Acute Coronary Syndromes + Aortic Dissection Flashcards
What is an acute coronary syndrome?
The rupture of an atherosclerotic plaque leads to the formation of a thrombus occluding one or more coronary arteries
What are the 3 types of acute coronary syndrome?
Unstable angina
NSTEMI (Non ST elevation myocardial infarction)
STEMI (ST elevation Myocardial Infarction)
What part of the heart does the right coronary artery supply?
Right atrium
Right ventricle
Inferior wall of heart (left ventricle)
Posterior septum
What 2 arteries does the left coronary artery become?
Circumflex artery
Left anterior descending (LAD)
What part of the Heart does the circumflex artery supply?
Left atrium
Posterior aspect of left ventricle
What part of the heart does the left anterior descending artery supply?
Anterior aspect of the left ventricles
Anterior aspect of septum
How does a pateint with an acute coronary syndrome typically present?
Central crushing/pressing chest pain
Pain radiates to jaw or arms
N+V
Sweating and clammy
Impending doom
Shortness of breath (pain not causes by breathing in or out)
Palpitations
Symptoms at rest (15mins or longer)
Does a non elevated troponin rule out an acute coronary syndrome?
No
Justly means the ruptured plaque has not yet caused myocardial ischaemia
What are some ECG changes that can be seen with a STEMI?
ST segment elevation
NEW LEFT BUDNLE BRANCH BLOCK.
What ECG changes can an NSTEMI have?
ST Segment depression
T wave inversion
What is the significance of pathological Q waves on an ECG?
Indicates full thickness/transmural infarction of the myocardium (normally shows up 6+ hrs after symptom onset)
What ECG leads would show changes if there is an acute coronary syndrome in the right coronary artery?
Inferior wall
II, III and aVF
What ECG leads would show changes if there is an acute coronary syndrome in the circumflex artery?
Lateral wall
I, aVL, V5 and V6
What ECG leads would show changes if there is an acute coronary syndrome in the Left anterior descending artery?
Anterior wall
V1, V2, V3 and V4
What other than myocardial ischaemia can cause an elevated troponin?
CKD
Sepsis
Myocarditis
Aortic. Dissection
Pulmonary embolism
What investigations would you do if you suspect an acute coronary syndrome?
CXR
Echocardiogram
ECG
U+E
LFT
Lipids
Glucose
What is needed to diagnose an NSTEMI?
Raised troponin with either:
-normal. ECG
-ECG changes like ST depression or T wave inversion
How is unstable angina diagnosed?
Troponin can be normal
ECG changes like ST depression or T wave inversion
Normally done with symptoms
What is the immediate medical treatment for a patient suffering a STEMI?
Aspirin 300mg (75mg day after)
Ticagrelor 180mg (90mg BD day after)
GTN
IV morphine or Diamorphine + Metoclopramide (antiemetic)
Oxygen
What is the benefit of giving GTN and morphine to a patient suffering a STEMI?
They are both venodilators
Systemic vasodilation leads to the heart having a reduced workload so reducing its oxygen demand
If pain improves immediately shows its an ACS cause
What is the benefit of giving oxygen to a patient suffering a STEMI despite having good oxygen sats?
Ensures working part of the heart is as well saturated as possible
Ensures if artery has some patency the blood going to the effected area is as oxygenated as possible
What is the gold standard intervention for treating a STEMI?
Percutaneous Coronary Intervention (PCI)
When should PCI be carried out to treat a STEMI from time of presentation?
PCI within 2hrs of symptoms/presentation
What intervention should be carried out if PCI cannot be carried out within 2hrs of presentation/medical contact for the STEMI?
Thrombolysis
What type of medication is used for thrombolysis in a patient with a STEMI?
What medication is used?
Tissue Plasminogen Activator
Alteplase
What are the contraindications to PCI?
WHEN CORONARY VESSEL OCCLUDED FOR MORE THAN 48HRS
Active bleeding or bleeding disorders
Moderate or worse dementia (non co-operative patient)
Patient refusal
Severe renal impairment (nephrotoxic contrast)
What is the favoured treatment for treating a STEMI?
PCI
Why is PCI for a coronary vessel occluded for more than 48hrs contraindicated?
Reperfusion injury will cause significantly more damage to the left ventricle
What is the immediate medical treatment for unstable angina or an NSTEMI?
Aspirin 300mg
2nd antiplatelet Clopidogrel 300mg or Ticagrelor 180mg
Enoxaparin 4 doses
Then immediately to the catch lab for PCI
When is Ticagrelor picked over clopidogrel when treating for an NSTEMI/unstable angina?
Patient is diabetic
Heading to PCI
Not a high bleed risk / younger
When is Clopidogrel given over Ticagrelor for managing an NSTEMI/unstable angina?
When patient has higher bleeding risk :
-elderly
-GI bleeds
-previous haemorrhagic strokes
-active bleeding
-coagulopaties
Hepatic impairment
What dosage of Enoxaparin (LMWH) should be given for the management of an NSTEMI or unstable angina?
Patients mass in kg but that in mg BD
E.g: patient is 70kg they will need 70mg Enoxaparin BD for 2 days
4 doses of enoxaparin over 2days
What medications are given for secondary prevention of Acute Coronary Syndromes?
Aspirin 75mg
Ticagrelor (90mg BD), clopidogrel (75mg) or Prasugrel for 1 year (depends on which one they were originally on)
Atorvastatin 80mg for 1 year then reduce according to their cholesterol levels
Bisoprolol
Ramipril or Losartan
What are the classes of medications you give for secondary prevention of Acute Coronary Syndrome?
2 antiplatelets (Aspirin + clopidogrel, Ticagrelor or prasugrel)
Anti-cholesterol
B-blocker
ACEi or ARB
What dose of bisoprolol is given as secondary prevention for Acute Coronary Syndromes?
1.25 - 10mg
What dose of Ramipril is given as secondary prevention for Acute Coronary Syndromes?
1.25 - 10mg
When is losartan given instead of ramipril in the secondary prevention of Acute Coronary Syndromes?
Ramipril causes the dry cough
What dose of losartan is given as secondary prevention for Acute Coronary Syndromes?
25mg - 100mg.
When is the 2nd antiplatelet clopidogrel, Ticagrelor or prasugrel discontinued following an acute coronary syndrome?
Continued for a year as secondary prevention then stopped
What other medication can be given as a form of secondary prevention for acute coronary syndrome when the patient has clinical heart failure?
Aldosterone receptor antagonists like Spironolactone
What needs to be carefully monitored in patients taking both ACEi (ramipril) and Aldosterone receptor antagonists (Spironolactone or eplerenone)?
Potassium levels
Risk of HYPERKALAEMIA
What seconadary prevention for ACS would you give to a patient whose Ejection fraction is 30% or less?
Normal medications
+
Dapagliflozin
Spironolactone
Entestro = Sacubitril/valsartan (STOP RAMIPRIL or Losartan)
What are some risk factors for developing an Acute Coronary Syndrome?
HTN
T2DM
High cholesterol
Smoke
1st degree relative died of vascular disease
What are the complications of an acute coronary syndrome?
Death
Ruptured heart septum or papillary muscles
Oedema/heart failure
Arrhythmias
Aneurysm
Dresslers syndrome
What is Dressler’s syndrome?
Localised immune response leading to inflammation of the pericardium leading to pericarditis
This happens 2-3weeks following an ACS
How does Dressler’s syndrome present?
Pleuritic chest pain
Low grade fever
Pericardial rub
Pericardial effusion
Pericardial tamponade
What is an aortic dissection?
The division between 2 layers of the aorta creating a false lumen
What 2 layers does blood accumulate between in an aortic dissection?
What layer needs to tear for this to happen?
Between tunica intima and tunica media
Tear in tunica intima
Which part of the aorta does dissection most commonly occur in?
Thoracic aorta
Abdominal aorta has an aneurysmal tendency
What are the risk factors for developing an aortic dissection?
HTN = main
Marfans syndrome
Ehlers Danlos syndrome
Aortopathy
FHx
How does HTN affect the pathophysiology of an aortic dissection/ which part is more commonly affected?
Will normally affect the right side/outer edge of the aortic arch / the more superior edge on the arch then as the aorta descends will more commonly affect the left side of the descending aorta
This is since this is where the blood pressure within the vessel is highest (imagine flow of river around a corner)
What is a Type A Aortic dissection?
Dissection starts anywhere from aortic arch to the Left Subclavian artery
What is the emergency treatment for a Type A aortic dissection?
Emergency surgical repair
What are some complications that can occur due to Type A aortic dissections?
Acute Aortic Regurgitation-> acute pulmonary oedema
Inferior STEMI
Cardiac tamponade
Ischaemic strokes
What are the 2 types of Ischaemic strokes that can occur as a result of a Type A aortic dissection?
Posterior circulation stroke/vertebrobasilar
Anterior circulation stroke
Why can a Type A aortic dissection cause a Posterior Circulation/vertebrobasilar stroke?
Can occlude the right subclavian artery which gives of the right vertebral arteries
What changes might be seen in a vertebrobasilar stroke due to a Type A aortic dissection?
Brainstem, cerebellum and occipital lobes may be affected
Dizziness
Ataxia
Visual disturbances
Dysphagia
Brainstem/cranial nerve deficits
Why can a Type A aortic dissection cause an anterior circulation stroke?
Right common carotid artery can be occluded which gives of the internal carotid artery which supplies into the anterior circulation via the anterior cerebral artery and middle cerebral artery
What is a type B aortic dissection?
Dissection that occurs after the left subclavian artery
What must you examine and why if you think a patient has a Type B aortic dissection?
Neurovascular examination of the lower limbs
Anterior spinal arteries next arteries to arise after the left subclavian artery
How do patients with type B aortic dissection often present?
Why?
Very high BP
Poor. Renal. Perfusion
Which kidneys typically has poor perfusion in Type B aortic dissection?
Left kidney
What is the medical management of a Type B aortic dissection?
Reduce BP to 120/80
GTN infusion (nitropruside)
Labetalol
What emergency intervention must you do if you have a Type B aortic dissection with lower limb muscle weakness?
Why?
Lumbar puncture to drain the CSF to reduce the pressure on the anterior spinal arteries
What other conditions do you give GTN infusion (Nitropruside) and labetalol to reduce blood pressure?
Type B aortic dissection
Malignant HTN
Pre-eclampsia
