ACS

Acute Coronary Syndrome Overview

Instructors

  • Mary Resler DNP, MSN Ed., RN

Learning Objectives

  • Understand contributing factors to patients who have angina.

  • Understand treatment and education for patients who have angina.

  • Recognize early signs of symptoms of unstable angina.

  • Understand contributing factors for patients with non-ST elevated myocardial infarcts (NSTEMI) and ST elevated myocardial infarcts (STEMI).

  • Understand early diagnostics and treatments for patients having both STEMI and NSTEMI.

Acute Coronary Syndrome (ACS)

  • Definition: ACS is a condition that develops when ischemia is prolonged and not immediately reversible.

  • Types of ACS:

    • Unstable Angina: A condition marked by unpredictable chest pain due to decreased blood flow to the heart.

    • Myocardial Infarction (MI): Can be categorized into:

    • ST-Elevation Myocardial Infarction (STEMI): Characterized by the presence of ST-segment elevation on an ECG.

    • Non-ST-Elevation Myocardial Infarction (NSTEMI): Characterized by the absence of ST-segment elevation on an ECG.

Angina

  • Causes:

    • Obstruction of coronary blood flow due to:

    • Atherosclerosis

    • Coronary artery spasm

    • Conditions increasing myocardial oxygen consumption.

Types of Angina

  • Unstable Angina:

    • Occurs unpredictably.

    • Increase in occurrence, duration, and severity over time.

    • May not be relieved by nitroglycerin.

  • Variant Angina (Prinzmetal or Vasospastic Angina):

    • Occurs due to spasm of coronary arteries.

  • Preinfarction Angina:

    • Associated with acute coronary insufficiency.

    • Lasts longer than 15 minutes.

    • Can occur days to weeks prior to an MI.

Angina Assessment

  • Symptoms to assess:

    • Pain

    • Dyspnea

    • Pallor

    • Sweating

    • Palpitations and Tachycardia

    • Dizziness and Syncope

    • Hypertension

    • Digestive Disturbance

Diagnostic Studies for Angina

  • Electrocardiography (ECG): Helps in assessing heart activity.

  • Stress testing: Evaluates heart's function under stress.

  • Cardiac enzymes and Troponin levels: For identifying heart damage.

  • Cardiac Catheterization: An invasive procedure to visualize coronary arteries.

Interventions for Angina

  • Assess pain and vital signs continuously.

  • Administer oxygen as ordered to improve oxygen supply.

  • Elevate head of the bed (HOB) and remain with the patient for support.

  • Obtain a 12 lead ECG: Critical in diagnosing cardiac conditions.

  • Establish intravenous (IV) access for medication administration.

  • Administer nitroglycerin as ordered for relief of chest pain.

  • Anticipate antiplatelet therapy to reduce the risk of acute myocardial infarction (MI).

Myocardial Infarction

  • Types: STEMI and NSTEMI.

Myocardial Infarction Risk Factors

  • Key Risk Factors Include:

    • Atherosclerosis (hardening of the arteries).

    • Coronary Artery Disease (CAD).

    • Elevated Cholesterol Levels.

    • Smoking.

    • Hypertension.

    • Obesity.

    • Physical Inactivity.

    • Impaired Glucose Tolerance.

    • Stress.

Differentiation of ACS Types

  • Acute Coronary Syndrome categorizes patients based on:

    • Clinical history

    • ECG changes

    • Elevated Troponin levels

STEMI vs. NSTEMI

  • NSTEMI diagnosis involves:

    • Non-ST elevation on ECG or ST depression present.

    • Troponins elevate within 4 hours, but levels stop rising after 6 hours.

  • Treatment for NSTEMI includes:

    • Oxygen therapy

    • Aspirin administration

    • Nitrates for pain relief

    • Additional testing (stress tests, perfusion imaging, cardiac catheterization)

    • Anticoagulation therapy

    • Beta Blocker or ACE Inhibitors are commonly prescribed.

    • Thrombolytic therapy is not indicated for NSTEMI patients.

STEMI Diagnosis and Treatment

  • In STEMI, an occlusive thrombus causes ST-elevation in the ECG leads facing the area of infarction.

  • Areas affected may include the:

    • Left Anterior Descending (LAD) artery

    • Circumflex artery

    • Right coronary artery

  • An emergency situation occurs if the artery is not opened within 90 minutes of presentation.

  • Possible treatment methods include:

    • Percutaneous Coronary Intervention (PCI)

    • Thrombolytic therapy (fibrinolytic), which is used if PCI is unavailable.

STEMI Assessment Symptoms

  • Classic symptoms that may occur include:

    • Pain (assessed using the PQRST method)

    • Nausea and Vomiting

    • Diaphoresis (sweating)

    • Dyspnea (difficulty breathing)

    • Dysrhythmias

    • Feelings of fear or anxiety

    • Pallor, cyanosis, or cold extremities

  • Not all patients experience typical MI symptoms; women may have atypical symptoms.

STEMI Diagnostics

  • Important Labs Include:

    • Troponin level

    • Total CK level (Creatine Kinase)

    • CK-MB (Myocardial Band)

    • Elevated white blood cell (WBC) levels indicating inflammatory response 2–7 days after the event.

    • 12 lead ECG for monitoring heart activity.

    • Cardiac Catheterization to assess coronary artery condition.

STEMI Interventions

  • Key interventions during STEMI include:

    • Continuous pain assessment.

    • Vital signs monitoring.

    • Obtain a 12 lead ECG quickly.

    • Administer oxygen to optimize oxygen delivery.

    • Establish IV access for efficient medication delivery.

    • Provide pain relief using nitroglycerin and/or morphine.

    • Administer aspirin therapy at a dose of 324 mg.

    • Thrombolytic therapy if PCI is not available.

    • Talk to the patient and family about the situation to offer emotional support and reassurance.

Immediate Actions during STEMI

  • During EMS Response (GET ON IT STAT):

    • EKG monitoring

    • Oxygen supplementation

    • Administer Nitroglycerin

    • Establish IV access

    • Administer Morphine or continued Nitroglycerin

    • Aspirin therapy to prevent further clotting after STEMI event.

Post-STEMI Medications

  • Medications may include:

    • ACE Inhibitors

    • Angiotensin Receptor Blockers (ARBs)

Sample ACE Inhibitors and ARBs

  • ACE Inhibitors Examples:

    • Benazepril (Lotensin)

    • Captopril

    • Enalapril (Vasotec)

    • Lisinopril (Prinivil, Zestril)

    • Ramipril (Altace)

    • Trandolapril (Mavik)

  • ARBs Examples:

    • Azilsartan (Edarbi)

    • Candesartan (Atacand)

    • Irbesartan (Avapro)

    • Losartan (Cozaar)

    • Telmisartan (Micardis)

    • Valsartan (Diovan)

Percutaneous Coronary Intervention (PCI)

  • An invasive procedure through cardiac catheterization.

  • Catheterization provides diagnostic information on:

    • Structure and performance of heart chambers

    • Coronary circulation performance.

Pre-Procedure Interventions for PCI

  • Obtain consent and assess for allergies (especially shellfish for contrast dye).

  • Ensure patient is NPO (nothing by mouth) for 6–8 hours prior to the procedure.

  • Document client’s height, weight, and baseline vitals.

  • Assess peripheral pulses to ensure quality.

  • Communicate with the patient regarding anesthetic use and possible sensations felt during the procedure.

  • Prepare and clean insertion site.

  • Ensure IV access is established, and assess medication use (e.g., metformin).

Thrombolytic Therapy

  • Indications for Thrombolytics:

    • Used when PCI is unavailable.

    • Most effective in STEMI cases.

    • Should be administered within 6 hours of symptom onset.

    • Ensure patients don’t have contraindications to treatment.

    • Establish three IV lines prior to administer therapy.

  • Common Thrombolytic Agents:

    • Alteplase (t-PA)

    • Reteplase (r-PA)

    • Streptokinase

Coronary Artery Stents

  • Purpose: Used during catheterization to improve vessel patency.

  • Procedure involves:

    • Inflation of a balloon catheter with the stent to open the artery.

  • Post-procedure care includes:

    • Antiplatelet therapy for several months.

    • Monitoring for acute thrombosis complications.

    • If stenting is not successful, Coronary Artery Bypass Grafting (CABG) may be needed.

Post-Procedure Interventions for PCI

  • Continuous monitoring of:

    • Vital signs

    • Cardiac rhythm

  • Assessing for chest pain.

  • Monitoring peripheral pulses, color, warmth, and sensation of extremity (the 5 P's).

  • Notify provider of any neurological deficits or extremity changes (e.g., numbness or cyanosis).

  • Encourage fluid intake if not contraindicated to facilitate kidney function.

  • Assess the insertion site for bleeding and adhere to hospital policy for managing such incidents.

  • Maintain the patient in a flat position for 4–6 hours as per provider's orders.

Complications of STEMI or NSTEMI

  • Possible complications include:

    • Dysrhythmias (e.g., AFIB, atrial flutter, V-tach)

    • Heart Failure

    • Pulmonary Edema

    • Cardiogenic Shock

    • Thrombophlebitis

    • Pericarditis

    • Mitral Valve Insufficiency

    • Post-infarction Angina

    • Ventricular Rupture

    • Dressler’s Syndrome

Coronary Artery Bypass Grafting (CABG)

  • Indications for CABG include:

    • Patients not responding to medical management or having severely occluded vessels.

Preoperative CABG Preparation

  • Educate: Expect sternal and donor site incisions after surgery.

  • Discuss the presence of an endotracheal tube and mechanical ventilation post-surgery.

  • Prepare the patient for postoperative pain management.

  • Teach splinting techniques and incentive spirometry use.

  • Encourage questions and addressing concerns to relieve anxiety.

  • Follow provider's orders regarding medication cessation prior to surgery.

Postoperative CABG Management

  • Monitor vital signs and various parameters including heart rate, rhythm, and urinary output.

  • Assess mediastinal chest tube drainage and ensure it does not exceed 100–150 mL/hr.

  • Monitor for signs of cardiac complications like tamponade.

  • Employ proper pain management techniques.

Cardiac Tamponade Post-CABG Assessment

  • Signs of cardiac tamponade include:

    • Pulsus paradoxus

    • Increased central venous pressure (CVP)

    • Jugular vein distention with clear lung sounds

    • Distant, muffled heart sounds

    • Decreased cardiac output

    • Narrowing pulse pressure

Interventions for Cardiac Tamponade

  • Administer IV fluids as indicated.

  • Utilize chest X-ray or echocardiogram to assess.

  • Potentially perform pericardiocentesis to drain excess fluid.

  • Consider surgical options (Pericardial window) if fluid accumulation recurs.

References

  • Hinkle, J. L., & Cheever, K. H. (2018). Brunner & Suddarth's Textbook of Medical-Surgical Nursing (14th ed.) Philadelphia, PA: Wolters Kluwer.

  • Silvestri, L., & Silvestri, A. (2020). Saunders Comprehensive Review for the NCLEX-RN Examination (8th ed.) St. Louis, MO: Elsevier.

  • Sole, M., Klein, D., & Moseley, M. (2017). Introduction to Critical Care Nursing (7th ed.). St. Louis, MO: Elsevier.