AV Blocks Dysrhythmias

Definition/Etiology:

• PCCN Focus: Identification, Cause & Treatment
• Definition
  • When the electrical signal that controls your heartbeat is partially or completely blocked by the AV Node – Slow HR or Skipped/Dropped beats
  • A good analogy for this is the movement of water in a pond. If you drop a stone into one corner of a pond a neat ripple moves across the pond. In the same way, during a normal rhythm, electricity spreads smoothly from the pacemaker across the atria to the ventricles.
    • Stones skip very slowly
    • Stones don’t get to skip as far as they should
• Types & Etiology/Cause
  • Fibrosis and sclerosis (50%)
  • CAD/ACS (40%)

Pathophysiology:

• Cardiac Conduction Pathway
  • SA node (sinoatrial node)
  • INTERNODAL PATHWAYS (Atria Contract)
  • AV node (Delay)
  • His-Purkinje Network (Ventricles COntract)
  • The SA node fires another impulse and the cycle begins again.
• AV Blocks
  • AV Junction
    • (Delay = TOO SLOW or BLOCKED)

Noticing: Assessment & Recognizing Cues:

• Subjective: Decreased Cardiac Output
  • Chest Pain
  • Weak/Fatigued/Dizzy
  • SOB/dyspnea
  • “Cold & Clammy”
• Objective: Decreased Cardiac Output
  • Vitals
    • Change in Hemodynamics
      • ↓BP, ↑HR, ↓pulses
  • Heart Sounds
    • Possible Irregular S1S2 (Afib)
    • S3 = Heart Failure
  • Lung Sounds
    • WET
  • Other Signs/Symptoms
    • ↓Mentation
    • ↓ Urine Output

Interpreting: Analyzing & Planning:

• Labs – Drawn quickly when calling RR
  • ABGs – Hypoxemia
  • Electrolytes – Decreased KCL/MAG
  • Troponin – Infarcts
  • BUN/Creatinine – Renal Function
• Diagnostics
  • ECG: Identify
    • First Degree AV Block
      • Looks like Sinus Rhythm but prolonged PRI
    • Second Degree – Type 1
      • PRI progressively get longer
      • Beat is dropped in a pattern
        • Wenckebach Poem
    • Second Degree – Type 2
      • PRI all same length
      • Beat randomly dropped – no pattern
    • 3rd Degree
      • P-P regular and R-R regular
      • Atria/Ventricles do not speak
      • No dropped beats but leads to cardiac arrest

Responding: Patient Interventions & Taking Action:

• Consider Rapid Response if symptomatic
• ABCs First
  • Airway, O2, Heart Monitor and IV
• Pathways
  • 1st Degree AV Block
    • Rarely needs treated = still perfusing
  • 2nd Degree AV Block Type 1
    • Rarely needs treated = still perfusing
    • Atropine if Symptomatic
  • 2nd Degree AV Block Type 2
    • Consider Meds (Example: Stop Digoxin)
    • Give Atropine
    • External Pacing → PPM
  • 3rd Degree
    • Consider Meds
    • Give Epinephrine
    • External Pacing → PPM

Reflecting: Evaluating Patient Outcomes:

• ECG Interpretation =Identify underlying cause!
• Pharmacology – Hold/Give Proper Medication
• Monitor for signs of ↑ Cardiac Output
  • Rhythm stabilized
  • Vitals Stable
  • Good Mentation
  • Heart/Lung Sounds Normal

Linchpins (Key Points):

• Notice
  • Assessing signs of ↓ Cardiac Output
• Interpret
  • ECG
• Respond
  • Treating underlying cause
  • CNp pulse = CRP ALWAYS
  • Follow Pathways
• Reflect
  • Return Stable Rhythm