Acute Coronary Syndromes Flashcards
1
Q
Define ACS
A
A spectrum of acute myocardial ischaemia/infarction
2
Q
3 conditions in ACS
A
- Unstable angina
- NSTEMI
- STEMI
3
Q
Definition for unstable angina
A
- New ST segment depression OR T wave inversion in the presence of ischaemic symptoms
- NO CK-MB or troponin (cardiac biomarkers)
4
Q
What does unstable angina present as
A
- Angina at rest
- New-onset angina
- Increasing angina
5
Q
Definiton for NSTEMI
A
- New ST segment depression OR T wave inversion PLUS CK-MB or troponin
NOTE - CK-MB or troponin may be raised several hours after presentation
6
Q
Definition for STEMI
A
- ST segment elevation OR new left bundle branch block PLUS elevated cardiac biomarkers
7
Q
What is CK-MB
A
Creatinine kinase - muscle brain
- Cardiac biomarker
- Bound combination of 2 variants (M and B) of the enzyme phosphocreatine kinase
8
Q
What is troponin
A
TnT
- Protein found in muscle that helps it contract
- Damage to heart muscle leads to cTnT and cTnI being released into the blood
- Increased troponin means cardiac muscle cell death
- Can also indicate sepsis, GI bleeding and CO/cyanide poisoning
9
Q
When does troponin rise with cardiac cell necrosis
A
- Elevation starts 2-3 hours post-event
- Peaks at 24 hours
- Persists 1-2 weeks
10
Q
Describe LBBB
A
- Normal direction of septal depolarisation is reversed - right ventricle to left ventricle
- Tall R waves
- Deep S waves
- Left axis deviation
- M wave in 1, V5, V6
- Elongated QRS
- Absent Q wave
11
Q
2 aetiology - unstable angina
A
- Coronary artery narrowing - thrombus
- Intense vasospasm of coronary artery (variant angina) - vascular SM or endothelial dysfunction
12
Q
Pathophysiology - ACS
A
- CAD - plaques, thrombi etc
- Occlusive - available collaterals??
- Myocardial supply/demand mismatch - increased O2 demand, decreased BF or decreased O2 delivery
13
Q
Clinical presentation ACS
A
- Chest pain - increased frequency and severity
- Retrosternal chest pain - may radiate to jaw, arm or neck
- Diaphoresis
- Nausea
- Increased HR
- Carotid bruit
- Poor peripheral pulses
14
Q
Atypical presentation ACS - who and what is it
A
Elderly, women, DM
- Epigastric pain
- Recent onset, indigestion
- Stabbling chest pain
- Pleuritic chest pain
- Isolated dyspnoea
15
Q
ECG and ACS
A
- May be normal
- ST depression (angina, NSTEMI)
- T wave inversion
16
Q
Imaging for suspected ACS
A
- CXR
- Echo
- Stress testing
- CTA (coronary artery anatomy and perfusion)
17
Q
Define ACS in terms of time
A
> 20 minutes of symptoms
18
Q
Score used for ACS prognosis
A
GRACE score
- Death or recurrent MI in the next year
19
Q
Unstable angina risk factors
A
- Female
- Personal CAD history
- Older
- Family history
- Chronic kidney disease
- Elevated CRP
- Hypertension
- Smoking
- Diabetes
- Hyperlipidemia
- Peripheral vascular disease
- Mediastinal radiation
Less risky
- Obesity
- High altitude
20
Q
DDx unstable angina
A
- Stable angina
- Variant/vasospastic angina
- NSTEMI or STEMI
- Congestive heart failure
21
Q
Acute management unstable angina
A
- Antiplatelets
- Antithrombotics
Initially - O2, aspirin, Clopidogrel, morphine, GTN
- Antiplatelet
- Beta/Ca channel blocker
- Statin
- IV nitrates
- ACEI
22
Q
Ongoing management of unstable angina
A
- Antiplatelet
- Statin/Ezetimibe
- Beta-blocker
- ACEI
- Cardiac rehab
23
Q
Epidemiology NSTEMI
A
- NSTEMI > STEMI
- NSTEMI 70% of ACS
- Mortality 6 months = 4-8%
- 10% have an adverse cardiovascular event within 12 months
24
Q
5 causes of NSTEMI - aetiology
A
- Near complete or transient occlusion
- Dynamic obstruction - artery spasm
- Severe progressive atherosclerosis
- Drug use
- Post-percutaneous coronary intervention
25
Factors determining the severity of myocardial damage
- Duration of ischaemia
- Time to reperfuse
- Extent of underlying atherosclerosis
- Presence of collateral blood flow to affected area
- Diameter of affected coronary vessel
- Degree of occlusion
- Presence of other comorbidities
26
What does the TIMI score measure
Risk of death and non-fatal cardiac ischaemic events - 7 risk indicators
27
What are the 7 risk indicators in the TIMI score
- Age >65
- Presence of >3 CAD risk factors
- Prior coronary stenosis >60%
- ST deviation on ECG
- Elevated cardiac biomarkers
- >2 anginal episodes in the past 24 hours
- Aspirin use past 7 days
28
Acute treatment NSTEMI
1. Antiplatelets + oxygen
- GTN
- Morphine
- Beta and calcium channel blockers
29
Ongoing treatment NSTEMI
1. Cardiac rehab
- Antiplatelets
- Beta blocker
- Statin
- ACEI
- Aldosterone antagonist
- Anticoagulant
30
ECG definition of STEMI
ST elevation in 2+ ECG leads (with symptoms)
31
What % of STEMI patients die as a result
15% (half in the first hour)
32
STEMI epidemiology
- Affects men at a younger age
- Incidence increases in women after menopause
- Average age 65 males and 72 females
- Make up 38% of ACS
33
STEMI risk factors
- Male
- Smoking
- Hypertension
- Diabetes
- Obesity
- Metabolic syndrome
- Dyslipidemia
34
Acute treatment STEMI - haemodynamically unstable
1. Revascularisation - PCI, CABG
2. Anticoagulation
3. Aspirin
4. Morphine
5. O2
35
Acute treatment STEMI - haemodynamically stable
1. Revascularisation
2. Hypothermia
3. Anticoagulation
4. Beta blocker
5. Statin
36
Ongoing management STEMI
- Dual antiplatelet - Aspirin, Tricagrelor
- ACEI
- Beta blocker
- Statin
37
STEMI prognosis
- Elevated troponin = worse prognosis
38
What is an important complication of STEMI
Often go into cardiogenic shock
