Myocardial Reperfusion Therapy Flashcards
What is the treatment of choice for a STEMI?
PCI
What are the 4 goals of myocardial reperfusion therapy?
- Re-establish early patency of coronary artery
- increase salvage of myocardial tissue
- preserve LV function
- increase survival from myocardial infarction
What are the two re-perfusion strategies?
- Thrombolytic therapy
2. PCI
How long within the onset of symptoms do patient need to be treated with PCI/thrombolytics?
12 hours, but best outcome is within 1 hour from onset.
The time to reperfusion (measured from first medical contact) is how long for primary PCI and how long for fibrinolysis?
90 minutes, 30 minutes.
What are 7 absolute contraindications to fibrinolytics?
- Prev hemorrhagic stroke at any time
- Ischemic stroke within 3 months, except acute ischemic stroke within 3 hours
- Known structural cerebral vascular lesion
- Known intracranial neoplasm
- Active internal bleeding
- Suspected aortic dissection
- Significant closed head or facial trauma within 3 months
What are 10 relative contraindications to fibrinolytics?
- Severe uncontrolled HTN on presentation (SBP >180, DBP >110)
- Hx of ischemic stroke greater than 3 months, dementia or known intracranial pathology not covered in contraindications
- Current use of anticoagulants in therapeutic doses (INR >2-3); known bleeding disorder
- Traumatic or prolonged (>10 min) CPR or major surgery (within 3 weeks)
- Recent (2-4 wk) internal bleed
- Non-compressible vascular punctures
- For streptokinase/anistreplase: prior exposure (more than five days ago) or prior allergic rxn to these agents
- Active peptic ulcer disease
- Pregnancy
- Current use of anticoags: the higher the INR the higher the bleeding risk
Nursing considerations after administering a thrombolytic agent?
Adequate IV access ensuring enough sites to accomodate IV infusions and blood sampling to avoid venipuncture x 24 hr. Use of NIBP should be avoided to prevent hematomas. Patient should not shave or brush teeth.
If PCI cannot be performed within 120 minutes, what should be considered for the patient?
Fibrinolytics
What is the initial dose of Aspirin? Maintenance dosing? How does ASA work?
Initial: 81 - 325 mg PO chew tablet. Maintenance: 81 mg. It inhibits synthesis of thromboxane A2 which results in irreversible inhibition of platelet aggregation.
What is the initial dose of Clopidogrel (Plavix)? Maintenance dose? How does it work? What are special considerations for this drug?
Initial: 600 mg. Maintenance: 75 mg. Reversibly inhibits ADP P2Y12 platelet receptor to block platelet activation Some patients may have a genetic resistance to clopidogrel, resulting in inadequate platelet inhibition.
What antiplatelet is recommended for use with Fibrinolytics? How long is use recommended after fibrinolytics?
Clopidogrel. 14 days up to 1 year.
How is TNK given? How does it work? What are special considerations?
Single IV bolus. Binds to fibrin at clot and promotes activation of plasminogen to plasmin. Anticoagulants are given concurrently (i.e. IV heparin). Dual antiplatelet therapy is started with administration and continued daily (ASA and clopidogrel).
What are benefits of using a beta blocker for patients experiencing a STEMI?
Decreased myocardial O2 needs which result from the decreasing HR and contractility. Also increase coronary artery filling by prolonging diastole. Noted to decrease ventricular remodelling following MI.
For what type dysfunction are ACE inhibitors recommended for? What things must be adequate before starting this medication? Why are they beneficial?
Left ventricle dysfunction that persists beyond the early acute phase of MI. BP and renal function must be adequate. ACE inhibitors can actually improve dec BP if its related to LV dysfx it may improve LV fx overall which improves CO and BP. ACE inhibitors decrease myocardial oxygen demand by decreasing afterload.
