STEMI

What are the advantages of fibrinolytic therapy? What are the disadvantages?

- Advantages: ease of availability in most EDs and high likelihood of adequate re-perfusion if done early - Disadvantages: Bleeding risk (especially intracranial hemorrhage), no benefit for patient in cardiogenic shock, decreased success at restoring blood flow if symptoms started more than 3 hours prior to presentation ("Window of opportunity")

A blockage in the LAD would lead to an infarction where? Which leads would display this?

- Anteroapical: V2-V5 - Anteroseptal: V1-V3

Which therapy MUST be initiated (unless contraindicated) in patients with ST elevation?

- Anti-platelet therapy - ASA and parenteral Heparin

What are the risks associated with PCI?

- Bleeding - Stroke - Infection - Allergic reactions - Vessel re-narrowing - Heart attack/arrhythmia - Kidney injury - Blood vessel damage

A patient with an MI would present how?

- Chest pain - Sweats - Dyspnea - Weakness - Anxiety - Nausea - Back/Arm pain - Sense of "impending doom" - Loss of consciousness/no pulse/primary cardiac arrest

What is the leading cause of death in the U.S.?

- Heart Disease

What are the advantages of PCI?

- High likelihood of re-perfusion even if done one hour (or greater) post presentation. - Significant benefits to patients in cariogenic shock or pulmonary edema. - Less risk of intracranial hemorrhage compared to fibrinolysis. - However, need to have a center with cath lab capability AND an interventional cardiologist

If a patient arrives at a non-PCI capable hospital with a STEMI, what is the best treatment option?

- Immediate transfer to PCI-capable hospital for primary PCI with an FMC-to-device time system goal of 120 minutes or less. - If FMC-to-device time exceeds 120 minutes, give fibrinolytic therapy unless contraindicated.

A blockage in the right coronary artery leading to infarction of the inferior wall would be visible on which leads on an EKG?

- Leads II, III, and AVF

A blockage in the circumflex coronary artery leading to infarction of the lateral wall would be visible on which leads on an EKG?

- Leads V5, V6, AVL

Aside from anti-platelet therapy, what other therapies should be initiated with ST elevation?

- Nitrates (topical or intravenous) - Beta Blockers: IV B-blockers at the time of STEMI to hypertensive patients who are not in heart failure, at risk for cariogenic shock, have low output state, or otherwise beta blocker intolerant.

What are "bare metal stents"?

- Non-drug eluting stents. - Drug eluting stents deliver meds slowly from the surface of the stent that reduce the risk of vessel re-stenosis.

What is the recommended method of re-perfusion for a patient with a STEMI?

- Primary PCI - Ideally, FMC-to-device time system goal of 90 minutes or less

What is the goal of treatment for an acute STEMI?

- Re-perfusion - Improved blood flow through the culprit artery so that it is patent. - Early intervention can salvage the myocardium and prevent scar tissue from replacing healthy myocardium

Give a brief overview of the pathophysiology of a STEMI.

- Ruptured fibrous plaque - Platelet adhesion and aggregation - Activated coagulation cascade - Thrombus formation - Reduction or cessation of blood flow - Myocardial ischemia - Myocardial cell death

Permanent cardiac damage can result from a STEMI. Explain how.

- Scar tissue replaces once viable/contractile myocardium, resulting in impaired cardiac function. - This can predispose a patient to CHF or malignant ventricular arrhythmias.

When fibrinolytic therapy is indicated/chosen as the primary re-perfusion strategy, what is the time-frame for administering it?

- Should be administered within 30 min of hospital arrival.

What is the time-frame for giving fibrinolytics to patients with a STEMI?

- Should give up to 12 hours of symptom onset, but most effective within first 3 hours.

Give a brief description of a primary PCI procedure.

- Small catheter inserted through an artery (typically the femoral) - Advanced to the heart under fluoroscopy - Contrast dye (radio-opaque) injected to create road map of coronary arteries and ID blockages. - Once identified, the blockage is ballooned and a stent is placed. - Stent acts a scaffold to keep the artery open. - Sometimes the clot is extracted.

Which leads would show an infarction of the anteroseptal wall?

- V1-V3

If a patient presents to a hospital without PCI capability and who cannot be transferred to a PCI center for intervention within 90 minutes of first medical contact, how should they be treated?

- With fibrinolytic therapy (TPA) within 30 minutes of hospital presentation, unless contraindicated.

A patient with a STEMI presents to a hospital with PCI capability. What is the time frame for treating this patient with a primary PCI?

- Within 90 minutes of first medical contact.

It is imperative to restore the blood flow to the myocardium when a thrombus forms. What are the two interventions to use once a clot has formed?

1. Fibrinolytic therapy 2. Primary percutaneous coronary angioplasty/stent (PCI)

What are the two modalities to achieve re-perfusion?

1. Pharmacologic therapy dismantles the fibrin plug that supports the coronary thrombus: Dissolution of the clot aka "clot busting" 2. Percutaneous coronary angioplasty (PCI) - emergency cardiac catheterization which includes inflation of a balloon in the occluded coronary artery to re-establish flow, and a stent placement to allow ongoing potency.