Transvenous pacing

Indications

• Failure of transcutaneous pacing + chronotropes
  • Sinus Arrest/Bradycardia
  • AV Block - 3rd or 2nd degree. May occur from MI, bacterial endocarditis, or Lyme disease
  • Drug OD - Digoxin toxicity
  • Overdrive pacing

Contraindications

• Asystolic cardiac arrest
• Hypothermiabradydysrhythmias

Procedure

File:Transvenous ECG.jpg

Pacing by location

1. Site selection: Right IJ or left subclavian for most smooth anatomical course
2. Equipment:
   • External generator: Shows rate (bpm), output (mA) and sensitivity
   • Cordis Kit (7 Fr): Gold strip on kit at Harbor. Contains cordis introducer sheath, TV pacer catheter and pacer wire sheath
     • Sheath size (internal diameter) should match pacer wire size (external diameter). Otherwise you will get leakage!
3. Similar to a central line, place single lumen catheter under ultrasound guidance.
4. Pacing catheter
   • Test small balloon for leaks prior to insertion with 1.5mL of air while balloon rests in a container of saline
   • Connect the positive and negative electrodes to the external generator
   • Advance the catheter through the introducer sheath and into cordis hub to roughly 20 cm (catheter has marked bars indicating 10cm)
5. External generator: Set HR 80, start at max current output (usually 20 mA), and sensitivity all the way down (paces no matter intrinsic rate)
   • Pearl - Digital generators have "emergency" button that goes to automatic settings
6. Advancing Pacing Catheter: Inflate balloon and advance slowly.
   • Blind approach: Monitor shows pacer spikes followed by a widened QRS (LBBB appearance)
   • Ultrasound approach: Have assistant give a subcostal/parasternal long axis, which gives visualization image of when electrode contacts final resting position
   • Sensing approach: Use alligator clip to connect negative pacer electrode to any precordial lead. Look for ST elevation when RV endocardium engaged.
   • Fluoroscopy: If time permits, use this method in a patient that has prior pacemaker/ICD. Placement of TV pacer with out fluoro can disrupt prior electrode placements.
7. Final resting position is when pacer wire is in RV apex
   • Take note of pacer wire depth in case it is accidentally moved
   • If you overshot your mark (ie IVC/Pulm artery), deflate balloon and pull back. YOU DO NOT WANT TO PULL INFLATED BALLOON THROUGH A VALVE.
   • Pearl - IVC pacing leads to coughing/hiccuping and ventilator alarms (ie high frequency)
8. Deflate balloon (leave syringe attached) and secure catheter in place
   • Lock sheath onto cordis hub and then fully extend it & curl around while holding pacer wire in place. Sheath gives sterile amount of wire for any future adjustments if needed.
   • Additional sutures can be placed to stabilize it
9. Final Settings
   • Output: Determine threshold level by reducing electrical current settings until capture lost. Final current set to twice the threshold level for pt
   • Sensitivity: Adjust level (not too high or too low) so it allows intrinsic beats, but supplements it if needed. You do not want oversensing or undersensing.
10. Placement confirmation
    • Good to obtain baseline CXR, which should show the catheter tip over the inferior border of the cardiac shadow
    • ECG shows paced QRS exhibiting a LBBB morphology, and a superior QRS axis

Complications

• Related to central venous access
  • Infection, pneumothorax, air embolism, arterial puncture and venous thrombosis
• Related to pacing catheter:
  • Valvular tear(s)/rupture(s)
  • Myocardial Peforation (atria/ventricle/septum) - consider tamponade
• Ventricular Arrhythmias: VT or VF

Links

• University of Cincinnati
  • Part 1: Walkthrough
  • Part 2: Procedural Slide Set
  • Part 3: Video
• Drexel Video
• Practical Pointers

See Also

• ACLS: Bradycardia
• Transcutaneous pacing

Authors

Ross Donaldson