Acute coronary syndrome Flashcards
What is the pathophysiology of ACS?
A thrombus from an atherosclerotic plaque blocking a coronary artery
What is a thrombus in a fast flowing artery usually made up of?
Platelets
This is why anti-platelet medication is the mainstay of ACS treatment - aspirin, clopidogrel and ticagrelor
What are the ECG leads corresponding to the heart areas and coronary vessels?
LCA - anterolateral - I, aVL, V3-V6
Circumflex - lateral - I, aVL, V5-V6
LAD - anteroseptal - V1-V4
RCA - inferior - I, II & avF
What heart areas does the RCA supply?
Right atrium
Right ventricle
Inferior aspect of left ventricle
Posterior septal
Which heart areas does the LCA supply?
Left atrium
Posterior aspect of left ventricle
Anterior aspect of left ventricle
Anterior aspect of septum
Which heart areas does the LAD supply?
Anterior aspect of the left ventricle
Anterior aspect of septum
What is the first investigation to perform when a patient presents with symptoms of ACS i.e. chest pain?
ECG
Which ECG changes suggest a STEMI?
ST elevation or
New left bundle branch block
Which ECG changes associated with NSTEMI?
ST depression
Deep T wave inversion
Pathological Q waves - suggests deep infarct & late sign
If there is no ST elevation on ECG what is the next investigation to perform?
Troponin blood test
If troponin is raised with other ECG signs e.g. ST depression, T wave inversion or pathological Q waves, what is the diagnosis?
NSTEMI
If troponin is normal and no ECG changes, what is the likely diagnosis?
Likely unstable angina or MSK related chest pain
What are the symptoms in ACS?
Central constricting chest pain associated with: Nausea, vomiting Sweating / clamminess Sense of impending doom Shortness of breath Palpitations Pain radiating to jaw or arms
WRT troponins, a diagnosis of ACS requires?
Serial troponins - baseline, 6 and 12 hours
What is troponin a sign of?
Myocardial ischaemia
Troponin is a protein released from ischaemic myocardium
What are the five alternative causes of elevated troponin
Chronic renal failure Sepsis Myocarditis Aortic dissection PE
What investigations would you perform in ACS
Physical examination (heart sounds, signs of HF, BMI) ECG FBC - look for anaemia U&Es - baseline prior to starting ACEi LFTs - baseline prior to starting statins Lipid profile TFTs HbA1c and fasting glucose
Chest xray to look for other causes of chest pain and pulmonary oedema
CT coronary angiogram to look for coronary artery disease
Echocardiogram to assess functional damage
Management of acute STEMI?
PCI (presentation within 2 hours) - insertion of catheter into brachial or femoral artery to the coronary arteries and stenting/ balloon expansion/ clot removal with other devices
Thrombolysis - if presentation after 2 hours - injection of fibrinolytic medication –> streptokinase, alteplase, tenecteplase
Acute NSTEMI treatment?
BATMAN
B - beta blockers unless contraindicated
A - aspirin 300mg stat dose
T - ticagrelor 180mg
M - morphine titrated to pain
A - anticoagulant - fondaparinux unless high bleeding risk
N - nitrates e.g. GTN
What is the GRACE score used for?
To assess the need for PCI in NSTEMI
The 6 month risk of death or repeat MI following NSTEMI
What does a GRACE score of 10% indicate?
<5% low risk
5-10% intermediate risk
>10% high risk
Intermediate to high risk are considered for early PCI within 4 days of admission for tx of coronary artery disease
What are the complications of MI?
Death Passing PRAED St
Death: VF, LVF, CVA Pump failure Pericarditis Rupture - myomalacia cordis Arrhythmias/ aneurysm Embolism Dressler's syndrome: pleuro-pericarditis
What is the secondary prevention lifestyle management?
Stop smoking Exercise Mediterranean diet Cardiac rehabilitation Optimise control of other comorbidities e.g. diabetes and hypertension
What is the secondary prevention medical management?
6 As
Aspirin 75mg once daily
Another antiplatelet: e.g. clopidogrel or ticagrelor for up to 12 months
Atorvastatin 80mg once daily
ACE inhibitors (e.g. ramipril titrated as tolerated to 10mg once daily)
Atenolol (or other beta blocker titrated as high as tolerated)
Aldosterone antagonist for those with clinical heart failure (i.e. eplerenone titrated to 50mg once daily)
Dual antiplatelet duration will vary following PCI procedures depending on the type of stent that was inserted. This is due to a higher risk of thrombus formation in different stents.
