Transvenous pacing

Indications

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

Contraindications

• Asystolic cardiac arrest
• Hypothermia bradydysrhythmias

Procedure

1. Site selection: Right IJ or left subclavian for most smooth anatomical course
2. Equipment:
   1. External generator: Shows rate (bpm), output (mA) and sensitivity
   2. Cordis Kit (7 Fr): Gold strip on kit at Harbor. Contains cordis introducer, TV pacer catheter and pacer wire sheath.
3. Similar to a central line, place single lumen catheter under ultrasound.
4. Pacing catheter
   1. Test small balloon for leaks prior to insertion with 1.5mL of air while balloon rests in a container of saline
   2. Connect the positive and negative electrodes to the external generator
   3. Advance the catheter through the introducer sheath to roughly 20 cm and insert through cordis diaphragm
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)
   1. Pearl - Digital generators have "emergency" button that goes to necessary settings
6. Advancing Pacer Wire:
   1. Blind approach: Inflate balloon and advance slowly until you see pacer spikes on monitor followed by a widened QRS (similar appearance to LBBB).
   2. Ultrasound approach: Have assistant give a subcostal/parasternal long axis, which gives visualization image of when electrode contacts the wall of the RV.
   3. Sensing approach: Use alligator clip to connect negative pacer electrode to any precordial lead. Look for ST elevation when RV endocardium engaged.
   4. Fluoroscopy: If time permits, use this method in a patient that has prior pacemaker/AICD. Placement of TV pacer w/o fluoro can disrupt prior electrode placements.
7. Deflate balloon (leave syringe attached) and secure catheter in place
   1. Make sure swan sheath fully extended, and locked onto cordis hub
   2. Take note of pacer depth in case it's accidentally moved
8. Final Settings
   1. Current: Determine threshold level by reducing electrical current settings until capture lost. Final current set to twice the threshold level for pt
   2. Sensitivity: Adjust so only paces when necessary (not too high or too low) to allow intrinsic beats and supplement if needed. Do not want oversensing or undersensing.
9. Placement confirmation
   1. Good to obtain baseline CXR, which should show the catheter tip over the inferior border of the cardiac shadow
   2. EKG shows paced QRS exhibiting a LBBB morphology, and a superior QRS axis

Complications

• Related to central venous access
  • Infection, PTX, 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

See Also

ACLS: Bradycardia