Acute Coronary Syndrome Flashcards
What is ACS?
ACS includes:
- Unstable angina
- STEMI
- NSTEMI
Acute Coronary Syndrome is usually the result of a thrombus from an atherosclerotic plaque blocking a coronary artery. When a thrombus forms in a fast flowing artery it is made up mostly of platelets. This is why anti-platelet medications such as aspirin, clopidogrel and ticagrelor are the mainstay of treatment.
what is the likely pathology of ACS?
- plaque rupture
- thrombosis
- inflammation
rarely due to: emboli, coronary spasm, or vasculitits
What does MI mean?
That there is myocardial cell death, releasing troponin
What does ischaemia mean?
Means a lack of blood supply +/- cell death.
NB - MIs have troponin rises, unstable angina does not.
What are the features of STEMI?
- ST elevation ( May present in V7-9 if posterior STEMI)
or new onset LBBB (WilliaM - V1 and V6).
What are the features of NSTEMI?
- Tropinin positive ACS without ST segment elevation - the ECG may show ST depression, T wave inversion, non-specific changes or be normal.
What are the non modifiable risk factors for ACS?
Non- modifiable:
• Age
• Gender
• Family history of IHD (MI in 1st degree relative <55yrs)
What are the modifiable risk factors for ACS?
Modifiable: • Smoking • Hypertension • DM • Hyperlipidaemia • Obesity • Sedentary lifestyle Cocaine use
What are the controversial risk factors for ACS?
Controversial risk factors include: • Stress • Type A personality • LVH • Increased fibrinogen • Hyperinsulinaemia • Increased homocysteine levels ACE genotype
ACS DDx?
- Coronary causes
- Aortic dissection
- pneumothorax
- Aortic rupture
- oesophageal rupture
What is the incidence of ACS?
5/1000 per annum (UK) for ST-segment elevation (declining in UK & USA)
What is the treatment of Acute STEMI?
Acute NSTEMI treatment: BATMAN
B – Beta blockers unless contraindicated
A – Aspirin 300mg stat dose
T – Ticagrelor 180mg stat dose (clopidogrel 300mg is an alternative)
M – Morphine titrated to control pain
A – Anticoagulant: Low Molecular Weight Heparin (LMWH) at treatment dose (e.g. enoxaparin 1mg/kg twice daily for 2-8 days)
N – Nitrates (e.g. GTN) to relieve coronary artery spasm
Give oxygen only if their oxygen saturations are dropping (i.e. <95%).
What is the treatment of STEMI?
Patients with STEMI presenting within 12 hours of onset should be discussed urgently with local cardiac centre for either:
Primary PCI (if available within 2 hours of presentation)
Thrombolysis (if PCI not available within 2 hours)
The local cardiac centre will advise about further management (such as further loading with aspirin and ticagrelor).
Percutaneous Coronary Intervention (PCI) involves putting a catheter into the patient’s brachial or femoral artery, feeding that up to the coronary arteries under xray guidance and injecting contrast to identify the area of blockage. This can then be treated using balloons to widen the gap or devices to remove or aspirate the blockage. Usually a stent is put in to keep the artery open.
Thrombolysis involves injecting a fibrinolytic medication (they break down fibrin) that rapidly dissolves clots. There is a significant risk of bleeding which can make it dangerous. Some examples of thrombolytic agents are streptokinase, alteplase and tenecteplase.
What is the GRACE score used for?
Used to assess for PCI in NSTEMI
Discuss the GRACE score?
This scoring system gives a 6-month risk of death or repeat MI after having an NSTEMI:
<5% Low Risk
5-10% Medium Risk
>10% High Risk
If they are medium or high risk they are considered for early PCI (within 4 days of admission) to treat underlying coronary artery disease.
What are the complications of MI?
Complications of MI (Heart Failure DREAD)
D – Death
R – Rupture of the heart septum or papillary muscles
E – “Edema” (Heart Failure)
A – Arrhythmia and Aneurysm
D – Dressler’s Syndrome
What is Dressler’s Syndrome?
This is also called post-myocardial infarction syndrome. It usually occurs around 2-3 weeks after an MI. It is caused by a localised immune response and causes pericarditis (inflammation of the pericardium around the heart). It is less common as the management of ACS becomes more advanced.
How is Dressler’s syndrome managed?
Management is with NSAIDs (aspirin / ibuprofen) and in more severe cases steroids (prednisolone). They may need pericardiocentesis to remove fluid from around the heart.
How is Dressler’s syndorme diagnosed?
A diagnosis can be made with an ECG (global ST elevation and T wave inversion), echocardiogram (pericardial effusion) and raised inflammatory markers (CRP and ESR).
How does Dressler’s syndrome present?
It presents with pleuritic chest pain, low grade fever and a pericardial rub on auscultation. It can cause a pericardial effusion and rarely a pericardial tamponade (where the fluid constricts the heart and prevents function).
Describe the secondary prevention medical management of ACS?
The 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.
Secondary prevention lifestyle of ACS?
- Stop smoking
- Reduce alcohol consumption
- Mediterranean diet
- Cardiac rehabilitation (a specific exercise regime for patients post MI)
- Optimise treatment of other medical conditions (e.g. diabetes and hypertension)
What does the left coronary artery become?
The Circumflex and Left Anterior Descending (LAD).
Which areas of the heart does the Right coronary artery supply?
Right Coronary Artery (RCA) curves around the right side and under the heart and supplies the:
- Right atrium
- Right ventricle
- Inferior aspect of left ventricle
- Posterior septal area
