ACS Flashcards
What are the different acute coronary syndromes?
Step up from stable angina.
Involves Unstable angina, NSTEMI, STEMI and Sudden cardiac death
What causes an ACS?
Either the rupture of a plaque or thrombosis which makes the occlusion of vessel worse than in stable angina
What is the difference between unstable angina and NSTEMI?
An NSTEMI is an actual infarct which causes necrosis and a rise in serum troponins or creatine kinase-MBs due to that breakdown of muscle
Unstable angina is kind of like stable angina at rest but not enough to cause a MI
Non-modifiable risk factors for an ACS?
Age
Gender
Family/genetics
Previous angina, cardiac event or surgery
Modifiable risk factors?
Smoking Bad diabetic control leading to hyperglycemia Hypertension Hyperlipidaemia Poor exercise/diet
What will you want to ask the patient about the angina pain?
Onset at rest
Relieving factors - does GTN spray help?
In a history - what would make you suspect unstable angina/NSTEMI?
Angina on rest
How does an NSTEMI typically start presenting - Angina getting progressively worse or angina on rest?
NSTEMI will show first as angina on rest
as it has reached that point and has been reclassified to an actal MI
Examination wise - will patients look very unwell on an end of bed inspection?
They can do, but not all the time
Is there any remarkable features to look for in an examination?
Not really
What should be checked in an examination anyway?
HR
BP
Auscultate for murmurs and crackles
What should you keep in mind when looking for symptoms for an ACS in different patients?
You always get atypical patients in which typical symptoms do not show
In this case - women, elderly or diabetics due to a reduced pain sensation
What symptoms should you keep your eye open for instead with atypical patients?
Breathlessness
Signs of heart failure
Nausea and vomiting
Epigastric (upper abdomen) pain
What to look for in an ECG?
Can have but not always;
ST segment depression
Transient ST segment elevation and/or T wave inversion
What happens to ECG changes in unstable angina when the pain subsides?
The ECG tends to return to normal
What happens to ECG changes in NSTEMI when the pain subsides?
Changes tend to persist
Should ECGs be done routinely?
Yes to detect any changes
What are some biomarkers which indicate a high risk of an adverse event?
Cardiac troponin - I and T proteins types
What is cardiac troponin?
Contractile apparatus unique to heart
Should cardiac troponin be detectable in normal instances?
No
Is troponin elevation always a sign of ACS?
No
What is the immediate treatment response to give to someone having an ACS?
MONA
Morphine/dimorphine
Oxygen
Nitrates - GTN spray or tablet
Aspirin - 300mg orally
What is the further medical treatment from someone with unstable ACSs?
Anti-platelet Anti-thrombotic (anticoagulants) Glycoprotein llb/lllb inhibitor Beta blockers Statins ACEIs
What are the anti-platelet drugs and doses?
Aspirin - 75-100mg
Clopidogrel - 300mg initially then 75mg daily
Ticagrelor - 60mg initially then 10mg daily
Prasugrel - 180mg then 90mg daily
How does aspirin work?
Platelet thromboxane A2 production inhibitor
Stops platelet aggregation and vasoconstriction
How does ticagrelor/prasugrel work?
ADP receptor blocker - stops pathway reaching Glycoprotein llb/lllb pathway
In turn stops platelet aggregation and fibrin linking
Should patients be on one or more than one of these antiplatelet drugs and for how long after an event should they be used?
Dual therapy for one year after event is best
Name some glycoprotein llb/lllb receptor blockers?
Tirofiban
What do these glycoprotein llb/lllb blockers do?
Stop the protein undergoing a conformational change and binding fibrinogen and activating platelets
Adverse effects of glycoprotein llb/lllb blocker therapy?
Bleeding
What are some anti-thrombotic (anti-coagulant) agents?
Unfractionated heparin
Low molecular weight heparin
Fondaparinux - a LMWH like drug
Which ones IV administered?
Unfractionated heparin
How is LMWH given?
Sub/c
Which one of the 2 heparins has a better clinical outcome and why?
LWMH
Easier to give
No need to be monitored
Name some IV beta blockers used to treat unstable angina/NSTEMI.
Atenolol
Metoprolol
Should oral beta blockers be started?
Yes - shown to reduce morality
How do beta blockers work?
Rate limiting
Reduce myocardial O2 consumption
B/Blocker contraindications?
Asthma
Heart failure
Bradycardia/Heart block
What type of patients have been shown to die if given beta blockers?
Over 70s HR is below 110bpm S. BP is below 120 Coronary vasospasm Cocaine use
Should stains be used?
Yes -acutely and chromically to reduce risk of further events
In who should ACEIs be used for a ACS?
Abnormal LV function, unstable angina or an MI
What are the 2 surgical ways to treat an ACS?
PCI
CABG
Why is a STEMI treated differently?
The occlusion is larger and needs to be reduced rapidly (I think)
What are the 2 main treatments for a STEMI?
Primary PCI (Surgical)
Fibrinolysis/Thrombolysis (medical)
Features of PCI.
Better than fibrinolytic therapy
Used to unblock artery and save muscle cells so time is muscle
When is fibrinolysis used?
When PCI not an option
What is fibrinolysis?
Drugs that thin out the thrombus that has grown on top of plaque and blocked artery even more
How does fibrinolysis work?
Serine proteases convert plasminogen to plasmin
Plasmin works to lyse a clot by breaking down fibrinogen and fibrin
2 types of fibrinogen agents?
Fibrin specific
Non fibrin specific
Name some fibrin specific agents?
Alteplase
Reteplase
Tenecteplase
Name the non-fibrin specific agent
Streptokinase
Contraindictions of fibrinolysis
Suspected aortic dissection
Bleeding due to HYPOcoagubiltiy
Brain tumours/bleeds/stokes
What increases the risk of an intra-cranial bleed in fibrinolysis therapy?
Over 75 Female Previous stroke history Low body weight Severe hypertension INR of over 4 Chronic kideny disease and elevated creatine
What is some secondary prevention regarding lifestyle after an ACS event?
Stop smoking
Better diet/exercise
Control co-morbities - BP/glycemia
What is some further medical therapy to use after an ACS?
Aspirin/clopidogrel for 1 year Beta blocker (if tolerable_
ACEIs if LV dysfuntion
What investigations should be done post ACS?
An echocardiogram for myocardial dysfunction
What is the most important determinant for an MI survival?
Age
LV ejection fraction
Sudden cardiac death - survival rate?
~2% are get past resus and survive
In those resus’d - what do they end up with?
about 80% have V-tachy or V-fib
How is sudden cardiac death seen?
Seen as V-fib. multiple wavelets on ecg - rapidly progresses to asytole
How to treat SCD?
Defib only way to treat a V-fib arrest
If progresses to asytole then prognosis isn’t good
List the major trials which have proven the advantage of thrombolytic therapy
local GREAT study
Describe rehabilitation following myocardial infarction
build up easy exercise and keep bp low
