ICS-STEMI Flashcards
Clinical Scenarios for Chronic Stable Angina
identified by obtaining a detailed history from the patient (patient is usually pain free at the time)
a. Stable angina means the pain is predictable 2. Acute onset of chest pain a. Rest angina: angina is prolonged (usually > 20 minutes) and occurs at rest b. New-onset angina: at least CCS Class III severity c. Increasing angina: previously diagnosed angina that is more frequent, longer in duration, or lower in threshold (increased CCS Class within 2 months to at least CCS Class III)
ST-segment elevation requiring immediate reperfusion therapy (STEMI)
AMI
ischemia is severe enough to cause sufficient myocardial damage and the release of markers of myocardial injury
NSTEMI
Pathophysiology of STEMI
Vulnerable plaque, plaque rupture, thrombus formation
Triggers for plaque rupture
physical exertion, mechanical stress, pulse rate, BP, and vasoconstriction
Initial Recognition of STEMI in the ED
- ST-segment elevation 0.1 mV in greater than or equal to 2 contiguous leads indicates STEMI and patients should be considered for immediate reperfusion therapy
- > 90% of patients will have elevated serum cardiac markers
- ST-segment depression indicates UA or NSTEMI
- Biochemical markers distinguish between these diagnoses
- If initial EKG is nondiagnostic, serial EKG at 15-30 minute intervals may be performed - Biomarkers of cardiac injury
- Preferred test due to cardiac specificity
- Low sensitivity early in MI (< 6 hours)
- Remain elevated for 5-14 days
Cardiac-specific troponins (TnT and TnI)
- Principal serum cardiac marker until recently
- Lack of cardiac specificity due to many isoforms
- Useful for early detection of MI (within 4 hours)
- Peak in 24 hours and may remain elevated for 3-4 days
Creatine kinase isoenzymes (CK-MB)
- Not cardiac specific but is released more rapidly from infarcted myocardium than CK-MB or troponins
- Detected as early as 2 hours but is elevated for less than 24 hours
Myoglobin
When are Serial enzyme sets (CK-MB, troponin, myoglobin) ordered
at 3 to 6 hour intervals
Other laboratory tests besides cardiac specific biomarkers
CBC, INR, aPTT, electrolytes and Mg, BUN, creatinine, glucose, serum lipids
Initial Management of ACS in the ED
MONA -
- Morphine (Analgesia)
- Oxygen for patients with PaO2 < 90%
- Nitroglycerin
- Aspirin
- Beta-blockers
Why give Morphine for ACS
Pain contributes to increased sympathomimetic activity
In addition to analgesic and anxiolytic effects, morphine causes venodilation and may further reduce myocardial oxygen demand
- does not decrease mortality
Dose of Morphine for ACS
Morphine sulfate 2-4 mg IV repeated at 5 to 15 minute intervals as needed
Adverse effects of Morphine
respiratory depression, nausea and vomiting, hypotension
AVOID in ACS patients
AVOID NSAIDS and Cox-2 inhibitors (except aspirin
When can oxygen be given for ACS
Can be administered for all patients within first 6 hours
- no mortality benefit
Dose of Nitroglycerin for ACS
a. SL NTG 0.4 mg q5min X 3 doses then assess the need for IV NTG
b. IV NTG indicated for relief of ongoing ischemia, control of HTN or management of pulmonary congestion
- Titrate until signs of ischemia are relieved or SBP does not tolerate
- no mortality benefit
DO NOT ADMINISTER IV Nitroglycerin IF
- SBP < 90 mm Hg or more than 30 mm Hg below baseline
- Severe bradycardia (< 50 bpm)
- Tachycardia (> 100 bpm)
- Suspected RV infarction
- Use of PDE for erectile dysfunction within the last 24 hours (48 hours for tadalafil)
can be used as an alternative or once patients have been pain free for 12 – 24 hours on IV NTG
Oral or topical nitrates
Dose of Aspirin in ACS
162 mg to 325 mg chewed if not taken before presentation to the ED
- Decreases mortality in patients with ACS (23% RRR in 35-day mortality)
Contraindications for beta-blockers
- Signs of heart failure, low output state or risk for cardiogenic shock
- Active asthma or reactive airway disease
- Heart block
Prompt IV therapy of beta-blockers can be used alternatively if
if tachyarrhythmia or hypertension is present
- decreased mortality in patients with ACS by the end of day 1 (prior to the reperfusion era) (IV or PO)
Dose of Metoprolol for ACS
- 5 mg IV q5min X 3 doses
- 50 mg PO q6h X 48 hours
- 100 mg PO twice daily thereafter
Dose of atenolol for ACS
- 5 mg IV q10min X 2 doses
- 50 mg PO q12h X 2 doses
- 100 mg PO once daily thereafter
In patients with contraindications to beta-blockers, what may be used
diltiazem or verapamil many be used but only if there are no signs of CHF, LV dysfunction or AV block
Additional Therapies for STEMI
- Reperfusion therapy
- Anticoagulation therapy
- Additional antiplatelet therapy
- Inhibitors of renin-angiotensin-aldosterone-system
- Lipid Management