Pacemaker complication

Nomenclature

• Position I
  • Chamber paced (A, V, or D (dual))
• Position II
  • Chamber sensed
• Position III
  • Response after Sensing
    • I = inhibited
    • T = triggered
    • D = Dual
• Position IV
  • Programmability
    • P = rate & output
    • M = multiprogramable
    • C = communicating
    • R = rate adaptive
    • O = none
• Position V
  • Arrhythmia Control
    • P = pacing
    • S = shock
    • D = dual (P+S)
    • O = none

Indications

1. History of sudden death
2. Severe heart failure
3. Non-ischemic cardiomyopathy

Pacemaker Malfunction

Problems with pocket

1. Infection
   1. Most commonly Staphylococcus aureus or S. epidermidis
2. Hematoma
   1. Typically occurs shortly after placement

Problems with leads

1. Lead separation results in failure to capture
2. Lead dislodgment may cause thrombosis or myocardial rupture
3. Lead infection can cause severe sepsis

Failure to pace

1. Causes include battery exhaustion, wire fracture, or electrode displacement
2. Tissue reaction around electrode may make myocardium insensitive

Failure to sense

1. Voltages of patient's intrinsic QRS complex is too low to be detected
2. New intrinsic arrhythmia, AMI, electrolyte abnormalities, lead separation, battery depletion

Runaway Pacing

1. Physiologic electrical activity (T waves, muscle potentials)
2. External electromagnetic interference
3. Signals generated by interaction of different portions of the pacing system

Work-Up

1. CXR
2. ECG
3. Troponin
4. Interrogation

Management

• Use magnet to convert pacemaker to asynchronous mode if oversensing or runaway pacing