1. Cardiac causes of cardiac arrest

2. Learning outcomes This lecture should enable you to:
describe the heart conditions that may cause cardiac arrest
explain the process that causes acute coronary syndromes (ACS)
describe the different types of ACS
explain how to recognise and assess an ACS
list the relevant immediate treatment for each type of ACS
discuss how to recognise and respond to other cardiac conditions that may cause cardiac arrest.

3. Acute coronary syndromes
Spectrum of clinical presentation caused by:
atherosclerotic plaque rupture
thrombus formation
smooth muscle constriction

4. Fissured plaque
No change

5. ABCDE Assessment Use ABCDE to assess 12 lead ECG
treat immediate issues
blood sample in ‘C’ for enzymes
reassess
12 lead ECG

6. Risk Stratification
Enzymes - Troponin
ECG changes
History

7. Acute coronary syndromes
Clinical syndromes caused by the same disease
process:
unstable angina
non-ST-elevation myocardial infarction
ST-elevation myocardial infarction

8. Unstable angina
1. angina on exertion with increasing frequency over a few days, provoked by less exertion or
2. angina occurring recurrently and unpredictably - not specifically on exercise
3. unprovoked and prolonged episode of chest pain
______________________________________________
ECG may be normal
No troponin release
ST segment depression suggests high risk

9. Acute ST depression
No change 9

10. Non-ST-elevation myocardial infarction (NSTEMI)
symptoms suggest acute myocardial infarction
ECG findings non-specific:
ST-segment depression
T-wave inversion
may be normal
troponin release

11. T-wave inversion in NSTEMI
Title expanded for clarity 11

12. ST-elevation myocardial infarction (STEMI)
symptoms suggest acute myocardial infarction
ECG shows acute ST-segment elevation
Q waves likely to develop
troponin release
early effective treatment may limit myocardial damage (and prevent Q wave development)

13. Anterolateral STEMI 13

14. Immediate treatment for all acute coronary syndromes
ABCDE approach
aspirin 300 mg orally (crush/chew)
consider other antiplatelet medication
nitrate (GTN tablet or patients own spray)
fentanyl/morphine
oxygen - if hypoxic or signs of shock
(SpO2 <94% or no measurement available)
Reordered bulets 3 & 4
Upper case to start bullet points

15. Unstable angina and NSTEMI
anti-thrombotic
aspirin
clopidogrel or ticagrelor (or prasugrel)
LMW heparin or fondaparinux
If very high risk: glycoprotein IIb/IIIa inhibitor
pain relief
nitrate
fentanyl/morphine
oxygen if hypoxaemic
myocardial protection
beta blocker
coronary angiography/PCI in most patients

16. STEMI (or acute MI with new LBBB)
Emergency reperfusion therapy:
optimal treatment - primary percutaneous coronary intervention (PPCI)
fibrinolytic therapy if PPCI is not available
when given very early, similar outcomes
avoid delay “time is muscle”

17. Access to emergency reperfusion

18. Left bundle branch block18

19. Other cardiac causes of cardiac arrest
in any cardiac arrest look for evidence of the cause
not all cardiac arrests are due to ACS
other causes may be ‘structural’ or ‘electrical’
some are inherited, some acquired, some congenital 19

20. Examples of other cardiac causes
Condition
Nature
Causation
Severe aortic stenosis
Structural
Mostly acquired
Sometimes congenital
Hypertrophic cardiomyopathy
Inherited
High-grade AV block
Electrical
Occasionally congenital
Long QT syndrome
Inherited, but…
there are other causes of a long QT interval
Anomalous coronary anatomy
Congenital 20

21. Long QT syndrome
New slide 21

22. Other cardiac causes: preventing cardiac arrest
be alert for warning symptoms (e.g. unexplained syncope)
arrange urgent specialist assessment and treatment (including genetic family)
with inherited conditions, don’t forget the family
New slide 22

23. Any questions?

24. Summary recognise the different presentations of ACS
use the ABCDE approach
start appropriate immediate treatment
arrange immediate PPCI when appropriate
be aware of other cardiac causes of arrest
these require different management
‘warning’ symptoms need urgent referral

25. Advanced Life Support Level 2 Course Slide set
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© Australian Resuscitation Council (June 2016)