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How to use the Esophagus , as an access for emergency cardiac pacing ?

Posted Jan 20 2011 11:43am

God has created  and arranged every organ in an order  with a purpose .  The unique  relationship  of the food tube and  the heart which run silently , posterior  to the heart has evoked much interest for the cardiologists.

Whenever LA is enlarged it pushes the Esophagus back .We also know  the vintage clinical entities   of cardiac  dysphagia that occurred with rheumatic mitral stenosis.

Since the  lower end of  esophagus just hugs  the left atrium , this anatomical concept was successfully exploited   for imaging heart in TEE.Now cardiac  anesthetists routinely use the esophagus as an imaging port during complex mitral valve surgeries.

How  esophagus can be utilized to resuscitate the heart at times of emergency ?

Note , the esophagus does a friendly hug as it crosses the heart posteriorly .It is a perfect anatomical sense , to Image and pace the heart from within the esophagus !

 

In a  cardiac  arrest  situation , when we need to   rapidly   access to heart  , we have  multiple  options  .Each has some  advantage and few draw backs.

  • Trans-venous pacing   is the standard method,   but even for experts  it needs   few minutes to reach the heart for pacing
  • Trans cutaneous pacing (Zoll)  is  a viable option , but  not widely  popular for some  unknown  reason (Patient discomfort ? High threshold ?)
  • Emergency trans-thoracic  needle pacing option is  a primitive method still can save a life or two on it’s day !

It was in 1980 ,  a dramatic  concept was conceived  . Why not    use the  esophagus as an access   for pacing  the  heart

after all ,  it  reaches as close as possible to the heart !

How to convert  a  Ryles tube into a  a  trans – esophageal  pacing lead ?

There was a certain article on this topic , which I read , when I was cardiology resident. It answers the following. Distance form mouth ,  Discomfort of  the lead ,   Pacing threshold ,  Esophageal burns .

I am unable locate that article. Will  post  it  once I get it.

Limitations of trans-esophageal pacing*

  • The most important limitation is it can pace only the atria with high degree of success.
  • Ventricular pacing is not that successful for the simple reason esophagus is anatomically insulated by the atrial chambers.
  • Tran gastric positioning  may reach  the basal aspects of Left ventricle , but the threshold needed  is too high that will invariably cause  discomfort.This can be used in a dying patient  when there is no  other option .

* Primarily  useful in acute SA nodal defects, sinus arrest or any other atrial electrical failure. Infra- nodal complete heart block trans esophageal pacing may not be effective .

Other potential uses  of trans-esophageal  leads

Over drive pacing

Overdrive entrainment of tachycardias ,  including resistant ventricular tachycardia is possible.

Trans esophageal ECG recording .

This can magnify p waves during supra ventricular tachycardias and aid in decoding narrow qrs tachycardias

Safety  Issues and Caution

Good earthing is necessary .Burns can occur.

Final message

Every cardiac physician is  expected to possess  the expertise to rapidly pace a heart  by trans jugular /subclavian access at times of  emergency .

Further , any modern CCU will have a defibrillator equipped with trans-cutaneous pacer as well. (The  disposable pads are too costly and is a deterrent in many hospitals  !).

This article  explores other possible way to pace the heart in dire emergency situations.

It has one more purpose !  It rekindles   the acumen , motivation  and hard work   of  our  cardiac  ancestors  (Which many of us are pathetically lacking !)

Role of trans-esophageal lead during EP study  atrial fibrillation


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