with ECG changes in I, aVL, V5-6
Lateral MI
91
For anteroseptal MI, name the:
i) ECG changes
ii) Coronary artery commonly affect
i) V1-V4
ii) Left anterior descending
92
For inferior MI, name the:
i) ECG changes
ii) Coronary artery commonly affect
i) II, III, avF
ii) Right coronary
93
For anterolateral MI, name the:
i) ECG changes
ii) Coronary artery commonly affect
i) V4-6, I, aVL
ii) Left anterior descending or left circumflex
94
For lateral MI, name the:
i) ECG changes
ii) Coronary artery commonly affect
i) I, aVL +/- V5-6
ii) Left circumflex
95
For posterior MI, name the:
i) ECG changes
ii) Coronary artery commonly affect
i) Reciprocal changes in anterior leads (V1-4)
ii) Usually left circumflex but also can be right coronary artery
