When do we perform Transcutaneous pacing (TCP)?

  • Symptomatic clinically significant bradycardias
    • Don't just treat a number. Treat those bradycardias associated with hypotension, pulmonary edema, or evidence of decreased cerebral perfusion that is unresponsive to initial first line measure

    • Initiate TCP while searching for correctable causes and concomitantly administering other therapies (i.e. fluids, atropine, digibind, glucagon, high dose insulin)
    • Three common causes of bradycardia in the emergency department include drugs (specifically overdoses, hyperkalemia, myocardial ischemia) :

 

  • While most textbooks may quote overdrive pacing for refractory tachyarrhythmias, practically speaking most of these will get simply get cardioverted

What about transvenous pacing (TVP)?

  • TCP is only a bridge until a transvenous pacemaker can be placed
  • There are a few instances where TCP may be preferable over TVP
    •  Patients who have received thrombolytics
    • Patients who may respond to  respond to therapy (eg. hyperkalemia, drug overdose)

Five Step Approach to Transcutaneous Pacing

 
  • Step 1: Apply the pacing electrodes and consider sedation (eg. versed)

    • Avoid placing the pads over an AICD or transdermal drug patches
    • There is little data on optimal placement however, try to place the pads as close as possible to the PMI (point of maximal impulse) [1,2]
Step 1 TC pacing.jpg
 
  • Step 2:  Turn on the monitor and set it to "pacing mode"

 
  • Step 3:  Select the pacing rate using the rate button (generally 60-70 bpm is adequate)

 
  • Step 4:  Increase current output from minimal until capture is achieved

 

Below is an ECG with incomplete capture. 

TC pacing ecgs.jpg

As the mA output is increased, complete capture is achieved.

 
  • Step 5: Confirm mechanical capture with pulse or ultrasound [3,4]

Complications

  • Induction of Vfib (rare)
  • Patient discomfort, burns (these are rare due to the large pads and lower outputs of today's TC pacing devices)
  • Failure to recognize an underlying treatable ventricular fibrillation due to obscuration of the ECG by pacer spikes
    • This can be troubleshooted by hitting the "cancellation button" on your monitor.   This will pause the TCP spikes for a few seconds so you can identify the underlying rhythm.                     
 

Written by Jeffrey A Holmes, MD


References

1.  Panescu D, Webster J G, and Tompkins W J et al.: Optimisation of transcutaneous cardiac pacing by three-dimensional finite element modelling of the human thorax. Med Biol Eng Comput. 1995; 33: 769. [PMID: 8558949]Potential Complications

2.  Panescu D, Webster J G, and Tompkins W J et al.: Optimisation of transcutaneous cardiac pacing by three-dimensional finite element modelling of the human thorax. Med Biol Eng Comput. 1995; 33: 769. [PMID: 8558949]

3.  Ettin D and Cook T.: Using ultrasound to determine external pacer capture. J Emerg Med.  1999; 17:1007–1009. [PMID: 10595889]

4.  Holger J S, Lamon R P, and Minnigan H J et al.: Use of ultrasound to determine ventricular capture in transcutaneous pacing. Am J Emerg Med.  2003; 21: 227. [PMID: 12811719]

 

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