Myocardial Infarction

• Myocardial Infarction

  MI is caused by inadequate myocardial tissue oxygenation.
• Myocardial Infarction

  The most characteristic manifestation of MI is crushing, severe, prolonged chest pain.
• Myocardial Infarction

  The universal sign of distress in MI is Levine's sign (chest-hand clutching)
• Myocardial Infarction

  Chest pain is caused by accumulation of lactic acid within ischemic parts of the myocardium.
• Myocardial Infarction

  ECG Changes

  • Zone of Ischemia - Inverted T wave
  • Zone of Injury - ST elevation
  • Zone of Infarction - pathologic Q wave
• Myocardial Infarction

  Elevated CK-MB, LDH, AST - these enzymes are produced by the myocardium in response to injury. The most cardiac-specific enzyme is CK-MB.
• MI: Management

  Morphine

  Oxygen

  Nitroglycerin

  Aspirin
• MI: Management

  1. Position: Semi-fowler's
  2. Diet: Low calorie, low cholesterol, low sodium
  3. Avoid valsalva maneuver
  4. Use bedside commode instead of bedpan.
  5. Avoid staining at stool. (stool softener)
• MI: Management

  Prevent complications:

  • most common and most major cause of death = dysrhythmias
  • most common dysrhytmia in MI = premature ventricular contractions
  • PVC of 6 or more per minute is life threatening
  • the main problem in dysrhythmias is decreased cardiac output
• MI: Management

  Ventricular Tachycardia

  1. Med: Epinephrine
  2. Cardioversion, if client is conscious
  3. Defibrillation, if client is unconscious
  4. Sodium Bicarbonate, to relieve lactic acidosis. Lactic acidosis causes unsuccessful defibrillation.
• Atrial Fibrillation 


  ECG Pattern: No distinct P waves
• Atrial Flutter 


  ECG Pattern: Distinct “sawtooth” pattern of P-waves
• Summary of Treatment of Dysrhythmias:

  Sinus Tachycardia

  • Propanolol

  Sinus Bradycardia

  • Atropine Sulfate

  Atrial Flutter

  • Diltiazem

  Atrial Fibrillation

  • Digoxin
• Cardiac pacemakers

  Patient teachings:

  • Take daily pulse for one full minute upon arising in the morning.
  • Keep pacemakers at least 6 inches away from: cellphones
  • cellphones
  • electronic cigarettes
  • headphones
  • metal detectors, welding machines
  • electrocautery: MRI, radiation therapy, shock wave lithotripsy)
  • Okay ang household appliances (eg. microwave appliances) or move 3 feet away.
• Cardioversion


  The synchronous application of an electrical shock of short duration to the heart through the use of chest paddles. Electric shock is applied during the R-wave, never on the T-wave. It is done to treat dysrhythmias except ventricular fibrillation.
• Defibrillation is unsynchronized passing of an electric shock of short duration to the heart to terminate ventricular fibrillation or ventricular tachycardia.
• During cardioversion and defibrillation:

  1. Anticoagulation is done before the procedure to prevent release of thrombi.2. The client should be in supine position, in a flat and firm surface.3. Apply interface gel on the chest and chest paddles to prevent burns and for better contact between the skin and chest paddles.4. Give command ("warning chant") for personnel to stand CLEAR of the patient and the bed. E.g. "Shock on three. One, I'm clear; Two, you're clear; Three, everybody clear."
• Cardiopulmonary resuscitation (CPR)

  • Manifestations of clinical death are breathlessness andpulselessness.
  • CPR is instituted within 4 to 6 minutes after the arrest, to prevent brain death.
  • The 2 types of CPR are basic life support (BLS) and advanced cardiac life support (ACLS).
  • BLS requires the hands, the mouth, and the sincere desire to givethe person a second chance for life.
  • ACLS involves BLS and use of drugs and equipment to monitorand stabilize the client's condition.
• Pericarditis (Dressler's Syndrome) in Ml is an antigen-antibody response. The antigen is the area of necrotic tissues. The condition may occur 1 to 6 weeks post - MI.
• Pericarditis

  Signs and Symptoms:

  1. Sudden, severe dyspnea.
  2. Sudden, severe chest pain that is aggravated by turning, twisting the torso and yawning, relieved by upright position.
  3. Fever
• Pericarditis

  Management:

  R - rest

  A - aspirin

  S - Steroid
• Cardiac tamponade is accumulation of blood in the pericardial sac.
• Cardiac Tamponade

  Manifestations: Beck's Triad

  1. Low BP
  2. Jugular Vein Distention
  3. Muffled heart sounds
• Cardiac Tamponade

  Management: Pericardiocentesis
• Cardiac Tamponade

  • If a client goes into cardiogenic shock, intraaortic balloon pump (IABP) is inserted into the aorta via the femoral artery.
  • The balloon of the IABP is inflated during diastole, to improve blood flow from the aorta to the coronary artery (diastolic filling).
  • Whereas, during systole, the balloon is deflated to allow blood flow in the aorta to the systemic circulation.
• CPR involves the CABD's of life support:

  C - restore circulation

  A - open airway

  B - restore breathing

  D - defibrillation