2.3 Management of Acute Coronary Syndrome

Question 1

The European Society of Cardiology requires biomarker elevation and one of the following for the diagnosis of acute MI to be made:

Answer 1

• ECG changes
• New regional wall motion abnormality (left ventricle not contracting properly)
• Imaging evidence of loss of viable myocardium
• Coronary thrombus

Question 2

Troponin level changes in chronic myocardial injury vs acute MI. What are the clinical implications of this in AMI?

Answer 2

AMI: Rises over a matter of hours, and falls over a matter of days (maybe longer if renal problems)
Chronic myocardial injury: Remains elevated, but not as high as AMI

Therefore, the timing of sampling is crucial; this is why multiple troponin levels may need to be taken.

Question 3

Patient has negative hs troponin-T assay within 2h of symptoms; in the next how long should another test be taken?

Answer 3

3 hours

Question 4

Type 1 vs Type 2 MI

Answer 4

Type 1: Typical MI; atherosclerotic plaque becomes thrombotic following rupture
Type 2: Supply-demand mismatch, patient often has narrowing in arteries, and an infection or sustained tachyarrhythmia cause infarction of myocardium.

Question 5

Which ECG leads correspond to the LAD?

Answer 5

V1-V4

Question 6

Which ECG leads correspond to the LCX?

Answer 6

I, aVL, V5, V6

Question 7

Which ECG leads correspond to the inferior aspect of the heart?

Answer 7

II, III, aVF

Question 8

Which ECG leads correspond to the posterior aspect of the heart? Which can be used to provide reciprocal information?

Answer 8

V8, V9, V1-4 with reciprocal

Question 9

What is the ECG criteria for STEMI?

Answer 9

ST elevation in two contiguous leads

Question 10

What does an abnormally wide and deep (i.e. pathologic) ECG Q-wave indicate?

Answer 10

Established transmural infarction

Question 11

Pre-hospital acute STEMI treatment

Answer 11

Fast, accurate diagnosis

Question 12

In hospital acute STEMI treatment

Answer 12

• Establish reperfusion (thrombolytics/PCI)
• Prevent rethrombosis
• Avoid, recognise and manage acute complications
• Educate and initiate 2° prevention

Question 13

Post-hospital acute STEMI treatment

Answer 13

• Maintain 2° prevention
• Monitor compliance and risk factors

Question 14

Describe immediate treatment of STEMI (before re-perfusion)

Answer 14

• 300mg aspirin
• Analgesia (nitrates, morphine, oxygen)
• Occasionaly IV metoprolol as 5mg boluses
• Maintain rest

Question 15

Why does an anterior STEMI usually require longer in hospital than a lateral STEMI?

Answer 15

Because there are more heart muscles in the anterior heart wall; poorer prognosis

Question 16

What are some factors that determine the severity of a myocardial infarction?

Answer 16

• Location
• Time before reperfusion
• Prior MI
• Success of reperfusion

Question 17

What factors affect the length of hospital stay after myocardial infarction?

Answer 17

• Severity
• Comorbidities (e.g. diabetes)
• Disease in other arteries
• Complications

Question 18

What are some potential complications of myocardial infarction?

Answer 18

• LV impairment
• Arrhythmia
• Mechanical (papillary muscle rupture, free wall rupture causing tamponade)
• Pericarditis

Question 19

How long after MI is an ECHO performed?

Answer 19

24-48hrs

Question 20

What does an ECHO assess for?

Answer 20

• Ventricular function
• Valve function
• Septal rupture
• Pericardial fluid

Question 21

When is cardiac MRI done?

Answer 21

When STEMI diagnosis is more ambiguous

Question 22

Under what circumstances would an NSTEMI become an emergency?

Answer 22

• Persistent chest pain
• Threatening ECG signs

Question 23

Describe the treatment of an NSTEMI prior to angiography

Answer 23

• 300mg aspirin
• Sublingual GTN
• Anticoagulants
• Statin
• Possibly ACE inhibitor

Question 24

What % of MI patients have PCI/CABG/non-invasive?

Answer 24

PCI: 65%
CABG: 10-15%
Non-invasive: 20-25%

Question 25

What fraction of patients in Australia die within 12 months of MI?

Answer 25

1 in 11

Question 26

Roughly how much more likely are you to die from a recurrent MI than an initial one?

Answer 26

About twice as likely (~20% vs 10%)

Question 27

What percentage of ACS are repeat events?

Answer 27

34%

Question 28

What medications does a patient take post-MI

Answer 28

• Aspirin: indefinitely
• Antiplatelet: ~12 months
• ACE inhibitor
• High dose of strong statin
• Beta blocker

Question 29

What are some lifestyle factors that should improve post MI?

Answer 29

• Smoking cessation
• Managing depression
• Physical activity/weight management

Question 30

How long after MI can a patient not drive?

Answer 30

2 weeks

Question 31

What antiplatelet drug is commonly used with aspirin? How long is it used?

Answer 31

Ticagrelor. Used for about a year to prevent stent from clotting.