Acute coronary syndrome Flashcards
what is ACS and its definitions?
ACS - acute dysfunction or damage of heart muscle due to myocardial ischemia and/or thrombosis secondary to arterial atherosclerosis
results in partial/full blockage of coronary artery - causes oxygen deprivation of myocardial tissue
ACS - collective term for myocardial infarction & unstable angina
unstable angina - symptomatic myocardial ischemia at rest or minimal exertion with minimal to none myocardial necrosis
myocardial infarction - acute myocardial injury with necrosis - cell death - with myocardial ischemia
ischemia - restriction in blood supply to tissues - resulting in shortage of oxygen needed for cellular metabolism
atherosclerosis - disease of the blood vessels associated with cellular changes causing atherosclerotic plaque formation - oxidation and build up of lipid, fibrous tissue and calcium
thrombosis - rupture of the atherosclerotic plaque, leads to platelet aggregation and clot formation - fully or partially blocking a blood vessel - leads to ischemia and infarction of tissues beyond
what are the classifications of ACS
NSTE-ACS-UA - no myocardial injury, partial occlusion of coronary artery
NSTEMI - myocardial injury, partial occlusion of coronary artery
STEMI - myocardial necrosis, full occlusion of coronary artery
typical symptoms - chest tightness at rest, can radiate to both arms neck and jaw, nausea vomiting, stomach pain
positive biomarkers such as troponin which is released from cardiac tissue
- if no damage, it will not come out to bloodstream
- if unstable angina - no necrosis - normal - negative troponin detected
- for NSTEMI - myocardial damage - troponin is high
- for STEMI - necrosis - troponin is very high
how do ECGs look different for the different diseases?
unstable angina - could look normal or slight change, but not ST segment elevation
NSTEMI - part of heart is necrotic/damage some changes like T inversion
STEMI - most severe totally occluded arteries, ST segment elevation on ECG
what are the early care strategies for STEMI?
1) offer cardio angiography and follow up PCI
- should be within 2 hours
if you cannot do PCI within 2 hours - give fibrinolysis
- when treating with fibrinolysis, give anticoagulant
- if patient still has residual ST elevation - need to do PCI asap
- cannot do fibrinolysis again
early care for NSTEMI and unstable angina?
anticoagulation + antiplatelet therapy - just medication
can give PCI but it is not a must
early care for all patients (STEMI, NSTEMI, unstable angina)
aim - symptom control + restore myocardial perfusion
all patients should receive analgesia and anti-ischemic medication asap (MONA +B)
M - morphine IV/diamorphine
O - oxygen - if saturation low
N - nitrates
A - aspirin (anti-platelet)
B - beta blocker - should be initiated in 24 hours in ACS - unless c/i or HF
anti-sickness - IV metoclopramide
plus antiplatelet + anticoagulant
what are the antiplatelet recommendation
1) aspirin given for all ACS patients at initial presentation with or without PCI
- standard dose of 81mg
2) dual antiplatelet therapy (DAPT) - aspirin + P2Y12 receptor inhibitor - clopidogrel, ticagrelor, prasugrel
- clopidogrel and ticagrelor - for ischemia guided strategy - medication route
- clopidogrel, ticagrelor and prasugrel for early invasive strategy (PCI)
- dont use prasugrel if no PCI
GP IIb/IIIa inhibitors - eptifibatide, tirofiban
- should be used in PCI thrombotic complication or in high risk PCI patients who have not used P2Y12 receptor inhibitors
what are the anticoagulant recommendations
anticoagulants are administered to reduce risk of intracoronary + catheter thrombus formation
only medication/ischemic:
- UFH, enoxaparin, fondaparinux
for primary PCI - UFH, bivalirudin
when fibrinolytic agent given
- UFH, enoxaparin, fondaparinux
for NSTEMI/unstable angina how do you know whether to use only medication or PCI + medication
use GRACE ICS mortality score to work out mortality
if < or equal to 3% use only med
if >3% immediate angiography and follow up PCI as well as medication
describe PCI
percutaneous coronary intervention (PCI)
- interventional reperfusion strategy - minimally invasive
- performed through the wrist or groin
- catheter inserted into the coronaries - unblocks the blocked artery using a balloon - opens up artery - restores blood supply
- stent inserted to maintain blood flow
- high success rate
describe fibrinolysis
pharmacological thrombolysis - only done if PCI not available or after 2 hours
fibrinolysis - breaks down fresh thrombus in affected coronary artery
- should be done without delay
- greatest benefit 0-6 hours
- no benefit >12 hours
- agents include - streptokinase, alteplase, tenectoplase
- these agents have many c/i and complications e.g. stroke, bleeding, allergic reactions
what is the drug therapy for secondary prevention of ACS?
1) ACEi (ARB if intolerant)
2) dual antiplatelet therapy - aspirin + another anti-platelet for 12 months
3) BB (or CCB if BB c/i)
- if HF then use BB
4) statin
5) if on anticoagulation - continue with clopidogrel
6) if HF with reduced ejection fraction - aldosterone antagonist e.g. spironolactone
for ACEi and BB titrate dose up
what are non pharmacological tips?
diet (reduce salt intake)
weight control
exercise
smoking cessation
reduce alcohol intake
cardiac rehabilitation
list the secondary prevention and discharge ABCDE method
A - Aspirin + ACEi or ARB
B - beta blocker + BP control
C - cholesterol lowering therapy (statin) + cigarette stopping
D - diet + diabetes control
E - exercise + eplerenone (aldosterone antagonist) - depending on ejection fraction
