Acute Coronary Syndrome Flashcards
what is ACS?
an atherosclerotic plaque that becomes a thrombus and blocks and artery
what is a thrombus in a fast flowing artery usually made up of?
platelets
what are the types of ACS?
unstable angina
none ST elevation MI (NSTEMI)
ST elevation MI (STEMI)
what does the aorta branch into?
the left ad right coronary arteries
what does the left coroanry artey become?
circumflex artery
left anterior descending
where is the circumflex artery?
it curves around the top, left and back of the heart
what does the circumflex artery supply?
the left atrium
the posterior aspect of the left ventricle
where is the LAD?
it travels down the middle of the heart
what does the LAD? supply?
the anterior left ventricle
anterior septum
what does the right coronary artery supply?
the right atrium
the right ventricle
the inferior left ventricle
posterior septal area
how would a patint with ACS present?
usually central constricitn chest pin, assoc w
radiatio to jaw or arm
nausea and vomiting
shortness of breath
sense of impending doom
sweats and claminess
palpitations
what is a silent MI?
when a patient has no typical chest pain during ACS
who is more at risk of a silent MI?
diabetics
how long should symptoms continue to likely be ACS?
at rest for mor than 15 minutes
what ECD chnages are see i an NSTEMI?
ST depression
T wave inversion
what ECG changes are seen in a STEMI?
ST elevation
new left buncdle branch block
what do pahtologicla Q waves suggest?
deep, transmura iinfarction
usually 6+ hours after inset of symptoms
what area of the heart is affected by each artery?
LCA - anterolateral
LAD - anterior
RCA inferior
circumflex - lateral
which ECG leads are affected by each artery?
LCA - I, aVL, v3-6
LAD- V1-4
RCA - II, III, aVF
circumflex - I, aVL, V5-6
what is troponin?
a protein in the myocardium and skeletal muscle
what is a rise in troponin assoc w and why?
myocardial ischaemia
as is released from ischael muscle tissue
what are troponin results used to diagnose?
NSTEMI
not STEMI (use ECG and clinical presentation)
in case of suspected ACS what troponin results indicate an NSTEMI?
high
or rising on repeated tests
why is troponin a non specific marker?
rise in troponin can also be caused by:
- chronic kidney disease
- pulmonary embolism
- aortic dissection
- myocarditis
- sepsis
what other investigations apart from ECG and troponin are done for suspected/cofirmed ACS?
baseline bloods - full blood count, urea and electrolytes, liver function test, lipids and glucose
chest x-ray - look for pulmonary oedema and any there causes of chest pain
echocardiogram - to check function damage to heart esp left ventricular function
what diagnoses a STEMI?
ST elevation
or
new left bundle branch block
what diagnoses and NSTEMI?
raised troponin with either
- normal ECG
- other ECG changes (not ST elevation) i.e ST depression or T wave inversion
what diagnoses unstable angina?
normal troponin with normal ECG or ECG changes that aren’t ST elevation
what would a patient with chest pain, normal ECG and normal troponin be diagnosed with?
either unstable angina or another cause of pain such as musculoskeletal pain
what is the initial management for ACS?
Call ambulance
Perform ECG
Aspirin 300mg
IV morphine (pain if needed) w antiemetic (metoclopramide)
Nitrate (GTN)
what should happen to a patient who is pain free but hs had constricting central chest pain in the last 72hrs?
should be admitted to hospital for same day assessment
usually seen in ambulatory care unit
may need emergency admission if ECG changes or complications - HF
what are the two management options for a STEMI and when is each used?
PCI - if available within 2hrs of presnting
thrombolysis - if PCI not available within 2hrs
what is a PCI?
PERCUTANEOUS CORONARY INTERVENTION
angiography
angioplasty or devices to remove/aspirate blockage
stent usually inserted to keep artery open
what is an angiography?
catheter is put into the radial or femoral artery - radial preferred
fed through using x-ray
contrast injected to identify blockage
what is an angioplasty?
balloons being used to widen lumen to treat a blockage
what medications may be advised before a PCI?
aspirin or prasugrel
what is thrombolysis?
injecting a fibrinolytic agent
what do fibrinolytic/thrombllytic agents do?
break down fibrin in blood clots
what makes thrombolysis dangerous?
significant bleeding risk
give examples of thrombolytic agents
streptokinase
alteplase
tenecteplase
what is the management of NSTEMI?
Base decision on angiogrpah/PCI on GRACE score
Aspirin 300mg stat dose
Ticagrelor 180mh stat dose
Morpgine titrated for pai
Antithrombin therapy with fondaparinux
Nitrate (GTN)
what would be used instead of ticagrelor if a patient with an NSTEMI has a high bleeding risk?
clopidogrel
what would be used instead of ticagrelor is a patient with an NSTEMI is getting an angiography?
prasugrel
when would a patient with an NSTEMI not be given fondaparinux as an antithrombin?
when they have a high bleeding risk or are getting an immediate angiography
what are unstable NSTEMI patients considered for?
an immediate angiography
what does the GRACE score measure?
the 6 month probability of death after an NSTEMI
what GRACE scores give what level of risk?
3% or less = low risk
greater than 3% = medium to high risk
what are patients with a medium-rhigh risk calculated by the GRACE score considered for?
an early angiography with PCI within 72hrs
what is the ongoing management of ACS?
once stable, an echocardiogram to asses function, especially left ventricular function
cardiac rehabilitation
secondary prevention
what is secondary prevention after an MI?
Aspirin 75mg once daily, indefinitely
Another anti platelet for 12months (usually clopidogrel or ticagrelor)
Atorvastatin 80mg once daily
ACEi titrated as high as tolerated (ramipril)
Atenolol (or other beta blocker - bisprolol) titrated as high as tolerated
Aldosterone antagonist for patients with clinical HF, eplerenone titrated to 5omg once daily
why can dual antiplatelet therapy vary after PCI?
depends on the stent used
what is important to monitor in patients taking ACEi and aldosterone antagonists and why?
renal function
can cause hyperkalaemia
what drug combination carries a risk o fatal hyperkalaemia?
spironolactone or epelerenone (aldosterone antagonists)
+
ACEi or ARB
what are the complications of a MI?
Death
Rupture of heart septum or papillary muscles
E oEdema - heart failure
Arrhythmia or aneurysm
Dressler’s syndrome
