Acute Coronary Syndrome Flashcards
Lack of oxygen and reduced blood flow to the myocardium resulting in an imbalance between myocardial oxygen supply and demand
Ischemia
Necrosis (death) of heart muscle caused by an imbalance between oxygen supply and demand
Infarction
“Chest pain”; pain or discomfort in the chest or adjacent areas which is due to myocardial ischemia
Angina pectoris
: Painless episodes of myocardial ischemia (75% of all ischemia)
Silent ischemia
Infarction occurring without chest pain or other common symptoms of ischemia; about 20% of all infarcts
Silent infarction
Unstable angina or acute myocardial infarction
Acute coronary syndrome
Typically results in an injury that transects the thickness of the myocardial wall
Following an MI pathologic Q-waves are seen on ECG
STEMI
Limited to sub-endocardial myocardium
Patients do not usually develop pathologic Q-wave
Differs from unstable angina in that ischemia is severe enough to produce myocardial necrosis
NSTEMI
causes of Acute coronary syndrome
rupture of atherosclerotic plaque with subsequent platelet adherence, activation, and aggregation (clotting cascade)
clot of fibrin and platelets form
what is a principle cause of morality and morbidity post MI
heart failure (due to remodeling)
what are key findings on an ECG indicative or MI or infarction
STE
ST- segment depression
T-wave inversion
appearance of new left bundle-branch block
2 biochemical markers that rise in blood following myocardial cell death
Troponin
CK-MB
when should you obtain blood samples for troponin and CK-MB.
3 times over 12-24 hours period to see the values rise
how many values of troponin or CK-MB must be elevated to dx a MI.
at least 1 troponin values or 2 Ck-MD values are greater than the MI decision limit
general tx principles for ACS.
Reduce myocardial oxygen demand (low HR, BP, reduce preload)
improve myocardial oxygen supply- dilate coronary arteries, enhance blood flow, prolong diastole
if percutaneous coronary intervention or fibrinolytic therapy preferred for tx acute STEMI
PCI
Useful in patients w/ stenosis of coronary artery, LAD, impaired Left ventricular function.
Coronary Artery Bypass Grafting (CABG)
anti-anginal, vasodilator
increases coronary blood flow
reduces cardiac workload
alleviate coronary spasm
Nitrates
contradindications for nitrates
100 bpm
SBP 30 below baseline
don’t use w/ phophodiesterase inhibitor
How should nitroglycerin be used for NSTEM/ UA/ STEMI
Take sublingual nitroglycerin and if chest pain hasn’t improved after 5 minutes call 911
get 3 doses total of SL nitroglycerin
after 3 doses- assess need for IV w/ nitro (48 hours)
how does morphine help with ACS?
decrease anxiety, HR, BP
pain after nitroglycerin
automatically give with STEMI
DOC for analgesia for STEMI
morphine
what are some fibrinolytics (most common).
Streptokinase
Alteplase
what is the only ACS that fibrinolytics are used in?
STEMI
new left branch bundle block
posterior MI
what timeframe can fibrinolytic therapy be initiated in?
within 12 hours symptoms started
lower recommendation for sx onset within prior 12-24 hours and continuing ischemic sx and ST elevation
for NSTEMI/UA how should ASA be taken?
ASA 162-325 mg should be chewed by patient who haven’t taken it (2 baby aspirin)
is someone is intolerant to ASA what should they be given?
Clopidogrel (Plavix)
conservative strategy with antiplatelets (
add clopidogrel to ASA ASAP after admission
continue combo for at least 1 month
Invasive strategy with antiplatelets
either clopidogrel or an IV GP IIaIIIb inhibitor added to ASA
what is the only GP IIaIIIB inhibitor approved is PCI is going to be used
Abciximab
should abciximab be used any other time but for PCI?
No
what prevents thrombus formation
anticoagulatns
Class I recommendation for NSTEMI/UA for anticoagulants
add enoxaparin or UFH should be added ASAP
Recommendations for those with STEMI undergoing fibrinolytics for anticoagulatns.
Reicieve anticoagulants for a minimum of 28 hours and preferably duration of hospitalization (8 days)
start with UFH (48 hours) move to Enoxaparin
what anticoagulant shouldn’t be used as the sole anticoagulant to support PCI (class III)
fondaparinux
what drug shoul not be used as alternative UFH as ancillary tx in patients over 75 w/ fibrinolytic tx or those with renal dysfunction.
low molecular weight heparin
beta blocks for ACS
IV beta blockers then switch to oral as soon as they can tolerate it. (cost savings)
precautions with BBs
HR <100) mod-severe LV dysfunction, COPD, asthma, signs of hypoperfusion
You can only give an ACEI or BB if the patient is what?
hemodynamically stable
when should ACEI be administered
within first 24 hours orally
Don’t give IV (huge risk of HPOTN)
is there additionally benefit with CCB for MI?
No, can actually increase mortality
when should CCB be given?
contraindications to BBs
what are the 2 CCB that could potentially be given for MI if BB not tolerated
verapamil
diltiazem
In patients with ACS what do you give ASAP
ASA
NTG
BB
ACEI
in an STEMI what meds should be given additionally?
Clopidogrel + UFH, enoxaparin or fondaparinux
Long Term Prevention for CAD
ASA indefinitely + Clopiogrel
Nitroglycerin
Beta Blockers
ACEI
what is a HMG-CoA reductase inhibitors
statins
should statins be started on someone with an MI who has good cholesterol?
Yes, should be considered regardless of baseline LDL-C
when can you not give verapamil and diltizaem?
severe left ventricular dysfunction or other contraindications (heart failure)
what is the oral anticoagulant
warfarin
what do you want INR to be between?
2.0 to 3.0
in patients on warfarin, clopidogrel and aspirin what should that INR be?
2.0 to 2.5
how long do you give warfarin post MI
short time frame in the absence of afib or flutter
