2.3 Management of Acute Coronary Syndrome Flashcards
The European Society of Cardiology requires biomarker elevation and one of the following for the diagnosis of acute MI to be made:
- ECG changes
- New regional wall motion abnormality (left ventricle not contracting properly)
- Imaging evidence of loss of viable myocardium
- Coronary thrombus
Troponin level changes in chronic myocardial injury vs acute MI. What are the clinical implications of this in AMI?
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.
Patient has negative hs troponin-T assay within 2h of symptoms; in the next how long should another test be taken?
3 hours
Type 1 vs Type 2 MI
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.
Which ECG leads correspond to the LAD?
V1-V4
Which ECG leads correspond to the LCX?
I, aVL, V5, V6
Which ECG leads correspond to the inferior aspect of the heart?
II, III, aVF
Which ECG leads correspond to the posterior aspect of the heart? Which can be used to provide reciprocal information?
V8, V9, V1-4 with reciprocal
What is the ECG criteria for STEMI?
ST elevation in two contiguous leads
What does an abnormally wide and deep (i.e. pathologic) ECG Q-wave indicate?
Established transmural infarction
Pre-hospital acute STEMI treatment
Fast, accurate diagnosis
In hospital acute STEMI treatment
- Establish reperfusion (thrombolytics/PCI)
- Prevent rethrombosis
- Avoid, recognise and manage acute complications
- Educate and initiate 2° prevention
Post-hospital acute STEMI treatment
- Maintain 2° prevention
- Monitor compliance and risk factors
Describe immediate treatment of STEMI (before re-perfusion)
- 300mg aspirin
- Analgesia (nitrates, morphine, oxygen)
- Occasionaly IV metoprolol as 5mg boluses
- Maintain rest
Why does an anterior STEMI usually require longer in hospital than a lateral STEMI?
Because there are more heart muscles in the anterior heart wall; poorer prognosis
What are some factors that determine the severity of a myocardial infarction?
- Location
- Time before reperfusion
- Prior MI
- Success of reperfusion
What factors affect the length of hospital stay after myocardial infarction?
- Severity
- Comorbidities (e.g. diabetes)
- Disease in other arteries
- Complications
What are some potential complications of myocardial infarction?
- LV impairment
- Arrhythmia
- Mechanical (papillary muscle rupture, free wall rupture causing tamponade)
- Pericarditis
How long after MI is an ECHO performed?
24-48hrs
What does an ECHO assess for?
- Ventricular function
- Valve function
- Septal rupture
- Pericardial fluid
When is cardiac MRI done?
When STEMI diagnosis is more ambiguous
Under what circumstances would an NSTEMI become an emergency?
- Persistent chest pain
- Threatening ECG signs
Describe the treatment of an NSTEMI prior to angiography
- 300mg aspirin
- Sublingual GTN
- Anticoagulants
- Statin
- Possibly ACE inhibitor
What % of MI patients have PCI/CABG/non-invasive?
PCI: 65%
CABG: 10-15%
Non-invasive: 20-25%
What fraction of patients in Australia die within 12 months of MI?
1 in 11
Roughly how much more likely are you to die from a recurrent MI than an initial one?
About twice as likely (~20% vs 10%)
What percentage of ACS are repeat events?
34%
What medications does a patient take post-MI
- Aspirin: indefinitely
- Antiplatelet: ~12 months
- ACE inhibitor
- High dose of strong statin
- Beta blocker
What are some lifestyle factors that should improve post MI?
- Smoking cessation
- Managing depression
- Physical activity/weight management
How long after MI can a patient not drive?
2 weeks
What antiplatelet drug is commonly used with aspirin? How long is it used?
Ticagrelor. Used for about a year to prevent stent from clotting.
