Medical Management of Myocardial Infarction

Medical Management of Myocardial Infarction (MI)

• Goals of treatment: limit infarct size, pain relief, prevent and manage complications, and preserve myocardial function
• Thrombolytic therapy or Emergent PCI (Percutaneous Coronary Intervention) may be used
• Thrombolytic therapy breaks up clots and restores blood flow to the myocardium

Laboratory Values for MI Diagnosis

• Troponin is the gold standard test for suspected MI
• Normal troponin levels: 0-0.04 ng/mL
• Abnormal troponin levels: >0.2 ng/mL
• Troponin tests should be taken every 6-8 hours, three times
• Other lab values to monitor: potassium (K+) and partial thromboplastin time (PTT)
• Normal K+ levels: 3.5-5.2 mEq/L
• Normal PTT: 25-35 seconds

Pulseless Cardiac Arrest Treatment

• Pulseless electrical activity (PEA) is a condition where the heart stops due to weak electrical activity
• Interventions for PEA include:
  • CPR for 2 minutes
  • Administer Epinephrine 1mg IV bolus every 3-5 minutes
  • Identify and treat the underlying cause (e.g., blood loss, MI, PE, electrolyte imbalance, trauma, toxins)
  • Analyze heart rhythm and deliver shock if necessary
  • Administer amiodarone or lidocaine as needed

Medication Calculations and Conversions

• 1 kg = 1000 g
• 1 g = 1000 mg
• 1 mg = 1000 mcg
• 1 kg = 2.2 lb
• 1 oz = 30 ml
• 1 cup = 8 oz
• 1 tsp = 5 ml
• 1 tbsp = 15 ml
• 1 tbsp = 3 tsp
• 1 L = 1000 ml
• 1 gallon = 4 qt
• 1 qt = 1 L
• IV Drip Rate Formula: multiply the hour by 60 to get minutes

Electrolyte Imbalances and Diuretics

• Diuretics decrease fluid volume and can cause electrolyte imbalances
• Loop diuretics (non-potassium sparing diuretics) increase excretion of Na, Cl, and K
• Patients taking diuretics may need K+ supplements

EKG Changes in MI

• 12-lead EKG changes are diagnostic for MI
• Changes include Q waves, ST elevation or depression

Patient Education and Medication Administration

• Patients taking sublingual nitroglycerin should be educated on:
  • Progression of symptoms to unstable angina
  • Taking prophylactic NTG prior to exertion
  • Replacing NTG after 6 months
  • Keeping NTG in the original bottle
  • Feeling a tingling sensation under the tongue
  • Repeating NTG every 5 minutes if chest pain persists
  • Calling 911 if chest pain is unrelieved

Thrombolytic Therapy

• TPA (tissue plasminogen activator) is administered to destroy thrombus and restore blood flow to the myocardium
• Nursing care:
  • Administer TPA ASAP (if no cath lab available)
  • Assess for signs of bleeding
  • Minimize punctures and invasive procedures