Module 1
Topic 1
Lesson 4

Is it far or is it close? – clinically important examples of far and near fields

Piotr Lodzinski

What will you learn?

  • what far and near field means
  • how to know what is in direct contact to my catheter
  • what is clinical importance of all that

About this scenario

  • Proper classification of potentials as a near-field and far-field potentials is one of the basic skills in EP
  • Near-field potentials represent locally recorded electrical activity: most frequently near-field potentials are sharp in shape and have a high amplitude.
  • Far-field potentials represent electrical activity observed from a distance: it is characterized by “blured” shape and lower amplitudes
  • Final classification whether observed potential is near- or far-field may require observation during manipulation of the catheter or by observing capture of the structure with stimulation.
  • In practice far-field and near-field potentials may help in catheter manipulation and placement (eg. within coronary sinus) or to assess lines of block.