Myocardial Infarction

  1. what causes ACS
    acute myocardial ischemia is caused by imbalance between myocardial oxygen supply and demand
    • NSTEMI (non-st elevated MI)
    • UA (unstable angina)
  3. definition of STEMI
    presence of a new ECG ST elevation in 2 or more leads
  4. points of emphasis for diagnosis
    • clinical presentation
    • ECG
    • cardiac biomarkers
    • rule out differential diagnosis
  5. differential diagnosis
    • aortic dissection
    • peptic ulcer
    • pericarditis
  6. clinical presentation
    • chest pain/discomfort
    • shortness of breath
    • diaphoresis
    • nausea/vomiting
    • dizziness or syncope (fainting)
    • fatigue/weakness
  7. cardiac biomarkers
    • CK-MB
    • Troponin
  8. when are cardiac biomarkers released into circulation and when do they apear
    they are released after cardiac cell injury and usuall appear within 3-6 hrs after myocardial damage
  9. when should you check cardiac biomarker levels
    at least 3 times in 24 hrs (q8h)
  10. which cardiac biomarker isĀ better for diagnosing re-infarction
  11. how long do troponin lvs stay elevated
    7-14 days
  12. what do risk scores predict
    predicts 30 day mortality after a MI
  13. treatment goals for mgmt of MI
    • control chest pain and assoc sx
    • restore blood flow and min infarct size
    • rule out differential dx
    • prevent complications
  14. complications of STEMI
    • ventricular remodeling
    • ventricular arrhythmias
    • HF
    • recurrent ischemia
    • re-infarction
    • cardiogenic shock
    • stroke secondary to LV thrombus embolization
  15. effects of nitroglycerin
    • venodilation (preload) and arterial vasodilation
    • reduces myocardial O2 demand
    • promotes coronary blood flow
  16. routes for nitroglycerin
    • sublingual (0.4mg)
    • topical (0.5-2inch)
    • intravenous gtts (5-10mcg/min)
  17. when is IV nitroglycerin usually used
    in STEMI if there is persistent ischemia, CHF, HTN
  18. AE of nitroglycerin
    • hypotension
    • flushing and HA
    • reflex tachycardia/bradycardia
    • tolerance to nitrate therapy
  19. counsel pt on nitroglycerin
    • sit down and put SL NTG under the tongue
    • watch out for above SE
    • store the tablet in the original container
    • call 9-1-1 if pain is not relieved in 5 min
  20. what study proves aspirin decreases mortality in MI pts
    ISIS-2 study
  21. avoid aspirin pts with
    • know hypersensitivity
    • active bleeding
    • severe bleeding risk
  22. how should O2 be used in STEMI pts
    • O2 therapy should be continued beyond the first 6 hours in STEMI pts with:
    • 1. oxygen desaturation
    • 2. overt pulmonary congestion
  23. when do you use caution in oxygen therapy
    caution with COPD and CO2
  24. use of Morphine in MI pts
    used for its analgesic and venodilatory effects
  25. effects of B-blockers
    decrease HR, contractility, and BP
  26. guidelines for oral B-blockers
    • 1. should be initiated within first 24 hrs in pts without any contraindications
    • 2. should be used during and after any pt with STEMI and with no contraindications to their use
    • 3. pts with initial contraindications to the use of B-blockers in the first 24 hours after STEMI should be reevaluated to determine their subsequent eligibility
  27. Metoprolol dosing range
    25-50 to 200mg/day
  28. carvedilol dosing range
    6.25mg PO BID to 25mg PO BID
  29. guidelines for IV B-blockers
    1. IND only in pts who are hypertensive or have ongoing ischemia and with no contraindications to their use
  30. IV metoprolol dosing
    5mg q5min x 3 as tolerated
  31. IV atenolol dosing
    5mg q5min x 2
  32. contraindications to using B-blockers during STEMI
    • sign of acute decompensated HF
    • low output state
    • increased risk of cardiogenic shock
    • second or third degree heart block
    • active asthma/ reactive airway disease
  33. what is the goal of reperfusion
    to restore myocardial perfusion in the infarct artery
Card Set
Myocardial Infarction
PT II Exam