STEMI resident survival guide

# 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.

# FIRE: Focused Initial Rapid Evaluation
A Focused Initial Rapid Evaluation (FIRE) should be performed to identify patients in need of immediate intervention.
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.

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

# 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.
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

# 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

# Long Term Management
Abbreviations: ACE: angiotensin converting enzyme; ARB: angiotensin receptor blocker; MI: myocardial infarction

# 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.
- Discontinue non-steroidal anti-inflamatory drugs immediately.
- 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
- 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
- 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
- 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
- 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.

# 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  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
- 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
- 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).

# 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, :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, 
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
Copyleft image obtained courtesy of,