Acute Coronary Syndromes Flashcards
What change/event in the atherothrombotic process can lead to ACS (MI, stroke, unstable angina)?
Plaque rupture consequently occluding critical areas (coronary artery)
Describe chronic/stable angina
Fixed stenosis due to atheroma limits blood flow
Pain on exertion, relieved by rest/GTN spray
What are the 3 (main) acute coronary syndromes?
Unstable angina
NSTEMI
STEMI
What factors favour plaque rupture?
Thin fibrous cap
Sudden intraluminal pressure changes
High lipid content of plaque
How does plaque rupture affect the endothelium in terms of platelets?
Blood is exposed to sites it doesn’t normally see
Platelets adhere to damaged areas through vWF and collectively form haemostatic plug
How does unstable angina differ from stable angina?
Pain caused by less and less exertion, in some cases eventually at rest
GTN becoming less effective
How does angina differ from acute MI?
Shorter (10 mins vs. 30 mins)
Pain on exertion (vs. rest)
GTN relief (vs. no relief)
What are typical ECG changes that occur in STEMI?
ST elevation
T wave inversion
Q wave formation
Why are Q waves “useful”?
Signal that there has been a previous MI
What characteristics must the ST elevation have in order to diagnose STEMI?
> 1mm STE in 2+ adjacent limb leads
>2mm STE in 2+ contiguous precordial leads
Which leads show STE in an inferior MI?
II, III, aVF
Which leads show STE in an anterior MI?
V1-V6
Which leads show STE in an anterolateral MI?
I, aVL, V1-V6
Which leads show STE in an anteroseptal MI?
V1-V4
Which two proteins are used for diagnosing MI?
Troponin T or ICK enzyme
When does CK production peak following an MI?
after 24 hours
Why is CK not commonly used solely anymore to diagnose MI?
Also present in skeletal muscle and brain, so elevated levels could be due to injury in these areas
What is the benefit of troponin T?
Highly specific for cardiac muscle damage
Outline immediate treatment of MI
Diamorphine IV Anti-emetic IV Oxygen if hypoxic Nitrate (GTN) if BP >90 Aspirin Clopidogrel PCI within 90 mins, or else thrombolysis
If PCI cannot be given within 60 mins of seeing STEMI on ECG, do thrombolysis. True/False?
False
If PCI cannot be given within 90 mins (incorporating 40min drive time), then do thrombolysis
If a patient fails to improve following thrombolysis, what is done?
Emergency angioplasty
What is Dressler’s syndrome?
Post-MI syndrome, occuring weeks after MI
Pleuritic pain, pericarditis, pericardial effusion
Could the ECG be normal in acute MI?
YES
In unstable angina, troponins may be normal. True/False?
True
In a patient with a bare metal stent, how long should clopidogrel therapy last?
3 months
Cardiac troponin levels are negligible in healthy people. True/False?
True
How long does it take for cardiac troponin levels to increase? How long do they remain elevated?
4-6 hours
Remain elevated for at least 7 days
Name some contraindications to thrombolysis
Trauma, haemorrhage Recent surgery (within 2wks) Recent stroke (within 6mths) Severe hypertension Active peptic ulcers
What are some risk factors for ACS?
Age Gender Smoking Drug abuse/alcohol Obesity DM High BP/cholesterol Family history Stress
What symptoms are typically described in STEMI?
Severe, crushing, central chest pain that radiates to left arm and jaw - can include sweating, nausea, vomiting
What is a common arrhythmic complication of MI? How is it managed?
Ventricular fibrillation
Defibrillation
What is the difference between a STEMI and a NSTEMI?
There is no acute occlusion - building up and breaking down of clot
what ECG changes can be seen in NSTEMI?
ST depression
NORMAL
How is NSTEMI managed?
Early coronoary angiography/revascularization
What secondary prevention methods are used following an MI?
Healthy lifestyle
BP control (<140/90mmHg)
Smoking cessation
Cholesterol e.g. statin therapy
