Ischemic Disease Pt2 Dr. Stewart Flashcards
Dr. Stewart EXAM VI
How does an ischemic injury manifest in an ECG?
-ST-segment elevation (distance between the S and T wave)
-ST-segment depression
-T-wave inversion
-may cause no ECG changes
-may indicate a severe ischemic injury or an ongoing infarction
Difference between STEMI and NSTE-ACS?
-STEMI: ST-elevation MI
ischemic injury with an ST-elevation
-total occlusion -> causing infarction (tissue death)
chest pain at rest -> needs to go to the ER
-NSTE-ACS: no ST-elevation still an urgent event,
no infarction, no necrotic tissue
partial occlusion
chest pain at exertion
PCP referral
Types of blood clot
-Red clot: DVT or PE –> anticoagualnt
-White clots: arteriosclerosis causing MI, stroke, PAD -> use antiplatelets
What are the drugs used for early treatment in ACS?
early: MONA
Morphine: with severe pain (also it will relax the patient -> relaxes the parasympathetic NS (and the heart) -> less oxygen needed for the heart
Oxygen: (only if they actually need it >90%, infusing it too rapidly can cause oxidative damage)
Nitroglycerin: paste on the chest or continuous infusion
Aspirin: can be given right away (pharmacy), 1x full dose (325 mg) + in the ER they would also get heparin
What are the drugs used for late treatment (home meds) in ACS?
SAAB
Statin (new studies: give it earlier)
ACEi: after the patient has stabilized, within 24 hr
Aspirin or DAPT
BB
What is the dose for Morp
-2 mg every 15 min PRN for chest pain
-only as much as needed -> could affect the absorption of antiplatelets or other drugs
-can decrease gut motility, cause N/V and impact absorption
What are possible ADRs when given O2?
-only given when O2 <90% (when patients really need it)
when given with O2 >90%
-Increases arterial resistance (coronary and SVR)
-Reduces CO
-Reactive oxygen species (free radicals)
MOA of Nitroglycerin
-more venodilator -> reduces preload (volume at the end of diastole - the heart is filling after contraction)
-nitric oxide causing vasodilation of smooth muscles of arteries and veins (more veins)
-when blood vessels spasm or constrict -> help to reduce O2 demand through vasodilation
-titrate to chest pain relief
What are the ADRs of nitroglycerin?
-Hypotension
-Headache (caused by vasodilation)
-lightheadedness/dizziness
-Nausea
-reflex tachycardia
Which drug is contraindicated with nitroglycerin?
EXAM
-PDE-5 inhibitor (sildenafil, tadalafil -> erectile dysfunction)
-artery is blocked and the myocardia doesn’t get enough blood
-2 vasodilator will further decrease the BP and perfusion -> heart attack
What are the doses (chronic and acute) for Aspirin in ACS?
Acute: 325 mg
Chronic: 81 mg preferred (75-100 mg) for lifetime
MOA: Inhibits platelet aggregation via TXA2 pathway
What are the types of ACS?
-STEMI treatment:
*primary PCI vs fibrinolytic therapy (if PCI is not available)
-NSTE-ACS treatment
aggressive or conservative
*medical therapy
*PCI
*CABG
PCI drugs
-Aspirin (already administered in the ER)
-Anticoagulants (d/c after PCI)
*UFH + GP IIb/IIIa (Eptifibatide, Abciximab - potent antiplatelet) -> preferred
*LMWH + GP IIb/IIIa
*Bivalirudin (direct thrombin inhibitor, fe dabigatran can be given w/o GP IIa/IIIb)
-Antiplatelets
GP IIb/IIIa (see above)
*P2Y12i: loading dose after known anatomy
Which drug is released by a drug-eluting stent?
-PCI: insertion of a balloon opening the vessel, and inserting the drug-eluting stent
-Immunosuppressant release for about 6 months
-the metal causes an immune reaction and it can cause scaring of the blood vessel
-after time the tissue should nicely overgrowth the stent -> so it doesn’t cause a reaction later (if that doesn’t occur and they stop their DAPT it can cause ACS)
-reduces the risk of thrombosis occurring in the stents
Risk reduction with drug-eluting stents
-reduced risk of in-stent thrombosis
-increased risk of late stent thrombosis
Why is the artery anatomy being checked before loading the patient with P2Y12 inhibitors?
-bc a loading dose blocks antiplatelet activity for 3-5 days
-they would not be able to undergo surgery -> so their arteries have to be checked (anatomy) before loading them to see if they need a surgery
P2Y12 inhibitor - Clopidogrel dosing in PCI therapy
Clopidogrel
– Loading dose: 300-600 mg
– Maintenance dose: 75 mg daily
P2Y12 inhibitor - Ticagrelor dosing in PCI
Ticagrelor (Brilinta)
– Loading dose: 180 mg
– Maintenance dose: 90 mg twice daily
P2Y12 inhibitor - Prasugrel dosing in PCI
Prasugrel (Effient)
– Loading dose: 60 mg
– Maintenance dose: 10 mg daily
Which of the antiplatelets are reversible P2Y12 agents?
-Clopidogrel
-Prasugel
longer half-life, but the effect is related to the lifetime of the platelets
-> since it is irreversible the platelet recovery (effect of the drug) is longer compared to ticagrelor
Which of the P2Y12 agents are metabolized through CYP2C19?
Clopidogrel (Plavix) and Prasugrel (Effient)
-both irreversible, given once a day
Why is Ticagrelor (Brilianta) given twice a day?
-bc it is reversible and the platelet recovery time is shorter
-benefit: patients on ticagrelor undergo surgery (if they need one, fe bypass) faster than patients on Prasugrel, bc the platelet recovery time is shorter
FYI: there is an assay that helps determine the levels of platelets to tell if the patient is ready to undergo surgery
Which of the P2Y12 inhibitors are contraindicated for stroke?
Prasugrel (Effient)
-potent antiplatelet
-it didnt show to have any benefit for stroke prevention, but it increases the risk for bleeding
Which if the P2Y12 antiplatelets are the most potent ones?
-new agents are more potent
-Prasugrel (Effient), Ticagrelor (Brilianta)
