STEMI resident survival guide

STEMI Resident Survival Guide Microchapters
Overview
Causes
Pre-Hospital Care
FIRE
Complete Diagnosis
Pre-Discharge Care
Long Term Management
Do's
Don'ts
Gallery

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Alejandro Lemor, M.D. [2]; Rim Halaby, M.D. [3]

Overview

ST elevation myocardial infarction (STEMI) is a syndrome characterized by the presence of symptoms of myocardial ischemia associated with persistent ST elevation on electrocardiogram and elevated cardiac enzymes. The management of STEMI should be initiated without delay and the following timelines should be minimized (the 4 D's):

Door to Data

If a patient presents with chest discomfort, an electrocardiogram must be obtained immediately and no later than 5-10 minutes after arrival. In the patient with chest discomfort, an electrocardiogram should be obtained prior to obtaining insurance / payment information.

Data to Decision

If the electrocardiogram shows ST segment elevation, ST segment depression consistent with posterior MI, or a new left bundle branch block, a decision must be made within 5 to 10 minutes as to whether to administer a fibrinolytic agent or to proceed to primary angioplasty.

Decision to Drug or Device

Once a decision is made to administer a fibrinolytic agent or to proceed to primary angioplasty this should be carried out within 30 minutes.

Causes

Life Threatening Causes

STEMI is a life-threatening condition and must be treated as such irrespective of the underlying cause.

Common Causes

Plaque rupture
Takotsubo cardiomyopathy (also known as broken heart syndrome or stress cardiomyopathy)
Aortic dissection with propagation to the right coronary artery
Cocaine

Pre-Hospital Care

Pre-hospital care can begin in the ambulance by Emergency Medical Services (EMS) personnel and it can decrease the delay in the management of STEMI patients. In the United States, volunteers and fire fighters are permitted to initiate emergency care prior to the arrival of highly trained paramedics by beginning CPR and if adequately trained, can defibrillate the patient using an automatic external defibrillator. Early access to EMS is promoted by a 9-1-1 system.

Prehospital Care ❑ Check the vital signs ❑ Perform 12 lead ECG and transmit it to the receiving hospital ❑ Establish large bore IV access ❑ Administer oxygen ❑ Administer medications (depending on the level of training) ❑ Non-enteric coated aspirin ❑ Sublingual nitroglycerin if an RV infarct and / or hypotension are not present ❑ In so far as the risk of emergency coronary artery bypass surgery is <1%, a thienopyridine such as Prasugrel, Ticagrelor or Clopidogrel can be administered ❑ Unfractionated heparin ❑ Glycoprotein IIb IIIa inhibitors ❑ Fibrinolytic therapy (especially in rural areas) ❑ Activate the cardiac cath team in the hospital ❑ Resuscitation in case of cardiac arrest ❑ CPR ❑ Automated defibrillator

FIRE: Focused Initial Rapid Evaluation

A Focused Initial Rapid Evaluation (FIRE) should be performed to identify patients in need of immediate intervention.^[1]

Abbreviations: LBBB: left bundle branch block; CABG: coronary artery bypass graft; COPD: chronic obstructive pulmonary disease; DVT: deep vein thrombosis; ECG: electrocardiography; GP IIb IIIa: glycoprotein IIb IIIa; LAD: left anterior descending; MI: myocardial infarction; PCI: percutaneous coronary intervention; SC: subcutaneous injection; STEMI: ST elevation myocardial infarction

Boxes in red signify that an urgent management is needed.

Identify cardinal findings of STEMI:

❑ Chest pain or chest discomfort

❑ Sudden onset

❑ Sensation of heaviness, tightness, pressure, or squeezing

❑ Duration> 20 minutes

❑ Radiation to the left arm, jaw, neck, right arm, back or epigastrium

❑ No relief with medications

❑ No relief with rest

❑ Worse with time

❑ Worse with exertion

❑ Associated symptoms of palpitations, nausea, vomiting and sweating

❑ Characteristic ECG changes consistent with STEMI

❑ ST elevation in at least 2 contiguous leads of 2 mm (0.2 mV) in men or 1.5 mm (0.15 mV) in women in leads V2–V3 and/or of 1 mm (0.1mV) in other contiguous chest leads or the limb leads

❑ ST depression in at least two precordial leads V1-V4 (suggestive of posterior MI)

❑ ST depression in several leads plus ST elevation in lead aVR (suggestive of occlusion of the left main or proximal LAD artery)

❑ New LBBB

Click here for the gallery of ECG examples below.

❑ Increase in troponin and / or CK MB

Rule out life threatening alternative diagnoses:

❑ Aortic dissection
(suggestive findings: back pain, interscapular pain, aortic regurgitation, pulsus paradoxus, blood pressure discrepancy between the arms)
❑ Pulmonary embolism
(suggestive findings: acute onset of dyspnea, tachypnea, hemoptysis, previous DVT)
❑ Cardiac tamponade
(suggestive findings: hypotension, jugular venous distention, muffled heart sounds, pulsus paradoxus)
❑ Tension pneumothorax
(suggestive findings: sudden dyspnea, tachycardia, chest trauma, unilateral absence of breath sound)

❑ Esophageal rupture
(suggestive findings: vomiting, subcutaneous emphysema)

Assess appropriateness of patients for perfusion therapy:

❑ Contraindications to fibrinolytics (click here for the complete list shown below)
❑ Assess the femoral pulses (strength, bruit)

❑ Pericarditis (suggestive finding: pericardial friction rub)

Consider right ventricular MI in case of:

❑ Hypotension
❑ Elevated jugular venous pressure
❑ Clear lung fields
❑ Peripheral edema
❑ ECG changes suggestive of an inferior MI

❑ ST elevation in leads II, III and aVF

Order a right sided ECG in all patients with ST elevation in leads II, III and aVF:

❑ Clearly label the ECG as right sided
❑ ST elevation of >1 mm in lead V4R suggests a right ventricular MI

Click here for right ventricular myocardial infarction resident survival guide

Check for hypoperfusion and left ventricular failure :

❑ Hypotension
❑ Tachycardia
❑ Cyanotic skin and nail bed
❑ Cold skin
❑ Skin mottling
❑ Patient lies still
❑ Confusion or disorientation

Click here for cardiogenic shock resident survival guide

Begin initial treatment:
❑ Administer 162 - 325 mg of non enteric aspirin

❑ Orally, crushed or chewed, OR

❑ Intravenously

❑ Administer 2-4 L/min oxygen via nasal cannula when saturation <90%

❑ Caution in COPD patients: maintain an oxygen saturation between 88% and 92%

❑ Administer beta-blockers (unless contraindicated) and titrate to the heart rate and blood pressure
Contraindicated in heart failure , prolonged or high degree AV block , reactive airway disease , high risk of cardiogenic shock and low cardiac output state

❑ Metoprolol IV, 5 mg every 5 min, up to 3 doses

❑ Carvedilol IV, 25 mg, two times a day

❑ Administer sublingual nitroglycerin 0.4 mg every 5 minutes for a total of 3 doses
Contraindicated in suspected right ventricular MI , recent use of phosphodiesterase inhibitors , decreased blood pressure 30 mmHg below baseline
❑ Administer IV morphine if needed

❑ Initial dose 4-8 mg

❑ 2-8 mg every 5 to 15 minutes, as needed

❑ Administer 80 mg atorvastatin
❑ Monitor with a 12-lead ECG all the time

Is PCI available?

YES

NO

Is first medical contact to device ≤ 120 min?

NO

YES

❑ Primary PCI within 90 minutes

❑ Fibrinolytic therapy within 30 min

❑ Transfer for primary PCI

Confirm that the patient has one of the following indications:

❑ Symptoms of ischemia <12 hours (Class I, level of evidence A)
❑ Symptoms of ischemia <12 hours and contraindications to fibrinolytics irrespective of time delay (Class I, level of evidence B)
❑ Cardiogenic shock irrespective of time delay (Class I, level of evidence B)
❑ Heart failure irrespective of time delay (Class I, level of evidence B)

❑ Ongoing ischemia 12-24 hours following onset (Class IIa, level of evidence B)

❑ Confirm that the patient has one of the following indications:

❑ Symptoms of ischemia <12 hours (Class I, level of evidence A)

❑ Ongoing ischemia 12-24 hours following onset (Class IIa, level of evidence C)

❑ Confirm that the patient has no contraindications to fibrinolytics (click here for the complete list shown below)

Administer ONE of the following antiplatelet agents (before or at the time of PCI):
❑ P2Y12 receptor inhibitors

❑ Clopidogrel 600 mg

❑ Ticagrelor 180 mg

❑ Prasugrel 60 mg

Prasugrel is contraindicated in case of prior history of strokes or TIAs, active pathological bleeding, age ≥75 years, when urgent coronary artery bypass graft surgery (CABG) is likely, body weight <60 kg, propensity to bleed, concomitant use of medications that increase the risk of bleeding
❑ IV GP IIb/IIIa inhibitors

❑ Abciximab

❑ Loading dose 0.25 mg/kg IV bolus

❑ Maintenance dose 0.125 mg/kg/min

❑ Eptifibatide

❑ Loading dose 180 mcg/kg IV bolus

❑ Another 180 mcg/kg IV bolus after 10 minutes

❑ Maintenance dose 2 mcg/kg/min

❑ Decrease infusion by 50% if creatinine clearance <50 mL/min

❑ Avoid in hemodialysis patients

❑ Tirofiban

❑ Loading dose 25 mcg/kg

❑ Maintenance dose 0.15 mcg/kg/min

❑ Decrease infusion by 50% if creatinine clearance <30 mL/min

Administer ONE of the following anticoagulant therapy:
❑ Unfractionated heparin

♦ If GP IIb/IIIa receptor antagonist is planned

❑ 50- to 70-U/kg IV bolus

♦ If no GP IIb/IIIa receptor antagonist is planned

❑ 70- to 100-U/kg bolus

❑ Bivalirudin

❑ 0.75-mg/kg IV bolus, then 1.75–mg/kg/h infusion

❑ Additional bolus of 0.3 mg/kg if needed

❑ Decrease infusion to 1 mg/kg/h when creatinine clearance <30 mL/min

Administer ONE of the following fibrinolytic therapy:

❑ Tenecteplase single IV bolus

❑ 30 mg for weight <60 kg

❑ 35 mg for weight 60-69 kg

❑ 40 mg for weight 70-79 kg

❑ 45 mg for weight 80-89 kg

❑ 50 mg for weight ≥90 kg^[2]

❑ Reteplase 10 units IV boluses every 30 min
❑ Alteplase

❑ Bolus 15 mg, infusion 0.75 mg/kg for 30 min (maximum 50 mg)

❑ Then 0.5 mg/kg (maximum 35 mg) over the next 60 min

❑ Streptokinase 1.5 million units IV administered over 30-60 min

Administer a P2Y12 inhibitor:
❑ Clopidogrel

♦ If age ≤ 75 years

❑ Loading dose 300 mg

❑ 75 mg daily for at least 14 days, up to one year

♦ If age > 75 years

❑ Loading dose 75 mg

❑ 75 mg daily for at least 14 days, up to one year

Administer ONE of the following anticoagulant therapy:
❑ Unfractionated heparin

❑ IV bolus of 60 units/kg (maximum 4000 units)

❑ Then infusion of 12 units/kg/hour (maximum 1000 units)

❑ Adjust the infusion for a aPTT of 50-70 sec for 48 hours or until revascularization

❑ Enoxaparin (for up to 8 days or until revascularization)

If age <75 years

❑ IV bolus 30 mg

❑ Then after 15 minutes, SC 1 mg/kg every 12 hours (maximum 100 mg for the first two doses)

♦ If age ≥75 years

❑ SC 0.75 mg/kg every 12 hours (maximum 75 mg for the first two doses)

♦ If creatinine clearance <30 mL/min

❑ SC 1 mg/kg every 24 hours

❑ Fondaparinux

❑ Initial dose of 2.5 mg IV

❑ Then, SC 2.5 mg daily (for up to 8 days or until revascularization)

❑ Do not administer if creatinine clearance <30 mL/min

Consider urgent CABG if the coronary anatomy is not amenable to PCI and one of the following:

❑ Ongoing and recurrent ischemia
❑ Cardiogenic shock
❑ Severe heart failure
❑ Other high risk features

Transfer to a PCI-capable hospital for non primary PCI, if there is:

❑ Cardiogenic shock (Class I, level of evidence B)
❑ Acute severe heart failure (Class I, level of evidence B)
❑ Spontaneous or easily provoked myocardial ischemia (Class I, level of evidence C)
❑ Failed reperfusion after fibrinolytics (Class IIa, level of evidence B)
❑ Reocclusion after fibrinolytics(Class IIa, level of evidence B)
❑ Successful fibrinolytic reperfusion, between 3 and 24 hours (Class IIa, level of evidence B)

Contraindications to Fibrinolytic Therapy

Shown below is a table summarizing the absolute and relative contraindications to fibrinolytic therapy among STEMI patients.

Absolute contraindications

Relative contraindications

❑ Prior intracranial hemorrhage

❑ Ischemic stroke within the last 3 months (unless within 4.5 hours)
❑ Structural cerebral vascular lesion
❑ Primary or metastatic intracranial malignancy
❑ Suspicion of aortic dissection
❑ Increased bleeding tendency or active bleeding
❑ Severe head or facial trauma within the last 3 months
❑ Intracranial or intraspinal surgery within the last 2 months
❑ Severe hypertension uncontrolled by emergency therapy
❑ Previous treatment with streptokinase within the last 6 months

❑ Oral anticoagulation therapy

❑ Pregnancy
❑ Active peptic ulcer
❑ Previous history of chronic severe hypertension that is poorly controlled
❑ Elevated blood pressure at presentation, such as systolic blood pressure >180 mmHg or diastolic blood pressure >110mmHg
❑ Previous history of ischemic stroke
❑ Dementia
❑ Intracranial pathology that does not meet the absolute contraindications
❑ CPR that lasted more than 10 min or that is traumatic
❑ Major surgery in the last 3 weeks
❑ Internal bleeding within the last 2-4 weeks
❑ Non compressible vascular punctures

Complete Diagnostic Approach

A complete diagnostic approach should be carried out after a focused initial rapid evaluation is conducted and following initiation of any urgent intervention.^[1]

Abbreviations: CABG: coronary artery bypass graft; ECG: electrocardiogram; LAD: left anterior descending; LBBB: left bundle branch block; MI: myocardial infarction; PCI: percutaneous coronary intervention; S3: third heart sound; S4: fourth heart sound; VSD: ventricular septal defect

Characterize the symptoms: ❑ Chest pain or chest discomfort ❑ Sudden onset ❑ Sensation of heaviness, tightness, pressure, or squeezing ❑ Duration> 20 minutes ❑ Radiation to the left arm, jaw, neck, right arm, back or epigastrium ❑ No relief with medications ❑ No relief with rest ❑ Worse with time ❑ Worse with exertion ❑ Dyspnea ❑ Weakness ❑ Palpitations ❑ Nausea ❑ Vomiting ❑ Sweating ❑ Loss of consciousness ❑ Fatigue



Obtain a detailed history: ❑ Age ❑ Baseline blood pressure ❑ Previous MI ❑ Previous PCI or CABG ❑ Cardiac risk factors ❑ Hypertension ❑ Diabetes ❑ Hypercholesterolemia ❑ Smoking ❑ Obesity ❑ List of medications ❑ Family history of premature coronary artery disease Identify possible triggers: ❑ Physical exertion ❑ Psychological stress (anger, anxiety, bereavement, work related stress, natural disasters, wars or sporting events) ❑ Sexual activity ❑ Air pollution or fine particulate matter ❑ Antecedant infection ❑ Heavy meal ❑ Cocaine ❑ Marijuana



Examine the patient: Vital signs ❑ Blood pressure ❑ Blood pressure lower than baseline, suggestive of: ❑ Cardiogenic shock (associated with tachycardia and end organ hypoperfusion), or ❑ Right ventricular MI (associated with increased jugular venous pressure and clear lung fields), or ❑ Bezold-Jarisch reflex (associated with either normal heart rate or bradycardia) ❑ Discrepancy between arms (suggestive of aortic dissection) ❑ Narrow pulse pressure (suggestive of heart failure) ❑ Wide pulse pressure (suggestive of mitral regurgitation or VSD) ❑ Heart rate ❑ Tachycardia (suggestive of heart failure) ❑ Bradycardia (suggestive of heart block) Pulses ❑ Femoral pulse (if a patient is to undergo PCI) ❑ Strength ❑ Bruits Skin ❑ Xanthelasma (suggestive of dyslipidemia) ❑ Xanthoma (suggestive of dyslipidemia) ❑ Edema (suggestive of heart failure) ❑ Cyanotic and cold skin, lips, nail bed (suggestive of cardiogenic shock) Heart ❑ Heart sounds ❑ S3 (suggestive of heart failure) ❑ S4 (associated with conditions that increase the stiffness of the ventricle) ❑ Murmurs ❑ Mitral regurgitation: blowing holosystolic murmur best heard at the apex ❑ VSD: holosystolic murmur along the left and right sternal border ❑ Free wall rupture: holosytolic murmur ❑ Aortic regurgitation: early diastolic high-pitched sound best heard at the left sternal border (suggestive of aortic dissection with propagation to the aortic arch) ❑ Pericardial friction rub (suggestive of pericarditis) Signs of right ventricular MI: ❑ Elevated jugular venous pressure ❑ Presence of hepatojugular reflux Lungs ❑ Rales (suggestive of heart failure)

Pre-Discharge Care

Abbreviations: ACE: angiotensin converting enzyme; LVEF: left ventricular ejection fraction; MI: myocardial infarction; PCI: percutaneous coronary intervention; PO: per os; STEMI: ST elevation myocardial infarction; VF: ventricular fibrillation; VT: ventricular tachycardia

Administer the following medications in patients without contraindications: ❑ Aspirin 81-325 mg (indefinitely) ❑ Beta blockers Contraindicated in heart failure, prolonged or high degree AV block, reactive airway disease, high risk of cardiogenic shock and low cardiac output state ❑ Metoprolol tartrate ❑ Begin with 25 to 50 mg PO every 6 to 12 hour ❑ Then, metoprolol tartrate twice daily or metoprolol succinate once daily for 2-3 days ❑ Titate to 200 mg daily, OR ❑ Carvedilol ❑ Begin with 6.25 mg twice daily ❑ Titrate to 25 mg twice daily ❑ ACE inhibitor in case of anterior MI, ejection fraction ≤ 40% or heart failure Contraindicated in hypotension, renal failure and hyperkalemia ❑ Lisinopril ❑ Begin with 2.5-5 mg ❑ Titrate to 10 mg or higher daily, OR ❑ Captopril ❑ Begin with 6.25-12.5 mg three times daily ❑ Titrate to 25 to 50 mg three times daily, OR ❑ Ramipril ❑ Begin with 2.5 mg twice daily ❑ Titrate to 5 mg twice daily, OR ❑ Trandolapril ❑ Begin with 0.5 mg daily ❑ Titrate to 4 mg daily, OR ❑ Valsartan (in case of intolerance to ACE inhibitors) Contraindicated in hypotension, renal failure and hyperkalemia ❑ Begin with 20 mg twice daily ❑ Titrate to 160 mg twice daily ❑ Atorvastatin 80 mg daily Administer antiplatelet therapy For patients who underwent PCI, for one year ❑ Clopidogrel 75 mg daily, OR ❑ Prasugrel 10 mg daily, OR ❑ Ticagrelor 90 mg twice a day For patients who underwent fibrinolysis, for at least 14 days, up to one year ❑ Clopidogrel 75 mg daily Manage complications of STEMI ❑ Implantable cardioverter-defibrillator at least 40 days following the MI in cases of: ❑ LVEF <30% among patients in NYHA functional Class I (Class I, level of evidence A) ❑ LVEF <35% among patients in NYHA functional Class II or III (Class I, level of evidence A) ❑ LVEF <40% (Class I, level of evidence B) ❑ An irreversible non-ischemia related VT/ VF after more than 48 hours following STEMI (Class I, level of evidence B)^[3] ❑ Temporary pacing for symptomatic bradycardia refractory to medical therapy (Class I, level of evidence C) ❑ Aspirin for pericarditis (Class I, level of evidence B) ❑ do not administer glucocorticoids or NSAIDs for pericarditis following STEMI (Class III, level of evidence B) Assess the patient for ischemia: ❑ Perform non invasive testing before discharge for the evaluation of ischemia among patients who did not undergo coronary angiography and in whom coronary angiography is not warranted due to the absence of high risk features (Class I, level of evidence B) ❑ Assess the LVEF (Class I, level of evidence C)

Long Term Management

Abbreviations: ACE: angiotensin converting enzyme; ARB: angiotensin receptor blocker; MI: myocardial infarction

❑ Prepare a list of all the home medications and educate the patient about compliance ❑ Aspirin 81-325 mg (indefinitely) ❑ Antiplatelet therapy ❑ Consider oral factor Xa inhibition with Rivaroxaban outside the US based upon EMA approval (Note Rivaroxaban is not FDA approved for use in ACS in the US) ❑ Beta blockers ❑ ACE inhibitors or ARB (in case of anterior MI, ejection fraction ≤ 40% or heart failure) ❑ Atorvastatin 80 mg daily ❑ Encourage lifestyle modification ❑ Smoking cessation ❑ Physical activity ❑ Dietary changes ❑ Ensure the initiation of the management of comorbidities ❑ Obesity ❑ Dyslipidemia ❑ Hypertension ❑ Diabetes ❑ Heart failure ❑ Educate the patient about the early recognition of symptoms of MI ❑ Educate the patient about the use of nitroglycerin 0.4 mg, sublingually, up to 3 doses every 5 minutes

Do's

A pre-hospital ECG is recommended. If STEMI is diagnosed the PCI team should be activated while the patient is en route to the hospital.

Administer reperfusion therapy for all patients presenting with STEMI within 12 hours of the beginning of the symptoms (Class I, level of evidence A).

Administer a loading dose followed by a maintenance dose of clopidogrel, ticagrelor or prasugrel (if PCI is planned) as initial treatment instead of aspirin among patients with gastrointestinal intolerance or hypersensitivity reaction to aspirin.

Administer sublingual nitroglycerin in patients with ischemic chest pain; however, administer IV nitroglycerin among patients with persistent chest pain after three sublingual nitroglycerins.^[4]

Discontinue non-steroidal anti-inflamatory drugs immediately.^[5]^[6]

Rule out any contraindications for fibrinolytic therapy before its administration. If contraindications to fibrinolytics are present, the patient should be transferred to another hospital where PCI is available.

Initiate therapeutic hypothermia among comatose patients with STEMI (Class I, level of evidence B).

Perform immediate angiography and PCI among STEMI patients who underwent resuscitation for cardiac arrest (Class I, level of evidence B).

Consider bare-metal stent among STEMI patients with any of the following (Class I, level of evidence C):
- High bleeding risk
- Lack of compliance for a one year regimen of dual antiplatelet therapy
- Surgery or invasive procedure within the next year

Achieve the following therapeutic activated clotting time when administering UFH:
- 200 to 250 seconds with the concomitant administration of GPIIbIIIa receptor inhibitor
- 250 to 300 seconds (HemoTec device) without the concomitant administration of a GPIIbIIIa receptor inhibitor
- 300 to 350 seconds (Hemochron device) without the concomitant administration of a GPIIbIIIa receptor inhibitor

Make sure the dose of P2Y12 receptor inhibitors is appropriate among patients undergoing PCI after fibrinolytic therapy:
- Patients who already received a loading dose of clopidogrel: No loading dose, clopidogrel daily
- Patients who did not receive a loading dose of clopidogrel and PCI is performed ≤ 24 hours after fibrinolytic therapy: loading dose of 300 mg clopidogrel
- Patients who did not receive a loading dose of clopidogrel and PCI is performed > 24 hours after fibrinolytic therapy: loading dose of 600 mg clopidogrel
- Patients who did not receive a loading dose of clopidogrel and PCI is performed >24 hours after therapy with fibrin specific agent, or >48 hours after therapy with a non-fibrin-specific agent: prasugrel 60 mg

Prepare the patient for urgent CABG when indicated by discontinuing the following:
- Clopidogrel or ticagrelor at least 24 hours prior to CABG
- Eptifibatide or tirofiban at least 2 to 4 hours prior to CABG
- Abciximab 12 hours prior to CABG

Consider using a mechanical circulatory support among hemodynamically unstable patients with STEMI requiring an urgent CABG (Class IIa, level of evidence C).

Recommend a long term maintenance dose of 81 mg of aspirin when the patient is administered ticagrelor.

Include aldosterone antagonist in the discharge medication list among patients who are already on ACE inhibitors and beta-blockers with a left ventricular ejection fraction <40% or diabetes or heart failure.^[1]

Don'ts

Do not administer IV beta-blockers among patients with elevated risk for cardiogenic shock, signs of heart failure, low ouput state, prolonged PR interval more than 0.24 seconds, second or third degree block or asthma (Class I, level of evidence B).

Do not administer IV GP IIb/IIIa inhibitors to patients with low risk of ischemic events or at high risk of bleeding and who are already on aspirin and P2Y12 receptor inhibitors therapy.

Do not administer nitroglycerine to patients with systolic blood pressure < 90 mm Hg or ≥ to 30 mm Hg below baseline, severe bradycardia (< 50 bpm), tachycardia (> 100 bpm), or suspected right ventricular myocardial infarction.

Do not delay the time for reperfusion.

Do not administer prasugrel among patients with any of the following:
- Prior history of strokes or TIAs (Class III, Level of evidence B)
- Active pathological bleeding
- Age ≥75 years of age, (except in high-risk patients such as diabetes or prior MI, where its use may be considered)
- Urgent coronary artery bypass graft surgery (CABG) is likely
- Presence of additional risk factors for bleeding such as body weight <60 kg, propensity to bleed, concomitant use of medications that increase the risk of bleeding^[7]

Do not administer fibrinolytic therapy to patients with known history of intracranial hemorrhage, cerebral arteriovenous malformation or to patients with suspected aortic dissection.

Do not withhold aspirin among patients who are planned to undergo urgent CABG (Class I, level of evidence C).^[1]

Gallery

Shown below is an EKG demonstrating the evolution of an infarct on the EKG. ST elevation, Q wave formation, T wave inversion, normalization with a persistent Q wave suggest STEMI.

Copyleft image obtained courtesy of ECGpedia, http://en.ecgpedia.org/wiki/File:AMI_evolutie.png

Shown below is an EKG demonstrating loss of R waves throughout the anterior wall (V1-V6). QS complexes in V3-V5. ST elevation in V1-V5 with terminal negative T waves.

Copyleft image obtained courtesy of, http://en.ecgpedia.org/wiki/Main_Page

Shown below is an EKG demonstrating ST elevation in leads II, III and aVF and ST depression in leads V1, V2 and V3 depicting a posterior MI.

Shown below is an EKG demonstrating acute MI in a patient with LBBB