STEMI



ABNORMAL EKG
ST-Depression
(NSTEMI)
ST-Elevation
(STEMI)

Ischemia

Infarct

Unstable Angina

MI
β-MONAH: CATH in < 1 hr
 
 CP Onset
< 12h
> 12h
β-Blocker
Morphine
O2
NTG
Aspirin
Heparin

-

TNK (prefer < 1-3 hr)
-or-
Angioplasty within 90 min or ED arrival

[Stents]
Elective CABG ?
Cardiology Consult
Contraindication:
- Melena
- Recent Surgery
- BP > 180/110
- Brain bleed (anytime in life)
- Aortic Dissection




ECG by Anatomy




Inferior MI = NO NITRO DRIP
 

Risk Assessment (TIMI Score)

Risk factors for CAD
Family Hx of CAD NOT modifiable
Male, Age > 45 yr
Hypertension

Modifiable
Diabetes
Hypercholesterolemia
Current Smoker
 
TIMI Risk Score Points
Age 65 1
3 risk factors for CAD 1
Known CAD (Stenosis 50%) 1
Aspirin use in past 7 days 1
Severe angina ( 2 episodes in last 24h) 1
ST Deviation 0.5 mm 1

 
TIMI Score Risk %
0/1 2.1 - 5.0
2 10.1
3 19.5
4 22.1
5 39.2
6/7 45 - 100


Physical Findings

  • Crushing substernal chest pain usually lasting 30 min.
  • Pain is unrelieved by rest or sublingual nitroglycerin or is rapidly recurring.
  • Pain radiates to the left or right arm, neck, jaw, back, shoulders, or abdomen and is not pleuritic in character.
  • Pain may be associated with dyspnea, diaphoresis, nausea, or vomiting.
  • There is no pain in 20% of infarctions (usually in diabetic or elderly patients).
  • Physical findings:
    • Skin may be diaphoretic, with pallor (because of decreased oxygen).
    • Rales may be present at the bases of lungs (indicative of congestive heart failure [CHF]).
    • Cardiac auscultation may reveal an apical systolic murmur caused by mitral regurgitation from papillary muscle dysfunction; S3 or S4 may also be present.
    • Physical examination may be completely normal.

Etiology

  • Coronary atherosclerosis and plaque rupture
  • Coronary artery spasm
  • Coronary embolism (caused by infective endocarditis, rheumatic heart disease, intracavitary thrombus)
  • Periarteritis and other coronary artery inflammatory diseases
  • Dissection into coronary arteries (aneurysmal or iatrogenic)
  • Metabolic derangements such as hypoxemia, anemia, sepsis, hypotension, or hyperthyroidism leading to ischemic necrosis due to supply-demand mismatch
  • MI with normal coronaries:
    • more frequent in younger patients and cocaine addicts. The risk of acute MI is increased by a factor of 24 during the 60 min after the use of cocaine in persons who are otherwise at relatively low risk.
    • Most patients with cocaine-related MI are young, nonwhite, male cigarette smokers without other risk factors for arteriosclerotic heart disease who have a history of repeated cocaine use.
    • Blood & urine toxicology screen for cocaine is recommended in all young patients who present with acute MI.
  • Hypercoagulable states, increased blood viscosity (polycythemia vera)

Diagnosis

LABORATORY TESTS
Cardiac troponin levels
• Most specific; high values predict complications and mortality
• Rises in 3-4 hours
• Peaks in 12-24 hours
• Normalizes in 7 days
• cTnT or cTnI tests can be falsely positive in patients with renal failure
Myoglobin
• Early detection; poor specificity
• Rises in 1-2 hours
• Peaks in 4-6 hours
• Normalizes in 24 hours
CK-MB isoenzyme
• Rises in 3-4 hours
• Peaks in 12-24 hours
• Normalizes in 1-2 days
ECG:
• Common ECG findings suggestive of acute myocardial ischemia include inverted T waves 1 mm deep and/or ST-segment depression >0.5 mm in two contiguous leads.
• The presence of pathologic Q waves indicates an area of infarction that usually develops hours to days after presentation.

IMAGING STUDIES
Chest radiograph
• To evaluate for pulmonary congestion and exclude other causes of chest pain
Echocardiography:
• To evaluate wall motion abnormalities and identify mural thrombus or mitral regurgitation, which can occur acutely after MI.

Non Pharmacologic Tx

  • Limit patient’s activity: bed rest for the initial 12 to 24 hr; if the patient remains stable, gradually increase activity.
  • Diet: nothing by mouth until stable, then no added salt and a low-cholesterol diet.
  • Patient education to decrease the risk of subsequent cardiac events (proper diet, cessation of smoking, regular exercise) should be initiated when the patient is medically stable.
     

Treatment (STEMI)

  1. Cardiac monitor, IV Access, Supplemental O2.
  2. Inferior MI = NO NITRO DRIP
Recommended Doses of Drugs Used in the Emergency Treatment of ST-Segment Elevation Myocardial Infarction
Antiplatelet Agents
Aspirin 160-325 mg PO.
Contraindication:
- aspirin intolerance and allergy
- Active bleeding
- Active retinal bleeding
- Hemophilia
- Severe untreated hypertension, or
- Active peptic ulcer
Clopidogrel Loading dose of 300 mg PO (consider 600 mg if percutaneous coronary intervention anticipated) followed by 75 mg/d. No loading dose is administered in patients >75 y old receiving fibrinolytics.
Antithrombins
Unfractionated heparin Bolus of 60 units/kg (maximum, 4000 units) followed by infusion of 12 units/kg/h (maximum, 1000 units/h) titrated to a partial thromboplastin time 1.5–2.5 x control.
Enoxaparin 30 mg IV bolus followed by 1 mg/kg SC every 12 h.
Regardless of age, if CrCl < 30 mL/min: 1 mg/kg subcutaneously q24h
Fondaparinux 2.5 mg SC.
Contraindicated if CrCl < 30 mL/min
Fibrinolytic Agents
Streptokinase 1.5 million units over 60 min. Adjunct to Fibrinolytics
Anistreplase 30 units IV over 2-5 min. - Heparin, LMWH, Arixtra
- Aspirin + Plavix.

*improves vessel patency and prevent reocclusion

NOTE:
Prasugrel (Effient) could also be used but is contraindicated in patients with a history of stroke or TIA
Alteplase Body weight >67 kg: 15 mg initial IV bolus; 50 mg infused over next 30 min; 35 mg infused over next 60 min.
Body weight <67 kg: 15 mg initial IV bolus; 0.75 mg/kg infused over next 30 min; 0.5 mg/kg infused over next 60 min.
Reteplase 10 units IV over 2 min followed by 10 units IV bolus 30 min later.
Tenecteplase (TNK) Weight Dose (total dose not to exceed 50 milligrams)
<60 kg 30 mg
60 but <70 kg 35 mg
70 but <80 kg 40 mg
80 but <90 45 mg
90 50 mg
Glycoprotein IIb/IIIa Inhibitors*
Abciximab 0.25 mg/kg bolus followed by infusion of 0.125 mcg/kg/min (maximum, 10 mcg/min) for 12-24 h.
Eptifibatide 180 mcg/kg bolus followed by infusion of 2.0 mcg/kg/min for 72-96 h.
Tirofiban 0.4 mcg/kg/min for 30 min followed by infusion of 0.1 mcg/kg/min for 48-96 h.
Other Anti-Ischemic Therapies
Nitroglycerin Sublingual: 0.4 mg q 5 min x 3 PRN pain.
IV: Start at 10 mcg/min, titrate to 10% reduction in MAP if normotensive, 30% reduction in MAP if hypertensive.
Contraindications:
• Recent use of erectile dysfunction drugs
• Severe hypotension or RV injury
• Severe AS
Morphine 2-5 mg IV q 5-15 min PRN pain.
Bradycardia: Atropine 0.5 mg IV q3-5min prn
Respiratory depression: Narcan 0.4 mg IV q2-3min prn
Metoprolol 50 mg PO q 12 hours first day, unless significant hypertension,
may consider 5 mg IV over 2 min every 5 min up to 15 mg; withhold β-blockers initially if the patient is at risk for cardiogenic shock/adverse effects.
Contraindications:
• CHF
• Hypotension
• Bradycardia
• Asthma, COPD, PVD
• Cocaine use
• Heart block

 

 

Complications

EARLY COMPLICATIONS OF AMI
Good Prognosis
• Bradycardia without hypotension
• Mobitz type 1 AV Block (Wenckebach)
• 3rd degree AV Block with inferior MI
• PVCs, PACs
• Early NSVT
Poor Prognosis
• Mobitz type II; 3rd degree AV block with anterior MI
• Likely need pacemaker due to structural loss of conduction tissue
• Persistent sinus tach, A-fib, SVT
• New RBBB, LBBB or bifascicular block
• Left posterior hemiblock
Cardiogenic Shock
• > 40% of LV infarction
Papillary Muscle Dysfunction
Acute Mitral Regurgitation
Persistent Chest Pain
LATE COMPLICATIONS OF AMI
Recurrent Chest Pain
Mural Thrombus Embolism
LV Aneurysm
Post-MI Pericarditis
• 1-7 days after transmural infarct
• Treated with NSAIDS
Arrhythmia
Dressler’s Syndrome
• Pericarditis 2-8 weeks post-MI presenting with fever, friction rub, pericardial and pleural effusions, leukocytosis
• Treated with NSAIDs and steroids
LV Rupture
• Acute tamponade, hypotension, death
Papillary Muscle Rupture
• Acute MR and resulting CHF
Septal Wall Rupture
• Acute VSD, CHF

 

Post-MI Management

Depression Post-MI
  • Pt with CAD has 17-27% risk of developing depression.
  • Depressed pt is at 2-3 fold increased risk of developing CAD in dependent of baseline cardiac function.
  • Depression is a common consequence of ST-elevation myocardial infarction (STEMI), with major depression occurring in 15%–20% of patients.
  • An independent predictor of mortality following MI.
  • Associated with poor compliance with risk-reducing treatment recommendations
  • Causes abnormalities in autonomic tone that may increase susceptibility to ventricular arrhythmias

Mechanism by which depression causes CAD:

  • Increased platelet activation.
  • Alteration in cardiac autonomic tone
  • Increase catecholamine level
  • Increase inflammatory process
  • Decrease Omega-3 fatty acid levels.

Treatment

  • Cardiac rehabilitation programs, social support, cognitive-behavioral therapy, and SSRIs are useful in the management of depression occurring in the year following MI.
  • TCA are not favored because they can cause
    •   resting HR
    • Orthostatic hypotension
    • Alter intracardiac conduction = susceptibility to ventricular arrhythmias.
  • TCA have a quinidine-like effect on cardiac rate and conduction, and they should be avoided in patients with ventricular arrhythmias and ischemic heart disease.

 

Diet Advise
Evidence derived from epidemiologic investigations, metabolic studies, and clinical trials over the past few decades indicates that dietary factors can play a significant role in preventing coronary heart disease (CHD).

GOOD

  • The greatest protection against CHD is associated with a diet containing:
    • Nonhydrogenated unsaturated fats as the predominant form of dietary fat,
    • Whole grains as the main form of carbohydrates,
    • An abundance of fruits and vegetables, and
    • Adequate omega-3 fatty acids.
      • Fish are a prime source of omega-3 fatty acids
      • Believed to reduce serum triglycerides, decrease thrombotic tendency, improve endothelial function, and prevent cardiac arrhythmias.
      • Fish particularly rich in omega-3 fatty acids include farmed salmon, anchovies, and herring.
         
  • Although nuts are high in fat, most of this fat is monounsaturated and polyunsaturated, both of which lower LDL-cholesterol.
  • Several studies have found a stronger protective effect for cereal fiber than for fruit or vegetable fiber.
     
  • Light to moderate alcohol consumption is associated with a lower risk of ischemic heart disease and all-cause mortality.
  • Current American Heart Association guidelines state that in patients who use alcohol, it might be reasonable for nonpregnant women to have one drink a day and for men to have one or two drinks a day, unless alcohol is contraindicated.
     

BAD

  • Trans fatty acids, found in stick margarine, vegetable shortenings, commercial baked goods, and deep-fried foods, have been shown to increase CHD risk via a number of possible mechanisms, including raising LDL-cholesterol, reducing HDL-cholesterol, increasing serum triglycerides and plasma levels of lipoprotein(a), and promoting insulin resistance.
  • The amount of trans fatty acid in foods varies depending on the content of partially hydrogenated oils.
  • Fully hydrogenated oils, typically listed on nutrition labeling as “hydrogenated,” do not contain trans fatty acids.

 

Admit Orders:

1. Admit to: Coronary care unit
2. Diagnosis:
 T-segment myocardial infarction. Acute coronary syndrome

3. Condition:

4. Vital Signs:
 q1h. Call physician if pulse >90, <60; BP >150/90, <90/60; R>25, <12; T >38.5°C.
5. Activity:
 Bed rest with bedside commode.
7. Nursing:
 If the patient has chest pain, obtain 12-lead ECG and call physician.
8. Diet:
 Cardiac diet, 1-2 gm sodium, low-fat, low-cholesterol diet.
9. IV Fluids:
 D5W at TKO
10. Special Medications:
  • Oxygen 2-4 L/min by NC.
  • Aspirin 325 mg PO, chew and swallow immediately, then aspirin 81 mg PO qd.
  • Nitroglycerin 10 mcg/min IV infusion (50 mg in 250-500 mL D5W, 100-200 mcg/mL). Titrate to control symptoms in 5-10 mcg/min steps, up to 1-3 mcg/kg/min; maintain systolic BP >90 
    OR
  • Nitroglycerin SL, 0.4 mg (0.15-0.6 mg) SL q5min until pain free (up to 3 tabs) 
    OR
  • Nitroglycerin spray (0.4 mg/aerosol spray) 1-2 sprays under the tongue q 5min until pain-free; may repeat x 2.
  • Heparin 60 U/kg IV (max 4000 U) push, then 12 U/kg/hr (max 1000 U/hr) by continuous IV infusion to maintain aPTT of 50-70 seconds. Check aPTTq6h x 4, then qd.
     
  • Thrombolytic Therapy (within first 6 hours of onset of chest pain)
    • Absolute Contraindications to Thrombolytics: 
      • Active internal bleeding, aortic dissection
      • Intracranial neoplasm,
      • Previous intracranial hemorrhagic,
      • Other strokes or cerebrovascular events,
      • Head trauma, pregnancy,
      • Recent non-compressible vascular puncture,
      • Uncontrolled hypertension (>180/110 mm Hg).
         
    • Relative Contraindications to Thrombolytics: 
      • Severe hypertension,
      • Cerebrovascular disease,
      • Recent surgery (within 2 weeks),
      • Prolonged cardiopulmonary resuscitation.
         
  • A. Alteplase (tPA, tissue plasminogen activator, Activase):
    1. 15 mg IV push over 2 min, followed by 0.75 mg/kg (max 50 mg) IV infusion over 30 min, followed by 0.5 mg/kg (max 35 mg) IV infusion over 60 min (max total dose 100 mg).
    2. Labs: INR/PTT, CBC, fibrinogen.
       
  • B. Reteplase (Retavase):
    1. 10 U IV push over 2 min; repeat second 10 U IV push after 30 min.
    2. Labs: INR, aPTT, CBC, fibrinogen.
       
  • Beta-Blockers:
    • Metoprolol (Lopressor) 25 mg PO q6h for 48h, then 100 mg PO bid; hold if heart rate <60/min or systolic BP <100 mmHg OR
    • Atenolol (Tenormin), 25-100 mg PO qd OR
    • Esmolol (Brevibloc) 500 mcg/kg IV over 1 min, then 50 mcg/kg/min IV infusion, titrated to heart rate >60 bpm (max 300 mcg/kg/min).
       
  • Angiotensin Converting Enzyme Inhibitor:
    • Lisinopril (Zestril, Prinivil) 2.5-5 mg PO qd; titrate to 10-20 mg qd.
       
  • Long-Acting Nitrates:
    • Nitroglycerin patch 0.2 mg/hr qd and increasing to 0.6 mg/hr. Removal of the patch from 6 to 8 PM.
    • Isosorbide dinitrate (Isordil) 10-60 mg PO tid [5, 10, 20, 30, 40 mg] OR
    • Isosorbide mononitrate (Imdur) 30-60 mg PO qd.
  • Aldosterone Receptor Blocker if EF <40%:
    • Eplerenone (Inspra) 24 mg PO qd
    • Spironolactone (Aldactone) 25 mg PO qd
  • Statins:
    • Atorvastatin (Lipitor) 10 mg PO qhs
  • P2Y12 Receptor Blockers:
    • For patients receiving fibrinolytic therapy, we recommend clopidogrel be added to aspirin.
      • < 75 yr old : The suggested loading dose of clopidogrel is 300 mg.
      • > 75 yr old : Clopidogrel 75 mg.
    • For patients scheduled for primary PCI:
      • Ticagrelor or Prasugrel in preference to clopidogrel. The loading dose for Prasugrel is 60 mg and for Ticagrelor is 180 mg.
         
  • Glycoprotein IIb/IIIa Blockers in High-Risk Patients and Those with Planned Percutaneous Coronary Intervention (PCI):
    • -Eptifibatide (Integrilin) 180 mcg/kg IVP, then 2 mcg/kg/min for 48-72 hours OR
    • -Tirofiban (Aggrastat) 0.4 mcg/kg/min for 30 min, then 0.1 mcg/kg/min for 48-108 hours. OR
    • -Bivalirudin (Angiomax) Initial bolus of 0.75 mg/kg followed by an intravenous infusion of 1.75 mg/kg per hour that is discontinued after PCI.
11. Symptomatic Medications:
  • Morphine sulfate 2-4 mg IV push prn chest pain.
  • Acetaminophen (Tylenol) 325-650 mg PO q4-6h prn headache.
  • Lorazepam (Ativan) 1-2 mg PO tid-qid prn anxiety
  • Zolpidem (Ambien) 5-10 mg qhs prn insomnia.
  • Docusate (Colace) 100 mg PO bid.
  • Ondansetron (Zofran) 2-4 mg IV q4h prn nausea or vomiting.
  • Famotidine (Pepcid) 20 mg IV/PO bid OR Lansoprazole (Prevacid) 30 mg qd.
  • Magnesium sulfate 1-2 gm in IV bolus over 15 min, or infuse 3-20 mg/min for 7-48h.
12. Extras: ECG stat and in 12h and in AM, portable CXR, echocardiogram. Cardiology consult.
13. Labs:
 CMP, CBC, magnesium, Phos, TSH, A1c, PT/PTT, INR, Fasting Lipid panel, Stool guiac, . Cardiac enzymes: troponin STAT and q6h x 3. high sesitivity CRP, UA.